LAUSR

BACKGROUND Preoperative opioid use has been shown to be associated with worse outcomes after surgery. However, little is known about the effect of preoperative benzodiazepines (BDZs) with and without opioids. The aim of this study was to determine the influence of preoperative substance use on outcomes after abdominal surgery. STUDY DESIGN Patients undergoing abdominal operations including ventral hernia, colectomy, hysterectomy, cholecystectomy, appendectomy, nephrectomy and hiatal hernia were identified in an Opioid Surgical Steward program by a regional NSQIP consortium in 2019-2021. ACS-NSQIP data were linked with custom substance use variables created by the collaborative. Univariable and multivariable analyses were performed for 30-day outcomes. RESULTS Of 4,439 patients, 64% (N=2,847) were female with a median age of 56 years. The most common operations performed were hysterectomy (22%), ventral hernia repair (22%) and colectomy (21%). Preoperative opioid use was present in 11% of patients (N = 472); 10% (N = 449) were on BDZs, while 2.3% (N = 104) were on both. Serious morbidity was significantly (p < 0.001) increased in patients on preoperative opioids (16% vs. 7.9%) and BDZs (14% vs. 8.3%) compared to their naïve counterpart, and this effect was amplified in patients on both substances (20% vs. 7.5%). Multivariable regression analyses reveal that preoperative substance use is an independent risk factor (p < 0.01) for overall morbidity and serious morbidity. CONCLUSIONS Preoperative opioid and benzodiazepine use are independent risk factors that contribute to postoperative morbidity. This influence on surgical outcomes is exacerbated when patients are on both substances.