Relationship between extubation failure and pulmonary arterial hypertension after corrective congenital heart surgery in children

Abstract

Objective: 1. To determine the relationship between extubation failure and postoperative pulmonary hypertension after congenital heart surgery. 2. To apply the result to the selective criteria for fast-track patients for better postoperative care. Setting: King Chulalongkorn Memorial Hospital. Method: A cohort study from April 2002 to January 2003 contained seventy five patients composed of 19 exposed and 56 non-exposed. The patients underwent surgical correction of the high pulmonary blood flow typed congenital cardiac abnormalities were enrolled in this study. The pulmonary arterial pressure was measured after the operation was finished. The exposed group were patients who had a mean pulmonary arterial pressure greater than 25. The extubation failure group were patients who had the endotracheal tube in place for more than 24 hours. The demographic characteristics i.e. age, gender, body weight, height and body surface area, intraoperative data i.e. cross clamp time, cardiopulmonary bypass time, pulmonary arterial pressure and extubation time were recorded. Result: The incidence of the extubation failure in the exposure group was 73.7% ( 14 in 19 patients) and in the unexposure group was 16.1% (9 in 56 patients). The relative risk (risk ratio) was 4.58 (95% CI = 2.38-8.84). The complex congeniatl defects group had relative risk of 7.24 to extubation failure. There was no strong correlation (highest Pearson?s correlation coefficient was 0.50) between pulmonary arterial pressure and other variables including intubated duration. The cardiopulmonary bypass time was positively correlated to the intubated duration (Spearman's rho = 0.647). The negatively correlated were found with body weight, height and body surface area (Spearman?s rho = -0.645, -0.634 and -0.638 respectively). The multivariate analysis using multiple logistic regression showed the odds ratio of 7.81, 1.05 and 13.24 for pulmonary hypertension, aortic cross clamp time and the complexity of the defects respectively. Conclusion: The postoperative pulmonary hypertension had a statistically significant to be a risk factor for extubation failure. Furthermore, the complexity of the defects, the aortic cross clamp time, the cardiopulmonary bypass time and the small size patient should be considered as risk factors to extubation failure as well.