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

Abstract

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.

Keywords: Airway Extubation; Cardiac Surgery; Mechanical Ventilation; Postoperative Care; Risk Factors; Tetralogy of Fallot.