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

Eligibility Criteria

• * Has been in the Mayo Clinic Florida ICU for the past 1 week.
• * PHQ-9 score of 10 or higher.
• * One of the following diagnoses: acute myocardial infarction; acute renal failure; chronic obstructive pulmonary disease (COPD); congestive heart failure; end-stage liver disease; patients requiring intra-aortic balloon pump (IABP) therapy or continuous renal replacement therapy (CRRT); post-bone marrow transplant; acute Hypoxemic Respiratory Failure; acute or chronic hypoxemic respiratory failure; pre- or post- lung, liver or heart transplant or surgical overflows (such as abdominal aortic aneurysm, thoracotomy or tracheostomy).
• * Poor vital sign stability hypoxia: O2 \< 95%, hypotension: SBP \< 90 hypertension: SBP \> 180.
• * Heart rate: \< 50 or \> 120, or Respiratory Rate: \< 10 or \> 30.
• * Altered mental status.
• * Patient is unwilling to participate or provide informed consent.
• * Any allergy to ketamine or diphenhydramine.
• * Patient is female of child-bearing age and unwilling to provide urine or blood for HCG analysis.
• * Pregnant or breastfeeding.
• * Presence of intracranial mass or vascular lesion.
• * Presence of a history of psychosis or hallucinations (as assessed by electronic chart review).
• * Weight greater than 115 kg or less than 45kg.
• * History of increased intracranial pressure/hypertensive hydrocephalus or increased intraocular pressure.
• * Patient is acutely psychotic.
• * Provider feels that patient currently or likely will require chemical and/or physical restraints.
• * History of prolonged QT-interval.
• * Current treatment includes any medication known to affect the N-methyl-D-aspartate receptor system (e.g., lamotrigine, acamprosate, memantine, riluzole, or lithium).
• * Patient in withdrawal from substance abuse or who have used hallucinogens (including cannabis) in the last month for any indication, as determined by the clinical interview and urine drug screening.