Urine dipstick testing to rule out rhabdomyolysis in patients with suspected heat injury

Background: Heat injury is a common, potentially life-threatening medical condition. In austere or mass-casualty conditions an easy to use, sensitive screening test could be a valuable tool to care providers and evacuation planners. Objective: The objective of the study was to determine if a simple urine dipstick test for blood is sensitive for detection of rhabdomyolysis in the suspected heat injury patient. Material and Methods: A convenience sample of patients presenting to a military community hospital Emergency Department during summer months with a presenting complaint consistent with suspected heat injury had urine dipstick testing performed for blood and compared with the results of formal urinalysis and serum creatine kinase. Results: 60 patients were enrolled in the study, seven had creatine kinase levels greater than 1000U/L, 14 had levels greater than 500U/L, and 26 had levels greater than 250 U/L. Using 1000U/L, urine dipstick testing had a sensitivity of 14% and a specificity of 85%. Conclusions: Urine dipstick testing for blood is not a useful screening test for rhabdomyolysis in patients suspected to have significant heat injury.