Randomised trial estimating length of endotracheal tube insertion using gestational age or nasal-tragus length in newborns: a study protocol

Introduction Endotracheal tube (ETT) insertion depth estimation is important for optimal placement of ETT tip and balanced ventilation of the lungs. Various methods are available to determine the ETT insertion depth. The Neonatal Resuscitation Programme recommends the gestational age and nasal-tragus length (NTL) methods for estimating ETT insertion depth during cardiopulmonary resuscitation. However, the prospective data comparing these two methods is lacking. Methods and analysis This is an open-label multi-centre randomised controlled trial, where gestational age and NTL methods will be used to determine the initial ETT insertion depth in term and preterm infants that are less than 28 days old, requiring oral intubation in the delivery room or neonatal intensive care unit (NICU). Sites and sample size The trial is aimed to recruit 454 infants over 3 years across tertiary level NICUs. Outcomes The primary outcome includes an optimally positioned ETT, defined as an ETT tip between the upper border of the first thoracic vertebra and the lower border of the second thoracic vertebra. The outcome is assessed by a paediatric radiologist, who will be masked to the group assignment. Secondary outcomes are malpositioned ETT tips, pneumothorax, ETT repositioning, chronic lung disease, invasive ventilation days, and death. Analysis Data will be analysed using the intention-totreat principle. The primary and categorical secondary outcomes will be compared using the chi(2) test. Adjusted risk ratios of outcomes will be calculated along with 95% Cls through multivariable logistic regression analysis, including covariates deemed biologically to influence the outcomes. Ethics and dissemination The study has been approved by the PNU Research Ethics Board (20-0148) and the respective ethical review boards of the participating centres. The results will be disseminated through conference meetings, social media platforms, and publications in scientific journals.