Outline for Shock Essay

12457 Words Apr 1st, 2014 50 Pages
I. Introduction - Shock (Chapter 11) A. Review of anatomy and physiology B. Pathophysiology Initiation | * Decreased tissue oxygenation * Decreased intravascular volume * Decreased Myocardial contractility (cardiogenic ) * Obstruction of blood flow (obstructive) * Decreased vascular tone (distributive) * Septic (mediator release) * Neurogenic (suppression of SNS) | No observable clinical indications Decreased CO may be noted with hemodynamic monitoring | Compensatory | * Neural compensation by SNS * Increased HR and Contractiliy * Vasoconstriction * Redistribution of blood flow from nonessential to essential organs * Bronchodilation * Endocrine Compensation (RAAS, ADH, glucocorticoid …show more content…
Stages of shock 1. Initiation * hypoperfusion – (inadequate DO2, inadequate extraction of o2, or both). No obvious clinical indication of hypoperfusion are noted - hemodynamic monitoring is used for pt assessment. 2. Compensatory Stage – * sustained reduction in tissue perfusion initiates a set of neural, edocrine, and chemical compensatory mechanisms (to maintain blood flow to vital organs and to restore homeostasis) * symptoms become apparent, but shock may still be reversed with minimal morbidity. a. Neural compensation - * Baroreceptors and chemo receptors (carotid sinus and aortic arch) detect the reduction in arterial blood pressure. Impulses go to vasomotor center in the medulla oblongata, stimulating the sympathetic release epinephrine and norepinephrine (adrenal medulla), both HR and contractility increase to improve CO. * Coronary arteries dilate (increase perfusion to meet demands for o2) * Systemic vasoconstriction (improves blood pressure, venous vasoconstriction increased preload and CO), * Blood is shunted to heart and brain (from the kidneys, gastrointestinal tract, and skin.) * Bronchial smooth muscles relax, (RR and Depth are increased) – improving gas exchange and oxygenation. * Catecholamine -increased blood glucose levels * Liver converts glycogen to glucose for energy production; * Pupils dilate; * Peripheral

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