了解石膏拆除过程中的噪声暴露：石膏锯类型和材料的影响。

Department of Orthopaedic Surgery, Dwight D. Eisenhower Army Medical Center, Fort Gordon, Georgia.

Defense Analysis Department, Naval Postgraduate School, Monterey, California.

J Bone Joint Surg Am. 2022 Sep 7;104(17):1573-1578. doi: 10.2106/JBJS.22.00158. Epub 2022 Jun 17.

BACKGROUND

Cast removal can be associated with considerable noise exposure, especially impacting the pediatric patient and provider. Although noise generation from cast saws has been deemed safe by the U.S. Occupational Safety and Health Administration and the U.S. Centers for Disease Control and Prevention standards, there are no current studies on the effects of cast material on noise levels generated.

METHODS

A simulated casting model utilizing plaster, fiberglass, and plaster with fiberglass overwrapping was used for experimental testing. Four different casting conditions were tested, with 5 samples in each group. Samples were tested using 2 different cast saws: a standard cast saw and a quiet saw. Each saw was used for 30 seconds of continuous cutting for each sample, measuring peak, mean, and minimum sound levels in decibels with sound level meters. Noise levels were measured at 18, 36, and 72 in (20, 91, and 183 cm) from the saw, comparing saw and cast types against ambient noise and baseline cast-saw noises. Between-group comparisons were performed using univariate analyses.

RESULTS

Mean noise generation differed between casting materials, with plaster material demonstrating significantly greater noise levels than fiberglass casts at all distances for each saw type. Increasing fiberglass thickness significantly increased the mean noise levels with standard (18-in distance for 10 and 5 ply: 87.4 and 85.8 dB; p = 0.0004) and quiet cast saws (78.3 and 76.1 dB; p = 0.041. Additionally, the quiet cast saw provided a 5.7 to 10.6 dB reduction in mean and peak noise levels, varying by casting material and distance.

CONCLUSIONS

Occupational noise exposure can be mitigated with the use of fiberglass casting material that is not >5 ply in thickness, with a quiet cast saw for removal. The use of a quiet cast saw substantially decreased noise exposure to patients and staff members over standard orthopaedic cast saws.

背景

拆除石膏可能会产生相当大的噪声，尤其是对儿科患者和医护人员造成影响。虽然美国职业安全与健康管理局和美国疾病控制与预防中心的标准认为石膏锯产生的噪声是安全的，但目前还没有关于石膏材料对产生噪声水平的影响的研究。

方法

使用石膏、玻璃纤维和玻璃纤维包裹的石膏制作模拟铸造模型，进行实验测试。测试了四种不同的铸造条件，每组有 5 个样本。使用两种不同的石膏锯进行测试：标准石膏锯和静音锯。每个锯在每个样本上连续切割 30 秒，使用声级计测量分贝的峰值、平均值和最小声级。在距锯 18、36 和 72 英寸（20、91 和 183 厘米）处测量噪声水平，比较锯和铸型类型与环境噪声和基线石膏锯噪声。使用单变量分析进行组间比较。

结果

不同铸造材料的平均噪声产生量不同，与每种锯类型的所有距离的玻璃纤维铸型相比，石膏材料的噪声水平明显更高。增加玻璃纤维厚度会显著增加标准（18 英寸距离的 10 层和 5 层：87.4 和 85.8 dB；p = 0.0004）和静音石膏锯（78.3 和 76.1 dB；p = 0.041）的平均噪声水平。此外，静音石膏锯可将平均和峰值噪声水平降低 5.7 至 10.6 dB，具体取决于铸造材料和距离。