A Study of Ketamine Infusions to Treat Clinically-depressed ICU Patients

This study is testing whether low-dose ketamine infusions can safely treat clinical depression in patients who are currently admitted to the ICU (intensive care unit) and are experiencing significant depressive symptoms on top of their critical illness. **You may be eligible if:** - You have been in the ICU at Mayo Clinic Florida for at least 1 week - You scored 10 or higher on a standard depression questionnaire (PHQ-9) - You have one of several serious medical diagnoses, such as heart attack, kidney failure, COPD, heart failure, liver disease, or are pre/post organ transplant **You may NOT be eligible if:** - Your vital signs are unstable (very low blood pressure, high blood pressure, low oxygen, abnormal heart rate or breathing) - You have confusion or altered mental status - You have a history of psychosis or hallucinations - You are allergic to ketamine or diphenhydramine (Benadryl) - You are pregnant or breastfeeding - You weigh more than 115 kg or less than 45 kg - You have increased pressure in the brain or eye Talk to your doctor to see if this trial is right for you.