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5 Cards in this Set
- Front
- Back
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What is the signal for shock? What phases are there?
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A lack of nutrients and oxygen arriving at the tissues.
Phases are compensated (non progressive) decompensated irreversible |
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Compensated stage: what happens to CO, BP, and what does it come from?
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Cardiac output and BP may both drop, but it is known to always result from a compromised delivery of nutrients to the tissues
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What is the general idea of the compensated phase of hypovolemic shock? what system is being activated? how?
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generally want to turn up sympathetics:
barroreceptors detect drop in pressure, they turn off their inhibition of sympathetic release stretch receptors: atria notice fall involume and stop releasing atrial naturietic peptide (ANP) = stop diuretic, also release vasopressin (antidiuretic) chemoreceptors detect hypoxia by noticing decrease in metabolism, turn up sympathetics via the NTS brain hypoxia - up sympathetics. mostly concerned with maintaining arterial blood pressure! |
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describe the decompensating phase:
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generally, stop copensating.
stop responding to the sympathetic outputs, either due to desensitization, running out of epinephrine, local pH drop causing the catecholamines to change shape and not fit in their receptors. also, local factors like adenosine and NO are released which cause DILATION, not a good thing. Vasodilation can also damage capilaries and cause edema, also loss of fluid which is bad. Cardiac function decreases over time, not sure why. As velocity decreases, viscosity goes UP and rolleaux formation happens! Hemoconcentration. |
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Up to what % of blood loss does compensation work?
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Up to 20% blood volume loss, compensation seems to be fine - small drop in CO, but that's due to increased sympathetic vasoconstriction.
after that, BP and cardiac output both tank. |
