Feasibility and Safety of Ketamine for Suicidal Patients in the Emergency Department

Inclusion Criteria: * Acutely Suicidality ("yes" answer to any of items 4 or 5 on C-SSRS "Suicidal Ideation" category) * Require inpatient stabilization for SI or actions based on clinical observation and interview * Are accepted for psychiatric stabilization at the University of Kansas Medical Center's Strawberry Hill campus * Have a Glasgow Coma Score (GCS) of 15 * Age 18-65 Exclusion Criteria: * Current or past history of psychosis * Current or recent (past 4 weeks) symptoms of mania/hypomania as defined by Young Mania Rating Scale (YRMS) score of 12 or greater * History of ketamine use disorder * History of liver transplant * Pregnancy or breastfeeding * Imprisonment or inability to consent * Positive urine drug screen or serum alcohol level * Hypertension (SBP \> 160 or DBP \> 100 before administration of ketamine) * Hypotension (SBP \< 90) * Presence of acute medical condition requiring admission to medical service * Allergy, intolerance, or previous adverse reaction to ketamine * Patient has 8+ lifetime ketamine exposures * The treating physician determines that the patient is not a good candidate for the study (e.g. medical condition/procedure, medication that would contradindicate ketamine treatment)