Impact of common surgical and anaesthetic strategies for pain control after elective gastrointestinal surgery: cohort study

Abstract

Introduction: Poor pain control after surgery is associated with chronic pain and opioid dependence. This study aimed to determine the incidence of patient reported pain control failure following gastrointestinal surgery, and to evaluate the impact of common preventative surgical and anaesthetic strategies.

Methods: Data were extracted from an electronic health record that linked real-time, ward-based pain scores with prescribing data. Adults undergoing major elective gastrointestinal surgery in 2011-18 were included. The primary endpoint was early pain control failure (≥1 instances of moderate or severe pain on postoperative days 0-2). Secondary outcomes were late (postoperative days 3-5) and persistent (both early and late) pain control failure.

Results: Of 2238 patients, half underwent planned open surgery (50.3%, 1126/2238). Patient controlled analgesia (PCA) was initially used in 49.7% (1113/2238) and epidural in 35.0% (784/2238). Early (54%, 1211/2238), late (33.7%, 755/2238), and persistent (24.9%, 557/2238) pain control failures occurred frequently. In multivariable analyses, minimally invasive surgery was associated with fewer early, late, and persistent pain control failures than open surgery. There was no association between initial epidural analgesia and early or persistent pain control failure, but there was an association with increased late failure (OR 1.37, 95% CI 1.08-1.73, p=0.009). Of patients with initial epidural analgesia, 39.3% (308/784) were subsequently converted to PCA.

Conclusion: Epidural analgesia offered no advantage over PCA, with pain control failure common irrespective of analgesic strategy. Increasing the uptake of minimally invasive surgery, through medical advances to down-stage disease, may offer a path to effectively improve postoperative pain failure.