Intraoperative and postoperative risk factors for prolonged mechanical ventilation after pediatric cardiac surgery

Background: Early extubation after cardiac surgery in children is feasible; however, predictors of prolonged mechanical ventilation (MV) should be recognized as soon as possible. Methods: At a tertiary pediatric cardiac center, prospective case series analyses were carried out with a total of 411 patients within 1 year of cardiac surgery. Perioperative factors were evaluated for strength of association with duration of MV > 61 h (medium, MMV) and > 7 days (long, LMV). Two multiple regression models were performed for both cut-off points: one model considered factors identified until 24 h postoperation, the other was performed with all parameters. Results: One hundred and three patients (25%) were still intubated after 61 h; 38 patients required LMV and they occupied 33% of total intensive care unit (ICU) bed days. If factors occurring until 24 h after surgery were analyzed, duration of cardiopulmonary bypass (CPB), intraoperative transfusion, post-CPB arterial oxygen tension (PaO2/FiO(2)), and fluid intake on the first day were found to be associated with MMV. Urea nitrogen value, nitric oxide treatment, delayed sternal closure, and tracheobronchomalacia, measured at the same point of time, were independent predictors of LMV. Of all the studied clinical predictors, MMV was associated with pulmonary hypertensive events, delayed sternal closure, peritoneal dialysis, nonvascular pulmonary problems, low output syndrome and fluid intake, while urea nitrogen (24 h), postsurgical neurological events, nitric oxide, tracheobronchomalacia, pulmonary hypertensive events and cardiac reoperations were identified as determinants of LMV. Conclusions: Causes of MV after surgery are heterogeneous, vary with time, and have variable impact on the duration of MV.