INTRODUCTION: The aim of this study is to test the usefulness of epiphysis of distal radius measurement as a surrogate parameter for endotracheal tube (ETT) size prediction in children. METHODS: Seventy-three children were intubated with cuffed ETT selected according to age-based formula. Transvers diameter of epiphysis of distal radius and subglottic diameter of trachea were measured by ultrasound (US). Correlation between the outer diameter of best-fit endotracheal tube and transvers diameter of both radius epiphysis and subglottic diameter were calculated. The need for tube exchange, time for ultrasound (US) measurements and the ease level of measurements were compared. RESULTS: First attempt success at intubation was 83.6%. The correlation of the epiphysis diameter of the distal radius and best-fit ETT was significant (p<0.001, r= 0.619, r2=0.383, 95% CI=0.419-0.838). Similarly the correlation of subglottic tracheal diameter and best-fit ETT was significant (p<0.001, r=0.744, r2=0.553, 95% CI=0.678-825). Estimated ETT sizes according to radial epiphysis diameter and subglottic diameter were optimal in 82.2% and 94.5% respectively. Time for the US measurements of radial epiphysis and subglottic area were 38.3±9.6 and 24.9±4.6 seconds respectively (p<0.001). The level of ease of US measurements were rated for radial epiphysis as 6 (5-9) and for subglottic area as 8 (7-9) (p<0.001). DISCUSSION AND CONCLUSION: US measured transverse diameter of distal radius epiphysis resulted in similar success rate to age-based formula in our child population. Subglottic diameter measured by US estimates ETT size more accurately; it is also less time consuming and easier.
The accuracy of ultrasound to predict endotracheal tube size for pediatric patients with congenital scoliosis