{"id":422,"date":"2017-01-16T16:09:33","date_gmt":"2017-01-16T16:09:33","guid":{"rendered":"http:\/\/www.deltexmedical.com\/decision_tree\/?page_id=422"},"modified":"2017-11-10T15:20:15","modified_gmt":"2017-11-10T15:20:15","slug":"vasoactive-and-inotropic-drugs","status":"publish","type":"page","link":"https:\/\/www.deltex-academy.com\/decision_tree\/vasoactive-and-inotropic-drugs\/","title":{"rendered":"Vasoactive and Inotropic Drugs"},"content":{"rendered":"<style>.entry-title {display:none;}<br \/><\/style>\n<style>.site-info {display: none;}<br \/><\/style>\n<h2 style=\"text-align: center;\"><strong><span style=\"color: #003087;\">VASOACTIVE AND INOTROPIC DRUGS<\/span><\/strong><\/h2>\n<h3><strong><span style=\"color: #003087;\">Terminology<\/span><\/strong><\/h3>\n<p>Inotrope\u00a0&#8211; an agent that affects contraction. Can be\u00a0positive or negative.<br \/>\nChronotrope &#8211; an agent that affects heart rate. Can be positive or negative.<br \/>\nVasopressor &#8211; an agent that tends to increase\u00a0blood pressure by increasing total peripheral resistance.<br \/>\nVasoconstrict &#8211; the narrowing of blood vessels resulting from\u00a0the contraction of the muscular wall.<br \/>\n\u200bVasodilate &#8211; the widening of the blood vessels.<\/p>\n<h3><strong><span style=\"color: #003087;\">Introduction<\/span><\/strong><\/h3>\n<p>This document summarises very briefly the effects that may be seen with central flow and\/or pressure when some common haemodynamic drugs are given. Note: patients may respond differently and this is only a guide.<br \/>\nThe autonomic nervous system is responsible for maintaining normal functions such as blood pressure and blood flow. It has two divisions; the parasympathetic and the sympathetic systems. The parasympathetic is generally concerned with conservation of energy and maintenance of organ function during periods of minimal activity, while the sympathetic acts when the \u2018fight or flight\u2019 response is required. There is a natural balance between the two systems.<br \/>\nThe parasympathetic nervous system contributes to regulation of heart function through the vagus nerve where it slows the rate, but has little or no control over the blood vessels.<br \/>\nThe sympathetic nervous system has an excitatory influence on heart rate and contractility and controls the smooth muscle tone of the blood vessels. It maintains them in a state of tonic activity (continuous activity). The increases in sympathetic activity will increase the constriction or visa versa. The main types of adrenergic receptors mentioned here are alpha (\u03b1), beta (\u03b2) and dopamine (DA), with some of their subtypes that interact with the sympathetic neuromediators. Only those associated with haemodynamics are discussed here. Generally, \u03b1 receptors cause constriction, while \u03b2 cause dilation and increased contractility. Some blood vessels are supplied with both these constrictor and dilator receptors.<br \/>\nAn adrenergic agonist is a drug that stimulates a response from the adrenergic receptors. Inotropes are agents that increase myocardial contractility (inotropy) e.g. adrenaline, dobutamine. Vasopressors are agents that cause vasoconstriction leading to increased systemic and\/or pulmonary vascular resistance (SVR, PVR) e.g. noradrenaline, metaraminol. Inodilators are agents with inotropic effects that also cause vasodilation leading to decreased SVR and\/or PVR e.g. dobutamine. Other agents included e.g. dopamine.<br \/>\nThe following mnemonics may help to understand where the adrenoreceptors are located and their general actions.<\/p>\n<ul>\n<li>\u20181 heart and 2 lungs\u2019 refers to\u00a0\u03b1<sub>1<\/sub> and \u03b2<sub>1<\/sub> being found in the heart, while \u03b1<sub>2<\/sub> and \u03b2<sub>2<\/sub> will be found in the lungs (remember also that \u03b1<sub>1<\/sub> and \u03b2<sub>2<\/sub> will be found in blood vessels).<\/li>\n<li>Alpha has the symbol \u03b1 &#8211; imagine this is a fish and is drawn as a piece of string. If the ends of the string are pulled apart, the circle of the symbol (representing the vessel) will constrict. Beta-receptors are \u2018B\u2019igger and \u2018B\u2019etter and dilate vessels and increase heart rate.<\/li>\n<\/ul>\n<p>A breakdown of the main adrenoreceptors only related to haemodynamics and their actions is listed in the following table:<\/p>\n<table style=\"width: 100%;\">\n<tbody>\n<tr>\n<th>Type<\/th>\n<th>Tissue<\/th>\n<th>Actions<\/th>\n<\/tr>\n<tr>\n<td rowspan=\"2\">Alpha <sub>1<\/sub> (\u03b1<sub>1<\/sub>)<\/td>\n<td>Most vascular smooth muscle<\/td>\n<td>Constriction<\/td>\n<\/tr>\n<tr>\n<td>Heart<\/td>\n<td>Increased force of constriction (inotropy)<\/td>\n<\/tr>\n<tr>\n<td>Alpha <sub>2<\/sub>(\u03b1<sub>2<\/sub>)<\/td>\n<td>Vascular adreneric nerve terminals<\/td>\n<td>Inhibition of sympathetic activity. Has central and peripheral effects &#8211; BP \u2191 or \u2193<\/td>\n<\/tr>\n<tr>\n<td>Beta <sub>1<\/sub>(\u03b2<sub>1<\/sub>)<\/td>\n<td>Heart<\/td>\n<td>Increased rate (chronotropy) and force of contraction<\/td>\n<\/tr>\n<tr>\n<td>Beta <sub>2<\/sub>(\u03b2<sub>2<\/sub>)<\/td>\n<td>Bronchi, uterine and vascular smooth muscle<\/td>\n<td>Relaxation &#8211; causes dilation<\/td>\n<\/tr>\n<tr>\n<td>Beta <sub>3<\/sub>(\u03b2<sub>3<\/sub>)<\/td>\n<td>Heart<\/td>\n<td>Increased force of contraction in healthy heart Cardioprotective in heart failure &#8211; has negative inotropic effect<\/td>\n<\/tr>\n<tr>\n<td>Dopamine (DA<sub>1<\/sub>)<\/td>\n<td>Vascular bed of brain, splanchnic organs&lt;, kidneys and coronary arteries<\/td>\n<td>Increases peripheral resistance (vasoconstriction) but can vasodilate renal and gut circulation. Can also increase vascular resistance systemically<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"text-align: left;\"><strong>Table 1. General details of alpha, beta and dopamine receptors.<\/strong><\/p>\n<p>The following drugs have these types of effects:<\/p>\n<table>\n<tbody>\n<tr>\n<th>Receptor<\/th>\n<th>Alpha 1<\/th>\n<th>Beta 1<\/th>\n<th>Beta 2<\/th>\n<th>DA1<\/th>\n<\/tr>\n<tr>\n<td>Metaraminol<\/td>\n<td>+++<\/td>\n<td>+<\/td>\n<td>0<\/td>\n<td>0<\/td>\n<\/tr>\n<tr>\n<td>Adrenaline (epinephrine)<\/td>\n<td>+\/++<\/td>\n<td>++<\/td>\n<td>+<\/td>\n<td>0<\/td>\n<\/tr>\n<tr>\n<td>\u00a0\u00a0Noradrenaline (norepinephrine)<\/td>\n<td>+++<\/td>\n<td>+++<\/td>\n<td>+<\/td>\n<td>0<\/td>\n<\/tr>\n<tr>\n<td>Phenylephrine<\/td>\n<td>++<\/td>\n<td>0<\/td>\n<td>0<\/td>\n<td>0<\/td>\n<\/tr>\n<tr>\n<td>Dobutamine<\/td>\n<td>+<\/td>\n<td>++<\/td>\n<td>+\/++<\/td>\n<td>0<\/td>\n<\/tr>\n<tr>\n<td>Dopamine<\/td>\n<td>++<\/td>\n<td>+<\/td>\n<td>0<\/td>\n<td>+++<\/td>\n<\/tr>\n<tr>\n<td>Dopexamine<\/td>\n<td>0<\/td>\n<td>+<\/td>\n<td>+++<\/td>\n<td>++<\/td>\n<\/tr>\n<tr>\n<td>Ephedrine<\/td>\n<td>++<\/td>\n<td>++<\/td>\n<td>0<\/td>\n<td>0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Table 2. Common haemodynamic drug actions on adrenorecptors.<\/strong><\/p>\n<p>Then consider how these drugs will affect <strong><em>central flow<\/em><\/strong> as seen by the ODM+ and <strong><em>blood pressure<\/em><\/strong>.<\/p>\n<table>\n<col width=\"50%\">\n<tbody>\n<tr>\n<th>Drug<\/th>\n<th>FTc<\/th>\n<th>PV<\/th>\n<th>HR<\/th>\n<th>SV<\/th>\n<th>CO<\/th>\n<th>BP<\/th>\n<\/tr>\n<tr>\n<td>Metaraminol<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2191<\/td>\n<\/tr>\n<tr>\n<td>Adrenaline (Epinephrine) low dose (no definition for low or high dose &#8211; is patient specific)<\/td>\n<td>\u2194<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191\u2193or\u00a0\u2194<\/td>\n<\/tr>\n<tr>\n<td>Adrenaline (Epinephrine) high dose (no definition for low or high dose &#8211; is patient specific)<\/td>\n<td>\u2193<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<\/tr>\n<tr>\n<td>Noradrenaline (norepinephrine)<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2193or <span style=\"font-size: small;\">occasionally<\/span>\u00a0\u2191<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2191<\/td>\n<\/tr>\n<tr>\n<td>Phenylephrine<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2191<\/td>\n<\/tr>\n<tr>\n<td>Dobutamine<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191\u2193or\u00a0\u2194<\/td>\n<\/tr>\n<tr>\n<td>Dopamine (low dose &#8211; 1-5 mcg\/kg\/min)<\/td>\n<td>\u2194<\/td>\n<td>\u2191<\/td>\n<td>\u2194<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2194<\/td>\n<\/tr>\n<tr>\n<td>Dopamine (medium dose &#8211; 5-10 mcg\/kg\/min)<\/td>\n<td>\u2194or\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191\u2193or\u00a0\u2194<\/td>\n<\/tr>\n<tr>\n<td>Dopamine (high dose &#8211; 10-15 mcg\/kg\/min)<\/td>\n<td>\u2193<\/td>\n<td>\u2193<\/td>\n<td>\u2191or\u2193<\/td>\n<td>\u2191or\u2193<\/td>\n<td>\u2191\u2193or\u00a0\u2194<\/td>\n<td>\u2191<\/td>\n<\/tr>\n<tr>\n<td>Dopexamine<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2191<\/td>\n<td>\u2193or\u00a0\u2194<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Table 3. Potential effects of common haemodynamic drugs on central flow and BP.<\/strong><\/p>\n<h3><strong><span style=\"color: #003087;\">Take hom messages<\/span><\/strong><\/h3>\n<p><strong>Take Home Messages<\/strong><\/p>\n<ul>\n<li>This is a complex subject and haemodynamic drugs may have more than one effect.<\/li>\n<li>Metaraminol (and noradrenaline to some extent) has effects that can be seen easily \u2013 if used to treat a falling BP, the flow will decrease as BP increases. This is not necessarily treating the underlying cause and in some instances, may make things worse for the patient (see \u2018Under Pressure?\u2019 document). Ideally CO should be optimised before commencing vasoactive drugs.<\/li>\n<li>Using ODM+ will allow central flow to be assessed precisely when these drugs are used.<\/li>\n<\/ul>\n<h3><strong><span style=\"color: #003087;\">Bibliography<\/span><\/strong><\/h3>\n<ul>\n<li>Benham-Hermetz J., Lambert M. and Stephens C.M.Core Training. Cardiovascular failure, inotropes and vasopressors. BJ Hospital Medicine 2012; 73(5). <a href=\"http:\/\/www.ucl.ac.uk\/anaesthesia\/StudentsandTrainees\">ucl.ac.uk\/anaesthesia\/StudentsandTrainees<\/a><\/li>\n<li>Critical Care Compendium. Inotropes, vasopressors and other vasoactive agents. Life in the Fast Lane. <a href=\"http:\/\/www.lifeinthefastlane.com\">lifeinthefastlane.com<\/a><\/li>\n<li>Murphy P. <em>Handbook of Critical Care. <\/em> Science Press.<\/li>\n<li>Overgard C.B. &amp; D\u017eav\u00edk V. Inotropes and Vasoporessors. 2008;118:1047-1056.<\/li>\n<li>Porth C.M. <em>Pathophysiology: Concepts of Altered Health States,<\/em> 2002 6<sup>th<\/sup> Lippincott, Williams and Wilkins.<\/li>\n<li>Pratt O. and Gwinnutt C. Tutorial of the Week. The Autonomic Nervous System. Anesthesia UK. <a href=\"http:\/\/www.anaesthesiauk.com\">anaesthesiauk.com<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>VASOACTIVE AND INOTROPIC DRUGS Terminology Inotrope\u00a0&#8211; an agent that affects contraction. Can be\u00a0positive or negative. Chronotrope &#8211; an agent that affects heart rate. Can be positive or negative. Vasopressor &#8211; an agent that tends to increase\u00a0blood pressure by increasing total peripheral resistance. Vasoconstrict &#8211; the narrowing of blood vessels resulting from\u00a0the contraction of the muscular &hellip; <a href=\"https:\/\/www.deltex-academy.com\/decision_tree\/vasoactive-and-inotropic-drugs\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Vasoactive and Inotropic Drugs&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-422","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/pages\/422","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/comments?post=422"}],"version-history":[{"count":64,"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/pages\/422\/revisions"}],"predecessor-version":[{"id":1225,"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/pages\/422\/revisions\/1225"}],"wp:attachment":[{"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/media?parent=422"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}