Zulfiqar Rana, MD, MPH, FACP

A stepwise approach to pre-op evaluation

The Algorithm

Step 1 High-risk surgery?

𑂽 Yes – proceed with caution, perioperative care optimized

𑂽 No – go to step 2

Step 2 Very high-risk patient?

Patients with recent MI (60 days) or unstable angina, decompensated heart failure, high-grade arrhythmias, or hemodynamically important valvular heart disease (aortic stenosis in particular) are at very high risk for perioperative MI, heart failure, ventricular fibrillation or primary cardiac arrest, complete heart block, and cardiac death?

𛲡 No – proceed to step 2

𛲡 Cardiology evaluation

Step 3 RCRI score <1% (use calculator 1)

𛲡Yes – proceed with surgery

𛲢NO – If no then measure functional capacity (calculator 2) 

Step 4 Functional Capacity  (use calculator 2)

𛲣 >4 METS – proceed with surgery

𛲡 <4 METS – need further cardiac evaluation (e.g., consider stress test or Echocardiogram, etc)

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Calculator 1: RCRI

Revised Cardiac Risk Index for Pre-Operative Risk

Estimates the risk of cardiac complications after noncardiac surgery.

High-risk surgery

No 0

Yes+1

Intraperitoneal; intrathoracic; suprainguinal vascular

No 0

Yes+1

History of ischemic heart disease

History of myocardial infarction (MI); history of positive exercise test; current chest pain considered due to myocardial ischemia; use of nitrate therapy or ECG with pathological Q waves

No 0

Yes+1

History of congestive heart failure

Pulmonary edema, bilateral rales or S3 gallop; paroxysmal nocturnal dyspnea; chest x-ray (CXR) showing pulmonary vascular redistribution

No 0

Yes+1 

History of cerebrovascular disease

Prior transient ischemic attack (TIA) or stroke

No 0

Yes+1

Pre-operative treatment with insulin

No 0

Yes+1

Pre-operative creatinine >2 mg/dL / 176.8 µmol/L

No 0

Yes+1

INTERPRETATION: 

0 pointsClass I Risk3.9 %30-day risk of death, MI, or cardiac arrest 1 pointsClass II Risk6.0 %30-day risk of death, MI, or cardiac arrest 2 pointsClass III Risk10.1 %30-day risk of death, MI, or cardiac arrest

ADVICE: 

According to the 2016 CCS Perioperative Guidelines:

• If the RCRI is ≥1, the patient’s age is ≥65, or they are between 45-64 with significant cardiac disease*, the next step is to measure the patient’s NT-ProBNP or BNP if this is available at your institution.

• If the NT-ProBNP is ≥300 ng/L or BNP is ≥92 ng/L, then there should be an EKG ordered in the PACU and troponins should be measured daily for 48-72 hours.

• If, after risk stratification, the NT-ProBNP is <300 ng/L or BNP <92 ng/L, no routine postoperative cardiac monitoring is warranted.

• If the institution does not have these assays available, then all patients should be monitored with an EKG in the PACU and troponin measurements daily for 48-72 hours if they meet one of the following: RCRI ≥1, age ≥65, or age 45-64 with the aforementioned cardiac disease.*

The data supporting the use of NT-ProBNP/BNP comes from a large 2014 meta-analysis of 18 studies with a total of 2,477 patients (Rodseth 2014). This study, which was in agreement with multiple previous meta-analyses, noted that for those patients with a pre-operative NT-ProBNP of <300 ng/l or BNP <92 ng/l, the rate of 30-day postoperative non-fatal MI or Death was 4.9% (3.9%-61%), and was 21.8% (19.0%-24.8%) in those with pre-operative NT-ProBNP is ≥300 ng/L or BNP is ≥92 ng/L.

 

*Known history of coronary artery disease, cerebral vascular disease, peripheral artery disease, congestive heart failure, severe PHTN or a severe obstructive intracardiac abnormality (e.g. severe aortic stenosis, severe mitral stenosis, or severe hypertrophic obstructive cardiomyopathy).

 

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Calculator 2: Duke Activity Status Index (DASI)

Estimates functional capacity

Is the patient able to:

Take care of self

e.g. eating, dressing, bathing, using the toilet

No 0

Yes +2.75

Walk indoors

No 0

Yes+1.75

Walk 1–2 blocks on level ground

No 0

Yes+2.75

Climb a flight of stairs or walk up a hill

No 0

Yes+5.5

Run a short distance

No 0

Yes+8 

Do light work around the house

e.g. dusting, washing dishes

No 0

Yes+2.7

Do moderate work around the house

e.g. vacuuming, sweeping floors, carrying in groceries

No 0

Yes+3.5

Do heavy work around the house

e.g. scrubbing floors, lifting or moving heavy furniture

No 0

Yes+8

Do yardwork

e.g. raking leaves, weeding, pushing a power mower

No 0

Yes+4.5

Have sexual relations

No 0

Yes+5.25

Participate in moderate recreational activities

e.g. golf, bowling, dancing, doubles tennis, throwing a baseball or football

No 0

Yes+6

Participate in strenuous sports

e.g. swimming, singles tennis, football, basketball, skiing

No 0

Yes+7.5

Calculation

 METs (metabolic equivalents) = 0.43 × DASI + 9.6 / 3.5

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