Does intravenous lidocaine prevent laryngospasm after extubation in children?

One hundred otherwise healthy children undergoing tonsillectomy were investigated in a double-blind study to examine the effect of intravenous lidocaine in preventing laryngospasm upon extubation. The children were anesthetized with N2O-O2-halothane and orally intubated. They were randomly given lidocaine, 1.5 mg/kg, or saline intravenously prior to extubation, which took place at the same depth of anesthesia, namely when there were signs of swallowing activity. Eleven children (2%) in each group of 50 developed laryngospasm. From our findings it is concluded that lidocaine, 1.5 mg/kg, does not prevent laryngospasm upon extubation when extubation is carried out at the start of swallowing activity.