Operating Room Sound Level Hazards for Patients and Physicians

Hypothesis: Exposure to certain new surgical instruments and operating room devices during procedures could cause hearing damage to patients and personnel. Background: Surgical instruments and related equipment generate significant sound levels during routine usage. Both patients and physicians are exposed to these levels during the operative cases, many of which can last for hours. The noise loads during cases are cumulative. Occupational Safety and Health Administration (OSHA) and National Institute for Occupational Safety and Health (NIOSH) standards are inconsistent in their appraisals of potential damage. Implications of the newer power instruments are not widely recognized. Methods: Bruel and Kjaer sound meter spectral recordings for 20 major instruments from 5 surgical specialties were obtained at the ear levels for the patient and the surgeon between 32 and 20 kHz. Results: Routinely used instruments generated sound levels as high as 131 dB. Patient and operator exposures differed. There were unilateral dominant exposures. Many instruments had levels that became hazardous well within the length of an average surgical procedure. The OSHA and NIOSH systems gave contradicting results when applied to individual instruments and types of cases. Background noise, especially in its intermittent form, was also of significant nature. Some patients and personnel have additional predisposing physiologic factors. Conclusion: Instrument noise levels for average length surgical cases may exceed OSHA and NIOSH recommendations for hearing safety. Specialties such as Otolaryngology, Orthopedics, and Neurosurgery use instruments that regularly exceed limits. General operating room noise also contributes to overall personnel exposures. Innovative countermeasures are suggested.