the effect of intravenous ketamine in suicidal ideation of emergency department patients

introduction: suicidal ideation is an emergent problem in the emergency department (ed) that often complicates patient disposition and discharge. it has been shown that ketamine possesses fast acting antidepressant and anti-suicidal effects. this study was conducted to examine the effects of a single intravenous bolus of ketamine on patients with suicidal ideations in ed. methods: forty-nine subjects with suicidal ideations with or without an unsuccessful suicide attempt, received 0.2 mg/kg of ketamine. scale for suicidal ideation (ssi) and montgomery-abserg depression rating scale (madrs) were evaluated before and 40, 80 and 120 minutes after drug intervention. the results were compared using the paired t-test and patients were followed up 10 days after ed admission for remnant suicide ideation. results: ssi (df: 3, 46; f=80.7; p<0.001) and madrs (df: 3, 46; f=87.2; p<0.001) scores significantly dropped after ketamine injection; the ssi score before and after 20, 40, and 80 minutes of ketamine injection were 23.0±6.7, 16.2±5.2, 14.3±4.3, and 13.6±4.0 respectively. the madrs scores were 38.2±9.3, 25.6±7.1, 22.7±6.3, and 22.1±5.95 at the same time intervals. 25.5% of patients were hospitalized, 63.3% received medications and 12.2% discharged. 6.2% of patients had suicidal ideations ten days after ed disposition.  conclusion: it seems that ketamine couldn't be a good choice for fast reduction of suicidal ideations in ed patients. further studies are needed to determine the optimal dose of ketamine for different patients.