“Novel Management of Depression Using Ketamine in the Intensive Care Unit”

Abstract

Background: Ketamine, a dissociative anesthetic, induces improvement in depressive symptoms by antagonizing glutaminergic NMDA receptors. Ketamine has been used previously in outpatient setting for treatment-resistant depression, but we showcase its utility in depression management at the Intensive Care Unit (ICU). Research Question: Can ketamine be used for depression treatment in ICU patients? Study Design and Methods: A retrospective chart review of ICU patients was done at a tertiary center from 2018 to 2021, to assess the ketamine usage. Among the patients reviewed, ketamine was used for depression in 12, and for analgesia & sedation in 2322 patients. Ketamine was administered in doses of 0.5mg/kg & 0.75mg/kg for depression. Each course consisted of 3 doses of ketamine administered over 3 days, and 7 in 12 patients received a single course of ketamine. The rest received 3–4 courses 1 week apart. Results: Ketamine was found to improve mood and affect in most of the patients with depression. 11 in 12 patients had a positive response with better sleep. It has a major advantage over conventional anti-depressants since it takes only a few hours to induce clinical improvement. Patients who were observably withdrawn from care team and family, were administered ketamine. Conclusion: A major drawback of ketamine is that the duration of clinical improvement is short, with the response lasting only up to seven days after a single dose. Hence, all the patients in our study were weaned off ketamine with a supporting antidepressant. Ketamine has been documented to cause cardio-neurotoxicity; however, only one patient had worsening lethargy in our study. To conclude, ketamine has a marked benefit in treating depression in the ICU. Although our study was associated with positive outcomes, there is a need for prospective studies with long-term follow-up assessments.