Systematic review of parenteral ketamine for managing acute agitation in emergency settings

Agitation, a significant psychiatric issue often linked to conditions like schizophrenia, bipolar disorder, and major depression, invariably pose challenges in emergency settings. Acute agitation occurs in 2.6 % of emergency cases and up to 12.2 % among patients with schizophrenia or bipolar disorder. With limited available options for effective management of acute agitation, ketamine is emerging as a fast-onset alternative to antipsychotics like haloperidol.

This systematic review, following PRISMA guidelines, searched databases in April 2024 for studies on parenteral ketamine for acute agitation in emergency settings. Data extraction included patient demographics, ketamine administration details, sedation time, need for additional doses, adverse events, and intubation rates.

The search yielded 7410 results, narrowing to 29 suitable studies with 1516 patients (mean age 35.5 ± 12.4 years, 67.9 % male). Ketamine was administered intramuscularly (IM) in 69 % of studies, intravenously (IV) in 6.9 %, and either IV or IM in 24.1 %. Most patients (86.5 %) received IM ketamine at a mean dose of 3.83 ± 1.07 mg/kg, while 13.5 % received IV ketamine at 2.09 ± 1.56 mg/kg. Sedation occurred on average in 6.1 min. However, 24.5 % needed rescue medications or additional doses. Adverse effects included tachycardia (5.1 %), hypertension (5.5 %), hypersalivation (5.6 %), nausea (2.1 %), emergence reactions (1.4 %), and, rarely, cardiac arrest (0.2). While 19.1 % required intubation, the reasons for the same could not be attributed to ketamine exclusively. Furthermore, there was no evidence for worsening or development of psychotic symptoms with ketamine.

This review highlights the effectiveness and safety of parenteral ketamine for managing acute agitation in emergency settings. However, further research is needed to optimize ketamine use in this challenging scenario.