The acute haemodynamic effects of intravenous verapamil in patients with chronic obstructive airways disease.
The haemodynamic effects of a single intravenous dose of verapamil have been investigated in patients with chronic obstructive airways disease both during an acute exacerbation and when in a stable clinical condition and compared with the effects of oxygen administered by nasal cannulae. In five patients studied during an episode of acute on chronic hypoxaemia (mean PaO2 = 5.4 kPa) there was a significant fall in pulmonary vascular resistance (p less than 0.03) following intravenous verapamil (10 mg) without any reduction in PaO2, cardiac index or oxygen delivery. Subsequent administration of oxygen by nasal cannulae at 2 l/min for 30 min produced similar pulmonary haemodynamic changes: pulmonary vascular resistance fell by 17 +/- 3 per cent following oxygen and by 22 +/- 4 per cent following verapamil. In a similar group of five patients in a stable clinical condition (mean PaO2 = 7.3 kPa) neither oxygen nor verapamil administered during acute exacerbations produced any significant changes in pulmonary vascular resistance, cardiac index or oxygen delivery.