0912 Protection from noise in the Neonatal ICU (NICU)

Neonatologists, architects and hospital administrators have for many years been concerned about the noise levels in NICU’s so as to provide an environment that will protect sleep, support vital signs, improve speech intelligibility for the infant and reduce potential adverse effects on auditory and general neurodevelopment. The American Academy of Pediatrics has recommended general noise levels that should not exceed 45dB, that should not exceed 50dB for >10% of the time, and should not exceed 65dB at any time. The US Environmental Protection Agency has added to this by setting a night shift target of 35dB. Articles published over the past decade abound with evidence of these standards being violated on a fairly routine basis, not only in terms of ambient noise generated by staff and patient-related measurements and activities, but also by the equipment. On average the noise levels are 20dB higher than recommended. Internally, incubators may generate noise levels in the 60dB range, while ambient peaks in the NICU itself may reach 120dB. A study comparing modern to older NICU’s has shown that levels are exceeded even when designing and building according to the standards. Almost all studies conclude that more attention must be paid to reducing the levels, however an alternative, as published in a recent article in the Journal of Perinatology, could be to use earplugs to protect patients. While patient number in that study was very small (34 VLBW infants randomized to earplugs vs standard care) outcome at 34 weeks post-menstrual age indicated that study infants were significantly heavier (by 222g), while at 18-22 months they scored 15.53 points higher on the Bayley MDI and had significantly higher head circumference (2.59cm). These results suggest that there might be effects that go way beyond protecting speech and hearing development, but much more research is required to confirm the results.

Read more:
J Perinatol, advance online 5 Feb 2009; doi:10.1038/jp.2008.236
Adv Neonatal Care 2008; 8: 165-75
Indian J Pediatr 2008; 75: 217-22
J Otolaryngol 2002; 31: 355-60