Attenuation of the pressor response to tracheal intubation with oral nitrendipine.

The effect of nitrendipine on the cardiovascular responses to tracheal intubation was studied in a placebo-controlled, randomised, double-blind trial. Thirty patients (ASA physical status 1) undergoing elective surgery received either 5 or 10 mg nitrendipine, or a placebo orally 3 h before induction of anaesthesia (n = 10 for each group). Anaesthesia was induced with sodium thiopentone 5 mg/kg i.v. and tracheal intubation was facilitated with vecuronium 0.2 mg/kg i.v. Patients receiving the placebo showed a significant increase in the mean arterial pressure and the rate-pressure product in response to tracheal intubation. These increases following intubation were reduced in nitrendipine-treated patients compared with the placebo group (P < 0.05). Oral administration of nitrendipine (5 or 10 mg, 3 h before induction of anaesthesia) was able to attenuate the hypertensive response to tracheal intubation in ASA 1 patients under light anaesthesia. We propose this pharmacological technique with supplementary doses of opioids and/or benzodiazepines for the management of patients with hypertension or coronary artery disease.

Effects of nilvadipine on the cardiovascular responses to tracheal intubation.

STUDY OBJECTIVE: To evaluate the efficacy of nilvadipine given orally in attenuating the hypertensive response to laryngoscopy and intubation. DESIGN: Controlled, randomized, double-blind study. SETTING: Induction of anesthesia for elective surgery at a university hospital. PATIENTS: Thirty normotensive patients (ASA physical status I) undergoing elective surgery were divided into three groups of ten patients each. INTERVENTIONS: Either 2 mg of nilvadipine, 4 mg of nilvadipine, or a placebo (control) was administered orally 90 minutes before induction of anesthesia. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide (N2O) in oxygen. Laryngoscopy lasting 30 seconds was attempted 2 minutes after administration of thiopental sodium and vecuronium. MEASUREMENTS AND MAIN RESULTS: Patients receiving the placebo showed a significant increase in mean arterial pressure (MAP) and heart rate associated with tracheal intubation. The increase in MAP following tracheal intubation was significantly lower in nilvadipine-treated patients than in the control group (p less than 0.05). However, neither dose of nilvadipine attenuated the tachycardic response to intubation. CONCLUSIONS: Oral administration of nilvadipine before induction of anesthesia is a simple and practical method for attenuating pressor response to laryngoscopy and tracheal intubation after standard elective induction under additional 1% enflurane-N2O anesthesia.

Partial attenuation of the cardiovascular responses to tracheal intubation with oral nisoldipine.

STUDY OBJECTIVE: To evaluate the efficacy and safety of nisoldipine given orally in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Induction of anesthesia for elective surgery at a university hospital. PATIENTS: Thirty normotensive patients (ASA physical status I) undergoing elective surgery were assigned to one of three groups; placebo, nisoldipine 5 mg, or nisoldipine 10 mg. Each group consisted of ten patients. INTERVENTIONS: Either 5 mg of nisoldipine, 10 mg of nisoldipine, or a placebo was administered orally 2 hours before induction of anesthesia. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. Laryngoscopy lasting 30 seconds was attempted 2 minutes after administration of thiopental sodium and vecuronium. MEASUREMENTS AND MAIN RESULTS: Patients receiving the placebo showed a significant increase in mean arterial pressure associated with tracheal intubation. These increases following tracheal intubation were significantly reduced in patients receiving nisoldipine 10 mg compared with patients receiving the placebo (p less than 0.05). CONCLUSIONS: Oral administration of nisoldipine before induction of anesthesia is a simple, practical, and safe method for attenuating pressor response to laryngoscopy and tracheal intubation.