The effect of chewing lidocaine soaked gauze on intubation conditions during awake videolaryngoscopy: a randomised controlled trial in the morbidly obese.

The increasing utilisation of the videolaryngoscope for awake tracheal intubation requires development and assessment of methods to decrease the gag reflex. We hypothesised that chewing gauze soaked with lidocaine would decrease the gag reflex during awake videolaryngoscope tracheal intubation. Twenty four morbidly obese patients assessed as having a potential difficult tracheal intubation were randomised to chew gauze soaked with 20 ml of 2% lidocaine or saline for 3 minutes. All patients then received 20 ml of aerosolised 2% lidocaine and underwent awake videolaryngoscope assisted tracheal intubation. Gagging scores, heart rate and blood pressure were assessed when best laryngeal view was obtained, when the tracheal tube was positioned at the cords, and when the tube was advanced into the trachea. In addition, serum lidocaine levels were measured. The primary outcome was the gagging score at best laryngeal visualisation, which was compared between groups with a Student's t-test. Gagging scores and hemodynamic parameters did not differ between groups, but the saline group had lower plasma levels of lidocaine after the intubation procedure. When used for awake videolaryngoscope assisted tracheal intubation of the morbidly obese, chewing lidocaine soaked gauze does not decrease the amount of gagging as compared to lidocaine aerosolisation, but does increase the plasma levels of lidocaine.

Awake videolaryngoscopy-assisted tracheal intubation of the morbidly obese.

Awake videolaryngoscopy may be useful for the tracheal intubation of the morbidly obese. This prospective, observational study enrolled 50 patients undergoing bariatric surgery. After sedation and topical anaesthesia of the airway, awake tracheal intubation was attempted, assisted by videolaryngoscopy, and terminated if there was severe gagging, coughing, or inadequate laryngeal view. After three attempts the procedure was considered a failure. Twenty-seven intubations were successful on the first attempt, fifteen on the second, six on the third and two were not successful, giving a success rate of 96% (95% CI 86-100%). In one failure, inserting the tracheal tube caused severe gagging in spite of an adequate view of the larynx, and the trachea was intubated with the videolaryngoscope after induction of anaesthesia. The second failure was due to gagging, with subsequent tracheal intubation successful using fibreoptic bronchoscopy. When managing the morbidly obese airway, awake tracheal intubation using videolaryngoscopy may be considered.