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

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.