The effects of dopamine and noradrenaline on cardiovascular function in patients with acute respiratory failure.

The short-term haemodynamic effects of terminating dopamine and/or a combination of noradrenaline and nitroglycerin infusions were studied in 21 patients in acute respiratory failure. Patients were studied during treatment and 10 min after infusions were stopped. Off treatment, stroke index and cardiac index decreased significantly from 40.2 to 36.9 ml m-2 (P < 0.02) and from 3.80 to 3.42 litres m-2 (P < 0.02), respectively. Cardiac filling pressures decreased significantly and systemic vascular resistance increased, when infusions were stopped. As to heart rate, mean arterial pressure, mean pulmonary arterial pressure, right and left ventricular ejection fraction there were no significant changes between the data obtained during and off treatment. Although the haemodynamic status was significantly better during treatment with dopamine and/or noradrenaline-nitroglycerin in some respects, the overall beneficial effects of inotropic support were much less than anticipated.