[Block of the superior laryngeal nerve for ORL endoscopy. Description of a simplified technique]. / Le bloc du nerf laryngé supérieur pour les endoscopies ORL. Description d'une technique simplifiée.

The usual anterior and lateral routes used for superior laryngeal (SL) nerve blocks are not often used because too difficult to carry out. A simpler and easier technique is described, which blocks the SL nerve at the level of the greater cornu of the hyoid bone. Because the nerve is not located accurately with this technique, a larger volume of local anaesthetic is required. This technique was tested in 31 patients scheduled for endoscopies with rigid tubes. The mean duration of endoscopy was 30 +/- 10 min. The use of 8 ml 1% lidocaine for the block 30 min surgical anaesthesia. In 2 patients, the SL nerve block alone was sufficient. In 26 others a complement with a benzodiazepine (flunitrazepam, n = 9, mean dose 0.8 mg; midazolam, n = 17, mean dose 5 mg) was required. In 4 of these patients, attempts of oesophagoscopy gave rise to hypertension and tachycardia. General anaesthesia with propofol and tracheal intubation were therefore used. In the last 3 patients, intercricothyroid jet ventilation was used, requiring general anaesthesia (propofol and succinylcholine). The SL nerve block was satisfactory in 24 patients with total vocal cord paralysis and no haemodynamic reaction to painful stimuli in the blocked area. No complication was observed. It is concluded that this technique is useful and easier to carry out than the usual ones.