0613 - Intro to Shock - RM Flashcards
Define Shock
A state of cardovascular disfunction resulting in generalised inadequacy of oxygen delivery (DO2) RELATIVE to metabolic requirements.
What are the four classes of shock?
Hypovolaemic CardiogenicSeptic/VasodilatoryObstructive
What is hypovolaemic shock?How does the body compensate?
Shock caused by a low volume of blood. Not getting enough blood into heart to give enough preload to get a good stroke volume. Need to increase HR and vasoconstrict to compensate.
What is cardiogenic shock?How does the body compensate?
Shock caused by failure of heart to pump enough blood out (either too much preload or low contractility) - i.e. low stroke volume.Need to increase HR and vasoconstrict to compensate
What is septic shock?How does the body compensate?
Shock caused by toxins/cytokines that trigger peripheral vasodilation, reducing SV and BP.Body struggles to compensate - need to give massive fluids and vasoconstrict.
What is obstructive shock?How does the body compensate?
Shock caused by a deficit in flow to the heart, while enough blood remains in the system. Reduces SV.Body increases HR to compensate, but need to fix the obstruction.
What is the O2 delivery Equation?
DO2 = COx([Hb]xSaO2x1.39) + PaO2x0.003