Adverse effect of noise in the operating theatre on surgical-site infection

Background: The aim of this pilot study was to evaluate the noise level in an operating theatre as a possible surrogate marker for intraoperative behaviour, and to detect any correlation between sound level and subsequent surgical-site infection (SSI). Methods: The sound level was measured during 35 elective open abdominal procedures. The noise intensity was registered digitally in decibels (dB) every second. A standard questionnaire was used to evaluate the behaviour of the surgical team during the operation. The primary outcome parameter was the SSI rate within 30 days of surgery. Results: The overall rate of SSI was six of 35 (17 per cent). Demographic parameters and duration of operation were not significantly different between patients with, or without SSI. The median sound level (43.5 (range 26.0-60.0) versus 25.0 (25.0-60.0) dB; P = 0.040) and median level above baseline (10.7 (0.6-33.3) versus 0.6 (0.5-10.8); P = 0.001) were significantly higher for patients who developed a SSI. The sound level was at least 4 dB above the median in 22.5 per cent of the peaks in patients with SSI compared with 10.7 per cent in those without (P = 0.029). Talking about non-surgery-related topics was associated with a significantly higher sound level (P = 0.024). Conclusion: Intraoperative noise volume was associated with SSI. This may be due to a lack of concentration, or a stressful environment, and may therefore represent a surrogate parameter by which to assess the behaviour of a surgical team.