Ohashi N, et al. - Determination of the appropriate tracheal tube size using formulas based on age or height often is inaccurate in pediatric patients with congenital heart disease (CHD), particularly in those with high pulmonary arterial pressure (PAP). A comparison of tracheal diameters between pediatric patients with CHD with high PAP and low PAP revealed larger tracheal diameters among those with high PAP vs those with low PAP. Pediatric patients with high PAP needed larger tracheal tubes compared with the size predicted using formulas based on age or height.