Catatonia-Like Syndrome Treated With Low-Dose Ketamine

Ketamine's application in psychiatry have expanded, but it appears never to have been previously used to diagnose and treat patients with catatonia-like syndrome that occasionally present to emergency departments.

A 23-year-old male was observed to suddenly stop talking. His ED GCS was 8 and had normal vital signs. While verbally unresponsive, he refused to open his eyes, demonstrated waxy flexibility of his arms, but the balance of his physical, neurological, and laboratory exams were normal. Strongly suspecting a catatonic state, they needed to rapidly confirm that diagnosis or begin evaluating him for potentially life-threatening non-psychiatric illnesses. Lacking other diagnostic modalities, they administered low-dose ketamine boluses. Ketamine 25 mg (1 mL) was diluted in 9 mL NS (2.5 mg/mL). Based on similar protocols, 1 mL of the solution (0.03 mg/Kg) was given intravenously every few minutes. After 12.5 mg ketamine, he was conscious and verbal. Subsequent history confirmed a prior episode requiring an extensive, non-productive medical evaluation. Psychiatry later confirmed the diagnosis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Patients with catatonia-like states pose a difficult diagnostic and therapeutic dilemma. Multiple interventions have been used with varying success. Optimal interventions provide a rapid resolution (or demonstrate that a psychiatric cause is not likely), be safe, encompass few contraindications, and be familiar to the clinician. In our patient, subanesthetic doses of ketamine fulfilled these criteria and successfully resolved the condition. If shown effective in other cases, ketamine would be a valuable addition to our psychiatric armamentarium.