Verapamil as a hypotensive agent during neuroleptanaesthesia

Area of Science:

• Cardiology
• Anesthesiology
• Pharmacology

Background:

• Verapamil is a calcium channel blocker with known cardiovascular effects.
• Understanding its haemodynamic impact during anesthesia is crucial for patient safety.

Purpose of the Study:

• To investigate the haemodynamic effects of a single intravenous bolus of verapamil.
• To assess changes in mean arterial pressure, total peripheral resistance, cardiac output, heart rate, and pulmonary artery pressure.

Main Methods:

• 11 patients undergoing anesthesia with thiopentone, fentanyl, and dehydrobenzperidol were studied.
• Muscle relaxation was achieved using suxamethonium and pancuronium bromide.
• Verapamil (0.07 mg/kg) was administered as a single intravenous bolus.

Main Results:

• Mean arterial pressure decreased from 108 to 84 mm Hg (P < 0.001).
• Total peripheral resistance decreased by 29% (P < 0.001).
• Cardiac output increased, while heart rate and mean pulmonary artery pressure showed minor alterations.

Conclusions:

• Verapamil effectively reduces arterial pressure and peripheral resistance during anesthesia.
• The observed haemodynamic changes are primarily driven by vasodilation, with a compensatory increase in cardiac output.