Introduction
Technology is highly valued, especially in health care for patients with serious conditions,
and sometimes technology is necessary to save lives. These technologies contribute
to increased noise, making environments uncomfortable.[1] The occupational risk due to high levels of noise in the hospital environment has
been recognized, and at the suggestion of the National Agency of Sanitary Surveillance
of the Ministry of Health,[2] evaluation and control of noise in hospital areas is recommended, especially in
areas with compressed air and vacuum generation in maintenance areas, workshops, and
laundries.
The recommendation for hospital areas is that the noise level should not exceed 55
dB.[3] Levels above this value are considered uncomfortable and can cause extra-auditory
effects in the body in general. Although there is variation from individual to individual,
people are directed to avoid exposure to noise levels that exceed 85 to 90 sound pressure
level ambiance [dBA].[3]
The Regulatory Norm (NR-17) covers aspects related to environmental conditions and
the organization of workplaces.[4] In work spaces where there is constant attention and performance using intellectual
activity, NR-17 recommends comfort conditions, which includes the noise level, following
the provisions of NBR 10152/87.[3]
According to the World Health Organization,[5] among the critical effects of noise in hospitals are communication interference,
including with warning signs of annoyance and sleep disturbance. Therefore, this Norm
recommends that the equivalent sound pressure level (Leq) not exceed 35 A-weighted
decibel scale (dBA) in rooms where patients are treated and observed. Special attention
to noise levels in the intensive care unit (ICU) and in operating rooms is recommended.[5]
However, studies in hospitals that analyzed the noise in various areas such as the
ICU,[6]
[7]
[8]
[9]
[10]
[11]
[12] emergency room (ER), material center, surgical center, pharmacy, pediatrics, kitchen,
laundry room,[10] corridors, and nursing station[13] showed high levels. The noise was associated with conversation among professionals,
movement of people, and various hospital medical equipment, including acoustic alarms,
which are essential to alert professionals to changes in clinical status of patients
or malfunctioning devices.[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13] In addition, noise hampers professionals' concentration.[14] It is recommended that emergency department team members be encouraged to better
know the noise of their own work environment.[15]
In this context, the ER deserves attention because nowadays it contains various hospital
medical equipment, a large team of professionals, accident victims and their families,
and rescue vehicles, thereby increasing the ambient noise.
The present study aimed to evaluate the ambient sound in the ER of a general hospital,
known for its trauma care, in the city of Curitiba, Paraná.
Methods
This is a descriptive cross-sectional study conducted in the ER of a general hospital
known for its trauma care in the city of Curitiba, Paraná in 2011. The project was
approved by the ethics committee of the hospital under number 167/2010.
Assessments followed the procedures outlined by the Standard for Occupational Hygiene
of FUNDACENTRO to characterize the exposure of all workers considered.[16] The instruments used to assess the noise were a Bruel & Kjaer (Denmark) brand type
2230 sound pressure level meter, carried by the evaluator, and a Bruel & Kjaer type
4230 sound level calibrator, all property of FUNDACENTRO/PR. The meter was properly
calibrated before the tests.
The minimum (Lmin), maximum (Lmax), and Leq were evaluated and expressed in decibels,
compensated for on the dBA. Measurements were taken at 10 sites inside the ER: the
Advanced Life Support (ALS) room, ALS anteroom, nursing station, in front of the nursing
station, suture room, main corridor, observation room, in front the service windows,
reception, tomography and X-ray viewing room, some equipment, and patient transport
helicopter.
The steps followed a sequence, with a 2- minute, 30-second evaluation at each site.
After going through all the selected locations, the evaluation was done three more
times, so that four measurements were taken at each site, with maximum, minimum, and
Leq, in the mornings between 7 am and 1 pm, in the afternoon between 1 pm and 7 pm, and at night between 7 pm and 7 am. During the evaluation, time was measured by a stopwatch and notes were taken about
events that altered the measurements. For the helicopter and equipment, a single measurement
was performed in the afternoon. The data are presented in table format.
Results
[Table 1] shows the noise levels in the ER. The greatest value of Leq dBA was recorded in
the ALS anteroom (68.8 dBA) during the night, and the lowest value of Leq dBA occurred
in the suture room (56.6 dBA) in the morning. The lowest Lmin was detected in the
suture room (44.1 dBA) at night. The room was empty. However, we measured the background
noise and the highest Lmin occurred in the ALS (59.5 dBA) in the morning. The highest
Lmax was detected in the suture room (96.3 dBA) in the afternoon in the presence of
four patients and a crying child, and the lowest Lmax occurred in front of the service
windows (73.2 dBA). In the 10 areas assessed, the highest Leq dBA frequency occurred
in the afternoon.
Table 1
ER noise levels at different periods of the day
|
Area
|
Period
|
Continuous noise [dBA Leq]
|
Lmin
|
Lmax
|
Notes
|
|
1. ALS
|
Morning
|
64.7
|
59.5
|
80.7
|
Radio on; AC on; 1 patient sleeping without respirator; 2 workers;
|
|
Afternoon
|
61.5
|
50.9
|
79.7
|
4–6 patients; 4 monitors; 2 patients on respirator; AC off
|
|
Night
|
64.1
|
56.4
|
85.3
|
AC on; 1 patient; 3 workers
|
|
2. ALS anteroom
|
Morning
|
61.8
|
53.5
|
78.2
|
No patients (clothing collection)
|
|
Afternoon
|
68.3
|
55.0
|
79.9
|
2 patients; 3 health care teams
|
|
Night
|
68.8
|
54.1
|
83.0
|
1 patient; 6 health care teams
|
|
3. Nursing station
|
Morning
|
63.2
|
50.4
|
80.4
|
4 health care teams; telephone ringing
|
|
Afternoon
|
67.3
|
55.2
|
79.6
|
5 health care teams
|
|
Night
|
63.8
|
50.5
|
79.8
|
4–5 health care teams
|
|
4. In front of nursing station
|
Morning
|
62.0
|
50.8
|
77.2
|
3–6 people without patient on gurney
|
|
Afternoon
|
65.8
|
54.2
|
77.0
|
3 patients on gurney
|
|
Night
|
63.6
|
51.3
|
81.6
|
5 people; 3 patients on gurney; 2 visitors
|
|
5. Suture room
|
Morning
|
56.6
|
44.2
|
68.9
|
Empty room; background noise
|
|
Afternoon
|
64.1
|
48.2
|
96.3
|
4 adult patients; 1 patient (child) crying
|
|
Night
|
60.4
|
44.1
|
82.2
|
2 patients; 1 visitor; 1 doctor (garbage lid noise)
|
|
6. Main corridor
|
Morning
|
62.3
|
50.6
|
76.6
|
Few people in corridor
|
|
Afternoon
|
66.3
|
53.8
|
85.6
|
Many people in corridor
|
|
Night
|
62.0
|
49.6
|
78.7
|
10 adults sitting
|
|
7. Observation room
|
Morning
|
|
|
|
CLOSED
|
|
Afternoon
|
62.0
|
47.4
|
80.6
|
4–5 patients; 2–3 visitors; 1 monitor on
|
|
Night
|
|
|
|
CLOSED
|
|
8. In front of service window
|
Morning
|
60.2
|
48.5
|
77.8
|
7 patients at windows
|
|
Afternoon
|
63.4
|
50.6
|
79.9
|
3 patients; 1 worker
|
|
Night
|
62.2
|
50.9
|
73.2
|
Patients with visitors
|
|
9. Imaging exam room (tomography; X-ray)
|
Morning
|
60.8
|
55.5
|
77.5
|
1 worker attending; AC on
|
|
Afternoon
|
63.6
|
55.4
|
85.0
|
3 workers
|
|
Night
|
59.0
|
49.7
|
75.8
|
1 worker
|
|
10. Reception
|
Morning
|
64.5
|
49.8
|
83.0
|
3–4 workers; client movement
|
|
Afternoon
|
66.8
|
46.0
|
86.0
|
4 workers; client movement at counter; falling object
|
|
Night
|
66.8
|
50.0
|
81.1
|
Client movement; drawer shut quickly
|
Abbreviations: AC, air conditioner; ALS, Advanced Life Support; ER, emergency room;
Leq, average equivalent level; dBA, compensated for on the A-weighted decibel scale;
Lmin, minimum sound pressure; Lmax, maximum sound pressure.
[Table 2] presents the levels of continuous Leq dBA noise found in various equipment operating
in the ER. Among the equipment, the cast saw had the highest measurements (90.0 dBA)
and the oximeter the lowest (61.0 dBA). The noise of the helicopter was 119 dBA, running
for 20 minutes on the landing pad.
Table 2
Noise level of equipment and transport
|
Equipment and transport
|
Continuous noise [dBA Leq]
|
Alarm noise [dBA Leq]
|
|
Respirator on
|
66.0
|
74.0
|
|
Oximeter on
|
61.0
|
70.0
|
|
Oxygen on
|
72.0
|
–
|
|
AC on
|
68.0
|
–
|
|
Phone ringing
|
75.0
|
–
|
|
Cast saw
|
90.0
|
–
|
|
Helicopter
|
119.0
|
–
|
Abbreviations: AC, air conditioner; Leq, average equivalent level; dBA, compensated
for on the A-weighted decibel scale.
Discussion
This study evaluated the sound environment in the ER of a general hospital known for
its trauma care in the city of Curitiba, Paraná. The results presented in [Tables 1] and [2] show that Leq values were above the acceptable comfortable noise levels for hospital
environments.[3]
[4]
Of the various noise sites evaluated ([Table 1]), the lowest Leq was measured in the suture room (56.6 dBA) and the highest in the
ALS anteroom (68.8 dBA). Accident victims arrive in this area, and it is also a meeting
place for various professional teams that send and receive patients, causing movement
of people and equipment and the need for oral communication, which increases sound
pressure level.
Few studies analyze the noise in ERs. However, one study evaluating an ER identified
the highest Leq, ranging from 65 to 73 dBA, in the triage area.[17] The authors considered the noise in the ER sufficiently high and worrisome because
the health staff works with a sense of urgency and needs to rely on oral communication.[17] In another study, when assessing areas of a teaching hospital, such as the ER, ICU,
hospital medical-surgical floors, and a nursing home, noise levels in the hospital
ranged from 55 to 70 dBA. The authors reported the highest level was in the ER and
concluded that the human factor is a major source of noise pollution.[18]
A study in four emergency units in Phoenix, Arizona, found in hospital A the lowest
noise intensity of 55.9 dBA, with an average of 69.1 dBA and a peak of 76.6 dBA; hospital
B, lowest intensity 65.5 dBA, averaging 70.1 dBA and a peak of 73.4 dBA; hospital
C, the lowest value 71.1 dBA, with an average of 73.0 dBA and peak of 75.6 dBA; and
hospital D, lowest value 65.3 dBA, an average of 66.6 dBA, and a peak of 75.2 dBA.
The author concluded that these levels are sufficient to cause deleterious psychological
and secondary physical effects to the team members. Also, the author reported that
reducing the level of ambient noise can improve patient care, reduce stress, and increase
employee job satisfaction.[15]
The Leq values found in the ER reception area ([Table 1]) ranged from 64.5 to 66.8 dBA and are in accordance with the noise assessment study
that evaluated the various internal areas of hospital service; the reception area
of the ER measured 64.2 dBA.[10]
In all sectors, the Leq in the afternoon was higher, ranging from 61.5 dBA to 68.3
dBA in the ALS and ALS anteroom. However, a higher Leq variation of 68.8 dBA occurred
in a single sector at night. The data are in accordance with other findings,[19] where the afternoon shift was considered the loudest, even including the neonatal
ICU (NICU).
However, this study did not corroborate other studies.[20]
[21] This divergence can be explained because the activities performed in ERs are different
from routines performed in other hospital areas. The environment of the ER does not
have a certain time of increased noise due to several activities that happen according
to the demand of the moment.
An unstructured observational study in a surgical inpatient unit of 28 beds, made
up of four rooms with six beds and one with four beds, concluded that the morning
noise level was higher because of the presence of the majority of health professionals
and the routine work in the wards (hygiene, changing linens, admission and transfer
of patients, referral for surgery as well as emergency admissions).[20] Likewise, in another study conducted in an NICU,[21] the noise level was higher in the morning, due to the conversations between people
and the jet of water from the hand washing sink. In the present study, the highest
Leq occurred in the ALS anteroom. This situation can be explained by the activities
at this site (i.e., reception of accident victims, meetings of various professionals,
transporting of victims). And because it is a teaching hospital, there is also much
movement of health care students adding to the noise.
We observed that noise levels altered slightly, reaching maximum values well above
80 dBA as stated in [Table 1]. This situation was observed when objects fell, materials and equipment such as
transport stretchers and dressing tables were manipulated, garbage carts were transported,
waste receptacle lids or drawers were opened and closed, clipboards were handled,
loud conversations were had, children cried, patients/families or professionals used
loud voices, patients were located for examinations, phones rang, and emergency alarms
buzzed in equipment such as respirators and monitors ([Table 2]).
A similar study regarding noise in the hospital workplace observed changes in noise
due to periodic disturbances caused by the increased flow of people talking loudly,
including students, teachers, clients, caregivers, and workers. Frequent noise caused
by trolleys, stretchers, wheelchairs, and phones was also detected. The study evaluated
the comfort levels of workers in a hospital ward, as determined by NR-174, and found
that the values were 50 dBA, 51 dBA, and 56 dBA in each ward,[22] which were lower than those detected in the ER.
Noise above the levels considered comfortable can impact overall health and lead to
nonperception of important sounds. In a study in which the noise ranged from 52.35
to 84.60 dBA, nursing professionals had hearing complaints like ringing and extra-auditory
problems such as irritation, sleep disturbance, headaches, and poor concentration.[23]
An environment in which the minimum level of background noise exceeds 45 to 50 dBA
will require people to raise their voices by ∼30 dBA above the noise, so that a difference
between the two signals occurs and understanding can happen[24]; this situation will require very high levels of speech at around 80 dBA like the
values found in [Tables 1] and [2], which cause discomfort and fatigue, leading to difficulty concentrating.[24] This is a worrisome situation that interferes with the performance of professional
tasks in the ER environment.
In [Table 2], the Leq value for the helicopter arrival corresponds to a high risk for hearing
professionals who are not properly using protective equipment. The daily maximum permissible
exposure values are 115 dBA for 7 minutes; the cast saw at 90 dBA corresponds to a
maximum of 4 hours of daily exposure.[25]
Besides hearing risk, researchers report that high noise levels can cause behavioral
disorders, and sound pressure intensity of 65 dBA can affect the hypothalamus and
pituitary, raising the levels of secretion of epinephrine, norepinephrine, and corticosteroids
as well as increasing blood pressure and changing heart rate and peripheral vasoconstriction.[7]
[12]
Therefore, it appears that the noise levels present in the ER can impact the overall
health of the population. The implementation of program promoting health and prevention
is recommended. Preventive/educational actions are strongly recommended for early
identification or avoidance of the onset of signs and symptoms related to noise exposure
to provide a better quality of life to health care teams. It is necessary to implement
effective measures to control noise in the ER, as well as providing for the satisfactory
use of ear protection equipment for employees exposed to noise. Workshops are important
to educate the team regarding self-care and improvements in health and work.
Conclusion
In all assessed points, noise levels were above the comfort levels recommended by
the Brazilian Association of Technical Standards (1987), which may harm users' and
professionals' health as well as influence professional performance in the emergency
ward. Leq levels of helicopter and cast saw entail high hearing hazard, requiring
professionals to use individual protection equipment, and point to the need of creation
and implementation of effective control measures of noise levels in emergency wards.
