Inhibitory Effect of Nicardipine on Cardiovascular Stimulation by Tracheal Intubation / 대한마취과학회지

BACKGROUND: Direct laryngoscopy and tracheal intubation frequently induce transient hypertension, tachycardia and arrhythmia. This study was to evaluate the effect of nicardipine on the changes of the blood pressure and heart rate induced by direct laryngoscopy and tracheal intubation. METHODS: Sixty patients were randomly divided into three groups: Group 1 (nicardipine 0.02 mg/kg, n=20), Group 2 (diltiazem 0.2 mg/kg, n=20), Group 3 (normal saline 3 cc, n=20). Two minutes after intravenous injection of 2 mcg/kg of fentanyl, thiopental 5 mg/kg and nicardipine or diltiazem or normal slaine was administered intravenously. Then succinylcholine 1.5 mg/kg was administered. One minute after succinylcholine injection, direct laryngoscopy and tracheal intubation was done and vecuronium 0.1 mg/kg was injected. Anesthesia was maintained with 50% nitrous oxide in oxygen and 2 vol % of enflurane. Blood pressure and heart rate were measured at the period of preintubation, immediately after intubation, 1, 3 and 5 minutes following intubation by noninvasive method. RESULTS: After tracheal intubation, the increase of systolic blood pressure was supressed significantly in nicardipine and diltiazem group compared with control group (nicardipine group 11%, diltiazem group 13%, control group 24%). The increase of heart rate was greatest in nicardipine group (nicardipine group 38% diltiazem group 29%, control group 20%). CONCLUSIONS: Nicardipine was effective in attenuating pressor responses to laryngoscopy and intubation, but in nicardipine group, increase of heart rate was greater than control group.

Effects of both Clonidine Premedication and Esmolol Administration on the Hemodynamic Changes by Tracheal Intubation / 대한마취과학회지

BACKGROUND: Tracheal intubation by direct laryngoscopy induces frequently transient hypertension, tachycardia and arrhythmia. The purpose of this study was to examine the effect of esmolol and clonidine in attenuating the changes of blood pressure and heart rate by tracheal intubation. METHODS: Eighty patients were randomly divided into four groups: Group 1 (control , n=20), Group 2 (esmolol 0.5 mg/kg IV, n=20), Group 3 (clonidine 4 mcg/kg PO, n=20) and Group 4 (clonidine 4 mcg/kg PO and esmolol 0.5 mg/kg IV, n=20). The clonidine premedication were given orally with a sip of water 90 minutes before induction of anesthesia. Anesthesia was induced with thiopental 5 mg/kg, vecuronium 0.1 mg/kg, 50% nitrous oxide in oxygen and 2 vol % enflurane. After 5 minutes, tracheal intubation was performed. Patients in the group 2 and group 4 were given esmolol 0.5 mg/kg 90 seconds prior to tracheal intubation. Blood pressure and heart rate were measured at ward, preinduction, preintubation, immediately after intubation, 1, 3 and 5 minutes after intubation. RESULTS: After tracheal intubation, the increase in systolic blood pressure was supressed significantly in the clonidine-treated patients (Group 3, Group 4) compared with control group (p<0.05). The attenuating effect on increase of mean arterial pressure(MAP) was sustained longer in group 4 than group 3. Heart rate increased after tracheal intubation in all groups, but were markedly increased in the control group (p<0.05). The differences of MAP which measured at preinduction and immediately postintubation were smaller in group 4 than control group (p<0.05). The differences of heart rate which measured at preinduction and immediately postintubation were smaller in group 4 than group 1 or group 3 (p<0.05). CONCLUSIONS: Esmolol 0.5 mg/kg given as bolus, is effective for controlling the increase of heart rate but not in attenuating increase of blood pressure. Oral clonidine is effective for controlling the increase of blood pressure but not in attenuating increase of heart rate. Therefore esmolol combined with oral clonidine results in effective control of both heart rate and blood pressure.

A Comparison of 10% Lidocaine Spray and Intravenous 2% Lidocaine on Mean ArterialPressure and Heart Rate Following Tracheal Intubation / 대한마취과학회지

BACKGROUND: Laryngoscopy and tracheal intubation for general anesthesia are potent stimuli to the cardiovascular system due to sympathetic stimulation. The aim of this study was to compare the hemodynamic responses with different administration routes of lidocaine on blood pressure and heart rate changes associated with tracheal intubation. METHODS: Sixty patients were randomly assigned to spray group (Group 1, n=20) received 10% lidocaine 1.5 mg/kg spray to intratracheally immediately before tracheal intubation, IV group (Group 2, n=20) received 2% lidocaine 1.5 mg/kg intravenously before 90 sec tracheal intubation and control group (Group 3, n=20). Anesthesia was induced with thiopental 5 mg/kg IV, vecuronium 0.1 mg/kg and 50% N2O-O2- 2vol % enflurane. After 5 minutes, tracheal intubation was performed. Mean arterial pressure and heart rate were measured at preintubation and immediately postintubation, 1, 3, 5 mins after tracheal intubation. RESULTS:The differences of mean arterial pressure which were measured at preintubation and immediately postintubation and 1 minute after intubation in group 1 were significantly lower than those in other group (p<0.05). The differences of heart rate which measured at preintubation and 1 minute after intubation were lower than those in group 3 (p<0.05). CONCLUSIONS: For the suppression of sympathetic stimulation following tracheal intubation, 10% lidocaine spray to the laryngotrachea is an effective method to suppress cardiovascular response.