Background and Objectives: Airway management is the fundamental responsibility of every anesthesia-logist. Difficult intubation is one of the major causes of anesthesia-related morbidity and mortality. The risk and complications related to difficult intubation can be reduced if difficult airway is anticipated preoperatively. There are many simple bed side tests to predict difficult intubation preoperatively. There are several studies comparing the different preoperative bedside tests in predicting difficult intubation with varying results. However, limited information is available on effect of combining these parameters in enhancing the preoperative prediction of a difficult airway

Aim: To assess the validity and efficacy of modified Mallampati test (MMT), sternomental distance (SMD), Thyromental distance (TMD) individually and in combination in predicting difficult intubation.

Methodology: This is an observational study, conducted in the department of Anaesthesiology Government Medical College Thiruvananthapuram, a tertiary care centre . 305 Patients aged between 18 to 65 years, undergoing elective major surgeries in Govt: Medical College Hospital, Thiruvananthapuram, Kerala, were selected as the study population. The airway was assessed by Modified Mallampati test (MMT), class III & IV were considered as difficult intubation. Thyromental distance (TMD) of every patient was recorded. A measurement of less than 6.5 cm was considered to be a predictor of difficult intubation. Sternomental distance (SMD) was measured and a measurement of less than 12.5cms was considered to be a predictor of difficult intubation.

A senior anesthesiologist with more than three years of experience assessed the laryngeal view by direct laryngoscopy using Cormack &Lehane grading during intubation. Grade 3 and 4 was considered difficult laryngoscopy and intubation.

The validity parameters such as sensitivity, specificity, false positive and negative values, positive predictive value (PPV) and negative predictive value (NPV) were calculated. The effect of combining different measurements on the validity was also studie

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Dr Madhusoodanan Pillai

Additional Professor, Department of Anaesthesiology,

Government Medical College Thiruvananthapuram