Influence of intravenous opioid dose on postoperative ileus

Ann Pharmacother. 2011 Jul;45(7-8):916-23. doi: 10.1345/aph.1Q041. Epub 2011 Jul 5.

Abstract

Background: Intravenous opioids represent a major component in the pathophysiology of postoperative ileus (POI). However, the most appropriate measure and threshold to quantify the association between opioid dose (eg, average daily, cumulative, maximum daily) and POI remains unknown.

Objective: To evaluate the relationship between opioid dose, POI, and length of stay (LOS) and identify the opioid measure that was most strongly associated with POI.

Methods: Consecutive patients admitted to a community teaching hospital who underwent elective colorectal surgery by any technique with an enhanced-recovery protocol postoperatively were retrospectively identified. Patients were excluded if they received epidural analgesia, developed a major intraabdominal complication or medical complication, or had a prolonged workup prior to surgery. Intravenous opioid doses were quantified and converted to hydromorphone equivalents. Classification and regression tree (CART) analysis was used to determine the dosing threshold for the opioid measure most associated with POI and define high versus low use of opioids. Risk factors for POI and prolonged LOS were determined through multivariate analysis.

Results: The incidence of POI in 279 patients was 8.6%. CART analysis identified a maximum daily intravenous hydromorphone dose of 2 mg or more as the opioid measure most associated with POI. Multivariate analysis revealed maximum daily hydromorphone dose of 2 mg or more (p = 0.034), open surgical technique (p = 0.045), and days of intravenous narcotic therapy (p = 0.003) as significant risk factors for POI. Variables associated with increased LOS were POI (p < 0.001), maximum daily hydromorphone dose of 2 mg or more (p < 0.001), and age (p = 0.005); laparoscopy (p < 0.001) was associated with a decreased LOS.

Conclusions: Intravenous opioid therapy is significantly associated with POI and prolonged LOS, particularly when the maximum hydromorphone dose per day exceeds 2 mg. Clinicians should consider alternative, nonopioid-based pain management options when this occurs.

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Analgesics, Opioid / administration & dosage*
  • Analgesics, Opioid / adverse effects*
  • Analgesics, Opioid / therapeutic use
  • Colorectal Surgery / adverse effects
  • Dose-Response Relationship, Drug
  • Female
  • Hospitals, Community
  • Hospitals, Teaching
  • Humans
  • Ileus / chemically induced*
  • Ileus / epidemiology
  • Ileus / etiology
  • Incidence
  • Injections, Intravenous
  • Length of Stay
  • Male
  • Middle Aged
  • Narcotics / administration & dosage
  • Narcotics / adverse effects
  • Narcotics / therapeutic use
  • Pain, Postoperative / drug therapy*
  • Postoperative Complications / chemically induced*
  • Postoperative Complications / epidemiology
  • Postoperative Complications / etiology
  • Retrospective Studies
  • Risk Factors
  • United States

Substances

  • Analgesics, Opioid
  • Narcotics