Cardiorespiratory response to a new isoquinoline derivative in critically III patients.

NC 7197, a new N-substituted tetrahydroisoquinoline derivative, was given in doses of 0.2 mg/kg body weight on 26 occasions to a series of 23 critically ill postoperative and posttraumatic patients who had been in moderate or severe degrees of shock. This agent was observed to improve pressure-flow and oxygen-transport variables, including increases in cardiac index, mean arterial pressure, central venous pressure, both left and right ventricular stroke work, central blood volume, systemic vascular resistance, oxygen availability, arteriovenous oxygen content difference, and oxygen consumption, and decreases in mean transit time and pulmonary vascular resistance. Previous studies on critically ill patients have suggested that these are the most commonly desired therapeutic actions for this type of patient. The agent has pronounced inotropic effect with minimal chronotropic effects, but with higher doses, chronotropic effects as well as alpha blocking effects may occur. The optimal effects may be obtained by adjusting the dose to an appropriate therapeutic range. It is concluded that, in the dose used, this agent produced both alpha and beta adrenergic actions in critically ill patients.