Cumulative Doses Predict the Risk of Furosemide-Induced Electrolyte Abnormalities in Critically Ill Neonates

Furosemide has limited indications in the term neonates. Its use in preterm neonates is off-label. Considering the dearth of data, we carried out a retrospective study evaluating the furosemide use and its effects on the electrolyte abnormalities in critically ill neonates.

Critically ill neonates receiving at least one dose of furosemide during their stay in the NICU were recruited. The following details were obtained: demographic characteristics and furosemide details (dose, frequency, route, and duration). Urine output, body weight, serum creatinine, electrolytes (sodium, potassium, calcium, bicarbonate, chloride, and magnesium) during furosemide therapy were extracted.

Ninety neonates were recruited. Elevated serum creatinine was observed in 21.1% of the patients, and electrolyte disturbances were observed in 52.2%. Those with electrolyte disturbances had significantly greater cumulative doses compared to those without [5.5 (1-34) vs 3.9 (0.9-30.2) mg/kg; p = 0.01]. Cumulative doses adjusted to body-weight were significantly lower in very preterm and extremely preterm neonates compared to late preterm category. A significant area-under-the-curve was observed for the cumulative dose (0.66; 95% CI: 0.54-0.78; p = 0.01) in predicting the risk of electrolyte abnormalities with a cut-off value of 4 mg/kg. Eight neonates received more than 10 mg/kg cumulative dose of furosemide of which one died. No significant differences were observed between the proportion of neonates with electrolyte disturbances with cumulative furosemide dose above 10 mg/kg (p = 0.3) and with mortality (p = 0.3).

We observed that our critically ill neonates received relatively higher cumulative doses of furosemide and electrolyte disturbances were observed in nearly half of the population. A cumulative dose of 4 mg/kg increases the risk of electrolyte abnormalities, particularly in preterm neonates. More diligence in the dose titration coupled with deprescribing and intense monitoring of all the potential adverse effects in this vulnerable population is needed.