Perioperative Medicine Flashcards
The Pre-op Assessment
The Checklist:
-Cardiac risk assessment
+ Don’t forget endocarditis prophylaxis
-Delirium Risk and Frailty
-Medications and withdrawal
-Anticoagulants
-Antiplatelets
-Heme considerations:
-VTE prophylaxis
-Anemia optimization
-Coagulopathies (liver, ITP,
VWD etc.)
-Metabolic: Diabetes, stress
steroids
Cardiac Risk Assessment
We DON’T delay emergent/urgent surgery
* Exceptions? … Active ACS, decompensated HF, unstable arrhythmia (things
you can emergently optimize)
– We DO delay purely elective surgery for medical optimization
* Example: patient with poorly controlled diabetes before elective TKA
Emergency surgery
(“A Case” life/limb in 6hrs ex. Trauma, AAA rupture, nec fasc)
If pt >65 or 18-64 w/ major CVD :
-postop Trop X 48-72h
-PACU ECG
-“shared care management”
Major/Significant CVD=
* Known CAD
* Cerebral vascular disease
* Peripheral Artery Disease
* CHF
* Severe pulmonary HTN
* Intracardiac obstruction
* severe aortic/mitral stenosis,
HOCM
Urgent Surgery = “B case” Surgery w/in 24-48h– SBO, Hip Fracture
Semi-urgent Surgery = Cancer (‘elective’ in that they are outpatients but you’re not going to delay it)
Go to OR
Consider pre-op tests only if you suspect:
- Severe obstructive cardiac condition (ex AS)
- Severe pulmonary HTN
- Unstable cardiac condition - active ACS or arrhythmia
If pt >65 or 18-64 w/ major CVD :
- postop Trop X 48-72h
- PACU ECG
- “shared care management”
Elective Surgery *requiring overnight hospital stay
Calculate RCRI score
to assess risk of MACE
Measure BNP if:
≧65y or
RCRI≧1 or
45-64y w/ major CVD
BNP Normal
= no additional routine postop
monitoring
BNP Abnormal
or BNP unavailable:
-postop trop x 48-72h
-PACU ECG
“shared care management”
Post-Op Troponin – why bother?
CCS: >65% of patients suffering a perioperative myocardial
infarction do not experience ischemic symptoms
* “MINS” myocardial injury after noncardiac surgery
* In CCS defined as elevation of Troponin T (4th generation
Tn) > 0.03 ng/mL
* Myocardial injury due to ischemic mechanism
– supply-demand mismatch… not due to other cause (renal failure, PE etc.)
– Asymptomatic MIs / MINS are associated with a similar increased risk of 30-day mortality as symptomatic myocardial infarctions
treating MINS
How do you treat someone with an asymptomatic post-op troponin elevation?
– 2016 Guideline less prescriptive about what to DO with the ↑troponin
* Start ASA, statin (Strong Recommendation)
* “Shared care”, Close follow-up by the thorough internist
- “Area of ongoing research”
– MANAGE Trial (Lancet, 2018) – dabigatran 110 mg BID ↓MACE (NNT 25) in postop MINS - Follow-up mean 16 months. Nearly 1⁄2 discontinued meds in both groups.
- No increased risk in MAJOR bleeding
- Rates of MACE 11% in dabigatran group, 15% in placebo
AHA 2021 Statement on treating MINS * MINS Treatment = Consider etiology:
* atherosclerotic plaque disruption (type 1 MI) – consider revascularization, DAPT, high
intensity STATIN, BB, ACE/ARB
* supply-demand mismatch (type 2 MI) : (eg) bleeding triggering demand ischemia.
– Rx antithrombotic if appropriate, statin, non-invasive testing.
Everyone: non pharm and pharm mgmt.
Valvular Disease
Request Echo if clinically suspected moderate-severe
stenosis/regurgitation
* If meet standard criteria for valve intervention,
should delay elective non-cardiac surgery for
cardiology assessment / valve replacement/repair
* If need for urgent/emergent OR, and suspicion of
severe AS/MR/AR/MS –Get Echo and inform anesthesia, get intra-op monitoring
and post-op monitored bed
Criteria for Valve Intervention to know:
Severe AS on echo
Abnormal systolic AV opening with
Vmax ≥ 4m/s or
Pmean gradient ≥ 40mmHg
Class 1 indications for AVR
– Class 1 indications to replace:
* Severe AS with symptoms
* OR Severe AS without symptoms, but EF <50%
* OR Severe AS going for other cardiac surgery ex CABG
Lookout for “Low Flow or Low Gradient AS”
Suspect if: Symptoms of Severe AS
but Vmax only 3-3.9m/s, or (LOW FLOW)
Pmean 20-39mmHg (LOW GRADIENT)
Classically, in patients with reduced LVEF, but can occur with preserved
EF and low stroke volume. The low output results in
‘pseudonormalization’ of gradients and will underestimate AS severity
What to do with “Moderate” AS
by ECHO w Severe AS Symptoms
KEY CONCEPTS: low flow / low gradient AS is
advanced stage AS + is symptomatic, but
does not meet ECHO criteria for severity
– If SYMPTOMATIC + EF <50 = order dobutamine
stress echo
* “Classical low-flow, low gradient” – 5-10% AS!
– If SYMPTOMATIC + EF >50 = AVR if expert
believes AS cause of symptoms
Perioperative A. Fib (POAF)
POAF is associated with higher risk of postoperative:
– Stroke
* Thromboembolism risk 3% per year in pts with POAF after noncardiac surgery;
similar to 3.2% risk in Nonvalvular afib
– MI
– Vascular and all-cause mortality
- For non-cardiac surgery patients, there is SPARSE guidance/RCTs
– Only about 20-30% of patients with perioperative A Fib receive anticoagulants
– ASPIRE-AF trial currently recruiting (McMaster led) to answer this question –
does NOAC given to treat POAF reduce risk of stroke and systemic
embolization, vascular mortality?
Post-operative Atrial Fibrillation (POAF)
Some reviews (not systematic) suggest anticoagulation if patient
has >48 hrs of a. fib and CHA2DS2-VASC is ≥ 2
- A recent retrospective study found that POAF portends similar risk
of embolism compared to non-valvular AF - Bottom line: Weigh risk benefit on each case
– Prolonged outpatient monitoring/clinic follow-up might be most prudent
– No wrong answer on oral exam [”weigh risk/benefits and follow-up”]
Delirium and Elective Surgery
T-here are validated tools to estimate pre-
op risk of delirium for elective non cardiac surgery
- There are validated screening tools to
detect delirium post-op (CAM) - There are interventions that reduce risk of
post operative delirium in at-risk patients
– Pre-op Comprehensive Geriatric Assessment 1
– Multicomponent interventions:
Perioperative Medication Management
– DON’T start β-blocker within 24 hours of noncardiac surgery (ref: POISE, 2008)
– DO CONTINUE β-blocker perioperatively if patients taking chronically
THE EXCEPTIONS:
In scenarios where a beta-blocker is clearly indicated (ex. Angina or arrhythmia like rapid AFIB… give beta blockade as you usually would, proceed to OR when appropriate)
ASA
Physicians should discontinue ASA at least 3 days before non- cardiac surgery to reduce the risk of major bleeding.
– UNLESS: recent coronary stent or pre-op major vascular surgery (or CVSx)
– “Recent” = 6 weeks BMS, 3-12 months DES [depends on stent generation]
REAL WORLD : Continue ASA with history of coronary stent even >1 year “wherever possible (unless procedure very very high risk bleeding ex.
neurosurgery)”… per CCS 2018 Antiplatelet Guidelines
Other antiplatlets:
Remember the caveat – if indication was a recent PCI, risk of stent thrombosis must
be weighed with risk of bleeding.
- Ticagrelor ≈ clopidogrel
– hold 5 days preop for most indications
– hold 7 days for very high bleeding risk - Prasugrel
– hold 7 days for most indications
– 10 d for very high bleeding risk - irreversible platelet inhibition
Statin
-We recommend continuing statin therapy perioperatively in patients who are on chronic statin therapy
– Patients with MINS should be considered to START statin therapy post-operatively
ACE Inhibitors / ARBs
– We recommend holding ACEI/ARB starting 24 hours before noncardiac
surgery in patients treated chronically with an ACEI/ARB. “Restart day 2 after
surgery if patient is hemodynamically stable”
DMARDs and Biologics
“I would consult with the surgeon and rheumatologist”
- 2022 Meta-analysis1 of biologics pre-orthopedic surgery suggested no difference in infection if continued but ↑ risk of rheumatologic flares if held pre-op
- 2022 American College of Rheumatology2 guidelines for the Perioperative
Management in Pts undergoing elective hip and knee replacement:
– Nonbiologic disease-modifying antirheumatic drugs may be continued throughout the
perioperative period.
– Severe (organ-threatening) SLE biologics continue w consult of rheum.
– Biologic medications should generally be withheld as close to 1 dosing cycle as
scheduling permits prior to elective THA/TKA & restarted after evidence of wound
healing. (eg) infliximab dosed q4 weeks: skip dose, surgery week 5
– Restart medication once wound shows evidence of healing, once staples/sutures out,
typically ~ 14d.
Timing of surgery with Stents
Elective surgery
* Delay 14 days after POBA
[AHA/ACC 2014, no guidance in CCS 2018]
* Delay at least 1 month after BMS
* Delay at least 3 months after DES
* If semi-urgent (ex. Malignancy, where
feasible) delay at least 1 month post-PCI
* Continue ASA wherever possible
[CCS 2018 Antiplatelet Guideline, weak recommendation]
* Hold clopidogrel / ticagrelor 5-7 days,
prasugrel 7-10 days
Urgent/Emergent surgery
* Do not delay. Book monitored bed,
counsel patient
– Decision to stop P2Y12 platelet receptor-
inhibitor = Talk to patient, cardiologist,
anesthesiologist and surgeon
– Usually surgery by being URGENT
means operation in <48h so even if you
stop clopidogrel, its effect will be active
for 3-5 day = no neuraxial anesthesia
* Restart DAPT after surgery “as soon as
deemed safe by surgeon”
Timing of surgery post-Stroke
Strokebestpractices.ca doesn’t give guidance on timing of surgery after acute stroke. - AHA/ACC
Scientific Statement suggests wait 6 months
Re Antiplatelets: “continue ASA for low/moderate risk bleeding procedures / interrupt ASA for high risk surgery/procedure”
Cardio + Vascular Surgeons are Special
Perioperatively, all patients undergoing elective vascular surgery need to be
on an antiplatelet
– Usually ASA 81mg-325mg
– 1 study (CAPRIE, ~6500 pts) showed monotherapy clopidogrel reduced MACE more
than ASA.
– For non carotid surgery, DAPT is not routine. They suggest “ASA, Clopidogrel or ASA +
Clopidogrel” for lower extremity bypass – surgeon specific, ask your surgeon.
- Carotid surgery
– Symptomatic extracranial Carotid stenosis –go for urgent revascularization (Carotid
Endarterectomy) = “ASA and P2Yi continued perioperatively” (if on SAPT continue ASA
perioperatively)
Cardiac Surgery
– GIM exam focuses on NON cardiac surgery.
– CV surgery patients continue ASA periop.
– P2Yi is usually held if going ”on pump” (bypass)
* Hold Clopidogrel 2-7 days based upon hemodynamic stability, anatomy etc [CCS 2023]
* Hold ticagrelor 2-3 days prior to CABG rather than 5-7 [CCS 2023]
* Recommend DAPT be restarted postop “as soon as it’s safe”
