Effects of combined intravenous nicardipine and diltiazem administration on the circulatory response to laryngoscopy and tracheal intubation

A Comparative Study of Dexmedetomidine and Diltiazem for Attenuating Pressor Responses to Laryngoscopy and Endotracheal Intubation: A Double-blind, Randomized Study

CONTEXT

Endotracheal intubation has been suggested to be one of the most invasive stimuli in anesthesia, particularly during induction and after tracheal intubation. The present study aims to evaluate the efficacy of dexmedetomidine as compared to diltiazem on hemodynamic response to laryngoscopy and intubation.

AIMS

To assess and compare the hemodynamic response of dexmedetomidine as compared to diltiazem in patients undergoing laryngoscopy and intubation and rate and type of side effects of the drugs if any.

SETTINGS AND DESIGN

This study design was a prospective, randomized, and double-blind trial.

SUBJECTS AND METHODS

The patients were randomly allocated into three groups: Group I (control), Group II (dexmedetomidine), and Group III (diltiazem) of 45 patients each. Group I (n = 45): 0.9% NaCl 10 ml was given to the patients over 10 min before intubation in Group I (control). Group II (n = 45): injection dexmedetomidine (0.5 μg/kg) in 10 ml normal saline was given to the patients over 10 min before intubation. Group III (n = 45): injection diltiazem (0.3 mg/kg) in 10 ml normal saline was given to the patients over 10 min before intubation.

STATISTICAL ANALYSIS USED

The data so collected were subjected to statistical analysis using Statistical Package for the Social Sciences version 15.0.

RESULTS

Mean percentage increase in systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) following intubation was 17.90%, 19.96%, and 19.04%, respectively, in control group, 9.04%, 6.32%, and 7.53%, respectively, in dexmedetomidine group, and 12.30%, 10.32%, and 11.14%, respectively, in diltiazem groups. Statistically, there was a significant difference in postintubation SBP, DBP, and MAP of the three groups (P < 0.001). Dexmedetomidine at a dose of 0.5 μg/kg showed to have a better attenuation of pressor response as compared to diltiazem at a dose of 0.3 μg/kg.

CONCLUSIONS

Both dexmedetomidine and diltiazem were safe and effective in attenuating the hemodynamic response following laryngoscopy and endotracheal intubation; however, between two trial drugs, dexmedetomidine had a better response.

Combined administration of diltiazem and nicardipine attenuates hypertensive responses to emergence and extubation

Diltiazem and nicardipine, when injected as a mixture during anesthesia, reduce blood pressure in an additive manner without changing heart rate. The author evaluated the use of this mixture for controlling the blood pressure during emergence from general anesthesia and at extubation. The subjects included 15 preoperative hypertensive (HT) patients who underwent various types of surgery and 18 patients with subarachnoid hemorrhage (SAH) who underwent clipping of a cerebral aneurysm. General anesthesia was maintained with isoflurane or sevoflurane, supplemented with fentanyl. A mixed solution containing 2.5 mg diltiazem plus 0.5 mg nicardipine in 1 mL was injected intermittently every 2 to 4 minutes to bring the blood pressure to its resting level from cessation of inhaled anesthetics to extubation. Untreated patients who underwent similar types of surgery and anesthesia were selected for comparison. The average systolic blood pressure during emergence and at extubation increased to 156 +/- 19 mm Hg (mean +/- standard deviation) and 170 +/- 10 mm Hg in the untreated HT group, and increased to 157 +/- 16 mm Hg and 170 +/- 5mm Hg in the untreated SAH group. Systolic blood pressure was well controlled at 127 +/- 14 mm Hg and 145 +/- 14 mm Hg in the treated HT group with 3.7 +/- 1.9 mL of the mixture, and at 120 +/- 9 mm Hg and 137 +/- 20 mm Hg in the treated SAH group with 7.1 +/- 2.5 mL of the mixture. No significant difference (P < .05) in the heart rate was found between the untreated and the treated HT or SAH groups. Two patients in the treated SAH group exhibited tachycardia. The combined administration of diltiazem and nicardipine can help control blood pressure in patients with a possible HT response to emergence from general anesthesia and extubation.