Noise in the operating room coincides with surgical difficulty

Background Noise in the operating room has been shown to distract the surgical team and to be associated with postoperative complications. It is, however, unclear whether complications after noisy operations are the result of objective or subjective surgical difficulty or the consequence of distraction of the operating room team by noise. Methods Noise level measurements were prospectively performed during operations in four Swiss hospitals. Objective difficulty for each operation was calculated based on surgical magnitude as suggested by the Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM), duration of operation and surgical approach. Subjective difficulty and distraction were evaluated by a questionnaire filled out by the operating room team members. Complications were assessed 30 days after surgery. Using regression analyses, the relationship between objective and subjective difficulty, distraction, intraoperative noise and postoperative complications was tested. Results Postoperative complications occurred after 121 (38%) of the 294 procedures included. Noise levels were significantly higher in operations that were objectively and subjectively more difficult (59.89 versus 58.35 dB(A), P < 0.001) and operations that resulted in postoperative complications (59.05 versus 58.77 dB(A), P = 0.004). Multivariable regression analyses revealed that subjective difficulty as reported by all members of the surgical team, but not distraction, was highly associated with noise and complications. Only objective surgical difficulty independently predicted noise and postoperative complications. Conclusion Noise in the operating room is a surrogate of surgical difficulty and thereby predicts postoperative complications.