BACKGROUND: Chronic pain, anxiety, depression, and posttraumatic stress disorder (PTSD) are frequently seen after traumatic injury. Ketamine infusions used to treat acute pain may decrease the risk of chronic pain and improve psychological outcomes of injured patients. We hypothesized patients receiving ketamine would have a lower incidence of chronic pain, anxiety, depression, and PTSD.
METHODS: A prospective, randomized, double-blind placebo-controlled trial of severely injured (Injury Severity Score ≥15) adult patients (age, 18-64 years) admitted to a Level 1 trauma center was conducted. Exclusion criteria included pregnancy and chronic opiate use. All patients were prescribed a patient-controlled analgesia and randomized to either adjustable dose ketamine (ADK) starting at 3 μg/kg/min or an equivalent rate of 0.9% normal saline. Quality of life (QoL) outcomes were measured using Depression and Anxiety (Depression Anxiety Stress Scales 21), PTSD (PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders-5), Trauma quality of life (TQOL), and pain (Brief Pain Inventory-Short Form) questionnaires at hospitalization, and 1, 3, and 6 months postdischarge. Linear regression analysis evaluated the relationship between groups and baseline pain and mental health outcomes at each follow-up.
RESULTS: Forty-four of 82 patients (54%) were randomized to ADK. Both groups were similar in demographics, injury mechanisms/severity, and baseline QOL measures. Patients in the ketamine group had significantly less anxiety symptom severity (p < 0.05) and PTSD (p < 0.05), with significantly less re-experiencing symptoms (subscale of PTSD) at 3 and 6 months (p < 0.05).
CONCLUSION: Ketamine infusion for acute pain treatment in severe traumatic injury may significantly reduce anxiety and PTSD 6 months after injury. This effect may be specific to the memory processes responsible for re-experiencing symptoms. Further research should explore the effects of acute ketamine administration on the neurobiological mechanisms implicated in the development of PTSD, as this could be a novel preventative intervention to improve QoL for injured patients.
LEVEL OF EVIDENCE/STUDY TYPE: Level 1, Therapeutic/Care Management.
