Intraoperative dexmedetomidine on postoperative pain in gastrointestinal surgery: an observational study

Background: Dexmedetomidine (DEX) is widely used for adjuvant sedation and analgesia in gastrointestinal surgeries. We aimed to reassess the effects of intraoperative DEX on acute pain by comprehensive analysis of the multiple dimensions of pain. Materials and methods: In this multicentre cohort study, patients undergoing gastrointestinal surgeries were prospectively enrolled in the China Acute Postoperative Pain Study. Patients were divided into DEX and non-DEX groups based on whether DEX was used during surgery. Patient satisfaction with pain treatment (rated on a numeric rating score, 0 - 10) and other pain-related outcomes were evaluated using the International Pain Outcome Questionnaire on the first postoperative day. The effects of intraoperative DEX were analysed using logistic or linear regression for dichotomous or continuous variables, respectively. Propensity score matching and subgroup analyses were performed to appraise the correlation between intraoperative DEX and postoperative pain outcomes. Results: Of the 1,260 patients eligible for analysis, 711 (56.4%) received intraoperative DEX. Propensity score matching resulted in 415 patients in each group. Intraoperative DEX was associated with higher patient satisfaction (β: 0.556; 95% confidence interval [CI], 0.366 - 0.745), and a decrease in the percentage of time spent in severe pain (β: -0.081; 95% CI, -0.104 to - 0.058), anxiety (odds ratio [OR]: 0.394; 95% CI, 0.307 - 0.506), helplessness (OR: 0.539; 95% CI, 0.411 - 0.707) and postoperative opioid consumption (β: -16.342; 95% CI, -27.528 to -5.155). Conclusions: Intraoperative DEX was associated with the prognosis of acute postoperative pain in multiple aspects in patients undergoing major gastrointestinal surgery, including increased patient satisfaction, and a reduction in the duration of severe pain, postoperative anxiety and helplessness, and postoperative opioid consumption. Future studies to determine the dose and timing of dexmedetomidine administration on pain-related outcomes are warranted.