Predisposing factors for posttraumatic stress disorder (PTSD) include experiencing a traumatic event, threat of injury or death, and untreated pain. Ketamine, an anesthetic, is used at low doses as part of a multimodal anesthetic regimen. However, since ketamine is associated with psychosomatic effects, there is a concern that ketamine may increase the risk of developing PTSD. This study investigated the prevalence of PTSD in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) service members who were treated for burns in a military treatment center.
The PTSD Checklist-Military (PCL-M) is a 17-question screening tool for PTSD used by the military. A score of 44 or higher is a positive screen for PTSD. The charts of all OIF/OEF soldiers with burns who completed the PCL-M screening tool (2002–2007) were reviewed to determine the number of surgeries received, the anesthetic regime used, including amounts given, the total body surface area burned, and injury severity score. Morphine equivalent units were calculated using standard dosage conversion factors.
The prevalence of PTSD in patients receiving ketamine during their operation(s) was compared with patients not receiving ketamine. Of the 25,000 soldiers injured in OIF/OEF, United States Army Institute of Surgical Research received 603 burned casualties, of which 241 completed the PCL-M. Of those, 147 soldiers underwent at least one operation. Among 119 patients who received ketamine during surgery and 28 who did not; the prevalence of PTSD was 27% (32 of 119) versus 46% (13 of 28), respectively (p = 0.044).
Contrary to expectations, patients receiving perioperative ketamine had a lower prevalence of PTSD than soldiers receiving no ketamine during their surgeries despite having larger burns, higher injury severity score, undergoing more operations, and spending more time in the ICU.
From the US Army Institute of Surgical Research (L.L.M., C.V.M., T.H.G., K.M.G.), Fort Sam Houston, Texas; and Brooke Army Medical Center (I.H.B.), Fort Sam Houston San Antonio, Texas.
Submitted for publication October 30, 2007.
Accepted for publication October 31, 2007.
Financial Support from US Army Institute of Surgical Research Battlefield Pain Control Task Area.
Disclaimer: The opinions and assertions contained in this article are solely the authors’ private ones and are not to be construed as official or reflecting the views of the United States Army or the Department of Defense. This article was prepared by United States Government employees and therefore cannot be copyrighted and may be copied without restriction.
Address for reprints: Laura McGhee, PhD, CPT, MS, US Army Institute of Surgical Research, 3400 Rawley E. Chambers, Fort Sam Houston, TX 78234; email: firstname.lastname@example.org.