Title: Back 2 Basic Series: Under Pressure - Vasopressors Part I<br/>Author: Haney Mallemat<br/><a href='http://umem.org/profiles/faculty/785/'>[Click to email author]</a><hr/><p>
Vasopressors are used in shock-states to increase mean arterial pressure (MAP) and improve distal tissue perfusion. Additionally, some agents have effects on the heart to augment cardiac output.</p>
<p>
Receptors that vasopressors work on include: </p>
<ul>
<li>
<strong>Alpha-1:</strong> increase arterial tone (increases MAP) and venous tone to reduce venous pooling and augment cardiac preload </li>
<li>
<strong>Beta-1:</strong> increase inotropy and chronotropy on heart muscle; also increases arterial tone</li>
<li>
<strong>Beta-2 and Dopamine:</strong> cause vasodilation but may actually be beneficial because this increases perfusion to cardiac, renal, and GI tissues.</li>
<li>
<strong>V1</strong>: arterial vasoconstriction to increase MAP</li>
<li>
<strong>The chart below is a summary; please note </strong><strong>that quoted receptor effects vary depending on the source reviewed</strong></li>
</ul>
<p>
<strong>Norepinephrine (NE)</strong>: excellent vasopressor for most types of shock and recommended as a first-line agent in the Surviving Sepsis Guidelines.</p>
<ul>
<li>
Works on alpha-1, beta-1, and beta-2 receptors. </li>
<li>
Initial dosing 0.05 mcg/kg/min with a maximum dose often cited as 0.5 mcg/kg/min (though there is technically no maximum dose).</li>
</ul>
<p>
<strong>Epinephrine (a.k.a. Adrenaline)</strong>: in several countries the first-line agent for shock (including sepsis).</p>
<ul>
<li>
Works similarly to NE on alpha-1, beta-1 and beta-2; it is a more potent inotrope than NE.</li>
<li>
One downside is the production of lactic acid, which can sometimes lead to confusion when following serial lactates during resuscitation. </li>
</ul>
<p style="text-align: center;">
<img alt="" src="https://umem.org/files/uploads/content/pearls/visual_diagnosis/vasopressorchart.png" style="width: 550px; height: 244px;" /></p>
<p style="text-align: center;">
</p>
<fieldset><legend>References</legend>
<p style="text-align: center;">
<span style="font-size: 12.222222328186px; text-align: center; font-weight: bold;">Follow me on Twitter (</span><a href="https://twitter.com/CriticalCareNow" style="font-size: 12.222222328186px; text-align: center; font-weight: bold;">@criticalcarenow</a><span style="font-size: 12.222222328186px; text-align: center; font-weight: bold;">) or Google+ (+criticalcarenow)</span></p>
</fieldset>