ABSTRACT
PURPOSE: In previous literature, urinalysis in rhabdomyolysis has been known to be positive for occult blood, but without overt hematuria. Recently, however, we have reported hematuria in patients with doxylamine overdose in association with rhabdomyolysis. We wanted to determine whether the hematuria resulted from the toxicity of doxylamine itself or from rhabdomyolysis, and further to investigate the relationship between hematuria, acute renal failure (ARF), and the presence of urine alkalinization. METHODS: The medical records of 167 patients diagnosed with rhabdomyolysis who were admitted to Kyung Hee Medical Center between 2000 and 2004 were retrospectively examined. Patients without laboratory results 3 times a day, patients with inaccurate records, and patients with diseases that could cause hematuria were excluded, leaving 79 patients for evaluation. The relationship between laboratory results, occurrences of ARF and urine alkalinization were compared and assessed. RESULTS: Hematuria was observed in 76 of 79 patients with rhabdomyolysis, irrespective to the cause of rhabdomyolysis. The percentage of dysmorphic RBC was 58% and MCV (mean corpuscular volume) was 76+/-15 fL found in hematuria. Urine alkalinization was not associated with the presence of hematuria. The laboratory results of ARF patients compared to those of non-ARF patients showed a significant difference in the average urine pH, and ARF with rhabdomyolysis was not associated with muscle enzyme levels but rather was associated with the duration of hematuria. CONCLUSION: Hematuria was found in patients with rhabdomyolysis irrespective of the cause of rhabdomyolysis. Therefore, hematuria is associated with rhabdomyolysis rather than doxylamine intoxication. The occurrence of hematuria in rhabdomyolysis is unrelated to urine alkalinization. The duration of hematuria in ARF group was significantly longer than in non-ARF group. It is therefore important to bear in mind the possibility that ARF will develop when hematuria lasts for a long time. Furthermore, we feel that additional prospective studies and investigations into the mechanism of hematuria in rhabdomyolysis should be done.