Patterns of Intramuscular Chemical Sedation Use for Patients Receiving a Mental Health Consultation While in the...

Disparities in physical restraint use among emergency department (ED) patients are well described. Less is known about the intramuscular (IM) administration of sedating medications. We evaluated patient characteristics and adverse outcomes associated with receiving IM chemical sedation in the ED.

This retrospective cross-sectional evaluation at Kaiser Permanente Northern California from January 1, 2017, to December 31, 2021, included ED patients aged 18-64 years who received a mental health consultation. We assessed the frequency of IM chemical sedation, associated characteristics, and adverse events. We estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) to assess characteristics associated with IM chemical sedation.

Of 94,204 ED visits (56,154 patients) meeting inclusion criteria, 11,048 (11.7%) received IM chemical sedation. Median patient age was 34 years (IQR 25-48), and 46,948 (49.8%) visits were for male patients. Higher adjusted odds of IM chemical sedation were observed for patients of Black race (aOR 1.38, 95% CI 1.27 to 1.50), concomitant physical restraint (aOR 33.05, 95% CI 30.28 to 36.08), Emergency Medical Services (EMS)/law enforcement arrival (aOR 1.51, 95% CI 1.43 to 1.60), and involuntary mental health hold placement (aOR 1.66, 95% CI 1.56 to 1.77). Patients' age, sex, and need for interpreter services were not associated with IM chemical sedation. Supplemental oxygen administration was the most common adverse event (n = 2,662, 2.8%).

Among ED patients with mental health consultation, IM chemical sedation was associated with EMS/law enforcement arrival, Black race, and involuntary mental health hold. Further work is needed to understand how comorbid mental health conditions, implicit bias, and unmeasured confounders may impact the use of IM chemical sedation.