Pediatric airways grow along with the patient, so selection of tube size must be tailored to the patient’s age and size. Broselow tape or other weight-based pediatric resuscitation tools also have estimated ETT sizes but may not always be available. Multiple formulae have been proposed for pediatric ETT size selection, with (age/4) + 3.5 being the most widely used for cuffed tubes.
Derek Tam (Fri,) studied this question.