BACKGROUND: Use of fascial plane blocks is increasing yet their impact on hospital length of stay (LOS) and opioid use within the context of an enhanced recovery after surgery (ERAS) pathway has been inconclusive. We address this gap by examining the impact of fascial plane blocks on postoperative LOS and opioid use for colorectal surgical procedures in a hospital setting with a robust ERAS program. METHODS: This is a retrospective cohort study using electronic health record data from a large, integrated health care delivery system with an established ERAS program in Northern California. Patients include adults who underwent non-emergent laparoscopic (n=5496) or non-laparoscopic (n=708) colectomy surgery from January 1, 2015 to May 20, 2021. The main exposure was type of anesthesia: general with long-acting fascial plane block, general with short-acting fascial plane block, or general only. Outcomes included postoperative LOS and average daily morphine milligram equivalents (MME) up to three days post-surgery. RESULTS: Most patients were older than age 50 (86% laparoscopic
83% non-laparoscopic), female (52% laparoscopic
58% non-laparoscopic), and non-Hispanic White (64% laparoscopic
62% non-laparoscopic). In LOS adjusted models for laparoscopic and non-laparoscopic surgery, there was no significant difference for LOS with general with long-acting fascial plane block or with general with short-acting fascial plane block, compared to general only. In MME adjusted models for laparoscopic surgery, general with short-acting fascial plane block was associated with higher MME compared with general only (RE: 1.14,[95% CI: 1.03-1.25], p-value=0.01). However, in non-laparoscopic surgery, general with long-acting fascial plane block was associated with lower MME (RE: 0.63, [95% CI: 0.42-0.93], p-value=0.02), compared with general only. CONCLUSION: Fascial plane blocks did not impact postoperative LOS in either surgical group but long acting resulted in lower overall postoperative opioid use for non-laparoscopic surgery.