Ionized hypocalcemia is an early event and is associated with organ dysfunction in children admitted to the intensive care unit.

PURPOSE: The purpose was to determine the frequency and risk factors of ionized hypocalcemia and to evaluate this disturbance as a predictor of mortality in a pediatric intensive care unit (ICU).

MATERIALS AND METHODS: In a prospective cohort study, 337 children admitted consecutively to an ICU were monitored regarding serum ionized calcium concentrations during the first 10 days of admission. The following variables were analyzed as independent of hypocalcemia: age; malnutrition; sepsis; Pediatric Index of Mortality 2; first 3 days organ dysfunction score (Pediatric Logistic Organ Dysfunction); and use of steroids, furosemide, and anticonvulsants. Hypocalcemia was defined as a serum ionized calcium concentration less than 1.15 mmol/L.

RESULTS: The rate of hypocalcemia was 77.15%. In a multivariate model, higher Pediatric Logistic Organ Dysfunction scores during the first 3 days of ICU stay were independently associated with hypocalcemia (odds ratio, 2.24; 95% confidence interval, 1.23-4.07; P=.008). Medications associated with hypocalcemia were furosemide (dose≥2 mg/[kg d]) and methylprednisolone (dose≥2 mg/[kg d]). No significant association was found between hypocalcemia and 10-day mortality.

CONCLUSIONS: Ionized hypocalcemia is common during the ICU stay, particularly in the first 3 days of admission. This disturbance was not found to be a predictor of mortality, but it is independently associated with more severe organ dysfunction.