Evaluation of distal radius epiphyseal diameter as a predictor of endotracheal tube size in paediatric patients

My study is aimed to evaluate the role of distal radius epiphysis diameter as a predictor of appropriate endotracheal tube size in paediatric patients.All children will undergo preanaesthetic checkup and cases included in study according to inclusion and exclusion criteria.Premedication will be given using nasal dexmedetomidine.Baseline parameters will be recorded after shifting them to operation theatre.Inhalational or intravenous induction of general anaesthesia will be carried out.Intravenous vecuronium will be used to facilitate muscle relaxation.After  three minutes,the first trial of intubation will be carried out using an uncuffed endotracheal tube which will be selected according to the age based formula.And then monitor the air leakage over the larynx using sthethoscope.If a leak occur at an airway pressure of less than 10cm H2O when the lungs are inflated or no audible leak at airway pressure more than 25cm H20 change ETT 0.5mm ID bigger or smaller respectively.Then the childs hand will be examined using a portable ultrasound device.The epiphyseal transverse diameter of the distal radius,the 3rd proximal phalanx,and the 5th proximal phalanx will be estimated.Circumferences of the wrist and the finger at the level of the 3rd and the 5th proximal phalanx will also be measured.