Hemodynamic Concepts Flashcards
what is SV dependent on?
preload, afterload, contractility
CO =
HR * SV
normal CO?
4-8L/min
CI
more meaningful than CO
2.5-4 L/min/m^2
if CO is low, what is the first sign?
increased HR, happens before BP drops
SV
Left ventricular ejected volume, 50-100mL/beat
What are each ventricles preload measurements?
Right- CVP
Left- PAOP
What is preload?
the volume/pressure in the ventricle at the END of diastole, after the AV valves close
What is afterload?
the pressure against which the ventricle must pump to open the pulmonic and aortic valve
What are each ventricles afterload measurements?
Right- pulmonary vascular resistance PVR
Left- systemic vascular resistance SVR
What measurements change when preload increases?
SV and CO increase to a point
What measurements change when afterload increases?
SV and CO decrease
What measurements change when contractility increases?
SV and CO increase
MAP formula
DBP + 1/3(SBP-DBP)
CI formula
CO / BSA
stroke index
25-45 mL/beat/m^2, SV + BSA
CVP normal
3-8 cm H20
pulmonary artery pressure normal
20/8-30/15 mmHg
pulmonary artery occlusion pressure
8 - 12 mmHg
systemic vascular resistance
800-1200 dynes/s/cm^-5
pulmonary vascular resistance
50-250 dynes/s/cm^-5
mixed venous oxygen saturation (Sv02)
60-75%
central venous oxygen saturation (Scv02)
> 70%
arterial oxygen saturation (Sa02)
95-99%
