IV Calcium Use and Outcomes After Congenital Heart Surgery in Infants Under 6 Months Old: Three-Center Retrospective Cohort, 2020-2022.

OBJECTIVES

IV calcium is used frequently in the pediatric cardiovascular ICU (CVICU) for neonates and infants undergoing congenital heart surgery (CHS). Since critical illness is associated with abnormal cellular calcium handling and adverse effects induced by hypercalcemia, we aimed to: describe calcium use across three CVICUs; determine explanatory factors related to hypercalcemia and calcium administration; and evaluate associations with outcome.

DESIGN

Retrospective cohort analysis from January 2020 to December 2022.

SETTING

Three university affiliated CVICUs.

PATIENTS: Children younger than 6 months undergoing CHS receiving postoperative monitoring of ionized calcium (iCa).

INTERVENTIONS: None.

MEASUREMENTS AND MAIN

RESULTS

Average iCa for every 24-hour period was calculated from tests drawn during the first 72 hours after CHS. Of 276 infants evaluated, 119 (43%) were neonates, 62 (23%) underwent The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) category 4 and 5 surgery, and 44 (16%) had single ventricle physiology. Median (interquartile range) age was 50 days (8-113 d). IV calcium utilization differed between centers, with calcium administered in 21%, 62%, and 96% of cohorts ( p < 0.001) at respective hospitals. Hypercalcemia was more prevalent in neonates ( p = 0.02), patients with longer cardiopulmonary bypass times ( p = 0.02), and patients with higher postoperative Vasoactive-Inotrope Scores ( p = 0.001). Children receiving top 10% of total calcium administration (compared with those receiving some calcium and no calcium) were younger ( p < 0.001), experienced higher rates of cardiac arrest ( p = 0.02), longer CVICU length of stay (LOS; p < 0.001), and lower survival rates ( p < 0.001). In multivariable analyses, we failed to identify associations between hypercalcemia and receiving top 10% calcium administration with LOS or mechanical ventilation duration.

CONCLUSIONS

In 2020-2022, post-CHS calcium management in neonates/infants varied across our three CVICUs. Increased calcium administration and hypercalcemia occurred in high-risk populations (e.g., neonates, STAT ≥ 4 category). Future experimental designs are needed to better understand these relationships and optimize CVICU postoperative calcium management.