Hemodynamic Response to Rapid Intravenous Injection of Phenylephrine in a Single Patient

(From Schwinn DA, Reves JG. Time course and hemodynamic effects of alpha-1-adrenergic bolus administration in anesthetized patients with myocardial disease. Anesth Analg. 1989;68[5]:571-578, with permission.)

Mean arterial pressure (MAP) and systemic vascular resistance (SVR) increase and cardiac output (CO) decreases in response to phenylephrine, with peak effects occurring 42 seconds after drug administration.