Local anaesthesia for awake fibreoptic nasotracheal intubation.

BACKGROUND: Awake fibreoptic nasotracheal intubation (FNI) is performed in potentially difficult airways under local anaesthesia. This observer-blinded study was designed to evaluate the efficacy of upper airway anaesthesia produced by nebulized lignocaine against combined regional block (CRB) for awake FNI.

METHODS: Forty-eight ASA 1 adults were randomly allocated to receive 4 ml of 4%-nebulized lignocaine (nebulization group) or translaryngeal block, bilateral superior laryngeal nerve block and three 4% lignocaine-soaked cotton swabs in the nose (CRB group). Facial grimace and patient comfort were assessed by grimace and airway reactivity scores. Patients reported their discomfort on a 4-point score.

RESULTS: All patients underwent successful FNI without significant discomfort; 79% in the nebulization group and 83% of the patients in the CRB group reported the procedure to be comfortable. A higher grimace score was recorded on insertion of the endotracheal tube (ETT) through the nostril in the nebulization group when compared to the CRB group, P<0.005. Similarly, patients in the CRB group were more comfortable during passage of the ETT into the glottis, as compared to the nebulization group. A progressive increase in heart rate was observed in all patients from the beginning of the procedure, but the rise in the nebulization group was greater, (P<0.05) and also lasted longer than in the CRB group (P<0.05). Mean arterial pressure was higher in the nebulization group when compared to the CRB group (P<0.05), with patients belonging to the CRB group demonstrating considerable haemodynamic stability.

CONCLUSIONS: Both nebulization and CRB produced satisfactory anaesthesia of the upper airway, but CRB provided better patient comfort and haemodynamic stability.