Intravenous chloroprocaine attenuates hemodynamic changes associated with direct laryngoscopy and tracheal intubation.
We compared the effects of an IV administration of chloroprocaine and lidocaine on circulatory responses associated with endotracheal intubation. Thirty patients were randomly allocated to receive normal saline (placebo), lidocaine (1.5 mg/kg), or preservative-free chloroprocaine (4.5 mg/kg) 45 s before endotracheal intubation. Blood pressures and heart rate and rhythm were recorded before laryngoscopy and at 0.5, 1, 1.5, 2, 3, and 5 min after intubation. Blood samples were analyzed for catecholamine and chloroprocaine concentrations. Chloroprocaine reduced increases in blood pressure in response to intubation when compared with patients receiving normal saline and lidocaine. Systolic blood pressures at 0.5 and 1 min after intubation were significantly lower in the chloroprocaine group when compared with both the control and lidocaine groups (P < 0.05). Diastolic and mean blood pressures were significantly lower in the chloroprocaine group at all time points until 5 min after intubation (P < 0.05). Chloroprocaine and, to a lesser degree, lidocaine, produced marked attenuation of intubation-induced increases in plasma concentration of epinephrine and norepinephrine. Plasma concentrations of norepinephrine were significantly smaller in the chloroprocaine group at 0.5, 1, and 1.5 min, and plasma concentrations of epinephrine were significantly smaller at 0.5 after intubation when compared with control and lidocaine groups (P < 0.05). Measurable concentrations of chloroprocaine were recorded in plasma samples for 2 min after its administration. No adverse chloroprocaine effects (i.e., circulatory disturbances, venous irritation) were detected. The IV administration of chloroprocaine effectively blunted cardiovascular response produced by laryngoscopy and endotracheal intubation, and this effect was more pronounced when compared with IV lidocaine.