In this episode, I’ll discuss the fastest way to sedate an aggressive or violent patient in the ED.
When acutely agitated patients present to the ED, one way to measure the severity of the agitation is with the Richmond Agitation and Sedation Scale.
At the upper end of the RASS scale is +3 which represents patients acting aggressively towards staff and +4 which represents combativeness, violence, or an immediate danger towards staff.
When a patient is exhibiting this level of agitation, chemical sedation is desired as rapidly as possible. Every minute passes like an hour as extensive resources are mobilized to attend to the safety of the staff and patient. Therefore using the fastest treatment that can safely provide for adequate sedation is preferred.
Researchers in Annals of Emergency Medicine recently published a randomized comparison of two commonly used treatments for aggressive and violent agitation in ED patients: IM ketamine vs combination therapy with haloperidol + midazolam.
81 patients presenting to the ED with a RASS of +3 or +4 were randomized between ketamine 5 mg/kg IM and the combination of midazolam 5 mg IM and haloperidol 5 mg IM. The primary outcome was the time from study medication administration to a RASS of -1 or less. This is an aggressive target as a RASS decrease to even to a score of 0 or +1 is enough to remove the immediate danger to staff, de-escalate the resources needed, and begin to address the underlying cause.
The trial was stopped early due to a moratorium on in-person clinical research during the COVID-19 pandemic. More patients in the ketamine group had a RASS of +4 than the midazolam/haloperidol group. The median time to sedation was 14.7 minutes for midazolam and haloperidol versus 5.8 minutes for ketamine, for a difference of almost 9 minutes that was statistically significant.
When faced with an aggressive or violent patient, a difference of almost 9 minutes to achieve a RASS of -1 is of tremendous clinical significance and could mean the difference between an injury or not for a staff member or the patient.
The safety outcomes were similar between groups with 2 patients in the ketamine group vs 1 in the midazolam/haloperidol group experiencing apnea. One patient who received ketamine experienced laryngospasm which resolved with minimal intervention. No patients in either group required endotracheal intubation or ICU admission.
While this study reflects very well on ketamine for this indication, it should be noted that ketamine, like other sedatives, does have a risk of respiratory adverse events despite it’s supposed lack of effect on respiratory drive. This is not a reason to avoid ketamine but rather it should mean that clinicians take care to not be lulled into a false sense of security thinking that giving ketamine means there is not a concern for respiratory events.
Ketamine was rapidly effective and demonstrated far more desirable outcomes compared with midazolam/haloperidol and I would much prefer it especially for a patient with a RASS of +4. While trials stopped early for benefit frequently overestimate treatment effects, the early stoppage of this trial was unrelated to the benefit of ketamine and should not reflect poorly on the outcome of the study.
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