Medición comparativa de la intensidad de ruido dentro y fuera de incubadoras cerradas

Introduction

Excessive auditory exposure in the preterm infant generates immediate physiological responses and long-term alterations. The American Academy of Pediatrics recommends a maximum noise level in the Neonatal Intensive Care Units of 45 decibels (dB) during the day and 35 dB during the night.

Objective

To measure and compare noise intensity outside and inside closed incubators.

Method

A prospective, observational study carried out in the Neonatal Intensive Care Units of the Spanish Hospital of Mexico during December 2016. The intensity of noise was measured inside and outside closed incubators, as well as a record of the presence or absence of active humidification and protective cover. Two sound level meters were used one placed inside and another outside the incubator. The noise level was recorded at the same time at one-second intervals for 36 total hours. Medians and interquartile ranges of measurements were calculated. The Wilcoxon test was performed for the comparison of medians in each case. A level of statistical significance of 0.05 was determined.

Results

A higher noise intensity was recorded inside closed incubators compared to outside (60.9 vs 58.7 dB); P< .001). In those with humidification, there was a higher internal noise (61.5 vs 60.2 dB, P< .001), and in the incubators with protective cover there was lower internal noise (58.8 vs 62 dB, P< .001),

Conclusions

The noise intensity inside closed incubators is greater than outside.