Prediction of optimal endotracheal tube cuff volume from tracheal diameter and from patient height and age: A prospective cohort trial

Abstract

Purpose Endotracheal tube intra-cuff pressure should be maintained between 20 and 30 cm H2O to prevent damage to the tracheal wall. However, cuff pressure is rarely measured, and clinicians estimate cuff pressure poorly. The goal of the present study was to predict the cuff volume that produces optimal cuff pressure either from tracheal diameter or from patient height and age. Methods In the development phase, initial cuff pressure and cuff volume were measured in 240 patients. Optimal cuff volume, defined as the volume halfway between the volumes required to produce cuff pressures of 20 and 30 cmH2O, was determined in each patient. Then, regression equations relating optimal cuff volume to tracheal diameter on chest X-ray, and between optimal cuff volume and a combination of height and age, were calculated. The primary outcome was the proportion of patients in a validation set (n = 104) who achieved a cuff pressure of 20-30 cmH2O when cuff volume was selected by each regression formula. Results Only 28 % of the cuffs were optimally inflated using clinical criteria during the development phase. There was good correlation between optimal cuff volume and tracheal diameter and moderate correlation between optimal cuff volume and both height and age. Predicted cuff volume was more likely to provide optimal cuff pressure when based on tracheal diameter (65 % of patients) than when based on both height and age (45 % of patients). Conclusions Optimal cuff volume was better estimated from tracheal diameter and patient height and age than from the manual palpation method. © Japanese Society of Anesthesiologists 2012.