1 / 19

Pathyophysiology and Classification of Shock

Pathyophysiology and Classification of Shock. KENNEY WEINMEISTER M.D. Definition. Shock is a physiologic state characterized by a significant, systemic reduction in tissue perfusion, thereby resulting in decreased tissue oxygen delivery. Stages of Shock. Early, Preshock, Warm shock

nam
Télécharger la présentation

Pathyophysiology and Classification of Shock

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Pathyophysiology and Classification of Shock KENNEY WEINMEISTER M.D.

  2. Definition • Shock is a physiologic state characterized by a significant, systemic reduction in tissue perfusion, thereby resulting in decreased tissue oxygen delivery.

  3. Stages of Shock • Early, Preshock, Warm shock • Compensation by body’s homeostatic mechanisms • Tachycardia, Peripheral vasodilatation and modest decrement in systemic BP

  4. Stages of Shock • Shock • Homeostatic mechanisms are overwhelmed • Signs and symptoms of organ dysfunction • Tachycardia, tachypnea, metabolic acidosis, oliguria, and cool and clammy skin • 20 to 25% fall in effective blood volume • Fall in CI to < 2.5L/min/M2 • Activation of mediators of sepsis

  5. Stages of Shock • End Organ Dysfunction • Pathophysiology • AG II & NE cause increased Ca+2 in cytosol • Ca + calmodulin = P+myosin • P+myosin + actin = Myosin ATPase • Myosin ATPase = muscle contraction

  6. Pathophysiology of End Organ Shock • Activation of ATP sensitive potassium channels • Activation causes hyperpolarization • Closure of Ca channels • Activated by decrease in cellular ATP and increases in cellular H+ and lactate • Natriuretic peptide and nitric oxide

  7. Pathophysiology of End Organ Shock • Increased production on Nitric Oxide • activation of myosin light-chain phosphatase • leads to dephosphoralation of myosin • Vasopressin deficiency • potentiates vasoconstrictor effects of NE • directly inactivates Katp channels • blunts increase in cGMP • decreases synthesis of NO synthase

  8. Pathophysiology of End Organ Shock • Vascular smooth muscle tone is lost • Resistant vasodilatation • End organ dysfunction and death

  9. Classification of Shock • Hypovolemic shock • Cardiogenic shock • Distributive shock

  10. Hypovolemic Shock • Results from decreased preload • Hemorrhagic • Trauma, GIB, Ruptured aneurysm • Volume loss • Third spacing, GI losses, burns, insensible losses

  11. Cardiogenic Shock • Pump failure • Cardiomyopathies • Ischemic right and left ventricle, • Dilated • Stunned myocardium

  12. Cardiogenic Shock continued • Arrhythmia's • Bradyarrhythmias • Tachyarrhythmias • Mechanical • Valvular; MR, AI, AS • VSD • Atrial myxoma

  13. Cardiogenic Shock continued • Obstructive • Massive PE • Tension pneumothorax • Constrictive pericarditis • Tamponade • Severe pulmonary hypertension

  14. Distributive Shock • Vasodilatory shock resulting in severe decrease in SVR • Septic shock • Activation of systemic inflammatory response • Toxic shock syndrome • Anaphylaxis • Drug or toxins

  15. Distributive Shock continued • Addisonian crisis • Myxedema coma • Neurogenic shock

  16. Evaluation • H & P • Labs • CXR • EKG

  17. Treatment • Goal is early intervention to prevent irreversible organ damage • Recognize early shock • Diagnose and correct the underlying cause • Early goal directed therapy in sepsis • In hospital mortality 46.5% vs 30.5% for treatment group • NEJM, vol 345,No 19 Nov 8 2001

  18. Treatment • Fluid resuscitation • CVP 8-12 • Vasopressors • Norepinephrin infuse mcg/min (4mcg/min) • Dopamine infuse mcg/kg/min • Epinephrine infuse mcg/min (range 1-10 mcg) • Vasopressin infuse units/min (range 0.01 to 0.1 units/minute)

More Related