The Impact of Incubators on Noise Transmission Produced by High-Frequency Oscillatory Ventilator Inside the Neonatal Intensive Care Unit

Abstract

Background: Use of the high-frequency oscillatory ventilator (HFOV) is a common practice inside the neonatal intensive care unit (NICU). There is a concern regarding the level of noise produced by HFOV inside the NICU. Objective: To evaluate and define the noise intensity produced by the HFOV and the impact of the incubator on the transmission of noise in different places inside the NICU. Methods: Using a noise analyzer, the noise produced by the HFOV was measured in two setups: inside a quiet room, and inside the NICU during working hours. Measurements were repeated three times: first, inside and outside the tested incubator, and secondly, inside and outside the neighboring incubator. Each measurement was recorded against different HFOV amplitude and frequency settings. Each measurement lasted five minutes, where the highest and lowest readings were recorded every minute, and the mean values of noise intensity were calculated. Results: Noise level was increased by more than 40% after using HFOV (50 dB vs. 84 dB and 45 vs. 78) both inside and outside the incubator during the test. The mean noise levels recorded inside the NICU and the quiet room were 86(±5) dB and 78 (±2) dB respectively. The noise records progressively reduced as HFOV ▲P decreased to 20 cmH2O no matter the frequency used. Conclusions: The HFOV produces significant noise which is of concern. The noise was augmented within the tested incubator while reduced inside the neighboring incubator. Given the data presented, it is recommended that noise protective tools should be used for infants receiving respiratory support using this machine as well as neighboring infants who are near a HFOV.