Hypokalemia and rhabdomyolysis.

Since the occurrence of rhabdomyolysis may elevate the serum concentration of potassium, hypokalemia as a cause of rhabdomyolysis often goes unrecognized in many instances. We undertook this study to evaluate the occurrence and determinants of rhabdomyolysis in the hypokalemic state. To identify patients with a hypokalemic state, we reviewed medical admissions for the period January 1988 through December 1989. A total of 120 patients (42 men and 78 women) were included in the present study. Thirty-eight hypokalemic patients showed biochemical evidence of rhabdomyolysis (serum creatine phosphokinase greater than 244 IU/l). The clinical and biochemical characteristics of the patients with rhabdomyolysis (group I) and the hypokalemic patients without rhabdomyolysis (82 patients, group II) were compared. There was no difference in age, sex and race of the patients of group I vs. group II. The mean serum values for potassium, bicarbonate, chloride, blood urea nitrogen, glucose, lactate dehydrogenase and uric acid were also not different between the two groups. The mean serum osmolality was higher (p less than 0.001) in patients with rhabdomyolysis (297.6 +/- 4.3 mosm/kg) than in those without rhabdomyolysis (283.5 +/- 5.0 mosm/kg). The levels of serum glutamic-oxaloacetic transaminase were elevated (p less than 0.001) in group-I patients (69.6 +/- 8.4 IU/l) but not in group-II patients (36.7 +/- 3.5 IU/l). The concentrations of serum creatinine were also higher (p less than 0.05) in patients with rhabdomyolysis (1.4 +/- 0.2 mg/dl) than in those without rhabdomyolysis (1.0 +/- 0.1 mg/dl). The mean values for serum sodium were higher (p less than 0.02) in group-I patients when compared to group-II patients.(ABSTRACT TRUNCATED AT 250 WORDS)