T1: Cardiovascular Assessment (3) Flashcards
3 ways to measure blood flow:
1) pulse contour
2) esophageal doppler
3) non-invasive doppler
With blood flow ___ ___ optimization should be the goal.
stroke volume
What is normal stroke volume variation (SVV)?
What are 2 ways we can evaluate the balance between oxygen supply and demand?
- lactate levels
- SvO2
What does lactate do?
Anaerobic metabolism of glucose (because not enough O2)
Serum lactate levels of _____ mmol/L indicates tissue hypoxia.
> 4 mmol/L
What does SvO2 measure?
O2 saturation of VENOUS blood
Where is venous oxygen saturation measured?
distal tip of the PA catheter or the central line catheter
SvO2 obtained from ___ line
PA (pulmonary artery) line
ScvO2 obtained from ___ catheter.
CV (central venous) catheter
Normal value of mixed venous oxygen saturation:
60-80%
What 2 things could be the cause behind a high SvO2?
1) the body just didn’t need as much O2 so there was some left over
2) the body could not use the O2 that was there
List 4 contributing factors to SvO2?
- cardiac output
- Hgb
- SaO2
- Tissue metabolism (VO2)
What do HIGH SvO2 values mean?
a lot of O2 on board
- hyperoxgenation
- anesthesia
- sepsis
- false reading
Why does sepsis reflect a high SvO2?
the cellular tissues are damaged and cannot use the available O2
