Comparison of Perioperative Systemic Lidocaine or Systemic Ketamine in Acute Pain Management of Patients With Opioid Use Disorder After Orthopedic Surgery.

INTRODUCTION AND AIMS: Patients with opioid use disorder experience great challenges during acute pain management due to opioid tolerance or withdrawal symptoms. Previous studies have recommended the use of adjuvant drugs in these patients. In this study, we compared the effect of intraoperative lidocaine with ketamine in postoperative pain management of these patients.

DESIGN AND METHODS: In this randomized clinical trial, 180 patients with opioid use disorder who underwent orthopedic surgery under general anesthesia were randomly allocated into 3 groups. Patients in groups A, B, and C received intravenous lidocaine, ketamine, or normal saline, respectively, during the operation. Then, postoperative pain scores, analgesic requirements, patient satisfaction, and patient sleepiness were recorded and compared among the 3 groups.

RESULTS: Numerical rating scales during the first hour postoperation were significantly lower in the lidocaine group than in the ketamine or control group (P < 0.001). The mean total amount of morphine consumption during the first 24-hour postoperation was 14.49 ± 26.89, 16.59 ± 30.65, and 21.72 ± 43.29 mg in the lidocaine, ketamine, and control group, respectively, being significantly lower in the lidocaine group in comparison with the other groups (P < 0.001). Patients in the lidocaine group were less restless, calmer, and less drowsy than patients in the ketamine and control group (P < 0.001).

DISCUSSION AND CONCLUSION: According to these findings, systemic lidocaine is more effective than systemic ketamine to improve the quality of acute pain management without causing any significant complications in patients with opioid use disorder.