Hypercalcemia associated with extracorporeal life support in neonates

Background/Purpose: Disturbances in calcium homeostasis are common at initiation of extracorporeal life support (ECLS). At the authors' institution many neonates undergoing ECLS have developed hypercalcemia. To determine the frequency of hypercalcemia in neonates during ECLS we performed retrospective chart review of neonates that required ECLS at our neonatal intensive care unit. Methods: The authors identified 76 consecutive neonates who underwent ECLS before 10 days of age at Cincinnati Children's Hospital Medical Center from July 1, 1991 to June 30, 1996. The hospital charts and ELSO forms were reviewed. Demographic, clinical, and laboratory data for each of the patients were reviewed, both before initiation and during ECLS. Hypercalcemia was defined as total serum calcium concentration of greater than 11 mg/dL (2.74 mmol/L) on at least one occasion beyond the first 24 hours of ECLS. Results: The hospital charts and ELSO forms from 70 patients were available for review. One patient was excluded because he was only on ECLS for 33 hours, and there were no calcium levels obtained after 24 hours of ECLS and until death. Twenty-five (36%) neonates undergoing ECLS had hypercalcemia (serum Ca > 11 mg/dL [2.74 mmol/L]). Hypercalcemia was associated with longer duration of ECLS (hypercalcemia group, 243 ± 115 hours and normocalcemia group, 139 ± 64 hours) and greater requirements for platelet transfusions (hypercalcemia group, 538 ± 282 mL and normocalcemia group, 372 ± 233 mL). This could not be explained by differences in primary diagnosis, amounts of calcium administered, and acid-base status. Conclusions: Hypercalcemia was found to be common in neonates that require ECLS and is associated with longer duration of ECLS support. Conservative calcium administration for neonates while on ECLS may be warranted.