Factors influencing the accuracy of ETT size prediction in children with CHD: A pilot study

Induction and intubation for pediatric patients with congenital heart defects (CHD) should be conducted with careful measures to avoid any complications due to anesthetic drugs. Proper endotracheal tube (ETT) size is essential to avoid reintubation. The aim of this study is to analyze factors affecting the accuracy of uncuffed ETT size prediction in paediatrics with CHD. This observational-analytic study included seventeen patients aged 0-8 years with CHD underwent general anesthesia with tracheal intubation. Subjects were classified as cyanotic or acyanotic heart disease. The ETT size was predicted by Cole's formula. The accuracy of prediction was analyzed according to age, body weight, height and type of CHD. The prediction of ETT size was accurate in 53% of the subjects. The prediction was inaccurate in 63% of cyanotic subjects, while only 16.7% of acyanotic subjects. Univariate analysis for all variables showed there was no significant factor to affect the accuracy of ETT size prediction. The smallest p value was subject's height. Height has a 69.8% affecting factor to predict the accurate ETT size. Thus, age, body weight, height and type of CHD are not statistically significant factors to affect the accuracy of ETT size prediction. But, height gives a better prediction to the accuracy of ETT size.