Noise in the ED
Noise in the ED
Marius A. Tijunelis MD, Elizabeth Fitzsullivan BA, Sean O. Henderson MD*
Department of Emergency Medicine, Keck School of Medicine, LAC+USC Medical Center, Los Angeles, CA 90033, USA
Received 13 January 2005; accepted 1 February 2005
Abstract
Background: The impact of noise pollution on both the patient and the care provider has been extensively studied in the neonatal intensive care unit and in other critical care units. Noise pollution makes errors more probable and is one of the risk factors for provider burnout and negative outcomes for patients. The Environmental Protection Agency (EPA) recommends that the acceptable noise level in a hospital should not exceed 40 dB.
Objectives: The purpose of this study was to record and analyze noise in a large urban level I emergency department (ED) and compare to the EPA guidelines.
Methods: A 3-channel dosimeter Quest Q300 (Quest Technologies, Oconomowoc, WI) was placed as a stand-alone unit on the wall of the resuscitation booth in the ED. Sound was sampled 16 times per second for 12 hours and was recorded as peaks and averages for each minute. The dosimeter was then placed in the pocket of a medical student with a small 8-mm shoulder-mount type 2 MIcrophone. The medical student followed an emergency medicine resident throughout an 8-hour shift in the main resuscitation area while monitoring and logging sound fluctuations in the environment. Sound pressure levels were logged in real time and subsequently correlated to the recorded peaks. Sound was sampled 16 times per second and recorded peaks and averages for each minute.
Results: In the initial part of the study, the time-weighted average was 43 dB. The average sound levels peaked approximately 25 times over 12 hours. Individually measured peak levels of 94 to 117 dB occurred every minute. In the second part of the study, the time-weighted average was 52.9 dB. Conclusions: When compared to EPA accepted noise levels for hospital (40 dB), the ED under study had excessive noise on a regular basis. There are easily identifiable sources of noise pollution in the ED. By identifying and modifying sources of noise, stress in the ED may be decreased.
D 2005
Introduction
Although much has been written about stress in emergen- cy medicine and threat of burnout among emergency physicians, the emergency department (ED) itself has been little studied. As a source of bstress in the workplace,Q the
T Corresponding author. Tel.: +1 323 226 6667; fax: +1 323 226 8044.
bright lights, loud noises, hard tile floors, lack of air circulation, and lack of food services at off-hours have not been examined. Interestingly, it is these stressors that a well designed ED should be able to improve that emergency health care workers have control over, that is, one may not be able to predict when the next Pediatric cardiac arrest will present, but one can control the lights, the noises, and the smells that characterize so many EDs. We attempted to quantify one of these factors, noise, in a large Inner city ED in Los Angeles.
0735-6757/$ - see front matter D 2005 doi:10.1016/j.ajem.2005.02.037
The impact of noise pollution on both patient and patient care provider has been extensively studied in the neonatal intensive care unit (ICU) and in other critical care units [1-5]. Noise pollution makes errors more probable and is one of the risk factors for provider burnout and negative outcomes for patients [6].
Table 1 Definitions
Average sound level The average sound level in decibel for (LAVG/LEQ) the measurement period on the basis
of exchange rate
Criterion level Constant sound level in decibel if
applied for 8 hours would accumulate a dose of 100%
Dose A percentage of the maximum allowable noise that a worker can be exposed to per day
Exchange rate Number of decibel that a sound must
change to double the rate of dose accumulation
Frequency weighting Sound filter
Peak level (LPEAK) The highest instantaneous sound
pressure in decibel that occurs during a given period
SPL A quantity in decibel displayed as maximum value for previous 1-s period
Threshold A preset level in decibel, below which sound is not accumulated or averaged into LAVG, LEQ, or dose
Time constant Response to a fluctuating noise
level-fast = 0.125 s; slow = 1 s
TWA Sound level in decibel that is accumulated for any period but with its average level compiled over 8 h period
Upper limit Dosimeter will record amount of time
that the sound level was at or greater than preset level
As there are no known published studies of the typical noise level in the ED, the purpose of this pilot study was to record and analyze noise in a large urban level I trauma center. The hypothesis was that there are excessive noise levels in the ED that may contribute to the already stressful work environment.
Methods
A 3-channel noise dosimeter, Quest 300 from Quest Technologies, was used in this study. A dosimeter (Fig. 1) is used to monitor workplace noise levels to ensure that they do not exceed Occupational Safety and Health Administra- tion (OSHA) regulations. It was calibrated according to the manufacturer specifications.
Initially, the dosimeter was placed as a stand-alone unit at an 8-ft elevation on the wall of the main resuscitation booth in the ED. One of the 3 channels was set to OSHA hearing conservation controls- threshold, 80 dB; exchange rate, 5 dB; criterion level, 90 dB; time constant, slow; upper limit, 115; and frequency weighting, A (Table 1). Sound was sampled at 16 times per second for 12 hours (7 pm to 7 am on October 2, 2002) and was recorded as peaks and averages for each minute.
The recorded variables of interest were dose, time- weighted average (TWA), average sound level over run- time, sound pressure level (SPL), and peak level (Table 1). During the first part of this study, the noise sources were not identified or logged. For the second portion of the study, the same dosimeter was used to record noise levels. This time, the 8-mm shoulder-mount type 2 microphone was placed on the shoulder of a volunteer medical student. The medical
student followed an emergency medicine resident through- out a clinical shift, and monitored and logged sound fluctuations in the environment.
Two of the 3 channels of the dosimeter were set-up with assistance of Quest engineering. The first channel was set-up per OSHA hearing conservation controls (except weighting C). The second channel was set-up to more closely resemble the physiological response of an eardrum at higher frequencies. Thus, the threshold was off; exchange rate, 3 dB; criterion level, 90 dB; time constant, fast; upper limit, 140 dB; and frequency weighting, C. Sound pressure levels were logged in breal time.Q Sound was recorded for 8 hours on a weekday shift (11 am to 7 pm). Upon conclusion of the recordings, the data were transferred to a personal computer and the results were compiled and analyzed. Quest Suite For Widows Data Management Software (Quest, Oconomowoc, WI) was used to configure data in tabular and graphic formats.
Results
In the first part of the study, given that the percentage dose doubles for every 5-dB change, the TWA for this study,
43 dB is greater than the dosage recommended by the
Table 2 Etiology of noise in the ED
Noise in the ED (SPL) (dB)
Patient care
Adjustment of oxygen tanks for transportation Alarms on monitors
95
87
Communication
Phones
Blood gas phone
Yelling for EKG technician, anticonvulsant medications, respiratory treatment, transportation
Overhead speaker
Conversations with attending physicians Conversations with Medical Students Coughing- patients/staff Laughing- staff
90
88
90
96
91
93
90
94
Linen can
Vacuum tube carrying system
a Since modified.
91
95
|
Cabinets slamming |
91 |
|
Isolation booth doors slamming |
86 |
|
Drawers slamming |
90 |
|
Garbage can closinga |
100 |
Environmental Protection Agency (EPA) for the 12 hours studied. The average sound levels peaked 25 times during that period. Individually measured peak levels of
90.1 (equal to a pneumatic drill) to 127.2 dB (equal to a boom box in a car) occurred every minute.
Our findings in part 2 of the study were similar. Once again, the averages stayed above the EPA guidelines. The TWA was 52.9 dB over the 8 hours studied and individually measured peak levels of 94 to 117 dB occurred every minute. The recorded sound peaks were correlated to the logged SPLs and the etiology of the peak noise levels were identified (Table 2). As anticipated from the first part of the study, there were multiple sources of noise pollution,
some of which appeared to be easily remedied.
Discussion
bJob stressQ is an expectation for physicians in emergen- cy medicine. The type of cases that present to the ED, the lack of control over who presents, the shift work, and the environment itself, all contribute to the stress placed on the health care providers. From the beginning of emergency medicine residency, Whitley et al [7] found that residents experience constant stress. Mean levels of stress and depression were higher for women residents, and unmarried residents reported more symptoms of depression. Initially, this stress can be invigorating and challenging, but over time, it often becomes a source of dissatisfaction. In a survey of emergency medicine physicians conducted by Doan-Wiggins et al [8], the stressful environment of the ED
M.A. Tijunelis et al.
was ranked as the fourth highest cause of dissatisfaction, just behind abusive patients, working nights and holidays, and malpractice/litigation. The key difference between the top 3 causes of dissatisfaction and the number 4 cause, the environment, is that changes can be made within the ED to reduce the stress induced by the environment.
Most of the literature evaluating stress related to the field of emergency medicine discusses issues outside the control of the health care provider. The study of Shockley and Marckovchick [9] on wellness issues related to emergency medicine discussED shift work, death telling, and the results of sudden illness or trauma as reasons for burnout. An earlier survey of wellness issues in emergency medicine by Lum et al [10] identified and discussed sources of stress in the ED that included scheduling difficulties, patient load, difficult/hateful patients, and malpractice liability. There was no mention in either of these studies of the ED environment as an additional stressor. Even in a compre- hensive review by Dorevitch and Forst [11], where a variety of occupational hazards were examined including infectious diseases, latex allergies, radiation exposure, violence, Nitrous oxide, rotating shift work, burnout, and emergency physician attrition, there again was no mention of the physical environment of the ED.
The concern regarding the effects of exposure to noise have prompted recommendations and regulations regarding the level of noise that is allowable for specific locations as well as allowable exposure times. The World Health Organization recommends that the acceptable noise level (LEQ) in a hospital should not exceed 30 dB during the day and night, whereas the EPA allows levels up to 40 dB. Our pilot study findings of 43 and 52.9 dB TWA easily exceed the recommendations of both groups.
A study by Kahn et al [4], which examined noise in the Medical ICU and Respiratory ICU, determined that 51% of the noise that occurred in the ICU was modifiable. They continued this study by implementing behavior modification strategies and then reexamining the environment. They discovered that simple behavior modification techniques allowed them to significantly reduce the mean peak noise level as well as the number of sound peaks in 3 of the
4 periods studied. In our study, we identified numerous sources of noise that could be easily modified, including the slamming of doors and drawers and conversations among attending physicians, staff, and medical students. One easily remedied source of noise in our ED were the metal trash cans used in the resuscitation area; 100 dB each time the lid was closed. After this study, the metal bins were replaced with plastic, thus, eliminating one of the sources of noise pollution in the ED.
Limitations
This study only examined the sources of noise pollution in a single ED over a limited period. Although we expect that the etiology of noise in our ED may be unique to our
institution, experience leads us to believe that the issue of noise is not. In addition, it would have been ideal to have a dosimeter that would allow both the peak and the SPL to be viewed simultaneously. It was difficult to correlate all recorded peaks with logged SPLs retrospectively and it is possible that all noise sources were not identified.
In addition, we made no measurements of the effect of noise on the providers either as an isolated stressor or as an additive one.
Conclusion
There indeed appears to be excessive noise levels in the ED, and the sources are easily identifiable. As is done in the ICUs, identification and modification of these noise sources may assist in decreasing job stress, provider burnout, and physician error. It will also allow us to provide a more pleasant and peaceful environment for our patients. Further research in this area might focus on the other modifiable environmental stressors within the ED that contribute to stress: lighting styles and distribution and air quality improvement.
In conclusion, Gallery et al [12] performed a study in which they found that although the vast majority of emergency physicians reported normal levels of stress, a disproportionate number reported high levels of stress and depression and plan on leaving the specialty of emergency medicine. The number of individuals planning to leave appeared to be greater than the number that will be replaced through residency training. Thus, we believe that it is our duty to minimize the impact of our environment on our daily stress exposure. As Tsiou et al [1] so eloquently put it, bgenerally workers in the field need to be made aware of and sensitive to the issue (of noise). Awareness means this: if the door squeaks- oil it, if the telephone rings loudly- lower the volume, if the trolley’s wheelbase is broken- have it replaced, don’t leave inhalers, respirators or other equipment switched on unnecessarily, when you speak- do not shout and keep your voice lower still at night.Q
Acknowledgments
We would like to thank Master Sergeant Ronald G. Courts and Major Arnold Zigman for the dosimeter and the use of the Quest software. In addition, special thanks to Tim Saunders for meticulously logging the noise sources in our ED.
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