Too Loud for Comfort: A Simulated Evaluation of Cast Saw Noise

Orthopaedic cast saws are an integral component to a pediatric orthopaedic practice but can also be associated with patient anxiety and noise exposure for patient. Although previous studies have deemed the noise generation from orthopaedic cast saws to be within safe occupational exposure levels, no study to date has compared the noise generation from a cast saw used in various exam room settings. METHODS: A simulated fiberglass cast model was used. Noise generation was assessed using calibrated sound level meters with measurements performed at 18 inches, 36 inches, and 6 ft measured from the cast saw. Measurements were performed in 1 of 2 clinical settings: (1) an open bay setting and (2) an enclosed exam room. In the enclosed exam room, the 6-foot measurement was performed behind the closed exam door. An orthopaedic cast saw with built-in vacuum was used to continuously cut the fiberglass model for 1 minute with measurements of peak and mean sound generation, recorded in decibels (dB), a logarithmic scale. Three measurements were recorded at each distance. Between group comparisons were performed with statistical significance set at P=0.05. RESULTS: Baseline sound levels were similar between cohorts with progressive decreases in mean sound with increasing distance from the saw. Mean sound levels were significantly higher in the enclosed room setting at 18 inches (92.8 dB, 95% confidence interval (CI): 91.72-93.88 vs. 90.6 dB, 95% CI: 89.91-91.29; P=0.043] and 36 inches (90.3 dB, 95% CI: 89.9-90.7 vs. 86.0 dB, 95% CI: 85.18-86.82; P=0.017). At 6-ft distance, however, the enclosed room demonstrated a 13.8-fold sound reduction compared with the open bay (72.0 dB, 95% CI: 71.59-72.4 vs. 83.4 dB, 83.14-83.72; P<0.001). CONCLUSION: By closing the exam door, a 13-fold reduction in noise exposure can be achieved for adjacent patients and personnel. Consideration should be given for using orthopaedic cast saws in an enclosed exam room to prevent unnecessary noise exposure with hearing protection of cast saw operators and treated patients. CLINICAL RELEVANCE: Orthopaedic cast removal.