Risk of noise-induced hearing loss in the spine surgeon

Abstract

Background: Occupation-related noise-induced hearing loss (NIHL) has both negative economic and quality of life implications. The risk spine surgeons undertake in regards to NIHL during operative intervention is unknown. Governing bodies, including the National Institute for Occupational Safety and Health, have recommended exposure limits not to exceed 85 decibels (dB) over 8 hours. The purpose of this study is to characterize noise exposure to spine surgeons in the operating room (OR).

Methods: Prospective collection of intraoperative recordings of spinal surgeries (cervical and thoracic/lumbar) was undertaken. Data gathered included procedure, operative duration, presence of background music, and noise information. Noise information included maximum decibel level (MDL), Peak level (LCPeak), Equivalent continuous sound pressure level, time weighted average (TWA), dose, and projected dose. Noise measurements were compared with baseline controls with and without music (empty ORs).

Results: Two hundred seven noise recordings were analyzed. One hundred eighteen of those being spinal surgeries, 49 baseline recordings without music, and 40 with music. Maximum decibel level reached a maximum value of 111.5 dBA, with an average amongst surgical recordings of 103 dBA. Maximum decibel level exceeded 85 dBA in 100% of cases and was greater than 100 dBA in 78%. The maximum LCPeak recorded was 132.9 dBC with an average of 120 dBC. Furthermore, the average dose was 7.8% with an average projected dose of 26.5%. The highest dose occurred during a laminectomy at 72.9% of daily allowable noise. Maximum projected dose yielded 156% during a 3-level anterior cervical discectomy and fusion.

Conclusions: Spine surgeons are routinely exposed to damaging noise levels (>85 dBA) during operative intervention. With spine surgeons often performing multiple surgeries a day, the cumulative risk of noise exposure cannot be ignored. The synergistic effects of continuous and impact noise places spine surgeons at risk for the development of occupation-related NIHL.

Keywords: Decibel; Hearing loss; Noise; Noise-induced hearing loss; Occupational hazard; Spine.

Figure

A comparison of baseline recordings without music, baseline recordings with music, cervical recordings and thoracic/lumbar recordings for average MDL, average LCPeak and average Laeq. Decibels on an A-weighted scale are noted dBA. Decibels on a C weighted scale are noted dBC. *Note: Per the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limitations, exposure of 100 dBA should not exceed 15 minutes in a given 24-hour time period. MDL, maximum decibel level; LCPeak, peak level; Laeq, equivalent continuous sound pressure level.