The Correlation Between Severity of Postoperative Hypocalcemia and Perioperative Mortality in Chromosome 22q11.2 Microdeletion (22q11DS) Patient After Cardiac-Correction Surgery: A Retrospective Analysis

OBJECTIVES The aim of our study was to elucidate the association between severity of postoperative hypocalcemia and the prognosis of the patients with 22q11DS. METHODS Data retrospectively were collected from 23 children with 22q11DS who underwent cardiac correction surgery. Area under the receiver operating characteristic curve (AUC) and diagnostic odds ratio were calculated to determine the tendency of perioperative mortality rate, according to the minimum levels of serum calcium and the duration of hypocalcemia. A novel risk assessment system for perioperative mortality was established according to these valid parameters. RESULTS The death group had lower minimum levels of serum calcium and longer duration of hypocalcemia. The AUC of minimum levels of serum calcium was 0.912 (95% CI: 0.753-1; P = .003) and qualified its high accuracy for perioperative mortality. The AUC of duration of hypocalcemia was 0.804 (95% CI: 0.561-1; P = .03) and qualified its moderate accuracy. The tendency analyses also indicated the correlation between these two parameters and perioperative mortality. Based on the cut-off values from ROC analysis, a novel risk assessment system for perioperative mortality was established according to these two parameters. The patients with the lowest serum calcium level 90.33 hours would be sorted into a high-risk group; others were divided into a low-risk group. The diagnostic odds ratio for this assessment system was 143(95% CI: 5.13-3982.52). No significant difference was found with regard to patient age, weight, preoperative serum total calcium, cardiopulmonary bypass (CPB) time, and aortic cross-clamp time between the high- and low-risk groups. CONCLUSIONS The minimum levels of serum calcium and duration of hypocalcemia were valid predictors for preoperative mortality of 22q11DS patients.