Perioperative Immunoglobulin Dynamics and Infection Risk in Infants Undergoing Congenital Heart Surgery: A Prospective Observational Cohort.

BACKGROUND

Infants with congenital heart disease (CHD) frequently undergo surgery during their first year of life. Infants undergoing CHD surgery experience systemic inflammation and hemodilution that can deplete circulating immunoglobulins (Ig).

METHODS

In this prospective single-center observational cohort study without healthy controls, we quantified IgG, IgA, and IgM at four perioperative time points (T0 = preoperative; T1 = 24 h; T2 = 72 h; T3 = day 7) in 300 infants (<12 months), including 280 with cardiopulmonary bypass (CPB) and 20 without CPB. Postoperative infections were defined using Centers for Disease Control and Prevention/National Healthcare Safety Network cardiothoracic criteria. Multivariable logistic and linear models assessed associations between Ig depletion, CPB characteristics, and clinical outcomes.

RESULTS

Mean IgG fell 23% at T1 (910 ± 160→700 ± 140 mg/dL, P < 0.001) and partially recovered by T3. Longer CPB was independently related to larger IgG decline ( β = 2.5% per 10 min, P < 0.001; R ² = 0.14). Infection occurred in 17% of infants and was associated with lower IgG at T1 (650 ± 135 vs. 725 ± 140 mg/dL, P < 0.001) and prolonged intensive care unit stay (median: 7 vs. 5 days, P < 0.01). Baseline IgG < 900 mg/dL (adjusted odds ratio [aOR]: 2.1), CPB > 120 min (aOR: 2.5), gestation < 37 weeks (aOR: 1.9), and surgical complexity (Risk Adjustment for Congenital Heart Surgery category ≥3; aOR: 1.8) independently predicted infection.

CONCLUSIONS

Substantial early postoperative IgG depletion correlates with infection risk and intensive care unit utilization after infant CHD surgery. Routine perioperative Ig monitoring may help stratify risk and identify candidates for Ig-based interventions.