An analytical study investigating noise levels in neonatal intensive care units within the public sector in the eThekwini district.

Abstract

Noise is a well-documented environmental stressor in the NICU and has emerged as a public health problem. The aim of this study was to investigate noise levels and identify contributing factors to the high noise levels, in NICUs within the public sector in the eThekwini District. The study used an analytical observational research design and a purposive sampling method. Noise measurements were conducted in four hospitals with the sound level meter (CEL 450 C) placed in the centre of each NICU for 48 hours on two consecutive days of the week (Sunday and Monday). A sample of sources of noise and their frequency of occurrence were identified through direct observation in the morning, as well as a frequency analysis using one-third octave bands were conducted. Mean LAeqs were above 45dBA in all hospitals and a marginal difference between LAeqs during the morning, afternoon and night was seen in hospital D (p=0,046). A significant difference between LAeqs on Sunday and Monday was found in hospital C (p=0,028). The majority of the sources of noise were from alarms of devices and human-related noise, with the most frequently occurring sources of noise being staff conversations (30.9%), alarms (21,0%) and closing of metal pedal bins (20,0%). Multiple high frequency alarms increased the LAeq to 74,6dBA and dropping a metal object increased the LZpeak to 116,0dBA. LAeqs higher than 45dBA were seen in the mid and high frequencies (250Hz-6300Hz) specifically during the afternoon in all hospitals. The findings have implications for education and training, as well as for the development of practice and policy guidelines in NICUs.