Serum albumin perturbations in cyanotics after cardiac surgery: Patterns and predictions

Abstract

Introduction: Hypoalbuminemia is a well-recognized predictor of general surgical risk and frequently occurs in patients with cyanotic congenital heart disease (CCHD). Moreover, cardiopulmonary bypass (CPB)-induced an inflammatory response, and the overall surgical stress can effect albumin concentration greatly. The objective of his study was to track CPB-induced changes in albumin concentration in patients with CCHD and to determine the effect of hypoalbuminemia on postoperative outcomes. Materials and Methods: Prospective observational study conducted in 150 patients, Group 1 ≤18 years (n = 75) and Group 2 >18 years (n = 75) of age. Albumin levels were measured preoperatively (T1), after termination of CPB (T2) and 48 h post-CPB (T3). Primary parameters (mortality, duration of postoperative ventilation, duration of inotropes and duration of Intensive Care Unit [ICU] stay) and secondary parameters (urine output, oliguria, arrhythmias, and hemodynamic parameters) were recorded. Results: The albumin levels in Group 1 at T1, T2, and T3 were 3.8 ± 0.48, 3.2 ± 0.45 and 2.6 ± 0.71 mg/dL; and in Group 2 were 3.7 ± 0.50, 3.2 ± 0.49 and 2.7 ± 0.62 mg/dL respectively. All patients showed a significant decrease in albumin concentration 48 h after surgery (P < 0.01). Analysis between the groups, however, showed no statistical difference. Eleven patients expired during the study period, and nonsurvivors showed significantly lower serum albumin concentration 48 h after surgery 2.3 ± 0.62 mg/dL versus 3.7 ± 0.56 mg/dL in the survivors (P < 0.05). Receiver operating characteristic curve showed that a baseline albumin cut-off value of 3.3 g/dL predicts mortality with a positive predictive value 47.6% and a negative predictive value of 99.2% (P < 0.05). A strong correlation was seen between albumin levels at 48 h with duration of CPB ( r2 = 0.6321), ICU stay ( r2 = 0.7447) and incidence of oliguria ( r2 = 0.8803). Conclusions: The study demonstrated similar fall in albumin concentration in cyanotic patients (both adult and pediatric) in response to CPB. Low preoperative serum albumin concentrations (<3.3 g/dL) can be used to identify and prognosticate subset of cyanotics predisposed to additional surgical risk.

Keywords

• Albumin; Cardiac biomarkers; Cardiopulmonary bypass; Cyanotic congenital heart disease; Prognosis; Risk-prediction; Tetralogy of Fallot