Early volume expansion during diarrhea and relative nephroprotection during subsequent hemolytic uremic syndrome.

OBJECTIVES To determine if interventions during the pre-hemolytic uremic syndrome (HUS) diarrhea phase are associated with maintenance of urine output during HUS. DESIGN Prospective observational cohort study. SETTINGS Eleven pediatric hospitals in the United States and Scotland. PARTICIPANTS Children younger than 18 years with diarrhea-associated HUS (hematocrit level <30% with smear evidence of intravascular erythrocyte destruction), thrombocytopenia (platelet count <150 × 10³/mm³), and impaired renal function (serum creatinine concentration > upper limit of reference range for age). INTERVENTIONS Intravenous fluid was given within the first 4 days of the onset of diarrhea. OUTCOME MEASURE Presence or absence of oligoanuria (urine output ≤ 0.5 mL/kg/h for >1 day). RESULTS The overall oligoanuric rate of the 50 participants was 68%, but was 84% among those who received no intravenous fluids in the first 4 days of illness. The relative risk of oligoanuria when fluids were not given in this interval was 1.6 (95% confidence interval, 1.1-2.4; P = .02). Children with oligoanuric HUS were given less total intravenous fluid (r = -0.32; P = .02) and sodium (r = -0.27; P = .05) in the first 4 days of illness than those without oligoanuria. In multivariable analysis, the most significant covariate was volume infused, but volume and sodium strongly covaried. CONCLUSIONS Intravenous volume expansion is an underused intervention that could decrease the frequency of oligoanuric renal failure in patients at risk of HUS.