Accuracy Comparison between Four Methods of Endotracheal Tube Diameter Estimation for Pediatric Patients: An Observational, Cross-sectional Study

Background: Successful intubation with the correct endotracheal tube (ETT) size is more difficult to achieve in pediatric patients. Several estimation methods exist, including ultrasonography and several conventional methods, but it is unclear which would be the most accurate method. Thus, this study aimed to compare the accuracy between several ETT diameter estimation methods. Materials and Methods: This was an observational study with a cross-sectional design. The sample includes pediatric patients (0–6 years) at a tertiary hospital recruited from January 2022 to March 2022. Primary data evaluated included age, gender, height, weight, actual ETT size used in the procedure, and the estimation of ETT size obtained by four different methods: ultrasonography, little finger diameter, little fingernail width, and age-based formula. Primary analysis was linear regression test between estimated diameter and the actual ETT diameter used in the procedure, controlling for potential confounders. The accuracy of each ETT size estimation method was seen from the values of the B and R2 coefficients from the linear regression test results. Results: Ultrasonography was found as the most accurate method, with B and R2 coefficients of 0.963 and 0.991, respectively. Among conventional methods, the diameter of the little finger was the most accurate (B = 0.918, R2 = 0.772). The age-based formula method was found to be the least accurate (B = 0.797, R2 = 0.735). Conclusion: Linear regression tests confirmed that the ultrasonography was the estimation method with the highest accuracy. For healthcare facilities with limited resources, the estimation method with little finger diameter should be considered.