Reduced Opioid Prescription Practices and Duration of Stay after TAP Block for Laparoscopic Appendectomy.

BACKGROUND: We evaluated whether TAP blocks performed at the time of appendectomy resulted in reduced total oral morphine equivalent (OME) prescribed and fewer 30-day opioid prescription (OP) refills. STUDY
DESIGN: Single institution review of historical data (2010-2016) was performed. Adults (≥ 18 years) that underwent appendectomy for appendicitis with uniform disease severity (AAST EGS grades I, II) were included. Opioid tolerance was defined as any preoperative OP ordered 1-3 months prior to appendectomy or < 1 month unrelated to appendicitis; opioid naïve patients were without OP. Intraoperative TAP blocks (admixture of liposomal/regular bupivacaine) were performed at surgeon discretion. Risk factors for discharge prescription > 200 OME were assessed using logistic regression and quantified using odds ratios (OR) and 95% confidence intervals (CI). RESULT: There were 960 patients with uniform appendicitis severity. During appendectomy, 145 (15%) patients received TAP blocks. There were 46 patients that were opioid tolerant (5%) and the majority of the cohort received discharge OP (n = 914, 95%) with a median prescription OME volume of 225 [150-300]. Only 76 patients required 30-day opioid prescription refill. On regression, factors associated with a discharge prescription > 200 OME included ≥ 65 years of age (OR 0.64 (95%CI 0.41-0.98)) and no TAP block (OR 1.7 (95%CI 1.2-2.5)) but not preoperative opioid utilization.
CONCLUSIONS: TAP blocks in low-grade appendicitis were associated with reduced OME prescribed, hospital duration of stay, and fewer refills without impacting operative time or total hospital costs.