Estimation of the optimum length of endotracheal tube insertion in adults

Abstract

IntroductionAn accurate estimation of the optimal length of endotracheal tube insertion can prevent complications such as endobronchial intubation, airway trauma and accidental extubation, all of which have a negative impact on patient safety and are associated with an increase in both morbidity and mortality. ObjectiveTo determine the optimal insertion length of endotracheal tubes in female and male adults according to their height. Materials and MethodsA cross-sectional analytical study conducted with 516 adult ASA I-II female and male patients who had different surgical procedures requiring endotracheal intubation. The mouth-carina distance was obtained using a flexible fiberoptic bronchoscope. The data analysis was performed using the SPSS 15.0 software. ResultsHeight and mouth-carina distance showed a direct and statistically significant correlation. Two equations for estimating optimal endotracheal insertion length were obtained, according to sex: men=11.413+(0.072×height in cm)−3; and women=13.555+(0.056×height in cm)−3. ConclusionThe traditional method of determining the insertion length of the endotracheal tube, 21cm for women and 23cm for men, shows a high incidence of endobronchial intubations in the analyzed population. The optimal insertion depth of the endotracheal tube can be reliably estimated through the use of prediction equations based on patient height, as proposed in this study.