ULTRA-SONOGRAPHIC ESTIMATION OF ENDOTRACHEAL TUBE SIZE IN PAEDIATRIC PATIENTS UNDERGOING SURGERY IN PRONE POSITION: A PROSPECTIVE OBSERVATIONAL CLINICAL STUDY

Background: ETT is important in securing paediatric airway and its right size plays crucial role in paediatric patients. The airway anatomy in paediatric patients is different from adults hence requires precise ETT size. The subglottic diameter being the narrowest portion of upper airway, determines the ETT size. USG is safe, reliable, non-invasive tool used to estimate the narrowest subglottic diameter to estimate the correct ETT size. Conventional formulae included age and height. Concerns in prone position include accidental extubation,secretions, difficult airway access, increased abdominal pressure, increased FRC. Methods: Sixty patients in the age group 1-4 years posted for PSARP under GA were included in the study. USG guided ETT size was estimated and compared with conventionally estimated size. Results:The size of ETT predicted by USG was more appropriate than that estimated by physical indices(p<0.005). ETT size estimated by age-based formula was 2nd nearest to best fit tube. 65% patients were intubated in 1st attempt while 31.6% required 2nd attempt and 3.33% needed 3 attempts to get intubated with the best fit ETT. Conclusion:USG is useful and reliable screening modality in estimating appropriate ETT size especially in paediatric patients undergoing surgery even in prone position such as PSARP.