High-Dose Phenylephrine Infusion in the Hemodynamic Support of Septic Shock

A 75-year-old man with hyperdynamic septic shock and vasodilation was successfully supported hemodynamically for 88.5 hours through the use of a continuous infusion of phenylephrine at dosages up to 360 micrograms/min. The only other vasoactive compound administered was dopamine at a dosage of 3.4 micrograms/kg/min. Hemodynamic evaluation indicated improvements in mean arterial pressure, cardiac output, and oxygen transport parameters during the period of hemodynamic support, which did not indicate a detrimental effect on perfusion of vital organs and tissues despite the use of this vasoconstrictor. Phenylephrine's pharmacologic properties may represent an advantage for its use as a vasoconstrictor over catecholamines such as norepinephrine and dopamine, particularly in patients who develop tachyarrhythmias with these agents. The pharmacology, dosage, and appropriate monitoring of therapy with phenylephrine in patients with septic shock are discussed.