Extubation failure after Norwood procedure in hypoplastic left heart syndrome patients

Hypoplastic left heart syndrome (HLHS) is the main cause of mortality due to congenital heart disease. The Norwood surgery is the first procedure of the surgical staging process towards a single ventricle physiology or Fontan-type operation and has a mortality rate of 10% to 30%. Extubation failure during the postoperative period occurs in up to 18% of these patients and is associated with increased mortality. Objective: To describe extubation failure rates and risk factors in pediatric patients with HLHS who underwent Norwood procedure. Patients and Method: Case-control study that included all the patients with HLHS managed with Norwood surgery at the Hospital Clinico de la Pontificia Universidad Catolica between January 2000 and February 2018. Cases and controls were defined as patients with extubation failure and as patients without this complication, respectively. The following variables were recorded demographic, surgical, and post-surgical ones, and univariate and multivariate analyses (logistic regression) were performed to determine risk factors associated with extubation failure. Results: Out of 107 patients, 26 of them presented extubation failure (24.3%). In the univariate analysis, longer mechanical ventilation time during the postsurgical period, atelectasis, pleural effusion, chylothorax, other respiratory morbidities (i.e. apneas and tracheitis), and longer infusion times of morphine and midazolam, all were associated with a higher extubation failure rate in this population. In the multivariable analysis, chylothorax, other respiratory comorbidities, and longer infusion time of midazolam remained associated with this complication, however, it was not associated with higher mortality. Conclusions: Chylothorax, respiratory comorbidities, and longer use of Midazolam should be addressed before planning airway extubation in order to avoid failure.