COMPARISON OF ACROMIOAXILLOSUPRASTERNAL NOTCH INDEX WITH ULTRASOUND PARAMETERS AND CORMACK LEHANE GRADING FOR PREDICTING DIFFICULT INTUBATION

Abstract

Background: Acromioaxillosuprasternal notch index (AASNI) and ultrasound ratio of pre epiglottic space and distance between epiglottis to midpoint of vocal cord (Pre-E/E-VC) are relatively new indicators for difficult laryngoscopy and intubation. Our aim was to compare AASNI with ultrasound ratio (Pre-E/E-VC) preoperatively for assessing difficult intubation.
Methods: This analytical cross-sectional study was done with 100 patients undergoing elective surgery requiring general anesthesia with endotracheal intubation. Sample size calculated based on Yamane equation was 100. Amongst these 99 patients met the inclusion criteria. Preoperatively Acromioaxillosuprasternal notch index and ratio of pre epiglottic space and distance between epiglottis to midpoint of vocal cord (Pre-E/E-VC) (ultrasound ratio) were determined. Cormack lehane grading was done with laryngoscopy once general anesthesia was established.
Results: Difficult laryngoscopy (Cormack lehane grade III &IV) was found in 26 patients. AASNI had better sensitivity (92.31%) compared to ultrasound ratio (Pre-E/ E-VC) (84.62%). But in terms of specificity both had little difference (AASNI – 97.26% & USG ratio (Pre-E/ EVC) – 95.89%). AASNI was more accurate when compared to ultrasound ratio (Pre-E/ E-VC) (95.96% v/s 92.93%).
Conclusion: AASNI proved to be a better predictor of difficult intubation when compared to ultrasound ratio