Characteristics and Hemodynamic Effects of Extubation Failure in Children Undergoing Complete Repair for Tetralogy of Fallot

This study aimed to identify the prevalence, etiology, and outcomes of extubation failure in children after complete repair for tetralogy of Fallot at a single tertiary-care, academic children’s hospital. The secondary aim of this study was to determine the cardiorespiratory effects of the transition from positive-pressure ventilation to spontaneous breathing in children with extubation success and extubation failure. For this study, extubation was defined as the need for reintubation within 96 h after extubation. Demographics as well as pre-, intra-, post-, and periextubation data were collected in a retrospective observational format for patients who underwent complete repair for tetralogy of Fallot during the period January 2001–June 2011. Patients with multiple aortopulmonary collateral arteries or associated complete atrioventricular septal defects were excluded from the study. The cardiorespiratory variables collected before and immediately after extubation included heart rate, respiratory rate, mean arterial blood pressure, central venous pressures, near-infrared spectroscopy, oxygen saturations, and lactate levels. The clinical outcomes evaluated included the success or failure of extubation and the hospital length of stay. Descriptive and univariate statistics were used to compare the group with extubation failure and the group with extubation success. Extubation failure occurred for 7 % (12/164) of the 164 eligible patients during the study period. The median age of the patients at surgery was 200 days (range 98–356 days), and their median weight was 6.8 kg (range 5.2–8.5 kg). For 6 % (10/164) of the patients, intubation was performed before surgery. The median duration of mechanical ventilation was 33 h (range 19.5–73 h), and the median hospital stay was 10 days (range 7–15 days). Of the 12 patients with extubation failure, 2 had extubation failure in first 2 h after extubation, 6 had failure in 2–24 h, 3 had failure in 24–48 h, and 1 had failure in 48–96 h. The patients in the extubation success and extubation failure groups were similar in age, sex, and body weight at the time of surgery. All preexisting conditions also were similar in the two groups. The intraoperative variables and postoperative complications did not differ between the two groups. The hospital stay was longer for the children with extubation failure (p < 0.001). The partial pressure of oxygen in arterial blood (PaO₂), tachycardia, mean arterial blood pressure, and inotrope score improved significantly at conversion from positive-pressure ventilation to spontaneous ventilation in the patients with extubation success. This study demonstrated that extubation failure in patients after complete repair for tetralogy of Fallot is low and that the etiology is diverse. The majority of extubation failures in these patients occurred in the first 24 h. Extubation success in the children after repair for tetralogy of Fallot was associated with improvement in PaO₂, tachycardia, and mean arterial pressure, with a decrease in inotrope score. Extubation failure is associated with a longer hospital stay.