TMHT - New Method of Difficult Intubation Prediction

Proper prediction of the occurrence of difficult intubation plays a crucial role in anaesthesiology. For years attempts have been made to develop methods allowing anaesthesiologists to correctly predict the occurrence of difficult intubation. None of the currently used tests and anthropometric measurements present satisfying predictive value. Recent studies show promise in Thyromental Height Test (TMHT), which base on the height between the anterior borders of the mentum and the thyroid cartilage, measured while the patient lies in the supine position with closed mouth, as a single, non-invasive predictor of difficult intubation. Use of double lumen endotracheal tubes during thoracic procedures, due to greater diameter of the tube, may lead to higher occurrence of difficult intubation. That is why, the purpose of this study is to assess the usefulness of the TMHT in prediction of difficult intubation using double lumen endotracheal tubes in patients scheduled for elective thoracic procedures and relate it to other, commonly used predictive tests.

During routine, preoperative anaesthetic visit thyromental height, thyromental distance, sternomental distance and Mallampati scale score are assessed. Then, during direct laryngoscopy and intubation, score in Cormack-Lehane scale and occurrence of difficult intubation are noted.

Inclusion criteria

• patients scheduled for elective thoracic procedures, requiring general anaesthesia, direct laryngoscopy and intubation with a Robertshaw type double lumen endotracheal tubes
• consent for participation in the trail
• older than 18

Exclusion criteria

• emergency procedures
• visible anatomic abnormalities
• patients scheduled for awake fibre optic intubation
• lack of consent for participation in the trail