Noise Levels in a Tertiary Neonatal Intensive Care Unit

1
Noise Levels in a Tertiary Neonatal Intensive
Care Unit

• Cindy T. Chavez, BA1
• Abbey L. Berg, PhD2,3
• Yula C. Serpanos, PhD1
• 1Adelphi University 2 Pace University 3College
  of Physicians Surgeons, Columbia University

American Speech-Language-Hearing
Association November 21, 2008
2
Specific Aims

• To monitor and examine noise levels in a tertiary
  neonatal intensive care unit (NICU) of a large
  urban regional perinatal center
• Morgan Stanley Children's Hospital of New York
  City

3
Rationale

• Excessive noise levels negatively effect overall
  health specifically, hearing, blood pressure,
  heart and respiratory rates, and sleep.1
• When exposed to intense noise in the NICU,
  premature infants behavioral and physiological
  responses change significantly, increasing
  susceptibility to poor overall development,
  length of stay in the hospital, and decreasing
  weight gain. 2,3

4
Rationale

• These infants are at greater risk of developing a
  hearing loss when compared to full-term babies as
  a result of the synergistic effects of
  aminoglycosides and loop diuretics, as well as
  potentially noxious levels of noise. 4
• The American Academy of Pediatrics (AAP, 1997)
  recommends that NICU noise levels not exceed 50
  dB(A). 5

5
Rationale

• Studies show average noise levels in NICUs range
  from 50-75 dB(A), with peak levels often reaching
  105 dB(A). 2,5
• Philbin (2000) found noise levels exceeding 77
  dB(A) caused discomfort to the neonate. 6

6
Rationale

• The NICU staff in this newly designed tertiary
  care facility was committed to providing an
  environment that supported infants needs and
  promoted their development.
• Concern remained that noise levels were greater
  than recommended. The staff of the Newborn
  Hearing Screening Program was approached about
  monitoring noise levels in the NICU and to
  identify noxious sources.

7
Design

• An Extech Instruments 407764 Sound Level Meter
  RS232/Data Logger range 30-130 dB(A) recorded
  noise levels in each of seven designated NICU
  areas for a 24 hour-seven days per week period,
  in 2 second time intervals.
• The dimensions of each area were
• 8 ft. x 24 ft. in area size
• 2-3 isolettes per area (one isolette on either
  side of the pod, with a third in the middle)

8
Design

• Each isolette (open or closed) was equipped with
  monitors, which measured infants heart rate,
  respiration, pulse oxidation, and oxygen
  saturation.
• Infant population, approximately,
• 50 had a feeding tube
• 25 were either on continuous positive air
  pressure (CPAP) or undergoing phototherapy
• 20 were attached to an intravenous (IV) drip
• lt5 required usage of a suction machine

9
Design

• The sound level meter (SLM) was positioned on a
  36-inch high counter and was equidistant,
  approximately 10 ft., from each isolette in each
  area being monitored.
• Calibration of the SLM was completed, pre- and
  post- data collection, using an Extech
  Instruments Model 407766 Sound Level Calibrator,
  to ensure accurate measurements.
• Data was downloaded to a Dell Inspiron 4000
  notebook and converted into Excel for analysis.

10
Results Table 1
Noise Levels Across Areas Over a 24-Hour Seven
Day Period
11
Results

• Noise levels from monitors, alarms, and equipment
  although always gt50 dB(A), rarely exceeded 75
  dB(A), range 52-79.5 dB (A), mean 58.88, SD
  5.51.
• Data analysis revealed that peak noise levels 82
  - 102.1 dB(A) consistently occurred in
  conversations during physician chart reviews and
  family visits.

12
Discussion

• The results of this investigation revealed noise
  levels in each of seven areas measured in this
  NICU to exceed the AAP (1997) recommendation of
  lt50 dB(A) for the majority of time within a
  typical day.
• The highest levels of noise gt75 dB(A) were
  noted to occur in conversations during medical
  rounds and family visits.
• The lowest levels of noise lt50 dB (A), occurred
  during the late evening and early morning, when
  NICU activity was reduced.

13
Discussion

• While prior research suggests excessive noise
  levels may occur in the NICU, this study served
  to confirm excessive levels and to identify
  sources.
• Study outcomes were presented to NICU attendings,
  fellows, nurses, and other staff during Grand
  Rounds to discuss strategies to lower noise
  levels in the general NICU environment and
  specific to the observed sources.

14
Recommendations to reduce noise in this NICU
include

• Modifications to the Physical Environment, e.g.
• rubber stoppers on cabinet doors
• blankets on top of isolettes
• use of flash-light vs. sound alarms 3,5,7
• installing door silencers
• disconnecting ventilators before suctioning
• not using the isolette as a writing surface
• closing isolette doors gently
• removing radios from NICU areas near the neonates8

15
Recommendations to reduce noise in this NICU
include

• Monitoring of Conversation Levels
• conduct medical rounds and other conversations at
  a remote location to ensure a more optimal
  environment
• post signs in each area as intended reminders for
  staff and visitors to monitor conversation levels
  while in the NICU

16
Conclusions

• Periodic monitoring of noise levels in the NICU
  environment is recommended in order to identify
  and modify potential new and unexpected instances
  of noxious noise sources.
• Education of new attendings, fellows, and medical
  students before they begin their rotation as well
  as veteran staff to alert and sensitize them to
  the adverse effects of noise to the premature
  neonate.

17
Conclusions

• These findings also serve to remind the
  audiologist of the importance of their role in
  the routine performance of noise measurements in
  the NICU.
• The findings and recommendations of this study
  may be useful to the oversight and management of
  noise levels in other NICU facilities.

18
References

• Bahadori, R.S. Bohne, B.A. (1993). Adverse
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• Morris, B.H., Philbin, M.K., Bose, C. (2000).
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• Bernard, P.A. (1981). Freedom from ototoxicity in
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• American Academy of Pediatrics (Committee on
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