Superior laryngeal nerve block as an adjuvant to General Anesthesia during endoscopic laryngeal surgeries A randomized controlled trial

AbstractBackgroundDirect rigid endoscopic laryngosurgery is a short procedure usually performed under general anesthesia. This is a double blinded randomized placebo-controlled trial, which was designed to evaluate the effect of bilateral block of the internal branch of superior laryngeal nerve (SLN) as an adjuvant to general anesthesia during endoscopic laryngeal surgery when smaller dose of muscle relaxant is used.MethodSeventy-six patients required endoscopic laryngosurgery in whom general anesthesia was preceded by bilateral superior laryngeal nerve block either with 2% lidocaine (L-group) or with saline (C-group).ResultsThe reaction to endotracheal tube insertion was better in L-group as less frequent cough occurred in L-group (one patient) compared to (8 patients) C-group (P value <0.05). The maximum pressor response was observed immediately after intubation, at which the increase in MAP from baseline in C-group (24.4%) was significantly higher than in L-group (6.4%) (P<0.05) and the increase in HR from baseline in C-group (29.5%) was significantly higher than in L-group (14.8%) (P