For a long time, nurses and nursing assistants were among the only women working at night in many countries (Gadbois 1981; Estryn-Béhar and Poinsignon 1989). In addition to the problems already documented among men, these women suffer additional problems related to their family responsibilities. Sleep deprivation has been convincingly demonstrated among these women, and there is concern about the quality of care they are able to dispense in the absence of appropriate rest.

Organization of Schedules and Family Obligations

It appears that personal feelings about social and family life are at least partially responsible for the decision to accept or refuse night work. These feelings, in turn, lead workers to minimize or exaggerate their health problems (Lert, Marne and Gueguen 1993; Ramaciotti et al. 1990). Among non-professional personnel, financial compensation is the main determinant of the acceptance or refusal of night work.

Other work schedules may also pose problems. Morning-shift workers sometimes must rise before 05:00 and so lose some of the sleep that is essential for their recovery. Afternoon shifts finish between 21:00 and 23:00, limiting social and family life. Thus, often only 20% of women working in large university hospitals have work schedules in synchrony with the rest of society (Cristofari et al. 1989).

Complaints related to work schedules are more frequent among health care workers than among other employees (62% versus 39%) and indeed are among the complaints most frequently voiced by nurses (Lahaye et al. 1993).

One study demonstrated the interaction of work satisfaction with social factors, even in the presence of sleep deprivation (Verhaegen et al. 1987). In this study, nurses working only night shifts were more satisfied with their work than nurses working rotating shifts. These differences were attributed to the fact that all the night-shift nurses chose to work at night and organized their family life accordingly, while rotating-shift nurses found even rare night-shift work a disturbance of their personal and family lives. However, Estryn-Béhar et al. (1989b) reported that mothers working only night shifts were more tired and went out less frequently compared with male night-shift nurses.

In the Netherlands, the prevalence of work complaints was higher among nurses working rotating shifts than among those working only day shifts (Van Deursen et al. 1993) (see table 1).

Table 1. Prevalence of work complaints according to shift

Source: Van Deursen et al. 1993.

Sleep disturbances

On workdays, night-shift nurses sleep an average of two hours less than other nurses (Escribà Agüir et al. 1992; Estryn-Béhar et al. 1978; Estryn-Béhar et al. 1990; Nyman and Knutsson 1995). According to several studies, their quality of sleep is also poor (Schroër et al. 1993; Lee 1992; Gold et al. 1992; Estryn-Béhar and Fonchain 1986).

In their interview study of 635 Massachusetts nurses, Gold et al. (1992) found that 92.2% of nurses working alternating morning and afternoon shifts were able to maintain a nocturnal “anchor” sleep of four hours at the same schedule throughout the month, compared to only 6.3% of night-shift nurses and none of the nurses working alternating day and night shifts. The age- and seniority-adjusted odds ratio for “poor sleep” was 1.8 for night-shift nurses and 2.8 for rotating-shift nurses with night work, compared to morning- and afternoon-shift nurses. The odds ratio for taking sleep medication was 2.0 for night- and rotating-shift nurses, compared to morning- and afternoon-shift nurses.

Affective Problems and Fatigue

The prevalence of stress-related symptoms and reports of having stopped enjoying their work was higher among Finnish nurses working rotating shifts than among other nurses (Kandolin 1993). Estryn-Béhar et al. (1990) showed that night-shift nurses’ scores on the General Health Questionnaire used to evaluate mental health, compared to day-shift nurses (odds ratio of 1.6) showed poorer general health.

In another study, Estryn-Béhar et al. (1989b), interviewed a representative sample of one-quarter of night-shift employees (1,496 individuals) in 39 Paris-area hospitals. Differences appear according to sex and qualification (“qualified”=head nurses and nurses; “unqualified”=nurses’ aides and orderlies). Excessive fatigue was reported by 40% of qualified women, 37% of unqualified women, 29% of qualified men and 20% of unqualified men. Fatigue on rising was reported by 42% of qualified women, 35% of unqualified women, 28% of qualified men and 24% of unqualified men. Frequent irritability was reported by one-third of night-shift workers and by a significantly greater proportion of women. Women with no children were twice as likely to report excessive fatigue, fatigue on rising and frequent irritability than were comparable men. The increase compared to single men with no children was even more marked for women with one or two children, and greater still (a four-fold increase) for women with at least three children.

Fatigue on rising was reported by 58% of night-shift hospital workers and 42% of day-shift workers in a Swedish study using a stratified sample of 310 hospital workers (Nyman and Knutsson 1995). Intense fatigue at work was reported by 15% of day-shift workers and 30% of night-shift workers. Almost one-quarter of night-shift workers reported falling asleep at work. Memory problems were reported by 20% of night-shift workers and 9% of day-shift workers.

In Japan, the health and safety association publishes the results of medical examinations of all the country’s salaried employees. This report includes the results of 600,000 employees in the health and hygiene sector. Nurses generally work rotating shifts. Complaints concerning fatigue are highest in night-shift nurses, followed in order by evening- and morning-shift nurses (Makino 1995). Symptoms reported by night-shift nurses include sleepiness, sadness and difficulty concentrating, with numerous complaints about accumulated fatigue and disturbed social life (Akinori and Hiroshi 1985).

Sleep and Affective Disorders among Physicians

The effect of work content and duration on young physicians’ private lives, and the attendant risk of depression, has been noted. Valko and Clayton (1975) found that 30% of young residents suffered a bout of depression lasting an average of five months during their first year of residency. Of the 53 residents studied, four had suicidal thoughts and three made concrete suicide plans. Similar rates of depression have been reported by Reuben (1985) and Clark et al. (1984).

In a questionnaire study, Friedman, Kornfeld and Bigger (1971) showed that interns suffering from sleep deprivation reported more sadness, selfishness and modification of their social life than did more-rested interns. During interviews following the tests, interns suffering from sleep deprivation reported symptoms such as difficulty reasoning, depression, irritability, depersonalization, inappropriate reactions and short-term memory deficits.

In a one-year longitudinal study, Ford and Wentz (1984) evaluated 27 interns four times during their internship. During this period, four interns suffered at least one major bout of depression meeting standard criteria and 11 others reported clinical depression. Anger, fatigue and mood swings increased throughout the year and were inversely correlated with the amount of sleep the preceding week.

A literature review has identified six studies in which interns having spent one sleepless night exhibited deteriorations of mood, motivation and reasoning ability and increased fatigue and anxiety (Samkoff and Jacques 1991).

Devienne et al. (1995) interviewed a stratified sample of 220 general practitioners in the Paris area. Of these, 70 were on call at night. Most of the on-call physicians reported having had their sleep disturbed while on call and finding it particularly difficult to get back to sleep after having been awakened (men: 65%; women: 88%). Waking up in the middle of the night for reasons unrelated to service calls was reported by 22% of men and 44% of women. Having or almost having a car accident due to sleepiness related to being on call was reported by 15% of men and 19% of women. This risk was greater among physicians who were on call more than four times per month (30%) than in those on call three or four times per month (22%) or one to three times per month (10%). The day after being on call, 69% of women and 46% of men reported having difficulty concentrating and feeling less effective, while 37% of men and 31% of women reported experiencing mood swings. Accumulated sleep deficits were not recovered the day following on-call work.

Family and Social Life

A survey of 848 night-shift nurses found that over the previous month one-quarter had not gone out and had entertained no guests, and half had participated in such activities only once (Gadbois 1981). One-third reported refusing an invitation because of fatigue, and two-thirds reported going out only once, with this proportion rising to 80% among mothers.

Kurumatani et al. (1994) reviewed the time sheets of 239 Japanese nurses working rotating shifts over a total of 1,016 days and found that nurses with young children slept less and spent less time on leisure activities than did nurses without young children.

Estryn-Béhar et al. (1989b) observed that women were significantly less likely than men to spend at least one hour per week participating in team or individual sports (48% of qualified women, 29% of unqualified women, 65% of qualified men and 61% of unqualified men). Women were also less likely to frequently (at least four times per month) attend shows (13% of qualified women, 6% of unqualified women, 20% of qualified men and 13% of unqualified men). On the other hand, similar proportions of women and men practised home-based activities such as watching television and reading. Multivariate analysis showed that men with no children were twice as likely to spend at least one hour per week on athletic activities than were comparable women. This gap increases with the number of children. Child care, and not gender, influences reading habits. A significant proportion of the subjects in this study were single parents. This was very rare among qualified men (1%), less rare among unqualified men (4.5%), common in qualified women (9%) and extremely frequent in unqualified women (24.5%).

In Escribà Agüir’s (1992) study of Spanish hospital workers, incompatibility of rotating shifts with social and family life was the leading source of dissatisfaction. In addition, night-shift work (either permanent or rotating) disturbed the synchronization of their schedules with those of their spouses.

Lack of free time interferes severely with the private life of interns and residents. Landau et al. (1986) found that 40% of residents reported major conjugal problems. Of these residents, 72% attributed the problems to their work. McCall (1988) noted that residents have little time to spend on their personal relationships; this problem is particularly serious for women nearing the end of their low-risk-pregnancy years.

Irregular Shift Work and Pregnancy

Axelsson, Rylander and Molin (1989) distributed a questionnaire to 807 women employed at the hospital in Mölna, Sweden. The birth weights of children born to non-smoking women working irregular shifts were significantly lower than that of children born to non-smoking women who only worked day shifts. The difference was greatest for infants of at least grade 2 (3,489 g versus 3,793 g). Similar differences were also found for infants of at least grade 2 born to women working afternoon shifts (3,073 g) and shifts alternating every 24 hours (3,481 g).

Vigilance and Quality of Work among Night-Shift Nurses

Englade, Badet and Becque (1994) performed Holter EEGs on two groups of nine nurses. It showed that the group not allowed to sleep had attention deficits characterized by sleepiness, and in some cases even sleep of which they were unaware. An experimental group practised polyphasic sleep in an attempt to recover a little sleep during work hours, while the control group was not allowed any sleep recovery.

These results are similar to those reported by a survey of 760 California nurses (Lee 1992), in which 4.0% of night-shift nurses and 4.3% of nurses working rotating shifts reported suffering frequent attention deficits; no nurses from the other shifts mentioned lack of vigilance as a problem. Occasional attention deficits were reported by 48.9% of night-shift nurses, 39.2% of rotating-shift nurses, 18.5% of day-shift nurses and 17.5% of evening-shift nurses. Struggling to stay awake while dispensing care during the month preceding the survey was reported by 19.3% of night-shift and rotating-shift nurses, compared to 3.8% of day- and evening-shift nurses. Similarly, 44% of nurses reported having had to struggle to stay awake while driving during the preceding month, compared to 19% of day-shift nurses and 25% of evening-shift nurses.

Smith et al. (1979) studied 1,228 nurses in 12 American hospitals. The incidence of occupational accidents was 23.3 for nurses working rotating shifts, 18.0 for night-shift nurses, 16.8 for day-shift nurses and 15.7 for afternoon-shift nurses.

In an attempt to better characterize problems related to attention deficits among night-shift nurses, Blanchard et al. (1992) observed activity and incidents throughout a series of night shifts. Six wards, ranging from intensive care to chronic care, were studied. In each ward, one continuous observation of a nurse was performed on the second night (of night work) and two observations on the third or fourth nights (depending on the wards’ schedule). Incidents were not associated with serious outcomes. On the second night, the number of incidents rose from 8 in the first half of the night to 18 in the second half. On the third or fourth night, the increase was from 13 to 33 in one case and from 11 to 35 in another. The authors emphasized the role of sleep breaks in limiting risks.

Gold et al. (1992) collected information from 635 Massachusetts nurses on the frequency and consequences of attention deficits. Experiencing at least one episode of sleepiness at work per week was reported by 35.5% of rotating-shift nurses with night work, 32.4% of night-shift nurses and 20.7% of morning-shift and afternoon-shift nurses working exceptionally at night. Less than 3% of nurses working the morning and afternoon shifts reported such incidents.

The odds ratio for sleepiness while driving to and from work was 3.9 for rotating-shift nurses with night work and 3.6 for night-shift nurses, compared to morning- and afternoon-shift nurses. The odds ratio for total accidents and errors over the past year (car accidents driving to and from work, errors in medication or work procedures, occupational accidents related to sleepiness) was almost 2.00 for rotating-shift nurses with night work compared to morning- and afternoon-shift nurses.

Effect of Fatigue and Sleepiness on the Performance of Physicians

Several studies have shown that the fatigue and sleeplessness induced by night-shift and on-call work leads to deteriorations of physician performance.

Wilkinson, Tyler and Varey (1975) conducted a postal questionnaire survey of 6,500 British hospital physicians. Of the 2,452 who responded, 37% reported suffering a degradation of their effectiveness due to excessively long work hours. In response to open-ended questions, 141 residents reported committing errors due to overwork and lack of sleep. In a study performed in Ontario, Canada, 70% of 1,806 hospital physicians reported often worrying about the effect of the quantity of their work had on its quality (Lewittes and Marshall 1989). More specifically, 6% of the sample—and 10% of interns—reported often worrying about fatigue affecting the quality of care they dispensed.

Given the difficulty in performing real-time evaluations of clinical performance, several studies on the effects of sleep deprivation on physicians have relied upon neuropsychological tests.

In the majority of studies reviewed by Samkoff and Jacques (1991), residents deprived of sleep for one night exhibited little deterioration in their performance of rapid tests of manual dexterity, reaction time and memory. Fourteen of these studies used extensive test batteries. According to five tests, the effect on performance was ambiguous; according to six, a performance deficit was observed; but according to eight other tests, no deficit was observed.

Rubin et al. (1991) tested 63 medical-ward residents before and after an on-call period of 36 hours and a subsequent full day of work, using a battery of self-administered computerized behavioural tests. Physicians tested after being on call exhibited significant performance deficits in tests of visual attention, coding speed and accuracy and short-term memory. The duration of sleep enjoyed by the residents while on call was as follows: two hours at most in 27 subjects, four hours at most in 29 subjects, six hours at most in four subjects and seven hours in three subjects. Lurie et al. (1989) reported similarly brief sleep durations.

Virtually no difference has been observed in the performance of actual or simulated short-duration clinical tasks—including filling out a laboratory requisition (Poulton et al. 1978; Reznick and Folse 1987), simulated suturing (Reznick and Folse 1987), endotracheal intubation (Storer et al. 1989) and venous and arterial catheterization (Storer et al. 1989)—by sleep-deprived and control groups. The only difference observed was a slight lengthening of the time required by sleep-deprived residents to perform arterial catheterization.

On the other hand, several studies have demonstrated significant differences for tasks requiring continuous vigilance or intense concentration. For example, sleep-deprived interns committed twice as many errors when reading 20-minute ECGs as did rested interns (Friedman et al. 1971). Two studies, one relying on 50-minute VDU-based simulations (Beatty, Ahern and Katz 1977), the other on 30-minute video simulations (Denisco, Drummond and Gravenstein 1987), have reported poorer performance by anaesthesiologists deprived of sleep for one night. Another study has reported significantly poorer performance by sleep-deprived residents on a four-hour test exam (Jacques, Lynch and Samkoff 1990). Goldman, McDonough and Rosemond (1972) used closed-circuit filming to study 33 surgical procedures. Surgeons with less than two hours of sleep were reported to perform “worse” than more-rested surgeons. The duration of surgical inefficiency or indecision (i.e., of poorly planned manoeuvres) was over 30% of the total duration of the operation.

Bertram (1988) examined the charts of emergency admissions by second-year residents over a one-month period. For a given diagnosis, less information on medical histories and the results of clinical examinations was gathered as the number of hours worked and patients seen increased.

Smith-Coggins et al. (1994) analysed the EEG, mood, cognitive performance and motor performance of six emergency-ward physicians over two 24-hour periods, one with diurnal work and nocturnal sleep, the other with nocturnal work and diurnal sleep.

Physicians working at night slept significantly less (328.5 versus 496.6 minutes) and performed significantly less well. This poorer motor performance was reflected in the increased time required to perform a simulated intubation (42.2 versus 31.56 seconds) and an increased number of protocol errors.

Their cognitive performance was evaluated at five test periods throughout their shift. For each test, physicians were required to review four charts drawn from a pool of 40, rank them and list the initial procedures, the treatments and the appropriate laboratory tests. Performance deteriorated as the shift progressed for both night-shift and day-shift physicians. Night-shift physicians were less successful at providing correct responses than day-shift physicians.

Physicians working during the day rated themselves as less sleepy, more satisfied and more lucid than did night-shift physicians.

Recommendations in English-speaking countries concerning the work schedules of physicians-in-training have tended to take these results into account and now call for work-weeks of at most 70 hours and the provision of recovery periods following on-call work. In the US, following the death of a patient attributed to errors by an overworked, poorly supervised resident physician which received much media attention, New York State enacted legislation limiting work hours for hospital staff physicians and defining the role of attending physicians in supervising their activities.

Content of Night Work in Hospitals

Night work has long been undervalued. In France, nurses used to be seen as guardians, a term rooted in a vision of nurses’ work as the mere monitoring of sleeping patients, with no delivery of care. The inaccuracy of this vision became increasingly obvious as the length of hospitalization decreased and patients’ uncertainty about their hospitalization increased. Hospital stays require frequent technical interventions during the night, precisely when the nurse:patient ratio is lowest.

The importance of the amount of time spent by nurses in patients’ rooms is demonstrated by the results of a study based on continuous observation of the ergonomics of nurses’ work in each of three shifts in ten wards (Estryn-Béhar and Bonnet 1992). The time spent in rooms accounted for an average of 27% of the day and night shifts and 30% of the afternoon shift. In four of the ten wards, nurses spent more time in the rooms during the night than during the day. Blood samples were of course taken less frequently during the night, but other technical interventions such as monitoring vital signs and medication, and administering, adjusting and monitoring intravenous drips and transfusions were more frequent during the night in six of seven wards where detailed analysis was performed. The total number of technical and non-technical direct-care interventions was higher during the night in six of seven wards.

Nurses’ work postures varied from shift to shift. The percentage of time spent seated (preparation, writing, consultations, time spent with patients, breaks) was higher at night in seven of ten wards, and exceeded 40% of shift time in six wards. However, the time spent in painful postures (bent over, crouched, arms extended, carrying loads) exceeded 10% of shift time in all wards and 20% of shift time in six wards at night; in five wards the percentage of time spent in painful positions was higher at night. In fact, night-shift nurses also make beds and perform tasks related to hygiene, comfort and voiding, tasks which are all normally performed by nurses’ aides during the day.

Night-shift nurses may be obliged to change location very frequently. Night-shift nurses in all the wards changed location over 100 times per shift; in six wards, the number of changes of location was higher at night. However, because rounds were scheduled at 00:00, 02:00, 04:00 and 06:00, nurses did not travel greater distances, except in juvenile intensive-care wards. Nonetheless, nurses walked over six kilometres in three of the seven wards where podometry was performed.

Conversations with patients were frequent at night, exceeding 30 per shift in all wards; in five wards these conversations were more frequent at night. Conversations with physicians were much rarer and almost always brief.

Leslie et al. (1990) conducted continuous observation of 12 of 16 interns in the medical ward of a 340-bed Edinburgh (Scotland) hospital over 15 consecutive winter days. Each ward cared for approximately 60 patients. In all, 22 day shifts (08:00 to 18:00) and 18 on-call shifts (18:00 to 08:00), equivalent to 472 hours of work, were observed. The nominal duration of the interns’ work week was 83 to 101 hours, depending on whether or not they were on call during the weekends. However, in addition to the official work schedule, each intern also spent an average of 7.3 hours each week on miscellaneous hospital activities. Information on the time spent performing each of 17 activities, on a minute-by-minute basis, was collected by trained observers assigned to each intern.

The longest continuous work period observed was 58 hours (08:00 Saturday to 06:00 Monday) and the longest work period was 60.5 hours. Calculations showed that a one-week sickness leave of one intern would require the other two interns in the ward to increase their workload by 20 hours.

In practice, in wards admitting patients during on-call shifts, interns working consecutive day, on-call and night shifts worked all but 4.6 of the 34 elapsed hours. These 4.6 hours were devoted to meals and rest, but interns remained on call and available during this time. In wards that did not admit new patients during on-call shifts, interns’ workload abated only after midnight.

Due to the on-call schedules in other wards, interns spent approximately 25 minutes outside their home ward each shift. On average, they walked 3 kilometres and spent 85 minutes (32 to 171 minutes) in other wards each night shift.

Time spent filling out requests for examinations and charts, in addition, is often performed outside of their normal work hours. Non-systematic observation of this additional work over several days revealed that it accounts for approximately 40 minutes of additional work at the end of each shift (18:00).

During the day, 51 to 71% of interns’ time was spent on patient-oriented duties, compared to 20 to 50% at night. Another study, conducted in the United States, reported that 15 to 26% of work time was spent on patient-oriented duties (Lurie et al. 1989).

The study concluded that more interns were needed and that interns should no longer be required to attend other wards while on call. Three additional interns were hired. This reduced interns’ work week to an average of 72 hours, with no work, excepting on-call shifts, after 18:00. Interns also obtained a free half-day following an on-call shift and preceding a weekend when they were to be on call. Two secretaries were hired on a trial basis by two wards. Working 10 hours per week, the secretaries were able to fill out 700 to 750 documents per ward. In the opinion of both senior physicians and nurses, this resulted in more efficient rounds, since all the information had been entered correctly.

Back

Health care workers (HCWs) confront numerous physical hazards.

Electrical Hazards

Failure to meet standards for electrical equipment and its use is the most frequently cited violation in all industries. In hospitals, electrical malfunctions are the second leading cause of fires. Additionally, hospitals require that a wide variety of electrical equipment be used in hazardous environments (i.e., in wet or damp locations or adjacent to flammables or combustibles).

Recognition of these facts and the danger they may pose to patients has led most hospitals to put great effort into electrical safety promotion in patient-care areas. However, non-patient areas are sometimes neglected and employee- or hospital-owned appliances may be found with:

• three-wire (grounded) plugs attached to two-wire (ungrounded) cords

• ground prongs bent or cut off

• ungrounded appliances attached to ungrounded multiple-plug “spiders”

• extension cords with improper grounding

• cords moulded to plugs not properly wired (25% of the x-ray equipment in one hospital study was incorrectly wired).

Prevention and control

It is critical that all electrical installations be in accordance with prescribed safety standards and regulations. Measures that can be taken to prevent fires and avoid shocks to employees include the following:

• provision for regular inspection of all employee work areas by an electrical engineer to discover and correct hazardous conditions such as ungrounded or poorly maintained appliances or tools

• inclusion of electrical safety in both orientation and in-service training programmes.

Employees should be instructed:

• not to use electrical equipment with wet hands, on wet surfaces or when standing on wet floors

• not to use devices that blow a fuse or trip a circuit breaker until they have been inspected

• not to use any appliance, equipment or wall receptacle that appears to be damaged or in poor repair

• to use extension cords only temporarily and only in emergency situations

• to use extension cords designed to carry the voltage required

• to turn off equipment before unplugging it

• to report all shocks immediately (including small tingles) and not to use equipment again until it has been inspected.

Heat

Although heat-related health effects on hospital workers can include heat stroke, exhaustion, cramps and fainting, these are rare. More common are the milder effects of increased fatigue, discomfort and inability to concentrate. These are important because they may increase the risk of accidents.

Heat exposure can be measured with wet bulb and globe thermometers, expressed as the Wet Bulb Globe Temperature (WBGT) Index, which combines the effects of radiant heat and humidity with the dry bulb temperature. This testing should only be done by a skilled individual.

The boiler room, laundry and kitchen are the most common high-temperature environments in the hospital. However, in old buildings with inadequate ventilation and cooling systems heat may be a problem in many locations in summer months. Heat exposure may also be a problem where ambient temperatures are elevated and health care personnel are required to wear occlusive gowns, caps, masks and gloves.

Prevention and control

Although it may be impossible to keep some hospital settings at a comfortable temperature, there are measures to keep temperatures at acceptable levels and to ameliorate the effects of heat upon workers, including:

• provision of adequate ventilation. Central air-conditioning systems may need to be supplemented by floor fans, for example.

• making cool drinking water easily accessible

• rotating employees so that periodic relief is scheduled

• scheduling frequent breaks in cool areas.

Noise

Exposure to high levels of noise in the workplace is a common job hazard. The “quiet” image of hospitals notwithstanding, they can be noisy places to work.

Exposure to loud noises can cause a loss in hearing acuity. Short-term exposure to loud noises can cause a decrease in hearing called a “temporary threshold shift” (TTS). While these TTSs can be reversed with sufficient rest from high noise levels, the nerve damage resulting from long-term exposure to loud noises cannot.

The US Occupational Safety and Health Administration (OSHA) has set 90 dBA as the permissible limit per 8 hours of work. For 8-hour average exposures in excess of 85 dBA, a hearing conservation programme is mandated. (Sound level meters, the basic noise measuring instrument, are provided with three weighting networks. OSHA standards use the A scale, expressed as dBA.)

The effects of noise at the 70-dB level are reported by the National Institute of Environmental Health Sciences to be:

• blood vessel constriction that can lead to higher blood pressure and decreased circulation in the hands and feet (perceived as coldness)

• headaches

• increased irritability

• difficulty in communicating with co-workers

• reduced ability to work

• more difficulty with tasks that require alertness, concentration and attention to detail.

Food service areas, laboratories, engineering areas (which usually includes the boiler room), business office and medical records and nursing units can be so noisy that productivity is reduced. Other departments where noise levels are sometimes quite high are laundries, print shops and construction areas.

Prevention and control

If a noise survey of the facility shows that employees’ noise exposure is in excess of the OSHA standard, a noise abatement programme is required. Such a programme should include:

• periodic measurement

• engineering controls such as isolating noisy equipment, installing mufflers and acoustic ceilings and carpets

• administrative controls limiting workers’ exposure time to excessive noise.

In addition to abatement measures, a hearing conservation programme should be established that provides for:

• hearing tests for new employees to provide baselines for future testing

• annual audiometric testing

• hearing protection for use while controls are being implemented and for situations where levels cannot be brought within approved limits.

Inadequate Ventilation

The specific ventilation requirements for various types of equipment are engineering matters and will not be discussed here. However, both old and new facilities present general ventilation problems that warrant mentioning.

In older facilities built before central heating and cooling systems were common, ventilation problems must often be solved on a location-by-location basis. Frequently, the problem rests in achieving uniform temperatures and correct circulation.

In newer facilities that are hermetically sealed, a phenomenon called “tight-building syndrome” or “sick building syndrome” is sometimes experienced. When the circulation system does not exchange the air rapidly enough, concentrations of irritants may build up to the extent that employees may experience such reactions as sore throat, runny nose and watery eyes. This situation can provoke severe reaction in sensitized individuals. It can be exacerbated by various chemicals emitted from such sources as foam insulation, carpeting, adhesives and cleaning agents.

Prevention and control

While careful attention is paid to ventilation in sensitive areas such as surgical suites, less attention is given to general-purpose areas. It is important to alert employees to report irritant reactions that appear only in the workplace. If local air quality cannot be improved with venting, it may be necessary to transfer individuals who have become sensitized to some irritant in their workstation.

Laser Smoke

During surgical procedures using a laser or electrosurgical unit, the thermal destruction of tissue creates smoke as a by-product. NIOSH has confirmed studies showing that this smoke plume can contain toxic gases and vapours such as benzene, hydrogen cyanide and formaldehyde, bioaerosols, dead and live cellular material (including blood fragments) and viruses. At high concentrations, the smoke causes ocular and upper respiratory tract irritation in health care personnel and may create visual problems for the surgeon. The smoke has an unpleasant odour and has been shown to have mutagenic material.

Prevention and control

Exposure to airborne contaminants in such smoke can be effectively controlled by proper ventilation of the treatment room, supplemented by local exhaust ventilation (LEV) using a high-efficiency suction unit (i.e., a vacuum pump with an inlet nozzle held within 2 inches of the surgical site) that is activated throughout the procedure. Both the room ventilation system and the local exhaust ventilator should be equipped with filters and absorbers that capture particulates and absorb or inactivate airborne gases and vapours. These filters and absorbers require monitoring and replacement on a regular basis and are considered a possible biohazard requiring proper disposal.

Radiation

Ionizing radiation

When ionizing radiation strikes cells in living tissue, it may either kill the cell directly (i.e., cause burns or hair loss) or it may alter the genetic material of the cell (i.e., cause cancer or reproductive damage). Standards involving ionizing radiation may refer to exposure (the amount of radiation the body is exposed to) or dose (the amount of radiation the body absorbs) and may be expressed in terms of millirem (mrem), the usual measure of radiation, or rems (1,000 millirems).

Various jurisdictions have developed regulations governing the procurement, use, transportation and disposal of radioactive materials, as well as established limits for exposure (and in some places specific limits for dosage to various parts of the body), providing a strong measure of protection for radiation workers. In addition, institutions using radioactive materials in treatment and research generally develop their own internal controls in addition to those prescribed by law.

The greatest dangers to hospital workers are from scatter, the small amount of radiation that is deflected or reflected from the beam into the immediate vicinity, and from unexpected exposure, either because they are inadvertently exposed in an area not defined as a radiation area or because the equipment is not well maintained.

Radiation workers in diagnostic radiology (including x ray, fluoroscopy and angiography for diagnostic purposes, dental radiography and computerized axial tomography (CAT) scanners), in therapeutic radiology, in nuclear medicine for diagnostic and therapeutic procedures, and in radiopharmaceutical laboratories are carefully followed and checked for exposure, and radiation safety is usually well managed in their workstations, although there are many localities in which control is inadequate.

There are other areas not usually designated as “radiation areas”, where careful monitoring is needed to ensure that appropriate precautions are being taken by staff and that correct safeguards are provided for patients who might be exposed. These include angiography, emergency rooms, intensive care units, locations where portable x rays are being taken and operating rooms.

Prevention and control

The following protective measures are strongly recommended for ionizing radiation (x rays and radioisotopes):

• Rooms that house radiation sources should be properly marked and entered only by authorized personnel.

• All films should be held in place by patients or members of the patient’s family. If the patient must be held, a member of the family should do so. If staff must hold film or patients, the task should be rotated through the staff to minimize the overall dose per individual.

• Where portable x-ray units and radioisotopes are used, only the patient and trained personnel should be allowed in the room.

• Adequate warning should be given to nearby workers when x rays using portable units are about to be taken.

• X-ray controls should be located to prevent the unintentional energizing of the unit.

• X-ray room doors should be kept closed when equipment is in use.

• All x-ray machines should be checked before each use to ensure that the secondary radiation cones and filters are in place.

• Patients who have received radioactive implants or other therapeutic radiology procedures should be clearly identified. Bedding, dressings, wastes and so forth from such patients should be so labelled.

Lead aprons, gloves and goggles must be worn by employees working in the direct field or where scatter radiation levels are high. All such protective equipment should be checked annually for cracks in the lead.

Dosimeters must be worn by all personnel exposed to ionizing radiation sources. Dosimeter badges should be regularly analysed by a laboratory with good quality control, and the results should be recorded. Records must be kept not only of each employee’s personal radiation exposure but also of the receipt and disposition of all radioisotopes.

In therapeutic radiology settings, periodic dose checks should be done using lithium fluoride (LiF) solid-state dosimeters to check on system calibration. Treatment rooms should be equipped with radiation monitor-door interlock and visual-alarm systems.

During internal or intravenous treatment with radioactive sources, the patient should be housed in a room located to minimize exposure to other patients and staff and signs posted warning others not to enter. Staff contact time should be limited, and staff should be careful in handling bedding, dressings and wastes from these patients.

During fluoroscopy and angiography, the following measures can minimize unnecessary exposure:

• full protective equipment

• minimal number of personnel in the room

• “dead-man” switches (must have active operator control)

• minimal beam size and energy

• careful shielding to reduce scatter.

Full protective equipment should also be used by operating-room personnel during radiation procedures, and, when possible, personnel should stand 2 m or more from the patient.

Non-ionizing radiation

Ultraviolet radiation, lasers and microwaves are non-ionizing radiation sources. They are generally far less hazardous than ionizing radiation but nevertheless require special care to prevent injury.

Ultraviolet radiation is used in germicidal lamps, in certain dermatology treatments and in air filters in some hospitals. It is also produced in welding operations. Exposure of the skin to ultraviolet light causes sunburn, ages the skin and increases the risk of skin cancer. Eye exposure can result in temporary but extremely painful conjunctivitis. Long-term exposure can lead to partial loss of vision.

Standards regarding exposure to ultraviolet radiation are not widely applicable. The best approach to prevention is education and wearing shaded protective eyeglasses.

The Bureau of Radiological Health of the US Food and Drug Administration regulates lasers and classifies them into four classes, I to IV. The laser used to position patients in radiology is considered Class I and represents minimal risk. Surgical lasers, however, can pose a significant hazard to the retina of the eye where the intense beam can cause total loss of vision. Because of the high voltage supply required, all lasers present the risk of electrical shock. The accidental reflection of the laser beam during surgical procedures can result in injury to the staff. Guidelines for laser use have been developed by the American National Standards Institute and the US Army; for example, laser users should wear protective goggles specifically designed for each type of laser and take care not to focus the beam on reflecting surfaces.

The primary concern regarding exposure to microwaves, which are used in hospitals chiefly for cooking and heating food and for diathermy treatments, is the heating effect they have on the body. The eye lens and gonads, having fewer vessels with which to remove heat, are most vulnerable to damage. The long-term effects of low-level exposure have not been established, but there is some evidence that nervous system effects, decreased sperm count, sperm malformations (at least partially reversible after exposure ceases) and cataracts may result.

Prevention and control

The OSHA standard for exposure to microwaves is 10 milliwatts per square centimetre (10 mW/cm). This is the level established to protect against the thermal effects of microwaves. In other countries where levels have been established to protect against reproductive and nervous system damage, the standards are as much as two orders of magnitude lower, that is, 0.01 mW/cm² at 1.2 m.

To ensure the safety of workers, microwave ovens should be kept clean to protect the integrity of the door seals and should be checked for leakage at least every three months. Leakage from diathermy equipment should be monitored in the vicinity of the therapist before each treatment.

Hospital workers should be aware of the radiation hazards of ultraviolet exposure and of infrared heat used for therapy. They should have appropriate eye protection when using or repairing ultraviolet equipment, such as germicidal lamps and air purifiers or infrared instruments and equipment.

Conclusion

Physical agents represent an important class of hazards to workers in hospitals, clinics and private offices where diagnostic and therapeutic procedures are performed. These agents are discussed in more detail elsewhere in this Encyclopaedia. Their control requires education and training of all health professionals and support staff who may be involved and constant vigilance and systemic monitoring of both the equipment and the way it is used.

Back

Several countries have established recommended noise, temperature and lighting levels for hospitals. These recommendations are, however, rarely included in the specifications given to hospital designers. Further, the few studies examining these variables have reported disquieting levels.

Noise

In hospitals, it is important to distinguish between machine-generated noise capable of impairing hearing (above 85 dBA) and noise which is associated with a degradation of ambiance, administrative work and care (65 to 85 dBA).

Machine-generated noise capable of impairing hearing

Prior to the 1980s, a few publications had already drawn attention to this problem. Van Wagoner and Maguire (1977) evaluated the incidence of hearing loss among 100 employees in an urban hospital in Canada. They identified five zones in which noise levels were between 85 and 115 dBA: the electrical plant, laundry, dish-washing station and printing department and areas where maintenance workers used hand or power tools. Hearing loss was observed in 48% of the 50 workers active in these noisy areas, compared to 6% of workers active in quieter areas.

Yassi et al. (1992) conducted a preliminary survey to identify zones with dangerously high noise levels in a large Canadian hospital. Integrated dosimetry and mapping were subsequently used to study these high-risk areas in detail. Noise levels exceeding 80 dBA were common. The laundry, central processing, nutrition department, rehabilitation unit, stores and electrical plant were all studied in detail. Integrated dosimetry revealed levels of up to 110 dBA at some of these locations.

Noise levels in a Spanish hospital’s laundry exceeded 85 dBA at all workstations and reached 97 dBA in some zones (Montoliu et al. 1992). Noise levels of 85 to 94 dBA were measured at some workstations in a French hospital’s laundry (Cabal et al. 1986). Although machine re-engineering reduced the noise generated by pressing machines to 78 dBA, this process was not applicable to other machines, due to their inherent design.

A study in the United States reported that electrical surgical instruments generate noise levels of 90 to 100 dBA (Willet 1991). In the same study, 11 of 24 orthopaedic surgeons were reported to suffer from significant hearing loss. The need for better instrument design was emphasized. Vacuum and monitor alarms have been reported to generate noise levels of up to 108 dBA (Hodge and Thompson 1990).

Noise associated with a degradation of ambiance, administrative work and care

A systematic review of noise levels in six Egyptian hospitals revealed the presence of excessive levels in offices, waiting rooms and corridors (Noweir and al-Jiffry 1991). This was attributed to the characteristics of hospital construction and of some of the machines. The authors recommended the use of more appropriate building materials and equipment and the implementation of good maintenance practices.

Work in the first computerized facilities was hindered by the poor quality of printers and the inadequate acoustics of offices. In the Paris region, groups of cashiers talked to their clients and processed invoices and payments in a crowded room whose low plaster ceiling had no acoustic absorption capacity. Noise levels with only one printer active (in practice, all four usually were) were 78 dBA for payments and 82 dBA for invoices.

In a 1992 study of a rehabilitation gymnasium consisting of 8 cardiac rehabilitation bicycles surrounded by four private patient areas, noise levels of 75 to 80 dBA and 65 to 75 dBA were measured near cardiac rehabilitation bicycles and in the neighbouring kinesiology area, respectively. Levels such as these render personalized care difficult.

Shapiro and Berland (1972) viewed noise in operating theatres as the “third pollution”, since it increases the fatigue of the surgeons, exerts physiological and psychological effects and influences the accuracy of movements. Noise levels were measured during a cholecystectomy and during tubal ligation. Irritating noises were associated with the opening of a package of gloves (86 dBA), the installation of a platform on the floor (85 dBA), platform adjustment (75 to 80 dBA), placing surgical instruments upon each other (80 dBA), suctioning of trachea of patient (78 dBA), continuous suction bottle (75 to 85 dBA) and the heels of nurses’ shoes (68 dBA). The authors recommended the use of heat-resistant plastic, less noisy instruments and, to minimize reverberation, easily cleaned materials other than ceramic or glass for walls, tiles and ceilings.

Noise levels of 51 to 82 dBA and 54 to 73 dBA have been measured in the centrifuge room and automated analyser room of a medical analytical laboratory. The Leq (reflecting full-shift exposure) at the control station was 70.44 dBA, with 3 hours over 70 dBA. At the technical station, the Leq was 72.63 dBA, with 7 hours over 70 dBA. The following improvements were recommended: installing telephones with adjustable ring levels, grouping centrifuges in a closed room, moving photocopiers and printers and installing hutches around the printers.

Patient Care and Comfort

In several countries, recommended noise limits for care units are 35 dBA at night and 40 dBA during the day (Turner, King and Craddock 1975). Falk and Woods (1973) were the first to draw attention to this point, in their study of noise levels and sources in neonatology incubators, recovery rooms and two rooms in an intensive-care unit. The following mean levels were measured over a 24-hour period: 57.7 dBA (74.5 dB) in the incubators, 65.5 dBA (80 dB linear) at the head of patients in the recovery room, 60.1 dBA (73.3 dB) in the intensive care unit and 55.8 dBA (68.1 dB) in one patient room. Noise levels in the recovery room and intensive-care unit were correlated with the number of nurses. The authors emphasized the probable stimulation of patients’ hypophyseal-corticoadrenal system by these noise levels, and the resultant increase in peripheral vasoconstriction. There was also some concern about the hearing of patients receiving aminoglycoside antibiotics. These noise levels were considered incompatible with sleep.

Several studies, most of which have been conducted by nurses, have shown that noise control improves patient recovery and quality of life. Reports of research conducted in neonatology wards caring for low-birth-weight babies emphasized the need to reduce the noise caused by personnel, equipment and radiology activities (Green 1992; Wahlen 1992; Williams and Murphy 1991; Oëler 1993; Lotas 1992; Halm and Alpen 1993). Halm and Alpen (1993) have studied the relationship between noise levels in intensive-care units and the psychological well-being of patients and their families (and in extreme cases, even of post-resuscitation psychosis). The effect of ambient noise on the quality of sleep has been rigorously evaluated under experimental conditions (Topf 1992). In intensive care units, the playing of pre-recorded sounds was associated with a deterioration of several sleep parameters.

A multi-ward study reported peak noise levels at the head of patients in excess of 80 dBA, especially in intensive- and respiratory-care units (Meyer et al. 1994). Lighting and noise levels were recorded continuously over seven consecutive days in a medical intensive-care unit, one-bed and multi-bed rooms in a respiratory-care unit and a private room. Noise levels were very high in all cases. The number of peaks exceeding 80 dBA was particularly high in the intensive- and respiratory-care units, with a maximum observed between 12:00 and 18:00 and a minimum between 00:00 and 06:00. Sleep deprivation and fragmentation were considered to have a negative impact on the respiratory system of patients and impair the weaning of patients from mechanical ventilation.

Blanpain and Estryn-Béhar (1990) found few noisy machines such as waxers, ice machines and hotplates in their study of ten Paris-area wards. However, the size and surfaces of the rooms could either reduce or amplify the noise generated by these machines, as well as that (albeit lower) generated by passing cars, ventilation systems and alarms. Noise levels in excess of 45 dBA (observed in 7 of 10 wards) did not promote patient rest. Furthermore, noise disturbed hospital personnel performing very precise tasks requiring close attention. In five of 10 wards, noise levels at the nursing station reached 65 dBA; in two wards, levels of 73 dBA were measured. Levels in excess of 65 dBA were measured in three pantries.

In some cases, architectural decorative effects were instituted with no thought to their effect on acoustics. For example, glass walls and ceilings have been in fashion since the 1970s and have been used in patient admission open-space offices. The resultant noise levels do not contribute to the creation of a calm environment in which patients about to enter the hospital can fill out forms. Fountains in this type of hall generated a background noise level of 73 dBA at the reception desk, requiring receptionists to ask one-third of people requesting information to repeat themselves.

Heat stress

Costa, Trinco and Schallenberg (1992) studied the effect of installing a laminar flow system, which maintained air sterility, on heat stress in an orthopaedic operating theatre. Temperature in the operating theatre increased by approximately 3 °C on average and could reach 30.2 °C. This was associated with a deterioration of the thermal comfort of operating-room personnel, who must wear very bulky clothes that favour heat retention.

Cabal et al. (1986) analysed heat stress in a hospital laundry in central France prior to its renovation. They noted that the relative humidity at the hottest workstation, the “gown-dummy”, was 30%, and radiant temperature reached 41 °C. Following installation of double-pane glass and reflective outside walls, and implementation of 10 to 15 air changes per hour, thermal comfort parameters fell within standard levels at all workstations, regardless of the weather outside. A study of a Spanish hospital laundry has shown that high wet-bulb temperatures result in oppressive work environments, especially in ironing areas, where temperatures may exceed 30 °C (Montoliu et al. 1992).

Blanpain and Estryn-Béhar (1990) characterized the physical work environment in ten wards whose work content they had already studied. Temperature was measured twice in each of ten wards. The nocturnal temperature in patient rooms may be below 22 °C, as patients use covers. During the day, as long as patients are relatively inactive, a temperature of 24 °C is acceptable but should not be exceeded, since some nursing interventions require significant exertion.

The following temperatures were observed between 07:00 and 07:30: 21.5 °C in geriatric wards, 26 °C in a non-sterile room in the haematology ward. At 14:30 on a sunny day, the temperatures were as follows: 23.5 °C in the emergency room and 29 °C in the haematology ward. Afternoon temperatures exceeded 24 °C in 9 of 19 cases. The relative humidity in four out of five wards with general air-conditioning was below 45% and was below 35% in two wards.

Afternoon temperature also exceeded 22 °C at all nine care preparation stations and 26 °C at three care stations. The relative humidity was below 45% in all five stations of wards with air-conditioning. In the pantries, temperatures ranged between 18 °C and 28.5 °C.

Temperatures of 22 °C to 25 °C were measured at the urine drains, where there were also odour problems and where dirty laundry was sometimes stored. Temperatures of 23 °C to 25 °C were measured in the two dirty-laundry closets; a temperature of 18 °C would be more appropriate.

Complaints concerning thermal comfort were frequent in a survey of 2,892 women working in Paris-area wards (Estryn-Béhar et al. 1989a). Complaints of being often or always hot were reported by 47% of morning- and afternoon-shift nurses and 37% of night-shift nurses. Although nurses were sometimes obliged to perform physically strenuous work, such as making several beds, the temperature in the various rooms was too high to perform these activities comfortably while wearing polyester-cotton clothes, which hinder evaporation, or gowns and masks necessary for the prevention of nosocomial infections.

On the other hand, 46% of night-shift nurses and 26% of morning- and afternoon-shift nurses reported being often or always cold. The proportions reporting never suffering from the cold were 11% and 26%.

To conserve energy, the heating in hospitals was often lowered during the night, when patients are under covers. However nurses, who must remain alert despite chronobiologically mediated drops in core body temperatures, were required to put on jackets (not always very hygienic ones) around 04:00. At the end of the study, some wards installed adjustable space-heating at nursing stations.

Studies of 1,505 women in 26 units conducted by occupational physicians revealed that rhinitis and eye irritation were more frequent among nurses working in air-conditioned rooms (Estryn-Béhar and Poinsignon 1989) and that work in air-conditioned environments was related to an almost twofold increase in dermatoses likely to be occupational in origin (adjusted odds ratio of 2) (Delaporte et al. 1990).

Lighting

Several studies have shown that the importance of good lighting is still underestimated in administrative and general departments of hospitals.

Cabal et al. (1986) observed that lighting levels at half of the workstations in a hospital laundry were no higher than 100 lux. Lighting levels following renovations were 300 lux at all workstations, 800 lux at the darning station and 150 lux between the washing tunnels.

Blanpain and Estryn-Béhar (1990) observed maximum night lighting levels below 500 lux in 9 out of 10 wards. Lighting levels were below 250 lux in five pharmacies with no natural lighting and were below 90 lux in three pharmacies. It should be recalled that the difficulty in reading small lettering on labels experienced by older persons may be mitigated by increasing the level of illumination.

Building orientation can result in high day-time lighting levels that disturb patients’ rest. For example, in geriatric wards, beds furthest from the windows received 1,200 lux, while those nearest the windows received 5,000 lux. The only window shading available in these rooms were solid window blinds and nurses were unable to dispense care in four-bed rooms when these were drawn. In some cases, nurses stuck paper on the windows to provide patients with some relief.

The lighting in some intensive-care units is too intense to allow patients to rest (Meyer et al. 1994). The effect of lighting on patients’ sleep has been studied in neonatology wards by North American and German nurses (Oëler 1993; Boehm and Bollinger 1990).

In one hospital, surgeons disturbed by reflections from white tiles requested the renovation of the operating theatre. Lighting levels outside the shadow-free zone (15,000 to 80,000 lux) were reduced. However, this resulted in levels of only 100 lux at the instrument nurses’ work surface, 50 to 150 lux at the wall unit used for equipment storage, 70 lux at the patients’ head and 150 lux at the anaesthetists’ work surface. To avoid generating glare capable of affecting the accuracy of surgeons’ movements, lamps were installed outside of surgeons’ sight-lines. Rheostats were installed to control lighting levels at the nurses’ work surface between 300 and 1,000 lux and general levels between 100 and 300 lux.

Construction of a hospital with extensive natural lighting

In 1981, planning for the construction of Saint Mary’s Hospital on the Isle of Wight began with a goal of halving energy costs (Burton 1990). The final design called for extensive use of natural lighting and incorporated double-pane windows that could be opened in the summer. Even the operating theatre has an outside view and paediatric wards are located on the ground floor to allow access to play areas. The other wards, on the second and third (top) floors, are equipped with windows and ceiling lighting. This design is quite suitable for temperate climates but may be problematic where ice and snow inhibit overhead lighting or where high temperatures may lead to a significant greenhouse effect.

Architecture and Working Conditions

Flexible design is not multi-functionality

Prevailing concepts from 1945 to 1985, in particular the fear of instant obsolescence, were reflected in the construction of multi-purpose hospitals composed of identical modules (Games and Taton-Braen 1987). In the United Kingdom this trend led to the development of the “Harnes system”, whose first product was the Dudley Hospital, built in 1974. Seventy other hospitals were later built on the same principles. In France, several hospitals were constructed on the “Fontenoy” model.

Building design should not prevent modifications necessitated by the rapid evolution of therapeutic practice and technology. For example, partitions, fluid circulation subsystems and technical duct-work should all be capable of being easily moved. However, this flexibility should not be construed as an endorsement of the goal of complete multi-functionality—a design goal which leads to the construction of facilities poorly suited to any speciality. For example, the surface area needed to store machines, bottles, disposable equipment and medication is different in surgical, cardiology and geriatric wards. Failure to recognize this will lead to rooms being used for purposes they were not designed for (e.g., bathrooms being used for bottle storage).

The Loma Linda Hospital in California (United States) is an example of better hospital design and has been copied elsewhere. Here, nursing and technical medicine departments are located above and below technical floors; this “sandwich” structure permits easy maintenance and adjustment of fluid circulation.

Unfortunately, hospital architecture does not always reflect the needs of those who work there, and multi-functional design has been responsible for reported problems related to physical and cognitive strain. Consider a 30-bed ward composed of one- and two-bed rooms, in which there is only one functional area of each type (nursing station, pantry, storage of disposable materials, linen or medication), all based on the same all-purpose design. In this ward, the management and dispensation of care obliges nurses to change location extremely frequently, and work is greatly fragmented. A comparative study of ten wards has shown that the distance from the nurses’ station to the farthest room is an important determinant of both nurses’ fatigue (a function of the distance walked) and the quality of care (a function of the time spent in patients’ rooms) (Estryn-Béhar and Hakim-Serfaty 1990).

This discrepancy between the architectural design of spaces, corridors and materials, on the one hand, and the realities of hospital work, on the other, has been characterized by Patkin (1992), in a review of Australian hospitals, as an ergonomic “debacle”.

Preliminary analysis of the spatial organization in nursing areas

The first mathematical model of the nature, purposes and frequency of staff movements, based on the Yale Traffic Index, appeared in 1960 and was refined by Lippert in 1971. However, attention to one problem in isolation may in fact aggravate others. For example, locating a nurses’ station in the centre of the building, in order to reduce the distances walked, may worsen working conditions if nurses must spend over 30% of their time in such windowless surroundings, known to be a source of problems related to lighting, ventilation and psychological factors (Estryn-Béhar and Milanini 1992).

The distance of the preparation and storage areas from patients is less problematic in settings with a high staff-patient ratio and where the existence of a centralized preparation area facilitates the delivery of supplies several times per day, even on holidays. In addition, long waits for elevators are less common in high-rise hospitals with over 600 beds, where the number of elevators is not limited by financial constraints.

Research on the design of specific but flexible hospital units

In the United Kingdom in the late 1970s, the Health Ministry created a team of ergonomists to compile a database on ergonomics training and on the ergonomic layout of hospital work areas (Haigh 1992). Noteworthy examples of the success of this programme include the modification of the dimensions of laboratory furniture to take into account the demands of microscopy work and the redesign of maternity rooms to take into account nurses’ work and mothers’ preferences.

Cammock (1981) emphasized the need to provide distinct nursing, public and common areas, with separate entrances for nursing and public areas, and separate connections between these areas and the common area. Furthermore, there should be no direct contact between the public and nursing areas.

The Krankenanstalt Rudolfsstiftung is the first pilot hospital of the “European Healthy Hospitals” project. The Viennese pilot project consists of eight sub-projects, one of which, the “Service Reorganization” project, is an attempt, in collaboration with ergonomists, to promote functional reorganization of available space (Pelikan 1993). For example, all the rooms in an intensive care unit were renovated and rails for patient lifts installed in the ceilings of each room.

A comparative analysis of 90 Dutch hospitals suggests that small units (floors of less than 1,500 m²) are the most efficient, as they allow nurses to tailor their care to the specifics of patients’ occupational therapy and family dynamics (Van Hogdalem 1990). This design also increases the time nurses can spend with patients, since they waste less time in changes of location and are less subject to uncertainty. Finally, the use of small units reduces the number of windowless work areas.

A study carried out in the health administration sector in Sweden reported better employee performance in buildings incorporating individual offices and conference rooms, as opposed to an open plan (Ahlin 1992). The existence in Sweden of an institute dedicated to the study of working conditions in hospitals, and of legislation requiring consultation with employee representatives both before and during all construction or renovation projects, has resulted in the regular recourse to participatory design based on ergonomic training and intervention (Tornquist and Ullmark 1992).

Architectural design based on participatory ergonomics

Workers must be involved in the planning of the behavioural and organizational changes associated with the occupation of a new work space. The adequate organization and equipping of a workplace requires taking into account the organizational elements that require modification or emphasis. Two detailed examples taken from two hospitals illustrate this.

Estryn-Béhar et al. (1994) report the results of the renovation of the common areas of a medical ward and a cardiology ward of the same hospital. The ergonomics of the work performed by each profession in each ward was observed over seven entire workdays and discussed over a two-day period with each group. The groups included representatives of all occupations (department heads, supervisors, interns, nurses, nurses’ aides, orderlies) from all the shifts. One entire day was spent developing architectural and organizational proposals for each problem noted. Two more days were spent on the simulation of characteristic activities by the entire group, in collaboration with an architect and an ergonomist, using modular cardboard mock-ups and scale models of objects and people. Through this simulation, representatives of the various occupations were able to agree on distances and the distribution of space within each ward. Only after this process was concluded was the design specification drawn up.

The same participatory method was used in a cardiac intensive-care unit in another hospital (Estryn-Béhar et al. 1995a, 1995b). It was found that four types of virtually incompatible activities were conducted at the nursing station:

• care preparation, requiring the use of a drain-board and sink

• decontamination, which also used the sink

• meeting, writing and monitoring; the area used for these activities was also sometimes used for the preparation of care

• clean-equipment storage (three units) and waste storage (one unit).

These zones overlapped, and nurses had to cross the meeting-writing-monitoring area to reach the other areas. Because of the position of the furniture, nurses had to change direction three times to get to the drain-board. Patient rooms were laid out along a corridor, both for regular intensive care and highly intensive care. The storage units were located at the far end of the ward from the nursing station.

In the new layout, the station’s longitudinal orientation of functions and traffic is replaced with a lateral one which allows direct and central circulation in a furniture-free area. The meeting-writing-monitoring area is now located at the end of the room, where it offers a calm space near windows, while remaining accessible. The clean and dirty preparation areas are located by the entrance to the room and are separated from each other by a large circulation area. The highly intensive care rooms are large enough to accommodate emergency equipment, a preparation counter and a deep washbasin. A glass wall installed between the preparation areas and the highly intensive care rooms ensures that patients in these rooms are always visible. The main storage area was rationalized and reorganized. Plans are available for each work and storage area.

Architecture, ergonomics and developing countries

These problems are also found in developing countries; in particular, renovations there frequently involve the elimination of common rooms. The performance of ergonomic analysis would identify existing problems and help avoid new ones. For example, the construction of wards comprised of only one- or two-bed rooms increases the distances that personnel must travel. Inadequate attention to staffing levels and the layout of nursing stations, satellite kitchens, satellite pharmacies and storage areas may lead to significant reductions in the amount of time nurses spend with patients and may render work organization more complex.

Furthermore, the application in developing countries of the multi-functional hospital model of developed countries does not take into account different cultures’ attitudes toward space utilization. Manuaba (1992) has pointed out that the layout of developed countries’ hospital rooms and the type of medical equipment used is poorly suited to developing countries, and that the rooms are too small to comfortably accommodate visitors, essential partners in the curative process.

Hygiene and Ergonomics

In hospital settings, many breaches of asepsis can be understood and corrected only by reference to work organization and work space. Effective implementation of the necessary modifications requires detailed ergonomic analysis. This analysis serves to characterize the interdependencies of team tasks, rather than their individual characteristics, and identify discrepancies between real and nominal work, especially nominal work described in official protocols.

Hand-mediated contamination was one of the first targets in the fight against nosocomial infections. In theory, hands should be systemtically washed on entering and leaving patients’ rooms. Although initial and ongoing training of nurses emphasizes the results of descriptive epidemiological studies, research indicates persistent problems associated with hand-washing. In a study conducted in 1987 and involving continuous observation of entire 8-hour shifts in 10 wards, Delaporte et al. (1990) observed an average of 17 hand-washings by morning-shift nurses, 13 by afternoon-shift nurses and 21 by night-shift nurses.

Nurses washed their hands one-half to one-third as often as is recommended for their number of patient contacts (without even considering care-preparation activities); for nurses’ aides, the ratio was one-third to one-fifth. Hand-washing before and after each activity is, however, clearly impossible, in terms of both time and skin damage, given the atomization of activity, number of technical interventions and frequency of interruptions and attendant repetition of care that personnel must cope with. Reduction of work interruptions is thus essential and should take precedence over simply reaffirming the importance of hand-washing, which, in any event, cannot be performed over 25 to 30 times per day.

Similar patterns of hand-washing were found in a study based on observations collected over 14 entire workdays in 1994 during the reorganization of the common areas of two university hospital wards (Estryn-Béhar et al. 1994). In every case, nurses would have been incapable of dispensing the required care if they had returned to the nursing station to wash their hands. In short-term-stay units, for example, almost all the patients have blood samples drawn and subsequently receive oral and intravenous medication at virtually the same time. The density of activities at certain times also renders appropriate hand-washing impossible: in one case, an afternoon-shift nurse responsible for 13 patients in a medical ward entered patients’ rooms 21 times in one hour. Poorly organized information provision and transmission structures contributed to the number of visits he was obliged to perform. Given the impossibility of washing his hands 21 times in one hour, the nurse washed them only when dealing with the most fragile patients (i.e., those suffering from pulmonary failure).

Ergonomically based architectural design takes several factors affecting hand-washing into account, especially those concerning the location and access to wash-basins, but also the implementation of truly functional “dirty” and “clean” circuits. Reduction of interruptions through participatory analysis of organization helps to make hand-washing possible.

Back

Epidemiology

The significance of back pain among instances of disease in developed industrial societies is currently on the rise. According to data provided by the National Center for Health Statistics in the United States, chronic diseases of the back and of the vertebral column make up the dominant group among disorders affecting employable individuals under 45 in the US population. Countries such as Sweden, which have at their disposal traditionally good occupational accident statistics, show that musculoskeletal injuries occur twice as frequently in the health services as in all other fields (Lagerlöf and Broberg 1989).

In an analysis of accident frequency in a 450-bed hospital in the United States, Kaplan and Deyo (1988) were able to demonstrate an 8 to 9% yearly incidence of injury to lumbar vertebrae in nurses, leading on average to 4.7 days of absence from work. Thus of all employee groups in hospitals, nurses were the one most afflicted by this condition.

As is clear from a survey of studies done in the last 20 years (Hofmann and Stössel 1995), this disorder has become the object of intensive epidemiological research. All the same, such research—particularly when it aims at furnishing internationally comparable results—is subject to a variety of methodological difficulties. Sometimes all employee categories in the hospital are investigated, sometimes simply nurses. Some studies have suggested that it would make sense to differentiate, within the group “nurses”, between registered nurses and nursing aides. Since nurses are predominantly women (about 80% in Germany), and since reported incidence and prevalence rates regarding this disorder do not differ significantly for male nurses, gender-related differentiation would seem to be of less importance to epidemiological analyses.

More important is the question of what investigative tools should be used to research back pain conditions and their gradations. Along with the interpretation of accident, compensation and treatment statistics, one frequently finds, in the international literature, a retrospectively applied standardized questionnaire, to be filled out by the person tested. Other investigative approaches operate with clinical investigative procedures such as orthopaedic function studies or radiological screening procedures. Finally, the more recent investigative approaches also use biomechanical modelling and direct or video-taped observation to study the pathophysiology of work performance, particularly as it involves the lumbo-sacral area (see Hagberg et al. 1993 and 1995).

An epidemiological determination of the extent of the problem based on self-reported incidence and prevalence rates, however, poses difficulties as well. Cultural-anthropological studies and comparisons of health systems have shown that perceptions of pain differ not only between members of different societies but also within societies (Payer 1988). Also, there is the difficulty of objectively grading the intensity of pain, a subjective experience. Finally, the prevailing perception among nurses that “back pain goes with the job” leads to under-reporting.

International comparisons based on analyses of governmental statistics on occupational disorders are unreliable for scientific evaluation of this disorder because of variations in the laws and regulations related to occupational disorders among different countries. Further, within a single country, there is the truism that such data are only as reliable as the reports upon which they are based.

In summary, many studies have determined that 60 to 80% of all nursing staff (averaging 30 to 40 years in age) have had at least one episode of back pain during their working lives. The reported incidence rates usually do not exceed 10%. When classifying back pain, it has been helpful to follow the suggestion of Nachemson and Anderson (1982) to distinguish between back pain and back pain with sciatica. In an as-yet unpublished study a subjective complaint of sciatica was found to be useful in classifying the results of subsequent CAT scans (computer assisted tomography) and magnetic resonance imaging (MRI).

Economic Costs

Estimates of the economic costs differ greatly, depending, in part, on the possibilities and conditions of diagnosis, treatment and compensation available at the particular time and/or place. Thus, in the US for 1976, Snook (1988b) estimated that the costs of back pain totalled US$14 billion, while a total cost of US$25 billion was calculated for 1983. The calculations of Holbrook et al. (1984), which estimated 1984 costs to total just under US$16 billion, appear to be most reliable. In the United Kingdom, costs were estimated to have risen by US$2 billion between 1987 and 1989 according to Ernst and Fialka (1994). Estimates of direct and indirect costs for 1990 reported by Cats-Baril and Frymoyer (1991) indicate that the costs of back pain have continued to increase. In 1988 the US Bureau of National Affairs reported that chronic back pain generated costs of US$80,000 per chronic case per year.

In Germany, the two largest workers’ accident insurance funds (Berufsgenossenschaften) developed statistics showing that, in 1987, about 15 million work days were lost because of back pain. This corresponds to roughly one-third of all missed work days annually. These losses appear to be increasing at a current average cost of DM 800 per lost day.

It may therefore be said, independently of national differences and vocational groups, that back disorders and their treatment represent not simply a human and a medical problem, but also an enormous economic burden. Accordingly, it seems advisable to pay special attention to the prevention of these disorders in particularly burdened vocational groups such as nursing.

In principle one should differentiate, in research concerning the causes of work-related disorders of the lower back in nurses, between those attributed to a particular incident or accident and those whose genesis lacks such specificity. Both may give rise to chronic back pain if not properly treated. Reflecting their presumed medical knowledge, nurses are much more prone to use self-medication and self-treatment, without consulting a physician, than other groups in the working population. This is not always a disadvantage, since many physicians either do not know how to treat back problems or give them short shrift, simply prescribing sedatives and advising heat applications to the area. The latter reflects the oft-repeated truism that “backaches come with the job”, or the tendency to regard workers with chronic back complaints as malingerers.

Detailed analyses of work accident occurrences in the area of spinal disorders have only just begun to be made (see Hagberg et al. 1995). This is also true of the analysis of so-called near-accidents, which can provide a particular sort of information concerning the precursor conditions of a given work accident.

The cause of low back disorders has been attributed by the majority of the studies to the physical demands of the work of nursing, i.e., lifting, supporting and moving of patients and handling heavy and/or bulky equipment and materials, often without ergonomic aids or the help of additional personnel. These activities are often conducted in awkward body positions, where footing is uncertain, and when, out of wilfulness or dementia, the nurse’s efforts are resisted by the patient. Trying to keep a patient from falling often results in injury to the nurse or the attendant. Current research, however, is characterized by a strong tendency to speak in terms of multicausality, whereby both the biomechanical basis of demands made upon the body and the anatomical preconditions are discussed.

In addition to faulty biomechanics, injury in such situations can be pre-conditioned by fatigue, muscular weakness (especially of the abdominals, back extensors and quadriceps), diminished flexibility of joints and ligaments and various forms of arthritis. Excessive psychosocial stress can contribute in two ways: (1) prolonged unconscious muscular tension and spasm leading to muscular fatigue and proneness to injury, and (2) irritation and impatience which prompts injudicious attempts to work hurriedly and without waiting for assistance. Enhanced ability to cope with stress and the availability of social support in the workplace are helpful (Theorell 1989; Bongers et al. 1992) when work-related stressors cannot be eliminated or controlled.

Diagnosis

Certain risk situations and dispositions may be added to the risk factors deriving from the biomechanics of the forces acting on the spine and from the anatomy of the support and movement apparatus, ones which are attributable to the work environment. Even though current research is not clear on this point, there is still some indication that the increased and recurrent incidence of psychosocial stress factors in nursing work has the capacity to reduce the threshold of sensitivity to physically burdensome activities, thus contributing to an increased level of vulnerability. In any case, whether such stress factors exist appears to be less decisive in this connection than how nursing staff manages them in a demanding situation and whether they can count on social support in the workplace (Theorell 1989; Bongers et al. 1992).

The proper diagnosis of low back pain requires a complete medical and a detailed occupational history including accidents resulting in injury or near-misses and prior episodes of back pain. The physical examination should include evaluation of gait and posture, palpation for areas of tenderness and evaluation of muscle strength, range of motion and joint flexibility. Complaints of weakness in the leg, areas of numbness and pain that radiate below the knee are indications for neurological examination to seek evidence of spinal cord and/or peripheral nerve involvement. Psychosocial problems may be disclosed through judicious probing of emotional status, attitudes and pain tolerance.

Radiological studies and scans are rarely helpful since, in the vast majority of cases, the problem lies in the muscles and ligaments rather than the bony structures. In fact, bony abnormalities are found in many individuals who have never had back pain; ascribing the back pain to such radiological findings as disc space narrowing or spondylosis may lead to needlessly heroic treatment. Myelography should not be undertaken unless spinal surgery is contemplated.

Clinical laboratory tests are useful in assessing general medical status and may be helpful in disclosing systemic diseases such as arthritis.

Treatment

Various modes of management are indicated depending on the nature of the disorder. Besides ergonomic interventions to enable the return of injured workers to the workplace, surgical, invasive-radiological, pharmacological, physical, physiotherapeutic and also psychotherapeutic management approaches may be necessary—sometimes in combination (Hofmann et al. 1994). Again, however, the vast majority of cases resolve regardless of the therapy offered. Treatment is discussed further in the Case Study: Treatment of Back Pain.

Prevention in the Work Environment

Primary prevention of back pain in the workplace involves the application of ergonomic principles and the use of technical aids, coupled with physical conditioning and training of the workers.

Despite the reservations frequently held by nursing staff regarding the use of technical aids for the lifting, positioning and moving of patients, the importance of ergonomic approaches to prevention is increasing (see Estryn-Béhar, Kaminski and Peigné 1990; Hofmann et al. 1994).

In addition to the major systems (permanently installed ceiling lifters, mobile floor lifters), a series of small and simple systems has been introduced noticeably into nursing practice (turntables, walking girdles, lifting cushions, slide boards, bed ladders, anti-slide mats and so on). When using these aids it is important that their actual use fits in well with the care concept of the particular area of nursing in which they are used. Wherever the use of such lifting aids stands in contradiction to the care concept practised, acceptance of such technical lifting aids by nursing staff tends to be low.

Even where technical aids are employed, training in techniques of lifting, carrying and supporting are essential. Lidström and Zachrisson (1973) describe a Swedish “Back School” in which physiotherapists trained in communication conduct classes explaining the structure of the spine and its muscles, how they work in different positions and movements and what can go wrong with them, and demonstrating appropriate lifting and handling techniques that will prevent injury. Klaber Moffet et al. (1986) describe the success of a similar programme in the UK. Such training in lifting and carrying is particularly important where, for one reason or another, use of technical aids is not possible. Numerous studies have shown that training in such techniques must constantly be reviewed; knowledge gained through instruction is frequently “unlearned” in practice.

Unfortunately, the physical demands presented by patients’ size, weight, illness and positioning are not always amenable to nurses’ control and they are not always able to modify the physical environment and the way their duties are structured. Accordingly, it is important for institutional managers and nursing supervisors to be included in the educational programme so that, when making decisions about work environments, equipment and job assignments, factors making for “back friendly” working conditions can be considered. At the same time, deployment of staff, with particular reference to nurse-patient ratios and the availability of “helping hands”, must be appropriate to the nurses’ well-being as well as consistent with the care concept, as hospitals in the Scandinavian countries seem to have managed to do in exemplary fashion. This is becoming ever more important where fiscal constraints dictate staff reductions and cut-backs in equipment procurement and maintenance.

Recently developed holistic concepts, which see such training not simply as instruction in bedside lifting and carrying techniques but rather as movement programmes for both nurses and patients, could take the lead in future developments in this area. Approaches to “participatory ergonomics” and programmes of health advancement in hospitals (understood as organizational development) must also be more intensively discussed and researched as future strategies (see article “Hospital ergonomics: A review”).

Since psychosocial stress factors also exercise a moderating function in the perception and mastering of the physical demands made by work, prevention programmes should also ensure that colleagues and superiors work to ensure satisfaction with work, avoid making excessive demands on the mental and physical capacities of workers and provide an appropriate level of social support.

Preventive measures should extend beyond professional life to include work in the home (housekeeping and caring for small children who have to be lifted and carried are particular hazards) as well as in sports and other recreational activities. Individuals with persistent or recurrent back pain, however it is acquired, should be no less diligent in following an appropriate preventive regimen.

Rehabilitation

The key to a rapid recovery is early mobilization and a prompt resumption of activities with the limits of tolerance and comfort. Most patients with acute back injuries recover fully and return to their usual work without incident. Resumption of an unrestricted range of activity should not be undertaken until exercises have fully restored muscle strength and flexibility and banished the fear and temerity that make for recurrent injury. Many individuals exhibit a tendency to recurrences and chronicity; for these, physiotherapy coupled with exercise and control of psychosocial factors will often be helpful. It is important that they return to some form of work as quickly as possible. Temporary elimination of more strenuous tasks and limitation of hours with a graduated return to unrestricted activity will promote a more complete recovery in these cases.

Fitness for work

The professional literature attributes only a very limited prognostic value to screening done before employees start work (US Preventive Services Task Force 1989). Ethical considerations and laws such as the Americans with Disabilities Act mitigate against pre-employment screening. It is generally agreed that pre-employment back x rays have no value, particularly when one considers their cost and the needless exposure to radiation. Newly-hired nurses and other health workers and those returning from an episode of disability due to back pain should be evaluated to detect any predisposition to this problem and provided with access to educational and physical conditioning programmes that will prevent it.

Conclusion

The social and economic impact of back pain, a problem particularly prevalent among nurses, can be minimized by the application of ergonomic principles and technology in the organization of their work and its environment, by physical conditioning that enhances the strength and flexibility of the postural muscles, by education and training in the performance of problematic activities and, when episodes of back pain do occur, by treatment that emphasizes a minimum of medical intervention and a prompt return to activity.

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