Presented at the 2013 AAPM Annual Meeting « Back

Perioperative Ketamine Reduces Post-Operative Opioid Consumption After Major Orthopedic Surgery in Patients with Fibromyalgia: A Retrospective Chart Review of 26 Cases

Jonathan A. Day, MD, jonathan_day@yahoo.com¹, Ramsha A. Kudia, BS¹, Roy Greengrass, MD FRCP¹, Bonnie L. Howe, RN BSN¹, Steven B. Porter, MD¹, Steve Clendenen, MD¹, Ilana Logvinov RN MSN CCRP¹, Beth Ladlie, MD MPH¹, (1) Mayo Clinic, Jacksonville, Florida

Introduction: Evidence is accumulating that use of low-dose ketamine may considerably reduce post-operative morphine consumption among patients on large dose opioids undergoing surgery. After anecdotal reports of improvement in fibromyalgia symptoms in fibromyalgia patients receiving ketamine, we conducted a retrospective study to provide a more systematic initial assessment of the potential impact of ketamine on fibromyalgia pain. With IRB approval, we conducted a retrospective chart review of 25 consecutive patients with fibromyalgia having total hip (n=10) or knee (n=15) arthroplasty all utilizing the same regional anesthetic blockade, except that 10 patients (5 hip, 5 knee) received low dose ketamine infusion, while the others did not. Our focus was on 48 hour post-operative oral morphine equivalent (ME) use. Data was analyzed using the stratified van Elteren test. 26 procedures of 25 patients (2 male, median age 60, range 28 to 82) met inclusion criteria from November 2009 to July 2011. Median 48 hour ME in patients without ketamine was 250mg, while the median with ketamine was 135mg. Despite the small sample size, this was marginally statistically significant with p=0.054, and consistent with the anecdotal reports. Fibromyalgia is a complicated disease process which despite modern treatment often leaves these patients in significant pain. The subsequent high use of narcotics further complicates their care. Low-dose ketamine, with its proven narcotic sparing effects, may provide a novel avenue of treatment for patients with fibromyalgia and more in depth prospective studies are warranted to investigate this further. References: 1) Loftus, R. et al. Intraoperative Ketamine Reduces Perioperative Opiate Consumption in Opiate-dependent Patients with Chronic Back Pain Undergoing Back Surgery. Anesthesiology 2010; 113: 639-646.

Funding: None

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