A Study To Evaluate Neck Circumference To Thyromental Distance Ratio To Predict Difficult Intubation In Patients Scheduled For Elective Surgeries Under General Anaesthesia

Abstract

Background: A comprehensive airway assessment requires an understanding of the anatomical features of the neck and upper airway. Accurately predicting a potentially difficult airway is a multifactorial challenge, dependent on patient-related factors, clinical context, and the anesthesiologist’s proficiency. Failure to anticipate a difficult airway remains a common cause of anesthesia-related complications.

The objective: To evaluate the relationship between the neck circumference to thyromental distance ratio (NC/TMD) and the incidence of difficult intubation in adult patients scheduled for elective surgeries under general anesthesia.

Methods. This study included 100 patients undergoing elective surgeries under general anesthesia with endotracheal intubation of ASA grades I and II. Patients were examined preoperatively and intraoperatively. Data collection using the patient proforma which includes the demographic data, body mass index (BMI), ratio of NC/TMD, thyromental distance (TMD), and Modified Mallampati Test (MMT). Statistical software (SPSS 20.0) was used for statistical analyses of the data.

Results: The current study examines the efficacy of the neck circumference/ thyromental distance ratio (NC/TM distance ratio) in comparison to the Mallampati score and neck circumference as more reliable indicators for predicting difficult intubation.

Conclusion: The NC/TMD ratio is a simple, effective, and non-invasive predictor of difficult intubation. It demonstrates superior sensitivity and specificity compared to MMG and NC alone. Routine incorporation of this measurement in preoperative airway assessment could improve anesthesia outcomes.