Excited delirium syndrome (ExDS) is characterized by delirium, agitation, and hyperadrenergic autonomic dysfunction. A guideline for ExDS management, which recommends the use of ketamine as a second-line agent, was implemented in our hospital's adult emergency department (ED).

The primary objective was to determine whether ketamine, 1 mg/kg intravenous (i.v.) or 2 mg/kg intramuscular (i.m.), is being used according to the ExDS guideline. Secondary objectives included evaluating the specific agents, routes, and dosages used to manage ExDS and the safety and efficacy of ketamine.

Single-center, retrospective chart review of patients who received ketamine for the management of ExDS in the ED. Efficacy was measured by documented Richmond Agitation Sedation Scale (RASS) scores. Safety was assessed through evaluation of vital signs and adverse effects.

Thirty-one patients met inclusion criteria. Eight (25.8%) of them received ketamine for ExDS in adherence with all aspects of the guideline. Administration of ketamine led to a statistically significant decrease in median RASS score of 4 (interquartile range [IQR] 3 to 4) vs. 0 (IQR 2 to -1) (p = 0.001). There were no statistically significant differences in vital signs or RASS scores in our subgroup analyses of patients treated according to protocol and of those treated with ketamine, 2 mg/kg i.m.

We found discordance between current practice and our department's ExDS guideline for patients managed with ketamine. Despite the lack of adherence to departmental guidelines and allowing for limitations of this analysis due to small sample size, the use of low-dose, 1 mg/kg i.v. or 2 mg/kg i.m., ketamine was effective and appears to be a reasonable option as second-line therapy for ExDS.