Special populations shannon Flashcards
The myocardium receives ___% of the oxygen delivered to it
70
If the heart requires more oxygen, it must ____
increase coronary blood flow, or CaO2 must increase
___ increases oxygen demand, and decreases oxygen delivery
Tachycardia
What can decrease CaO2?
Hypoxemia
Anemia
What can increase O2 demand?
Tachycardia
HTN
SNS
Increased LVEDV, inotropy, wall tension, afterload
What is the most useful measure of coronary perfusion?
MAP
BNP is release in response to ___
Wall stress, and is a marker for HF diagnosis
ANP is released in response to ____
FVO
Degree of HF as per EF
Normal >50%
Mild 41-49
Moderate 36-40
Severe <24%
“dont stress this”
Causes of SHF
CAD/ ischemia
Dilated CMP
FVO (from valve regurg)
Systolic HF anesthetic considerations (preload, afterload, inotropy, HR)
Preload- avoid FVO, diuretics if too high
Afterload- decrease but maintain CPP, SNP works well if volume adequate
Inotropy- augment with inotropes if needed, avoid reducing inotropy
HR- usually high, if EF is low, give anticholinergics?
What is the most common type of HF in women and the elderly?
Diastolic dysfunction
Causes of diastolic HF
MI
Stenoses valves
HCMP
HTN
Cor pulmonale
Obesity
Diastolic HF anesthetic considerations (preload, afterload, inotropy, HR)
Pre- Volume required (LVEDP does NOT correlate with LVEDV)
Afterload- already elevated, use phenyl to keep it high to maintain perfusion to thick myocardium
Inotropy- avoid depressing
HR- keep is slow to max CPP
What agents will increase PVR?
N2O and des