Case 2 - Recent MI Flashcards
Patient comes to your pre-op clinic for evaluation and clearance prior to surgery. How would you assess the cardiac history?
1) severity and reversibility of CAD
* RF, anginal patterns, history of MI
2) LV and RV function
* excercise capacity, pulm edema, pulm HTN
3) presence of sympatomic arrhythmias
* palpitations, syncopal or presyncopal episodes
4) coexisting valvular disease
5) presence of PPM or ICD
What is considered 4 METs, what is considered less than 4 METs
METs 1 to 3:
- eat, dress, use toilet
- walk indoors around house
- walk a block or 2 on level ground
METs of 4 or greater:
- do light work around house (washing dishes)
- climb a flihgt of stairs or walk up a hill
- run a short distance
What are active Cardiac condtions that require noninvasive testing?
Active Cardiac Conditions / Major Clinical Risk Factor
- Unstable coronary syndromes
- unstable angina
- Recent MI (w/i 7-30 days -> high rate of reinfarct)
- decompesated CHF
- Significant arrhythmias
- 3rd degree AVB, mobitz type 2
- symptomatic ventric arrhythmias
- SVT with RVR (> 100 bpm)
- symptomatic bradycardia
- Severe valvular disease
- Severe AS
- mean pressure gradient > 40 mm Hg
- AVA < 1.0
- symptomatic - angina, DOE, syncope
- severe MS
- symptomatic (DOE, exertinal presyncope, CHF)
- Severe AS
What are considered high risk surgeries? What makes them high risk surgeries?
high risk surgery
-
procedures with greater potential for hemodynamic cardiac stress
- alterations HR, BP fluctuation, fluid volume shifts, clotting issues, oxygenation issues, neurohumoral activation, blood loss, pain
- all factors lead to increase in periop cardiac events (PCE)
- aortic and other major vascular surgery
- peripheral vascular surgery
Review the algorithm for managing a patient with CAD underoing noncardiac surgery
clinical risk factors:
revised cardiac risk index
- ischemic heart disease
- CHF
- DM (insulin dependent)
- CVA
- SCr > 2
You go through algorithm and decided to order a noninvasive cardiac test (like dobut stress echo), it shows reversible drug induced ischemia. Which patients should be considered for coronary revascularilzation before noncardiac surgery?
Coronary revascularization:
- includes percu coronary angioplastic, stent, and CABG
coronary revasc before noncardiac surgery:
- stable angina with left main coronary stenosis
- stable angina with 3-V disease
- stable angina with 2-V disease + significant proximal LAD stenosis and EF < 50% or ischemia on noninvasive testing
- STEMI
- unstable angina or NSTEMI
what are the recommendations for stent/PCA and noncardiac surgery?
patients should remain on dual antiplatelet therapy prior to elective surgery for…
PCA - wait > 4 weeks
BMS - wait > 6 weeks
DSE - wait > 12 months
**CABG - no specific recommendation. **
- resonable to wait 4-6 weeks with CABG
continue ASA in all cases during perioperative period
patient has a recent DES placed (2 months ago), and he comes for emergent surgery. Should his dual anti plt therapy be continued during periop period?
- dual antiplatelet therapy should be continued in periop period if possible
- if not, then continue ASA and restart thienopyridine (plavix) ASAP
- ALWAYS asses risk vs benefit: does decrease in surgical bleeding outweigh risk of stent thrombosis
What intraop monitors would you use in a recent MI patient presenting for emergent surgery?
1) Arterial line
- beat to beat blood pressure monitoring
- maintain BP within 20% of preop values
- facilitate lab testing: glucose, acid-baes status, h/h
- hyperglycemia independent risk factor of periop cardiac event
2) temperature
- normothermia. hypothermia inc o2 demand
3) EKG
- multilead EKG. Lead II and V5 - detects >90% ischemic episode
- ST segment continuous analysis
- not useful in LVH, LBBB, Ventric PPM, conduction abnormalities
4) PAC
- V waves on PCWP is an indication of myocardial ischemia (not reliable)
- intravascular volume status
- SVo2
- calculate PVR, SR, SV
5) TEE
- most sensitive detector of intraop ischemia
- RWMA
- LVEF, intravasc status, LV/RV function
patient is having ischemia and hemodynamic aberrations intraop, what will you do treat?
myocardial supply and demand imbalance
- goal: increase supply, decrease demand
-
Decrease demand
- dec HR - BB
- dec contractility - BB
- decrease afterload - BB and NTG
- decreaes preload - nitroglycerin
-
increase supply
- SaO2 increase
- h/h
- increase aortic diastolic pressure - phenylephrine
what are your anesthetic managemnet goals in a patient with recent MI, presenting for surgery?
no anesthetic technique proven to be superior
Goals: maintain o2 supply and demand balance
-
avoid tachycardia (ketamine, panc)
- opioid for pain control
- avoid inc afterload
-
avoid inc preload
- judicious fluid use. use vasopressor for hypotension
-
avoid inc contracility
- use inhaled anes / IV anesthetic - dec myocardial contracility, venodilator and dec SVR
how would you manage this patient who underwent emregent surgery with a recent MI postoperatively?
- ICU for continous monitoring
- hemodynamic alterations, hypothermia, ischemia)
- **Most common time for periop cardiac events is w/i 48 hrs of surgery**
- serial troponin measurement with chest pain or EKG changes
- proper pain managment to avoid excess sympathetic stimulation -> inc o2 demand
