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SHOCK. Dr Begashaw M (MD). Introduction. i s a life-threatening condition occurs when the circulatory system fails to deliver oxygen and nutrients to the body tissues & becomes unable to remove waste products
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SHOCK Dr Begashaw M (MD)
Introduction • is a life-threatening condition • occurs when the circulatory system fails to deliver oxygen and nutrients to the body tissues &becomes unable to remove waste products • may rapidly progress to an irreversible state with subsequent multi-organ failure and death
DEFINITION • a pathological state causing inadequate oxygen delivery to the peripheral tissues and resulting in lactic acidosis, cellular hypoxia &disruption of normal metabolic condition
CLASSIFICATION 1. Hypovolemic 2. Cardiogenic 3. Obstructive 4. Distributive - Septic shock - Neurogenicshock - Anaphylactic shock
Shock Hypovolemic Hemorrhage Anemia Fluid loss Obstructive Aortic valve stenosis Distributive Sepsis Thyrotoxicosis Anaphylaxis Cardiogenic Decompensated CHF Acute coronary syndrome Dysrhythmia Myocarditis
Hypovolemic • Hemorrhage • Anemia Preload • Cardiogenic • CHF • ACS • Dysrhythmia Shock Inotropy MAP = (SV x HR) x SVR • Distributive • Sepsis • Thyrotoxicosis • Obstructive • Aortic valve stenosis Afterload
Cardiac Performance Left ventricular size Peripheral resistance Preload Stroke volume Arterial pressure Myocardial fiber shortening Cardiac output Contractility Heart rate Afterload
Hypovolemic shock • inadequate vascular volume • results from loss of fluid from circulation, either directly or indirectly E.g ▪ Hemorrhage • Loss of plasma due to burn • Loss of water &electrolytes in diarrhea • Third space loss
Where do ptbleed enough to die? • Remember, there are only 5 places into which a person can bleed enough to cause hemodynamic instability • Chest • Peritoneum • Retroperitoneum • Thighs • World Not the mediastinum
Cardiogenic shock • impaired cardiac function • myocardial infarction • pericardial tamponade
Obstructive Shock • Resistance to cardiac outflow • ↑ afterload • Aortic stenosis • Tension pneumothorax
Septic Shock (vasogenic shock) • as a result of the systemic effect of infection • result of a septicemia with endotoxin and exotoxin release by gram-negative and gram-positive bacteria • impaired extraction as a result of impaired metabolism
Neurogenic shock • disruption of the sympathetic nervous system - to pain - loss of sympathetic tone, as in spinal cord injuries
PATHOPHYSIOLOGY OF SHOCK • stimulates a physiologic response - conserve perfusion to the vital organs (heart and brain) - vasoconstriction of skin, splanchnic & renal vessels leads to renal cortical necrosis and acute renal failure
Hypovolemic shock: physiology • Reduced blood volume • Reduced preload • Reduced stroke volume • Reduced cardiac output • Response to shock - physiology • Cathecholamines , ADH • Vasoconstriction, tachycardia • Improve venous return and CO
CLINICAL FEATURES • Tachycardia • Feeble pulse • Narrow pulse pressure • Cold extremities (except septic shock) • Sweating, anxiety • Breathlessness / Hyperventilation • Confusion leading to unconscious state
MANAGEMENT OF SHOCK • restoring oxygen delivery to the cells of vital organs
General Management • Priority-ABC • Stop bleeding • Fluid resuscitation-crystalloids • Head down position-flat • Transfusion • Oxygen , inotropic • Monitoring -determine hourly urine output, BP, pulse rate
Specific Management • Hypovolemic Shock • Restore vascular volume • Fluid and blood replacement • Oxygen support
Specific Management Septic Shock • antibiotics • Inotropic–adrenaline,dopamine • Surgical eradication of the infection focus Cardiogenic shock • Inotropes Neurogenicshock • Pain relief • Treat the causes, give supportive measures - inotropic support
COMPLICATIONS OF SHOCK 1. Shock lung (ARDS) 2. Acute renal failure 3. Gastrointestinal ulceration 4. Disseminated intravascular coagulation 5. Multiorgan failure 6. Death