Methamphetamine abuse and rhabdomyolysis in the ED: A 5-year study

Patients with methamphetamine toxicity are presenting in greater numbers each year to emergency departments (ED) in the US. These patients are frequently agitated, violent, and often require physical and chemical restraint. The incidence and risk of rhabdomyolysis in this subpopulation is unknown. We conducted a 5-year retrospective review of all ED patients who received the final diagnosis of rhabdomyolysis. Patients with toxicology screens positive for methamphetamine were identified, and demographics, laboratory results, resource utilization, disposition, and outcome were compared to the remaining patients. Of the total 367 patients identified, 166 (43%) were toxicology positive for methamphetamine. Methamphetamine patients differed significantly from nonmethamphetamine patients with regard to demographics and hospital utilization. Methamphetamine patients had significantly higher mean initial creatine phosphokinase (CK), 12,439 U/L versus 5,678 U/L (P = 0.02), and lower mean peak CK, 16,827 U/L versus 19,426 U/L (P = 0.03). The development of acute renal failure was not significantly different between the 2 groups. There were 16 total deaths in the study population, 11 from concomitant infection/sepsis. An association between methamphetamine abuse and rhabdomyolysis may exist, and CK should be measured in the ED as a screen for potential muscle injury in this subpopulation. Patients with rhabdomyolysis with an unclear cause should be screened for methamphetamine or other illicit drugs.