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Understand Cardiogenic, Hypovolemic, & Distributive shock types, recognize in scenarios, apply treatment guidelines for optimal patient outcomes. Improve survival chances with early care.
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Objectives • Understand the definition of the three different types of shock • Be able to recognize the different types of shock in patient scenarios • Understand and apply treatment guidelines for the different types of shock
What is Shock? • Shock is the “physiologic state characterized by significant reduction of systemic tissue perfusion, resulting in decreased tissue oxygen delivery.” • Tissue perfusion is dependent on systemic vascular resistance (SVR) and cardiac output (COP). • Imbalance between oxygen delivery and oxygen consumption which leads to cell death, end organ damage, multi-system organ failure, and death
Three Types of Shock • Cardiogenic • Hypovolemic • Distributive • Septic • Anaphylactic • Neurogenic • Combined
Cardiogenic Shock • Shock caused as a result of cardiac pump failure • Results in a decrease in COP • SVR is increased in an effort to compensate to maintain organ perfusion • Causes: • Myocardial Infarction • Arrythmias (Atrial fibrillation, ventricular tachycardias, bradycardias, etc) • Mechanical abnormalities (valvular defects) • Extracardiac abnormalities (PE, pulm HTN, tension pneumothorax) Medscape Reference. 1994 (Online accessed 22 August 2013) URL: http://emedicine.medscape.com/article/152191-treatment#showall
Treatment of Cardiogenic Shock • Correct hypotension: • Fluid resuscitation to correct hypovolemia • Inotropic or Vasopressor support: • Dobutamine • Milrinone • Norepinephrine • Dopamine • Epinephrine • Oxygenation • If MI – Aspirin, Heparin, and Revascularization • If arrthymia – correct arrthymia • If extracardiac abnormality – reverse or treat cause
Hypovolemic Shock • Shock caused by decreased preload due to intravascular volume loss (1/5 of blood volume) • Results in decreased COP • SVR is typically increased in an effort to compensate • Causes: • Hemorrhagic – trauma, GI bleed, hemorrhagic pancreatitis, fractures • Fluid loss induced – Diarrhea, vomiting, burns Medscape LLC. 2013 (Online access on 22 August 2013) URL: http://emedicine.medscape.com/article/760145-treatment#2
Treatment of Hypovolemic Shock • Maximize oxygen delivery • Control further blood loss • Tourniquets • Surgical intervention • Fluid resuscitation • NS fluid boluses • Blood product administration
Distributive Shock • Shock as a result of severely diminished SVR • COP is typically increased in an effort to maintain perfusion • Subtypes: • Septic – secondary to an overwhelming infection • Anaphylactic – secondary to a life-threatening allergic reaction • Neurogenic – secondary to a sudden loss of the autonomic nervous system function Gaieski et al. 2009 (Online accessed 22 August 2013) URL: http://lijhs.sandi.net/faculty/rtenenbaum/ap-biology-folder/Links/Shock.utd.pdf
Treatment of Septic Shock • Resuscitate • 30cc/kg of NS bolus • Identify Source • Pan cultures • CT scan • Line removal • Foley removal • Surgical exploration • Antibiotics Dellinger, R et al. Surviving Sepsis Campaign: International Guidelines for Management of Severe Sepsis and Septic Shock:2012, 41: 580-637, 2013.
Treatment of Anaphylactic Shock • Remove offending agent • Establish an airway and return circulation • Pharmacologic support: • Epinephrine – reverses peripheral vasodilation, dilates bronchial airways, increases myocardial contractility, and suppresses histamine/ leukotriene release • Antihistamine (benadryl) – may help counter histamine-mediated vasodilation and bronchoconstriction • Corticosteroids (hydrocortisone) – may help shorten reaction • Bronchodilators
Treatment of Neurogenic Shock • Establish an airway to maintain adequate oxygenation and ventilation • Fluid resuscitation for MAP>65mmHg • Inotropic support • Dobutamine • Dopamine • Atropine for severe bradycardia • High dose methylprednisolone therapy
All three types of shock can occur at the same time to have a combined shock picture.
Summary Survival and outcomes improve with early perfusion, adequate oxygenation, and identification with appropriate treatment of the cause of shock.