Risk factors prolonging ventilation in young children after cardiac surgery: Impact of noninfectious pulmonary complications

Objective To determine risk factors for prolonged ventilation after cardiac surgery in young children and assess the impact of noninfectious pulmonary complications on ventilatory duration. Design Retrospective case series analysis. Setting A tertiary pediatric cardiac center. Patients Clinical records of 222 consecutive children aged ≤3 yrs undergoing cardiac surgery for congenital heart disease were reviewed. Fifteen patients, consisting of six premature babies and nine who died within 72 hrs of surgery, were excluded. Measurements and Main Results The demographic data, preoperative risk factors, surgical procedures performed, intraoperative variables, and postoperative complications of the remaining 207 children were reviewed. Univariate analysis was performed to compare patients who required prolonged ventilation (>72 hrs) to those who could be extubated at ≤72 hrs, and multivariate analyses were performed to identify significant determinants on ventilatory duration and impact of noninfectious complications. Of the 182 patients undergoing open heart surgery, 45 (25%) required prolonged ventilation for a median of 8 days. The latter were significantly younger in age and lighter in weight and were more likely to have Down syndrome, preoperative pulmonary hypertension and ventilatory support, undergone more complex surgery requiring longer bypass and circulatory arrest time, postoperative cardiovascular and pulmonary complications, and extubation failure (all p values <.01). Of the 25 patients who had closed heart surgery, five (20%) required prolonged ventilation for a median of 14 days. The latter were more likely to require preoperative ventilation, have undergone more complex surgery, had postoperative cardiovascular and pulmonary complications, and had extubation failure (all p values <.05). Cox proportional hazard regression identified body weight (p < .001), Down syndrome (p = .02), need for preoperative ventilation (p < .001), complexity of surgery (p < .001), cardiovascular complications (p < .001), and infective (p < .001) and noninfective (p < .001) pulmonary complications to be significant factors that determined the ventilatory duration. Noninfectious pulmonary complications occurred in 31.9% (58/182) and 20% (5/25) of patients after open and closed heart surgery, respectively. In the absence of other risk factors, the median time to extubation was similar between patients with and without noninfectious complications (1 vs. 0.8 day). However, in the presence of other risk factors, noninfectious pulmonary complications prolonged the median time to extubation from 8 to 18 days. Logistic regression identified Down syndrome (p = .005), preoperative ventilation (p = .001), complexity of surgery (p = .006), and bypass time (p = .005) as risk factors for development of noninfectious pulmonary complications. Conclusions Noninfectious pulmonary complications that occurred commonly after cardiac surgery in young children prolong ventilatory duration only in the presence of other risk factors, with which it acts in a synergistic fashion.