Effects of Noise in the Operating Room

The operating room (OR) can be loud, with noise arising from sources such as power tools, monitoring equipment, forced air blankets, music, human traffic, and conversation. Nonporous surfaces necessary for hygiene in OR environments can prolong noises generated from other sources because sound waves are reflected.

Increased noise in the OR has been associated with detrimental effects on communication, surgeon focus, veterinary staff stress, and incidence of complications and infections.^1-3 The World Health Organization has noted that consistent recognition of speech in relaxed conversation is possible at noise levels of 45 dBA and subsequently recommends that workplace noise levels do not exceed 55 dBA.³ High background noise can be stressful and has been correlated with higher endogenous cortisol levels in surgeons.⁴

In this study, the mean, median, and maximum noise levels during 77 surgeries at an academic teaching hospital were recorded. Overall mean, median, and maximum decibel levels were 71.7 dBA, 69.4 dBA, and 90.3 dBA, respectively. Neurologic procedures had significantly higher mean and median decibel levels, presumably due to use of surgical power tools. Music significantly increased mean and median decibel levels (mean, 73.3 dBA with music vs 70.6 dBA without music; median, 71.3 dBA with music vs 68.2 dBA without music). Neither number of humans present nor number of staff members scrubbed in for a procedure significantly affected decibel levels.⁵

These results demonstrated decibel levels that substantially exceeded World Health Organization recommendations. To avoid risking miscommunication, verbal communication in this environment would need to exceed normal speaking volume. Although this study did not evaluate effects of high noise levels on outcomes such as complication rates or stress levels, the decibel levels measured were high enough to affect veterinary staff stress, based on results of a previous study.⁴ In addition, music was associated with significantly higher noise levels, representing a controllable, if controversial, source of noise.

Key pearls to put into practice:

Taking inventory of sources of noise in the OR and subsequently considering ways to lower the noise volume (eg, setting monitors at a lower volume) is recommended.

Turning down the music volume and polling staff should be considered. Asking staff to note their perceived level of stress or calm before and after the volume is reduced, then evaluating the need for raised voices, the frequency of repeated requests, and whether staff relax after a source of noise is eliminated can be helpful in determining the effect of noise in an OR.

A quiet environment should be created throughout the practice. Concentration, communication, and calm are key elements of a successful veterinary practice. Where possible, discussing and reducing unnecessary noise in the practice environment may provide a subtle yet substantive benefit.