The Incidence of and Risk Factors for Emergence Delirium in U.S. Military Combat Veterans

The purpose of this research was to identify the incidence and potential risk factors for emergence delirium (ED) in a U.S. military combat veteran surgical population at Naval Hospital Camp Pendleton. ED is a postanesthetic phenomenon that occurs immediately after emergence from general anesthesia and is characterized by agitation, confusion, and violent behavior. Clinical evidence suggests that ED is increasingly seen among military personnel returning from the wars in Iraq and Afghanistan, and that the incidence of anxiety, depression, and post-traumatic stress disorder (PTSD) are higher in this population than in noncombat troops or nonmilitary populations. The incidence of ED in this sample of 130 postoperative military personnel with combat exposure was 20% (n = 26). Those previously diagnosed with a psychological disorder had a higher rate of ED (50%) than those who did not (17.5%), χ2 = 5.53, P < .05. There was a positive relationship between ED in veterans who reported greater amounts of anxiety, PTSD symptoms, and depression [state anxiety: r(128) = 0.40, P < .001; trait anxiety: r(128) = 0.40, P < .001; PTSD: r(128) = 0.35, P < .001; and depression: r(128) = 0.25, P = .002]. This study revealed the incidence of ED and identified anxiety, PTSD, and depression as risk factors. Regression modeling suggested that state-anxiety served as the best predictor. These findings increase clinicians' understanding of ED among combat veterans and give direction to future studies that should focus on preventive treatment.