Impact of noise exposure during emergence on acute pain after orthopedic surgery: A prospective observational study

Abstract

Background

Noise exposure is common during emergence from general anesthesia, particularly after orthopedic surgery.

Objective

We aimed to evaluate the direct impact of noise in the post-anesthesia care unit on postoperative pain and analgesic requirements in patients undergoing orthopedic surgery.

Design

Prospective observational study.

Settings

This prospective observational study was conducted at a tertiary, university-affiliated teaching hospital in Chongqing, China.

Participants

A total of 288 Chinese patients who underwent elective orthopedic surgery under general anesthesia were included.

Materials and methods

After surgery, noise levels in the post-anesthesia care unit were continuously monitored. The average noise intensity and the proportion of time that environmental noise levels exceeded 70 dB were calculated. Participants were allocated to a higher noise group and a lower noise group based on noise intensity. Postoperative pain was assessed using a numerical rating scale in the post-anesthesia care unit and during the first 24 h after post-anesthesia care unit discharge. Analgesic consumption during the same period was recorded.

Results

Noise intensity was significantly associated with the maximum pain numerical rating scale in the post-anesthesia care unit (adjusted regression coefficient = 0.46; 95 % CI 0.33 to 0.713; P < 0.001). A noise threshold of 68.945 dB was identified as the optimal cut-off value for predicting a numerical rating scale ≥ 6. Based on this threshold, patients were categorized into a high-noise group (mean noise intensity > 68.945 dB) or a low-noise group (< 68.945 dB). The high-noise group reported significantly higher maximum pain numerical rating scale scores than those of the low-noise group during the first 12 h (P < 0.001) after post-anesthesia care unit discharge, 12–24 h (P < 0.001), and over the entire 24 h (P = 0.001). Additionally, the incidence of pain with numerical rating scale ≥ 4 within 24 h after surgery and the requirement for rescue analgesia were both significantly higher in the high-noise group than in the low-noise group.

Conclusion

For patients undergoing orthopedic surgery, increased noise exposure in the post-anesthesia care unit was associated with greater postoperative pain during anesthesia recovery, as well as higher pain intensity and increased analgesic use within 24 h after post-anesthesia care unit discharge.