Predictive value of bronchoscopy after infant cardiac surgery: a prospective study

Abstract

Airway evaluation following infant cardiac surgery often reveals evidence of tracheobronchial narrowing. We studied the association between airway narrowing and extubation failure (EF) in this population. Prospective cohort study of infants (age ≤6 months) from March-September 2009. Flexible bronchoscopy (FB) evaluations were obtained using a standardised protocol after operative intervention. The primary endpoint was the development of extubation failure (EF; defined as the need for invasive mechanical ventilation ≤48 h after primary extubation) and several secondary endpoints. Fifty-three patients were evaluated at a median age of 81 [interquartile range (IQR) 13-164] days and weight of 4.2 (IQR 3.2-6.0) kg; 13 (25 %) of the patients had single ventricle palliations and two subsequently underwent heart transplantation. Significant airway narrowing was noted in 15 of 30 [50 %, 95 % confidence interval (CI) 31-69 %] patients who underwent FB; ten of the 53 patients (19 %, 95 %CI 10-32 %) subsequently developed EF. Narrowed airway calibre on bronchoscopy had a sensitivity and specificity of 50 % (95 %CI 28-71 %) and 50 % (95 %CI 28-71 %), respectively, for EF. The single greatest predictor of EF by univariate analysis was the need for preoperative ventilation [odds ratio (OR) 6.5, 95 %CI 1.3-33.2, p = 0.03]. Patients with EF had a greater likelihood of intensive care readmission (OR 4.8, 95 %CI 1.1-21, p < 0.04) during the same hospital admission. Airway narrowing on FB is noted frequently after infant cardiac surgery. Overall assessment and presence of narrowing on bronchoscopy had poor sensitivity and specificity for EF in our cohort. Expert assessment of tracheobronchial narrowing on FB has poor to moderate inter-rater reliability.