RT Journal Article SR Electronic T1 New decision formulas for predicting endotracheal tube depth in children: analysis of neck CT images JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP emermed-2017-206795 DO 10.1136/emermed-2017-206795 A1 Se Uk Lee A1 Jae Yun Jung A1 Do Kyun Kim A1 Young Ho Kwak A1 Hyuksool Kwon A1 Jun Hwi Cho A1 Joong Wan Park A1 Yoo Jin Choi YR 2018 UL http://emj.bmj.com/content/early/2018/02/05/emermed-2017-206795.abstract AB Introduction The purpose of this study was to construct a prediction model for endotracheal tube depth using neck CT images.Methods A retrospective image review was conducted that included patients who had undergone neck CT. Using sagittal neck CT images, we calculated the length between upper incisor and mid-trachea and then derived the model via regression analysis. The model was validated externally using chest radiographs of patients who had undergone endotracheal intubation. We compared performance of our model with that of other methods (Broselow tape and APLS formula) via Bland-Altman analysis and the percentage of estimations within 10% of the measured values.Results A total of 1111 children were included in this study. The tube depth obtained from CT images was linearly related to body weight (tube depth (cm)=5.5+0.5×body wt (kg)) in children younger than 1 year and to height (tube depth (cm)=3+0.1×height (cm)) in children older than 1 year. External validation demonstrated that our new model showed better agreement with the desired tube depth than Broselow tape and APLS formula. The mean differences in children younger than 1 year were 0.61 cm and −1.24 cm for our formula and Broselow tape, respectively. The mean differences in children older than 1 year were −0.43 cm, −1.98 and −1.64 cm for our formula, Broselow tape and APLS formula, respectively. The percentages of estimates within 10% of the measured values were 52.7% and 35.8% for our formula and Broselow tape in children younger than 1 year, respectively, and 54.3%, 33.8% and 37.2% for our formula, Broselow tape and APLS formula in children older than 1 year, respectively (P<0.01).Conclusion Our new formula is useful and more accurate than the currently available methods.