Western Journal of Emergency Medicine: Integrating Emergency Care with Population Health

Background: In the Philadelphia region, there has been an increase in the potency of illicit opioids as well as the addition of nonopioid adulterants. Currently, medetomidine, a veterinary anesthetic that acts as an alpha-2-adrenergic agonist, is a common adulterant in the illicit opioid supply, causing both unique overdose and withdrawal syndromes. Although opioid withdrawal alone is not deadly, with added adulterants, especially medetomidine, this is no longer the case. Dexmedetomidine is an alpha-2-adrenergic agonist frequently used for sedation in the emergency department and intensive care unit. Dexmedetomidine is also used off-label to treat the life-threatening withdrawal from alpha-2-agonists.

Objective: This study describes the dosing and hemodynamic effects associated with the interfacility administration of dexmedetomidine in patients with alpha-2 adrenergic agonist withdrawal. Secondarily, we describe the safety of dexmedetomidine in this patient population.

Methods: We conducted a retrospective case review of patients receiving dexmedetomidine infusions in the interfacility setting for presumed alpha-2–adrenergic agonist withdrawal. Demographic data, dosing, and vital signs were analyzed descriptively.

Results: Over a six-month period, of 217 cases identified, 182 contained complete hemodynamic data. The average age was 39.5 years, and 67% were male. The average transport time was 15.7 minutes (range, 5-40 minutes). The mean dexmedetomidine infusion rate was 1.32 (0.31) mcg/kg/hr. The average mean arterial pressure decreased from 122.1 mm Hg (21.7) at the time of initial patient contact to 118.3 mm Hg (21.7) (mean difference, 3.80; 95% CI, 1.96-5.64) at final patient interaction. Heart rate also showed a minimal change from 104.9 (23.7) to 103.6 (21.8) beats/min (mean 1.3; 95% CI, -0.48 to 3.08). No cases of severe hypotension or clinically significant bradycardia requiring intervention were documented (one-sided 95% CI, 0-1.7%).

Conclusion: In this case series of patients, prehospital dexmedetomidine infusions to treat alpha-2-agonist withdrawal were associated with stable hemodynamics without significant bradycardia or hypotension. These findings support the safety of dexmedetomidine infusions for interfacility transport and provide a rationale for examining whether advanced life support clinicians can safely transport patients receiving dexmedetomidine infusions for this indication.