RAAS to the Rescue: Angiotensin II for the Treatment of Vasodilatory Shock

Kyle Savio, Mercer University College of Pharmacy

Vasodilatory shock is characterized as hypotension resulting from peripheral vasodilatation and poor response to vasopressor therapy. Sepsis is considered the main cause for vasodilatory shock by reducing the body’s ability to constrict blood vessels and maintain hemodynamics. Therapy is claimed to be reliant on adrenergic vasopressors such as norepinephrine, but these may fail in refractory vasodilatory shock. The renin-angiotensin-aldosterone system (RAAS) is noted to play an important role in preserving the vasculature to prevent vasodilatory shock. [1]

In vasodilatory shock, RAAS failure may present without a known mechanism. It is believed that the endothelial cells are blocked or hyperpolarized, preventing a response to angiotensin II. The lungs have shown production and storage of angiotensin converting enzyme I and II which can limit effectiveness of RAAS in septic patients. Supplementing the body with angiotensin II may serve as therapy to reverse these vasodilatory effects. [2] Continue reading

Advertisements

Trial of Early, Goal-Directed Resuscitation for Septic Shock

Jane Oh, Mercer University College of Pharmacy 2015

Early, goal-directed therapy (EGDT) is a recommendation by the Surviving Sepsis Campaign (SSC) 2012 to resuscitate patients in early septic shock. In the event of persistent arterial hypotension despite volume resuscitation or blood lactate levels > 4 mmol/L, SSC recommends to maintain adequate central venous pressure.1

Two goals during these first six hours of EGDT are to maintain adequate central venous pressure (CVP) to carry out other hemodynamic adjustments, and to maximize mixed or central venous oxygen saturation (ScvO2). During the first six hours of resuscitation, the following goals are recommended by SCC as Grade 1C (“1”= strong evidence for care, “C”= well-done observational or cohort studies with controls): CVP 8-12 mmHg, Mean Arterial Pressure > 65 mmHg, urine output > 0.5mLŸkg-1Ÿhr-1, and central venous (superior vena cava) 70% or mixed venous oxygen saturation >65%.2 The SCC states that this recommendation was influenced largely from a randomized controlled study from Rivers, et al. which showed reduced hospital mortality and hospital stay.1

Continue reading