Risk Factors Associated with Prolonged Mechanical Ventilation after Corrective Surgery for Tetralogy of Fallot

Introduction. This study examined early postoperative results to identify perioperative factors that are associated with prolonged mechanical ventilation (PMV) in tetralogy of Fallot (TOF) patients undergoing corrective surgery. Methods. We retrospectively examined the role of perioperative variables in determining the period of mechanical ventilatory support in TOF patients undergoing corrective surgery. A total of 821 patients were included in the study. The cohort was divided into a PMV group that included patients with >90th percentile for duration of mechanical ventilation and a non-PMV group which included all other patients. Results. Non-PMV group consisted of 751 patients (454 males, 297 females; median age 12 months, interquartile range 8-19 months; mean weight 9.60 +/- 2.98 kg). PMV group consisted of 70 patients (51 males, 19 females; median age 8 months, interquartile range 6.75-13 months; mean weight 8.64 +/- 1.95 kg). No patients died in the non-PMV group compared with two deaths due to acute respiratory distress syndrome in the PMV group. Univariate risk factors for PMV included age, weight, left ventricular end-diastolic volume index (LVEDVI), McGoon ratio, Nakata index, previous palliative operations, cardiopulmonary bypass (CPB) time, aortic cross-clamp (ACC) time, preoperative major aortopulmonary collateral arteries (MAPCAs) occlusion by coils in hybrid procedure, postoperative right ventricular/left ventricular systolic pressure ratio, central venous pressure (CVP), left atrial pressure (LAP), endotracheal reintubation, vasoactive-inotropic score (VIS), renal replacement therapy, and early-onset ventilator-associated pneumonia (VAP). In a multivariable model, age, LVEDVI, McGoon ratio, Nakata index, previous palliative operations, CPB time, blood returning to left atrium during surgery as a surrogate marker for significant aortopulmonary collateral presence, and early-onset VAP were the independent risk factors for PMV. Conclusions. The risk factors for PMV were age, LVEDVI, McGoon ratio, Nakata index, previous palliative operations, CPB time, VIS, LAP, blood returning to left atrium during surgery, and early-onset VAP.