Comparison of Acromio-Axillo-Suprasternal Notch Index (AASI) with Hyomental Distance Ratio Test (HMDR) in Predicting Difficult Visualization of the Larynx.

Background: Safe airway management during anesthesia induction is a challenging issue. Airway-related morbidity can be prevented by carefully evaluating patients and formulating a difficult airway management strategy. The purpose of this study is to investigate and compare two indices, AASI, and HMDR, in predicting difficult laryngoscopic visualization.

Materials and methods: Six hundred and twenty-two patients, who entered the operating room for any type of elective surgery and were candidates for general anesthesia, underwent AASI and HMDR measurements after filling out a questionnaire containing personal information, oral examinations, and history of illness or surgery before anesthesia prescription. The Cormack grade was recorded during laryngoscopy, and finally, the predictive value of the two methods was compared.

Results: Based on analysis, AASI has a higher specificity than HDMR (87.5% vs. 76.1%) and the positive predictive value of AASI is 97%. Therefore, both HMDR and AASI are valid and significant indicators for predicting difficult laryngoscopy.

Conclusion: AASI has a better diagnostic profile than HMDR regarding sensitivity and positive predictive value, Additionally, AASI is more convenient to use because it is simpler and visually predictable, making it a reliable clinical predictor.