Effects of anaesthesia type on development of persistent postoperative opioid utilisation: a South Korean nationwide cohort study.

Abstract

Previous studies comparing the effects of general and regional anaesthesia on postoperative opioid use have focused primarily on the immediate postoperative period, with limited investigations into long-term outcomes. This retrospective cohort study included 558,944 patients aged ≥ 18 y who underwent one of nine surgical procedures (thoracotomy; total hip arthroplasty; total knee arthroplasty; shoulder arthroplasty; transurethral resection of the prostate; inguinal hernia repair; knee arthroscopy; varicose vein surgery; and caesarean section) that required regional anaesthesia, general anaesthesia or combined general/regional anaesthesia. The primary outcome was the incidence of persistent postoperative opioid utilisation, which was defined as having filled ≥ 10 prescriptions or a supply of > 120 days between postoperative days 91 and 365. Age, sex, medical comorbidities, pre-operative medications and surgery type were balanced among regional anaesthesia, general anaesthesia and combined general/regional anaesthesia using pairwise propensity score matching. General anaesthesia had significantly higher odds than regional anaesthesia for the development of persistent postoperative opioid utilisation (odds ratio 2.13, 95%CI 1.50-3.01, p < 0.001). The odds ratio of general anaesthesia vs. combined general/regional anaesthesia was significant in patients undergoing thoracotomy (odds ratio 1.47, 95%CI 1.25-1.74, p < 0.001). In the overall population, the regional anaesthesia group consumed fewer opioids than the other groups. Among the patients undergoing thoracotomy, the combined general/regional anaesthesia group consumed fewer opioids than the general anaesthesia group. This study found that regional anaesthesia was associated with a reduction in persistent postoperative opioid utilisation, particularly in patients undergoing thoracotomy.