BACKGROUND: Although prophylactic IV administration of lidocaine attenuates the response to a variety of inhalation challenges, its effect on airway resistance after endotracheal intubation in patients with asthma is unclear. We tested the hypothesis that IV lidocaine attenuates intubation-evoked bronchoconstriction in patients with asthma. METHODS: Thirty patients with asthma (age 49.1 +/- 15.6 yr [mean +/- sd]) undergoing intubation after standardized anesthetic induction (etomidate 0.3 mg/kg, fentanyl 5 microg/kg, rocuronium 0.6 mg/kg, 50% nitrous oxide) were studied. Airway resistance was measured immediately after intubation and 5, 10, and 15 min later. Five minutes after intubation, either lidocaine (2 mg/kg IV for 5 min, followed by 3 mg x kg(-1) x h(-1) for 10 min) or saline was administered. RESULTS: Airway resistance immediately after intubation averaged 23 +/- 12 cm H2O x s x L(-1). Airway resistance further increased (+38%) after administration of saline, but decreased (-26%, P < 0.004) to less than the initial values after lidocaine. CONCLUSIONS: IV lidocaine given after endotracheal intubation mitigates bronchoconstriction in patients with asthma.
BACKGROUND: Although prophylactic IV administration of lidocaine attenuates the response to a variety of inhalation challenges, its effect on airway resistance after endotracheal intubation in patients with asthma is unclear. We tested the hypothesis that IV lidocaine attenuates intubation-evoked bronchoconstriction in patients with asthma. METHODS: Thirty patients with asthma (age 49.1 +/- 15.6 yr [mean +/- sd]) undergoing intubation after standardized anesthetic induction (etomidate 0.3 mg/kg, fentanyl 5 microg/kg, rocuronium 0.6 mg/kg, 50% nitrous oxide) were studied. Airway resistance was measured immediately after intubation and 5, 10, and 15 min later. Five minutes after intubation, either lidocaine (2 mg/kg IV for 5 min, followed by 3 mg x kg(-1) x h(-1) for 10 min) or saline was administered. RESULTS: Airway resistance immediately after intubation averaged 23 +/- 12 cm H2O x s x L(-1). Airway resistance further increased (+38%) after administration of saline, but decreased (-26%, P < 0.004) to less than the initial values after lidocaine. CONCLUSIONS: IV lidocaine given after endotracheal intubation mitigates bronchoconstriction in patients with asthma.