Vasoactive drugs in the intensive care unit.

PURPOSE OF THE REVIEW: Vasoactive drugs are the mainstay of hemodynamic management of vasodilatory shock when fluids fail to restore tissue perfusion. In this review, studies published during the past year that increase our understanding of the use of vasoactive drugs in the intensive care unit are discussed.

RECENT FINDINGS: In septic shock, there is no benefit in increasing mean arterial pressure from 65 to 85 mmHg. Norepinephrine did not worsen renal function. Epinephrine induced visceral hypoperfusion and hyperlactatemia, and worsened organ function and survival compared with norepinephrine and vasopressin. There are a number of reports of the safety and efficacy of vasopressin but it is not currently recommended as first line therapy, and if used, should be given as a continuous low dose infusion. Terlipressin is showing promise but decreases cardiac output. Metaraminol is being investigated as an alternative to norepinephrine. Dopamine may improve splanchnic flow mainly by increasing cardiac output. Dobutamine improves oxygen delivery and may improve mesenteric blood flow.

SUMMARY: Over the last 40 years, there have been few controlled clinical trials to guide clinicians on the use of vasoactive drugs of treating shock states. It is not known whether the currently favored combination of norepinephrine and dobutamine is superior to traditional therapy with dopamine. Epinephrine is not recommended as the first-line therapy. The role of vasopressin and terlipressin remains unknown. Three large ongoing clinical trials will be completed soon and the results should clarify the role of these various agents.