Human-Caused Sound Distractors and their Impact on Operating Room Team Function.

Background: Patient safety in the Operating Room (OR) depends on unobstructed team communication. Yet the typical OR is loud, containing numerous sounds from surgical machinery overlayed with human-caused sounds. Our objective was to compare machine vs human-caused sounds for their loudness and distraction, and potential impact on team communication.

Methods: After surveying OR staff about sounds that interfere with job performance and team communication, we recorded 19 machine and 48 human-caused sounds measuring their acoustical intensity. We compared peak measures of machine vs human-caused sound loudness, using Student's t-test. We observed the effect of these sounds on OR staff in 59 live surgeries, rating level of interference with team function. We visually depicted competing sounds through a spectral analysis.

Results: The survey response rate was 62.8%. 93% of respondents indicated that OR noise, especially human-caused sounds such as irrelevant conversations, interfere with team communication, hearing, and focus. OR peak decibel levels ranged from 56.8 dB (surgical packaging) to 105.0 dB (kicked metal stepstool). Human-caused sounds were comparable to machine-caused sounds in terms of mean peak dB levels (77.0 versus 73.8 dB, p = 0.32), yet were rated as more interfering with surgical team function. The spectral analysis illustrated both machine and human-caused sound sources obscuring the surgeon's instructions.

Conclusions: Avoidable human-caused sounds are a major source of disruption in the OR and interfere with communication and job performance. We recommend surgical team training to minimize these distractions.