A comparative study to evaluate different airway tests used to determine difficult intubation in adult patients in SMS medical college jaipur

Inadequate maintenance of a patient’s airway represents a major cause of anaesthesia related morbidity and mortality. The

prevalence of difficult laryngoscopic intubation is reported to range from 1.5 to 20% cases

Unanticipated difficult airway remains a major concern for anaesthesiologists due to serious consequences of failed

endotracheal intubation. The identification of patients with difficult airways is crucial during preoperative evaluations.

A variety of tests are used to evaluate potentially difficult airways in advance of the procedure . However, it is not clear

which test has best sensitivity to predict difficult airway.

Commonly used tests are Modified Mallampati test with tongue protrusion (MMT-TP), modified mallampati test without

tongue protrusion (MMT-NTP), inter incisor gap (IIG), thyromental distance (TMD), sternomental distance (SMD),

mandible protrusion test (MPT) for prediction of difficult intubation relative to the Cormack Lehane grading for

Laryngoscopic view.

Modified Mallampati Test (MMT) is the oldest bedside test that predicts difficult intubation by assessing mouth opening and

visibility of pharyngeal structure.

For predicting difficult intubations, the mandible protrusion test is well established and relatively simple grading system.

Thyromental distance is measured along a straight line from the thyroid cartilage prominence to the lower border of the

mandibular mentum with full head extension and mouth closed. It is a common method to predict difficult airways. The

smaller the TMD is, the greater the probability of a difficult airway Sternomental distance (SMD is an indicator of head

and neck mobility . IIG is a major single predictor for difficult airways. It reflects craniocervical extension, which is

restricted in cervical spondylosis patients

.