title: Intravenous lidocaine as a suppressant of coughing during tracheal intubation.
abstract: Effects of intravenously administered lidocaine on cough suppression during tracheal intubation under general anesthesia were evaluated in two studies. In study 1, 100 patients received either a placebo or 0.5, 1.0, 1.5, or 2.0 mg/kg lidocaine intravenously 1 min before tracheal intubation. All visible coughs were classified as coughing. The incidence of coughing decreased as the dose of lidocaine increased. A dose of 1 mg/kg or more of intravenous lidocaine suppressed the cough reflex significantly (P less than 0.01). Coughing was suppressed completely by 2 mg/kg of intravenous lidocaine. In study 2, 108 patients received 2 mg/kg lidocaine intravenously or a placebo 1, 3, 5, 7, 10, or 15 min before intubation. The same criteria for determining whether a patient did or did not cough during tracheal intubation were used as in study 1. The incidence of coughing decreased significantly (P less than 0.01) when 2 mg/kg of lidocaine was injected intravenously between 1 and 5 min before our attempting intubation. Cough reflex was suppressed completely by plasma concentrations of lidocaine in excess of 3 micrograms/ml.
mesh_terms: D000293:Adolescent; D000328:Adult; D000770:Anesthesia, Endotracheal; D003371:Cough / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007442:Intubation, Intratracheal; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D012018:Reflex / Q000187:drug effects*
chemical_list: D008012:Lidocaine