Noise in cesarean deliveries: a comprehensive analysis of noise environments in the Labor and Delivery operating room and evaluation of a visual alarm noise abatement program

Abstract

Cesarean deliveries are the most common major surgery worldwide. Noise in healthcare settings leads to impaired communication, concentration, and stress among health care providers. Limited information is available about noise at cesarean delivery. Our aim was to achieve a comprehensive analysis of noise that occurs during cesarean deliveries. Sound level meters are used to determine baseline noise levels and to describe the frequency of acute noise that is generated during a cesarean that will cause a human startle response. Secondarily, we will evaluate the effectiveness of a visual alarm system to mitigate excessive noise. We completed a pre-intervention/post-intervention observational study of noise levels during cesarean deliveries before and after introduction of a visual alarm system for noise mitigation between 2/15/2021 to 8/26/2021. There were 156 cases included from each study period. Sound pressure levels were analyzed by overall case median decibel levels and by time epoch for relevant phases of the operation. Rapid increase noise events capable of causing a human startle response, "Startle events" were detected a by retrospective analysis, with quantification for baselines and analysis of frequency by case type. Median noise levels with inter-quartile ranges [I.Q.R.] are presented. Data are compared between epochs and case characteristics with non-parametric two-tailed testing. The median acoustic pressure for all cesarean deliveries was 61.8 [58.8, 65.9] dBA (median [I.Q.R.]). The median dBA for the full case time period was significantly higher during cases with NICU team presence, 62.1 [60.5, 63.9]; neonatal admission to the NICU, 62.0 [60.4, 63.9]; 5-minute APGAR score less than 7, 62.2 [61.1, 64.3]; multiple gestations, 62.6 [62.0, 64.2]; and intraoperative tubal sterilization, 62.8 [61.5, 65.1]. The use of visual alarms was associated with a statistically significant reduction of median noise level by 0.7 dBA, from 61.8 [60.6, 63.5] dBA to 61.1 [59.8, 63.7] dBA, (p<0.001). The noise intensities recorded during cesarean deliveries were commonly at levels that affect communication and concentration, and above the safe levels recommended by the W.H.O. Although noise was reduced by 0.7 dBA, the reduction was not clinically significant to reduce noise a discernible amount (a 3dB change) nor in reducing "startle events". Isolated use of visual alarms during cesarean deliveries is unlikely to be a satisfactory noise mitigation strategy.