Creatinine phosphokinase elevation among exertional heat stroke patients

Background: Rhabdomyolysis, which can be defined as a CPK level greater than five times the upper limit of normal, is related to muscle breakdown and hypovolemia in heat stroke patients. 1 CPK levels will likely be higher because of increased muscle breakdown in exertional heat stroke when compared with classic heat stroke. Methods: We reviewed 50 patients who came into the Emergency Department of Hamad General Hospital during the months of July to September 2015, and who were diagnosed with exertional heat stroke. Results: In 44 out of 50 heat stroke patients, the level of serum CPK was markedly elevated (mean 20,300 ± 25,500 U/l) compared with the elevated levels of other lab values (serum myoglobin 2500 ± 3000 ng/ml, creatinine 1.8 ± 2.4 mg/dL, BUN 90 ± 104 mg/dL, potassium 2.6 ± 3.6 mEq/L, sodium 135 ± 155 mEq/L) on admission. The repeated lab values after the 12th hour showed that the CPK rose further (28,500 ± 32,500 U/L) while the others (serum myoglobin 800 ± 1,200 ng/ml, creatinine 1.1 ± 1.4 mg/dl, BUN 35 ± 60 mg/dL, potassium 2.2 ± 3.4 mEq/L, sodium 110 ± 130 mEq/L) recorded a decrease. Conclusion: In our cohort of patients, CPK levels were significantly high in the setting of exertional heat stroke. A possible relation to renal failure need to be explored in a prospective research design. Keywords: exertional heat stroke, rhabdomyolysis, creatinine phosphokinase REFERENCE: [1] Santelli J, Sullivan J. An evidence based approach on emergency medicine. Emerg Med Prac . 2014;16:6–15.