Noise in the OR has been on the rise for decades, prompting researchers to look into the links between sound levels, health impacts on surgeons, and patient outcomes.
A recent literature review found that noise levels in operating rooms frequently exceed OSHA guidelines for safe work environments. The OSHA recommendation for hospitals in general is 45 time-weighted average decibels (dbA) with a maximum peak of 140 dbA for “impulsive noise” events (Anesthesiology 2014;121:894-8). The sources of noise are many: moving of equipment, clashing metal instruments, pumps, suction apparatus, air warming units, monitors, alarms, nonclinical conversation, and background music. The review found evidence of the impact of noise on communication among staff, concentration of the surgeon, performance of complex tasks by surgeons and anesthesiologists and, potentially, patient outcomes. Noise was found to be greater at the beginning and closing of procedures, and routine peak levels reported were in excess of 100 dBA for various procedures and as high as 131 dBA in some instances.
Another study linked communication gaps in the OR to high noise levels (J. Am. Coll. Surg. 2013:216:933-8). The amount of noise from equipment, staff conversation, and background music was found to have a negative impact on surgeon performance, especially when complex tasks were in process.
Noise pollution during surgery is now being studied in terms of patient outcomes, postop complications, and surgical-site infections (SSIs) in particular.
A pilot study in the United Kingdom looked at noise in the OR as a possible surrogate marker for intraoperative behavior and a potential predictor of SSIs. With a small sample of 35 elective open abdominal procedures, a significant correlation was detected between noise levels and the 30-day postop SSI rate in these patients (Br. J. Surg. 2011;98:1021-5).
Another study has found that high noise levels in the operating room were linked to surgical site infections after outpatient hernia repair (Surgery 2015 Feb. 28 [doi: 10.1016/j.surg.2014.12.026]). “Noise levels were substantially greater in patients with surgical site infections from time point of 50 minutes onwards, which correlated to when wound closure was occurring,” wrote Dr. Shamik Dholakia and his associates at the Milton Keynes General Hospital in Buckinghamshire, England.
The researchers found that music and conversation were the two main contributors to increased noise levels in the OR. “Both of these factors may have distracting influences on the operator and contribute to lower levels of concentration, and so need to be considered as potential issues that could be improved to reduce error,” they said.
Past studies have linked surgical site infections (SSI) with lapses in aseptic technique, which can occur if the OR team is distracted. To assess the role of OR noise in SSI risk, the investigators prospectively studied 64 male, otherwise healthy outpatients who underwent left-side inguinal hernia repair at a single hospital. All patients received a prophylactic dose of 1.2 grams of co-amoxiclav antibiotic, and the same kind of mesh and suture were used for all cases, the investigators said.
The researchers used a decibel meter to measure sound levels in the OR during surgeries, and interviewed patients weekly for the next 30 days to detect SSI.
Five patients (7.8%) developed SSI, all of which were superficial. Swabs from these patients grew mixed skin flora that were sensitive to penicillin, said the researchers.
The mean level for background noise was 47.6 dB before the procedure started. On average, noise levels during procedures for which patients developed SSI were 11.337 dB higher than during other procedures. “Although the actual formula is complex, the accepted rule is that an increase of 10 decibels is perceived to be approximately twice as loud,” the investigators said. “Hence, we believe that this increase in loudness is significant enough to effect the operation. On the basis of our results, we hypothesize that poor concentration caused by high levels of noise may affect one’s ability to perform adequate aseptic closure and increase the probability of developing SSI.”
Surgical assistants usually closed the surgical wounds, which was notable because music’s effects on concentration vary with experience, the researchers noted. “Music may have a soothing, calming, and positive effect on senior experienced operators, whereas it may be distracting and reduce ability to concentrate on junior operators who are not experienced and still learning how to perform the procedure,” they said. “This finding is an important one that the lead surgeon needs to be aware of.”The investigators reported no funding sources or conflicts of interest.