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109 ch. 15
Shock
Question | Answer |
---|---|
Definition of shock | tissue perfusion is inadequate to deliver O2 |
what are three components affected by shock | pump, vascular tree, blood volume |
Classifications of shock | hypovolemic, cardiogenic, septic, neurogenic, anaphylactic |
what is hypovolemic | decr intravascular volume due to fluid loss |
what is cardiogenic | impairment or failure of myocardium |
what is septic shock | overwhelming infection causing hypovolemia |
what is neurogenic shock | loss of sympathetic tone causing relative hypovolemia, warm skin b/c no SNS |
what is anaphylactic shock | severe allergic reaction producing overwhelming systemic vasodilation, hypovolemia |
what is cellular effect of shock | fluid surrounds cell and Na leaks into cell then water and K leaks out |
what happens in anaerobic metabolism | produce lactic acid, cells swell, incr permeability, impaired Na/K pump, cell death |
How does BP respond to shock | barorecepters, kidneys: angiotension I to II = vasoconstriction, aldosterone (hold Na & H2O), ADH(hold H2O) |
How do you get MAP | 2xDBP + SBP/3 SV = 50-70 PP = DBP-SBP |
three stages of shock | compensatory, progressive, irreversible |
what is compensatory shock | SNS causes vasoconstriction (cool to touch), incr HR, incr heart contractility. Blood shunted causing clammy skin, decr urine, acidosis, resp incr to cause resp alkalosis |
What happens wtih progressive stage of shock | DBP decr, then SBP decr, confusion, lungs begin to fail, dysrhythmias, ischemia |
MAP below 65 means | GFR not fx so acute renal failure, DIC- clotting everywhere, organs fail(MODS), can't survive |
Tx for shock | fluid replacement(crystalloid, colloid), nutritional support, vasoactive therapy, modified trendelenburg |
what is primary goal for cardiogenic shock | oxygenation drugs: dobutamine, nitro, dopamine |
septic, neurogenic, anaphylactic shock all constitute | circulatory shock |
what is last thing to change in shock pts when declining | pupils last to change in neuro changes |
what is typical order of events for changes | lungs, hepatic/renal dysfx(7-10d), hematological, cardiovascular, neurological |