Translaryngeal absorption of lidocaine

Our study was conducted to determine the appropriate dose of lidocaine using the larynx and to characterize the onset and duration of therapeutic serum levels. A mean dose of 5.67 +/- 1.2 mg/kg was topically administered to the subglottic region of seven comatose patients through a cricothyroid membrane puncture. Serial serum lidocaine levels showed that therapeutic levels were attained in 5.1 +/- 3.2 minutes with a mean maximum level of 3.16 +/- 1.52 micrograms/ml and were reached at 18.71 +/- 8.71 minutes. Therapeutic serum levels were maintained for 68.4 +/- 29.7 minutes. Absorption of lidocaine via the airway yields sustained levels, although the duration of onset is less rapid and the maximum serum level is lower than that from an equivalent intravenous dose.