Sternomental distance ratio as a predictor of difficult laryngoscopy: A prospective, double-blind pilot study

Abstract

Background: No single test has shown to be an accurate predictor of difficult laryngoscopy. Aims: This study aims to evaluate the effectiveness of the ratio of the sternomental distance (SMD) in neutral and full neck extension position SMD ratio (SMDR) as a predictor of difficult laryngoscopy and any need of assisted intubation. Settings and Design: Prospective, double-blind pilot study. Materials and Methods: This study included 221 consecutive adult patients scheduled to undergo elective surgery under general anesthesia. Physical and airway characteristics, SMDR, difficult laryngoscopy (using Cormack/Lehane [C/L] scale), and any kind of assisted intubation were assessed. Statistical Analysis: The optimal cutoff point for SMDR was identified using receiver operating characteristic (ROC) analysis. The association between SMDR and the intubation method was evaluated through multiple logistic regression analysis. Results: A SMDR below 1.55 led in 33% of the cases to assisted intubation and 33%–53% of C/L III–IV glottic views for McCoy and Macintosh blades, respectively. On the other hand, SMDR above 1.9 led to no C/L IV glottic views for both blades and 4% and 11% C/L III views glottic views for McCoy and Macintosh, respectively. The best sensitivity and specificity cutoff point as defined by the ROC curve was identified for an SMDR value of 1.7 (area[s] under the curve: 0.815; 95% confidence interval: 0.743–0.887). Assisted intubation rates were significantly higher in patients with an SMDR inferior to 1.7 (30.5% compared to 3.5%, P < 0.001). Conclusions: SMDR is a simple, objective, and easy to perform test. The present study indicates that SMDR may be helpful in predicting difficult laryngoscopy and assisted intubation.

Predicting difficult laryngoscopy in morbidly obese Thai patients by ultrasound measurement of distance from skin to epiglottis: a prospective observational study

“…The anesthesiologists always need to prepare for difficult ventilation and intubation especially in morbid patients. Kopanaki et al [ 14 ] and Prakash et al [ 15 ] found that sternomental distance was one of conventional parameters of airway assessment. We found that thyromental distance and sternomental distance predicted difficult laryngoscopy among obese Thai patients.…”

Sternomental Displacement and Neck Circumference. A New Look for the Neck as a Difficult Airway Predictor in Obese Surgical Patients. A Cohort Study

“…The authors concluded that SMDD provides a rapid, simple, objective measure for predicting patients at risk of DLV. Another recent study conducted by Kopanaki E et al in 2020 19 included 221 surgical patients with a mean BMI of 27.1±5.1 kg/m 2 .…”

Predicting Difficult Laryngoscopy in Morbidly Obese Patients by Ultrasound of Distance from Skin to Epiglottis: A Prospective Observational Study

“…Hypoxic arrest is the worst complication which can be happened if we cannot secure the patients' airway even we follow the guidelines of Difficult Airway Society Guidelines (DAS) 14 and Practice guidelines for management of the difficult airway reported by American Society of Anesthesiologists(ASA). 15 Kopanaki et al 16 and Prakash et al 17 found that sternomental distance was one of conventional parameters of airway assessment to predict difficult laryngoscopy among obese patients. We found that thyromental distance and sternomental distance predicted difficult laryngoscopy among obese Thai patients.…”