Formula-based calculation of the tube size for preclinical emergency medicine

Incorrect placement of the endotracheal tube in newborns and infants following unilateral ventilation and accidental extubation may lead to deleterious consequences, such as volutrauma or hypoxia. The aim of the present study was to identify and compare the published formulas in order to estimate the correct endotracheal tube placement in children. Aim of the present study was to identify and compare the published formulas by searching PubMedA (R) and MEDLINEA (R) in order to estimate the correct endotracheal tube placement in children. Formulas on oro- and nasotracheal intubation depth were discussed. Formulas published for newborns and infants were presented separately. The keywords paediatric/pediatric, anaesthesia/anesthesia, anaesthesiology/anesthesiology, endotracheal tube, placement, position, length, depth and insertion were used. Publications and formulas were assessed and classified by two independent colleagues. In the specified timeframe, a total of N = 806 publications were reviewed, of which 16 were considered relevant. 13 different formulas could be identified: for children from 1-16 years we found six age-related formulas and one formula based on the patient's weight. For newborns and infants we found four formulas using the patient's weight and one formula using the patient's length. One formula was based on the gestational age. Publications and formulas were assessed and classified by two independent colleagues. Among the formulas based on age, an exact match of both groups was seen in only 81 %, both for oro- and for nasotracheal intubation. For prehospital pediatric emergencies, no universal and all-embracing formula can be recommended. Only one formula based on the gestational age seems to have substantial impact. Especially for decisions that have to be taken under time pressure, a reliably implementable formula is indispensable