NC/TMD Ratio As a Difficult Airway Predictor in Obese Patients

Neck Circumference to Thyromental Distance Ratio As a Reliable Indicator for Predicting Difficult Intubation in Obese Patients for Elective Surgery Under General Anesthesia

To assess accuracy of NC/TM distance ratio in terms of sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) for predicting difficult intubation in obese patient with Intubation difficulty score (IDS) as gold standard.

At Preanaesthesia clinic patients , neck circumference to Thyromental distance ratios of obese patients with BMI >30Kg/m2 will be calculated and patients will be divided into two groups on the basis of Nc/TMD ratio as anticipated easy intubation ( NC/TMD<5) And anticipated difficult intubation ( NC/TMD ≥5).

Intra-operatively, patients Intubation difficulty scale score will calculated and the data obtained from IDS score will be compared with NC/TMD ratio as a predictor of difficult Intubation and diagnostic accuracy of NC/TMD as a reliable indicator of difficult intubation in obese patients will be calculated by statistical analysis.

Inclusion Criteria:

1. ASA physical status I to III
2. Body Mass Index (BMI) of 30kg/m2 or more
3. age 18-65 years

Exclusion Criteria:

1. non consenting
2. ASA class greater than III,
3. patients undergoing general anesthesia without tracheal intubation or under regional anesthesia,
4. patients with upper airway pathology such as maxillofacial fractures, upper airway tumors or cervical spine fracture, obstetric patients, refusal of the patient, previous head and neck surgery or radiotherapy.