Clinical and echocardiographic risk factors for extubation failure in infants with congenital diaphragmatic hernia

Infants after surgical correction of congenital diaphragmatic hernia are at high risk for extubation failure, but little is known about contributing factors. Therefore, our study aimed to analyze clinical and echocardiographic parameters.

Data of 34 infants with congenital diaphragmatic hernia treated at our department (July 2013-December 2015) were analyzed. Inclusion criteria were: presence of congenital diaphragmatic hernia and echocardiography performed within 48 hours before the first, and, in case of reintubation, the final extubation attempt. Infants were allocated to group A (extubation failure) and group B (extubation successful).

Extubation failure occurred in 12/34 infants (35%). Infants in group A had a higher proportion of intrathoracic liver herniation (P = 0.001, OR 17 [2.8/104.5]) and lower rates of the lung-to-head ratio (P = 0.042, 95% CI [-0.4/20]), even as higher rates of extracorporeal membrane oxygenation (P = 0.001, 95% CI [2.7/80.9]). The oxygenation index and the PaO₂ /FiO₂ ratio differed significantly between both groups (both P = 0.000; 95% CI [-11/-4.1] and [79/215], respectively). The mean airway pressure and fraction of inspired oxygen prior to extubation was significantly higher in group A (P = 0.008; 95% CI [-3.9/-1.4]; P = 0.000; 95% CI [-0.6/-0.2], respectively). In addition, the respiratory severity score was higher in group A (P = 0.000; 95% CI [-7.3/-2.6]). In group A, administration of sildenafil and the vasoactive inotropic score were significantly higher (P = 0.037; OR 9 [0.9/88.6] and P = 0.013; 95% CI [-14/-1.8], respectively). More infants in group A had need for a surgical patch repair of the diaphragm (P = 0.017; OR 7.2 [1.3/41.1]) and showed higher rates of relevant pleural effusions prior the extubation (P = 0.021; OR 6 [1.2/29.5]). The total duration of the ventilation and the length of hospital stay were longer in group A (P = 0.004; 95% CI [-915/-190] and P = 0.000; 95% CI [-110/-39], respectively). The prevalence of pulmonary hypertension was more frequent in group A (P = 0.012; OR 12 [1.3/114]), the time to peak velocity in the main pulmonary artery was significantly lower in group A (P = 0.024; 95% CI [2/25.6]), and these infants suffered more often from cardiac dysfunction (P = 0.007; OR 10 [1.6/63.1]).

Our results demonstrate that extubation failure in infants with a congenital diaphragmatic hernia is associated with several clinical and echocardiographic risk factors.