Abstract PR261

Abstract

Background & Objectives: Having proper size of endotracheal tube (ETT) is crucial in pediatric patients. The practice of using age-based formulas to calculate the ETT size is easy, practical and commonly used today. However, the incidence of inappropriate tube size is still judicious, hence increasing risk from changing tube such as trauma and aspiration. This study was aimed to proof that selecting ETT size using ultrasound measurement of subglottic diameter is a reliable method and lead to less frequency of changing tube size than age-based formula. Materials & Methods: Ninety-three patients, aged between 1-6 years with normal airway anatomy whom undergoing elective surgery under general anesthesia with endotracheal intubation were enrolled and randomized into 2 groups. Group F (n=46),was using modified Cole formula to select ETT size,and group US (n=47) was using ultrasound measurement of subglottic diameter to select the ETT size Proper tube size was clinically determined by leakage at airway pressure of 20-25 cmH2O. Both groups were measured transverse subglottic diameter in supine position at apnea, inspiratory pressure(IP) 10 cmH2O and 20 cmH2O before intubation to find correlation with outer diameter of the proper ETT. Results: The incidence of inappropriate ETT size led to changing ETT in formula group was 47.8% (n=22/46), whereas in US group was 21.3% (n=10/47) which was significantly different (p<0.01). Using US measured at transverse cricoid diameter in all 93 patients (at apnea, inspire pressure 10 and 20 cmH2O) before intubation in each patient compared with the outer diameter of final proper ETT size. The Intraclass correlation coefficacy three phase of US measurement had strong relationship with OD of proper ETT (The value of intraclass correlation coefficiency at apnea= 0.9 IP 10 cmH2O = 0.85 IP 20 cmH2O =0.8) The mean time of ultrasound measurement of the airway was 78.25 (±31.9) seconds. There was no complication occurred during the studies in both groups. Conclusion: Using ultrasound measurement of the subglottic diameter to guide the selection of ETT size reduced the need to change ETT size by providing more appropriate size than age based formula in anesthetized paediatric patients. Disclosure of Interest: None declared