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DEFINE
- Is a syndrome characterized by:
- decreased tissue perfusion and impaired cellular metabolism which =>
- imbalance b/w the supply of and demand for O2 and nutrients => hypoperfusion
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CLASSES OF SHOCK
LOW BLOOD FLOW (cardiogenic and hypovolemic)
MALDISTRIBUTION OF BLOOD FLOW (septic, anaphylactic, and neurogenic shock)
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CARIOGENIC SHOCK
- systolic dysfunction inability of the heart to pump blood forward
- ie. MI, cardiomyopathy
- diastolic dysfunction inability of the heart to fil during diastole
- ie. pericardial tamponade
- dysrhythmias (bradydysrhythmias, tachydysrhythmias)
- structural factors valvular abnormality (stenosis or regurgitation), ventricular septal rupture, tension pneumothorax
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HYPOVOLEMIC SHOCK
- absolute hypovolemia
- external loss of whole blood (hemorrhage from trauma, surgery, gi bleeding
loss of other body fluids (vomiting , diarrhea, excessive diuresis, diabetes isnipidus, DM)
- Relative hypovolemia
- pooling of blood or fluids (bowel obstruction)
- fluid shifts (burn injuries, ascities)
- internal bleeding (fx of long bones, ruptured spleen, hemothorax, severe pancreatitis)
- massive vasodilation (sepsis)
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MALDISTRIBUTION OF BLOOD FLOW
NEUROGENIC SHOCK
- hemodynamic consequence of injury and/or disease to the spinal cord at or above T5
- spinal anesthesia
- vasomotor center depression (severe pain, drugs, hypoglycemia, injury)
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maldistribution
anaphylactic shock
contrast media, blood/blood products, drugs, insect bites, anesthetic agents, food/food additives, vaccines, environmental agents, latex
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maldistribution of blood flow
shock
septic shock
infection (urinary tract, respiratory tract, invasive procedure, indwelling lines and catheters)
- At risk:
- older adults, pts w chronic diseases (/dm, chronic kidney disease, HF) immunosuppressive therapy or who are malnourished or debilitated
Gram-negative bacteria most common; gram positive bacteria, viruses, fungi, and patasites
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Shock
=>
SYSTEMIC INFLAMMATORY RESPONSE SYNDROME (SIRS)
=>
Multiple Organ dyfunction Syndrome (MODS)
Mediator excess: cytokines (tumor necrosis factor, interleukins), oxygen free radicalss
widespread endothelial injury and dysfunction
vasodilation and increased capillary permeability
tissue edema
neutrophil entrampment in microcirculation
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MODS - multiple organ dysfunction syndrome
- Target organs
- cardiovascular dysfunction
- lung dysfunction
- GI dysfunction
- liver dysfunction
- CNS dysfunction
- Renal dysfunction
- Skin dysfunction
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