Are potassium levels in children with hemolytic uremic syndrome predictive of outcome?

Objective: To ascertain the role of serum potassium levels in predicting clinical outcomes in diarrhea-associated hemolytic uremic syndrome (HUS D+). Methods: We reviewed clinical and laboratory data from HUS D+ patients at our tertiary care institution from 2001 to 2008. Serum potassium concentration at presentation and during the acute phase of acute renal failure were recorded and related to laboratory parameters and clinical outcomes. Results: 15 HUS D+ cases were identified. E. coli 0157:H7 was found in 9/15 cases (70%). Potassium levels were not predictive of clinical outcomes. Normal serum potassium levels were found in the majority of patients. Potassium levels <3.6 mmol/L were evident at presentation in 3/15 patients (23%), and no patient manifested hyperkalemia even when creatinine levels were concurrently increase. Conclusions: This study suggests the presence of vigorous compensatory mechanisms in the homoestasis of serum potassium levels during HUS D+ disease since neither the increase stool volumes associated with diarrhea nor the presence of renal failure resulted in clinically significant changes in serum potassium levels.