INDEX catecholamines

Vasopressin is emerging as a potentially useful therapy in the hemodynamic support of vasodilatory septic shock. Case series and small clinical trials have reported its use in patients who remain hypotensive on vasopressors. Arginine vasopressin has little pressor activity in normal subjects but markedly increases blood pressure when sympathetic nerve function is impaired, including in septic shock. Unlike the catecholamine vasopressors, vasopressin is a direct vasoconstrictor agent and does not have inotropic or chronotropic effects. As a result, it may decrease cardiac output and hepatosplanchnic flow. In fact, studies of vasopressin in septic shock generally do not enroll patients with a cardiac index of less than 2 to 2.5 L/m per minute. 

Patients with left atrial hypertension may have an elevated pulmonary vascular resistance because the cardiac index is low, the pulmonary vasculature is constricted, or there is fixed pulmonary vascular obstructive disease with a reduction in recruitable lung vessels. Peroperative assessment may be aimed at increasing cardiac output with drugs such as dobutamine or by combining vasodilation and an increase in cardiac output with drugs such as nitroprusside or prostacyclin. The use of catecholamines or systemic vasodilators is not without risk, especially in patients with left ventricular outflow tract obstruction, as in two of our patients, or in patients with... 

A study in 20 patients undergoing spinal anaesthesia with tetracaine found that propofol sedation (as measured by bispectral index monitoring (BIS)) was enhanced when adrenaline was added to the intrathecal tetracaine." A study in sheep found that adrenaline, noradrenaline and dopamine decreased propofol concentrations during a continuous propofol infusion, with the result that propofol anaesthesia was reversed. This was thought to be due to increased first pass clearance of propofol secondary to increased cardiac output. It was concluded that this could be of clinical importance if propofol is used in hyperdynamic circulatory conditions induced by either catecholamine infusions or disease states such as sepsis. ... 

The maximum elastance l%iax. the slope of the ESPVR, has acquired considerable significance as an index of cardiac contractility that is independent of ventricular loading conditions. As the inotropic state of the myocardium increases, for example with catecholamine infusion, max increases, and with a negative inotropic effect such as a reduction in coronary artery pressure, it decreases. 

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