Airway assessment before any type of anaesthesia is mandatory. Failure to maintain a patent airway after induction of anaesthesia leads to irrevocable catastrophic sequelae such as brain damage or death. Maintaining a patent airway is essential for adequate oxygenation and ventilation and failure to do so, even for a brief period of time, can be life threatening that significantly increases the morbidity and mortality of general anaesthesia. Ability to ventilate the patient with bag and mask is extremely important in the unfortunate scenario of inability to intubate. We find that intubation may be easy even though mask ventilation is difficult. There are many bed side tests to assess difficult airway and mask ventilation which are easy to perform and need no special equipment. But all these tests have limitations and no single one is complete. No single airway test can provide a high index of sensitivity and specificity for prediction of difficult airway. Therefore, it has to be a combination of multiple tests.

The primary aim of this study is to evaluate acromio-axillo-suprasternal notch index, upper lip bite test and ratio of height to thyromental distance for prediction of difficult mask ventilation and difficult intubation.