Exertional Rhabdomyolysis: A Retrospective Population-based Study
PURPOSE: To evaluate the incidence and characteristics of exertional rhabdomyolysis (ER) in a population-based cohort. METHODS: A retrospective cohort study was performed in Olmsted County, Minnesota, from 2003–2015. Incident ER cases were ascertained through the Rochester Epidemiology Project (REP) medical record linkage system through electronic searches of ICD-9 codes and clinical note text. Population incidence rate was calculated using corresponding calendar-year- and sex specific REP census populations. Descriptive statistics were used. RESULTS: 431 cases in 430 patients met inclusion criteria for rhabdomyolysis; 4.9% of cases (n= 20; males n=18; Caucasian n=17) were ER, with one recurrence. There were no deaths secondary to ER. The age and sex adjusted incidence rate of ER was 1.06 ± 0.24 (95% CI 0.59–1.52) per 100,000 person-years. Endurance activity (n=7), manual labor (n=5), and weight lifting (n=4) were common causes. Complications included kidney injury (n=5), mild electrolyte abnormalities (n=10), elevated transaminases (n=12), and minor electrocardiographic abnormalities (n=4). A majority of patients were hospitalized (n=16) for a median of two days, had mild abnormalities in renal and liver function, and electrolytes; and were discharged without sequelae. CONCLUSION: ER in the civilian population occurs at a much lower incidence than the military population. The most common causes were endurance exercise, manual labor, and weight lifting. The majority of cases were treated conservatively with intravenous fluid resuscitation during a brief hospital stay, and all were discharged without sequela. Only one case of recurrence occurred in this cohort, indicating the recurrence rate was low.