Preoperative ultrasonographic evaluation of the airway vis-à-vis the bedside airway assessment to predict potentially difficult airway on direct laryngoscopy in adult patients—a prospective, observational study

Chhabra, Anita Rajeev; Thannappan, Sindhuja; Iyer, Hemalata R.

doi:10.1186/s42077-022-00297-0

Preoperative ultrasonographic evaluation of the airway vis-à-vis the bedside airway assessment to predict potentially difficult airway on direct laryngoscopy in adult patients—a prospective, observational study

Authors

10.1186/s42077-022-00297-0

Abstract

Background
Unanticipated difficult airway remains a challenge for the anesthesiologist with no established standard criteria to predict difficulty in intubation. Our aim was to correlate the pre-anesthetic ultrasonographic (USG) airway assessment parameters with Cormack-Lehane (CL) grade at direct laryngoscopy view under general anaesthesia.
Results
The incidence of difficult laryngoscopy was 22.7%. The sonographic distance from anterior neck surface to epiglottis (ANS-E) > 1.67 cm was observed to be a statistically significant USG predictor of difficult laryngoscopic view with sensitivity of 64.71% and specificity of 78.45% ( = 0.000). The sonographic distance from anterior neck surface to hyoid bone (ANS-H) or to anterior commissure (ANS-AC) did not corelate with difficult laryngoscopy. The ultrasound (US) parameters had higher negative than positive predictive value.
Conclusions
We found ANS-E distance to be the most significant predictor of difficult laryngoscopy in our study. USG is a useful tool to identify the “at-risk” patients for difficult airway.

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