Modified Cormack Lehane Scores Evaluated by Laryngoscopy During Awake Versus Under General Anesthesia

Nowadays, 5-step modified Cormack-Lehane scoring (MCL) system is frequently used in the observation of laryngeal structures by direct laryngoscopy. Upper airways with flexible fiberoptic laryngoscopy are routinely evaluated in patients who are predicted to be difficult intubation, who have undergone head or neck surgery previously and who require vocal cords to be evaluated preoperatively. During this examination patients are awake; so the upper airway and the muscles in the base of the mouth have normal tonus and airway reflexes are active. When general anesthesia is applied to the same patients during direct laryngoscopy, the laryngeal view may not be as clear as awake flexible fiberoptic laryngoscopy, since a tonus loss occurs in the muscles after general anesthesia. The aim of the study is to investigate the relationship between preoperative awake flexible fiberoptic laryngoscopy performed by ear- nose- throat (ENT) physicians in patients undergoing total thyroidectomy, and the MCL score during direct laryngoscopy after general anesthesia in the same patients. Thus, investigators would like to determine the reliability of airway evaluation with preoperative awake flexible fiberoptic laryngoscopy in predicting intubation conditions during tracheal intubation under general anesthesia.