Preoperative assessment Flashcards
Which 5 conditions confer a 1.5 x increase of perioperative death?
All 1.5 x risk
MI HF CVA PVD RF
To what extent does T1DM and T2 DM increase the risk of perioperative death
T1DM - 3 x risk
T2DM - 2 x risk
To what extent does SBP consistently above 160 mmHg increase perioperative mortality?
1.5 x
What effect does small reductions in high BP have on the perioperative morbidity and mortality risk?
They reduce stroke risk
They do not reduce MI or mortality risk
The reduction in stroke risk provided by pre-operative antihypertensive treatment should be weighed against the cost of delaying surgery
Compare the risk risk of dying the month before an MI with the month after an MI
Risk of dying in the month after MI is 50 x the risk of dying the month before and MI
What is the risk of dying at 12 months after an MI
1.5 - 3.0 times
How long should surgery be delayed post MI
3 - 6 months
How long after the placements of coronary stents/CABG is the perioperative risk of dying no longer elevated?
6 months
What is the risk of perioperative death 12 months after coronary artery stent placement if clopidogrel is stopped (for surgery) and what are the implications?
5 x increased risk of perioperative mortality
Implicaitons: Management of patient’s receiving anti-platelet medication should be jointly planned with the cardiologist
Compare the absolute risk of arterial thromboemboli for new biological Aortic valves not on warfarin with the absolute risk of arterial thromboemboli for new mechanical MITRAL valve on warfarin
Mechanical mitral valve on warfarin: 1:1000 monthly risk
Biological aortic valve NO warfarin: 1:2400 monthly risk
What should AF rate be prior to surgery?
< 100 bpm
What determines if patients on warfarin should be changed to heparin for the peri-operative period?
This depends on the nature of the surgery
Under what circumstances and when should aspirin be stopped prior to surgery
If aspirin is stopped, it should be stopped 5 days before surgery.
The risk of bleeding if aspirin is continued is exceeded by the risk of thrombosis except for surgeries: brain, spinal canal, prostate.
In what types of surgeries should aspirin be stopped ad why
Brain
Spinal cord
Prostate
Risk of bleeding exceeds risk of thrombosis in these surgeries
When should statins be stopped before surgery
DON’T STOP. reduce the risk of myocardial infarction, angina and heart failure,
When should CCB’s be stopped and why
DON’T STOP. reduce the risk of myocardial infarction, angina and heart failure,
When should BB be stopped and why
DON’T STOP. reduce the risk of myocardial infarction, angina and heart failure,
When should ACE I / ARB be stopped?
Stop ACE I in patients with major risk of haemorrhage or those planned for epidural anaesthesia.
Profound hypotensive episodes with regional and general anaesthesia
Should thiazide diuretics and spironolactone be stopped and why
DON’T STOP. reduce the risk of myocardial infarction, angina and heart failure,
When SHOULDN’T warfarin be stopped?
When the surgery can be performed with elevated INRs:
Eye,
dental,
endoscopies (bladder/bowel/uterus)
How long before surgery should warfarin be stopped?
The last does of warfarin should be taken 5 days before surgeries for which the risk of bleeding exceeds the risk of thrombosis.
When should warfarin be replaced by subcutaneous high dose LMWH
When the absolute risk of thrombosis is high
- a mechanical mitral valve or previous CVS events require LMWH
Example of a low risk patient: AF only (normal valves, no previous CVS events) –> in these circumstances LMWH not required