Journal of clinical anesthesia
-
Randomized Controlled Trial Clinical Trial
Effect of labetalol or lidocaine on the hemodynamic response to intubation: a controlled randomized double-blind study.
Labetalol, a combined alpha 1- and nonselective beta-adrenergic blocking drug, was compared to lidocaine or saline to minimize the hypertensive and tachycardic response to intubation in a controlled randomized double-blind study in patients undergoing surgical procedures under general anesthesia. Forty adult patients were divided into four groups of 10 each: placebo (saline), lidocaine 100 mg, labetalol 5 mg, or labetalol 10 mg. The double-blind preparation was administered as an IV bolus just prior to induction and 2 min before the stimulus of laryngoscopy and intubation. ⋯ Labetalol 10 mg prevented a rise in heart rate after intubation compared to patients who received placebo, lidocaine 100 mg, or labetalol 5 mg. The hypertensive response to intubation was similar in all four groups. Labetalol 10 mg IV just prior to induction of anesthesia is a safe and cost-effective means of preventing tachycardia but not hypertension in response to laryngoscopy and intubation.
-
Randomized Controlled Trial Clinical Trial
Partial attenuation of hemodynamic responses to rapid sequence induction and intubation with labetalol.
The effectiveness of labetalol (a combination nonselective beta and alpha-1-adrenergic receptor antagonist) in modifying hemodynamic responses associated with rapid sequence induction and tracheal intubation was evaluated. In a double-blind study, 24 ASA physical status I or II male patients scheduled for elective surgery were given either IV labetalol, 0.25 mg/kg (n = 8) or 0.75 mg/kg (n = 8), or a saline placebo (n = 8). Five minutes later, patients were given oxygen by mask and IV vecuronium, 0.01 mg/kg. ⋯ Within 30 seconds after intubation, patients in all three groups exhibited increases in heart rate, mean arterial pressure, total peripheral resistance, and rate pressure product and a decrease in stroke volume. However, patients in the 0.25 and 0.75 mg/kg labetalol groups, compared to those in the placebo group, had significantly lower increases in peak heart rate (33 +/- 2 and 27 +/- 3 vs. 44 +/- 7 beats/minute), peak mean arterial pressure (38 +/- 6 and 38 +/- 7 vs. 58 +/- 7 mmHg), and peak rate pressure product (7,726 +/- 260 and 7,215 +/- 300 vs. 14,023 +/- 250 units). The results show that these doses of labetalol significantly blunt, but do not completely block, autonomic responses to rapid sequence induction and intubation.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Onset of action between bupivacaine 0.5% and bupivacaine 0.5% plus fentanyl 75 mcg.
This study tested the hypothesis that the addition of fentanyl 75 mcg to bupivacaine 0.5% at the onset of epidural anesthesia for cesarean section reduces the onset time for T4 sensory blockade. The study was conducted in a randomized, double-blind fashion. The same observer performed sensory testing using pain to pinprick. ⋯ For group 1, the mean times for sensory loss at T7, T6, T5, and T4 were 13.1 +/- 3.8 minutes, 15.0 +/- 4.0 minutes, 16.9 +/- 4.3 minutes, and 19.3 +/- 4.9 minutes, respectively; for group 2, the mean times were 8.1 +/- 0.9 minutes, 9.9 +/- 1.1 minutes, 11.3 +/- 1.5 minutes, and 12.7 +/- 2.0 minutes, respectively. Two-factor analysis of variance between groups 1 and 2 showed a significant difference (p less than 0.0001), representing a 35% reduction of mean onset time. The coefficient of variation of the mean onset times for group 1 subjects was 26.6% +/- 1.7% and for group 2 subjects 12.7% +/- 2.2% (p less than 0.001), representing a 50% reduction in between-subject variation.(ABSTRACT TRUNCATED AT 250 WORDS)
-
Randomized Controlled Trial Clinical Trial
A controlled trial of esmolol for the induction of deliberate hypotension.
Twenty-five patients scheduled for lumbar fusion or cerebrovascular surgery were enrolled in an open label treatment controlled study comparing blood pressure and heart rate responses during deliberate hypotension with either esmolol or nitroprusside during steady-state N2O/isoflurane anesthesia. The first 5 patients were empirically assigned to the esmolol group; the remaining 20 patients were randomized to receive either esmolol or nitroprusside. The target of 15% reduction in mean arterial pressure (MAP) from baseline determined during anesthesia was attained with esmolol 195 +/- 10 micrograms/kg/min (mean +/- SEM) for the group (n = 15) or nitroprusside 1.9 +/- 0.3 micrograms/kg/min for the nitroprusside group (n = 10). ⋯ No patient in either group suffered any adverse reaction to hypotension. It is concluded that in moderate doses esmolol is a safe and effective hypotensive agent during isoflurane anesthesia, with no reflex tachycardia and no significant potential for rebound hypertension. A MAP reduction of 30% from preanesthesia baseline was readily obtained with this combination.