IV Acetaminophen Effects on Hyperalgesia After Cardiac Surgery

Condition(s) targeted: Pain; Chronic Pain

Intervention: iv acetaminophen 1g (Drug)

Phase: Phase 4

Status: Recruiting

Sponsored by: University of Washington

Official(s) and/or principal investigator(s):
Lisa Flint, BS, Study Director, Affiliation: University of Washington
Philippe Richebe, MD PhD, Principal Investigator, Affiliation: University of Washington

Overall contact:
Philippe RICHEBE, MD PhD, Phone: 2066163348, Email: prichebe@uw.edu

Coronary artery bypass grafting (CABG) is one of the most commonly performed major surgical procedures with around 160,000 CABG procedures performed in 2010 in the United States. Despite the decreasing mortality and morbidity associated with CABG, pain that persists after the sternotomy remains often unrecognized, but significant clinical problem. The prevalence of chronic post-sternotomy pain (PSP) ranges from 11 to 56% and approaches limb amputation and thoracotomy as the surgeries with highest risk of chronic post-surgical pain (CPSP) development.

Post-operative acute pain and analgesic consumption appear to be associated with the development of chronic PSP. The amount of secondary hyperalgesia surrounding the surgical incision also contributes to the amount of post-operative acute pain. Prior studies have suggested a possible link between post-operative hyperalgesia and the risk of CPSP. Therefore, there is a need to optimize the treatment of post-operative acute pain and reduce the amount of secondary hyperalgesia since these interventions could lead to reduced incidence of CPSP.

The addition of intravenous acetaminophen to analgesic regimen in cardiac surgery patients represents a new strategy to decrease post-operative acute pain and central sensitization (i. e., hyperalgesia), which in turn may lead to reduced risk of chronic pain after cardiac surgery.

The investigators study is designed as a prospective, randomized, double-blind placebo-controlled trial to evaluate the effects of adding intravenous acetaminophen versus placebo to standard opioid analgesia regimen on post-operative 24-hour opioid consumption in cardiac surgery patients. Our secondary aims include the evaluation of intravenous acetaminophen effectiveness in reducing secondary or dynamic hyperalgesia, acute surgical and non-surgical pain and development of chronic PSP.

Official title: A Double-blind, Randomized, Placebo-controlled Study to Compare the Effectiveness of Perioperative IV Acetaminophen in Reducing Post-Operative Pain and Hyperalgesia After Cardiac Surgery

Study design: Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Primary outcome: Consumption of hydromorphone PCA in mg at 24hs after cardiac surgery

Secondary outcome:

Pain scores

Hyperalgesia area

Hydromorphone consuption in mg

Intraoperative pain level

Side effects of opioids

Chronic pain and rehabilitation at 6 months after surgery

Minimum age: 18 Years. Maximum age: 75 Years. Gender(s): Both.

Criteria:

Inclusion Criteria:

- (1) subjects who clinically consented to elective sternotomy for CABG, heart valve

repair or replacement under general anesthesia, and (2) ages between 18 and 75 years

Exclusion Criteria:

- (1) subject refusal, (2) non-English speaking, (3) previous chronic or neuropathic

pain, (4) previous chronic use of opioids, (5) history of psychiatric disorder, (6) allergy to acetaminophen, (7) severely impaired liver and kidney function and (8) previous sternotomy

Philippe RICHEBE, MD PhD, Phone: 2066163348, Email: prichebe@uw.edu

University of Washington Medical Center, Department of ANesthesiology and Pain Medicine, Seattle, Washington 98195, United States; Recruiting
Philippe Richebe, MD PhD, Phone: 206-616-3348, Email: prichebe@uw.edu
Srdjan Jelacic, MD, Sub-Investigator
Cyril Rivat, PhD, Sub-Investigator
Peter Von Homeyer, MD, Sub-Investigator
Eliot Fagley, MD, Sub-Investigator
Kei Togashi, MD, Sub-Investigator
Gabriel Aldea, MD, Sub-Investigator
Jack Sun, MD, Sub-Investigator

Starting date: July 2012
Last updated: July 18, 2012