Does the endotracheal tube insertion depth predicted by formulas in children have a good concordance with the ideal position observed by X-ray?

ABSTRACT Objective: To evaluate the effectiveness of the different formulas for estimating the insertion depth of an endotracheal tube in children. Methods: This was an observational and cross-sectional study that included children between 29 days and 2 years of age who were hospitalized in a pediatric intensive care unit and mechanically ventilated. The formulas based on height [(height/10) + 5], the inner diameter of the tube (endotracheal tube × 3), and weight (weight + 6) were evaluated to determine which of them showed better concordance with the ideal insertion depth of the endotracheal tube as evaluated by X-ray. Results: The correlation between the height-based calculation and the ideal depth observed on X-ray was strong, with r = 0.88, p