Perioperative Risk Assessment

Matt Brugger MD

Rush University Hospitalists

Division of Hospital Medicine

Director of Clinical Operations

Rush University Medical Center

October 2, 2015

•No disclosures or conflicts related to this presentation.•Focused on the Perioperative risk evaluation for patients undergoing Non-Cardiac surgery.

Objectives

• Evaluate a patient’s perioperative risk assessment using the patient’s risk factors, surgical risks, and functional status.

• Show several different risk assessment tools.• Demonstrate use of revised cardiac risk index in

specific cases. • Provide updates from the 2014 guidelines and

updated risk algorithm.

Example: Case 1

• 44 year old female with history of CAD, diabetes on insulin, stroke who presented with dysfunctional uterine bleeding.– Asked to provide pre op risk evaluation for exam under

anesthesia, possible hysterectomy.• Functional status adequate

• Surgery intermediate to high risk (pending if abdominal hysterectomy consider high risk)

– Low or elevated risk?• Elevated

– Further testing warranted?• Stress testing

• Stress deferred as further information received on review of OSH records (has 3 vessel CAD), bypass recommended 2 years prior.

• Patient refused further evaluation by CV Surgery, stated she would not have bypass. Uneventful hysterectomy performed.

• Many patients going for non cardiac surgery are at risk for perioperative cardiac event.

• Major adverse cardiac events (MACE) may include non fatal myocardial infarction, non fatal cardiac arrest, cardiac death, pulmonary edema, ventricular fibrillation, complete heart block, need for revascularization.

• Most recent guidelines from ACC/AHA were released in August 2014, previous update was in 2007.

• Perioperative risk evaluation prior to surgery is commonly asked of cardiologists, internists, and anesthesiologists.– It is not a cardiac clearance, but a risk

evaluation/assessment. – It can be a complex decision, that takes cardiac

and non cardiac factors into account.– Perioperative cardiac evaluation is not the only

aspect that can be addressed by these evaluations.

Example: Case 2

• 73 year old female with past medical history of RA, COPD, HTN, DM2, neuropathy who presented with shoulder RA and arthropathy for right reverse total shoulder arthroplasty.

– DM type 2 (not on insulin)

– Intermediate risk surgery

– No SOB/CP

– Adequate functional status

– Elective surgery

– Any further testing?

Perioperative Course

• No further testing done, proceeded to OR. • T inversions in OR• EKG with mild inversions, slight ST depression

– Repeat EKG similar, but persistent mild ST depressions

– TTE normal.

– Stress markedly abnormal• Found to have severe 3 vessel CAD on coronary angiogram

• CABG scheduled (within 2 weeks)

• Developed new crushing left sided chest pain with subsequent cardiogenic shock, required emergent CABG

– Was low risk on evaluation by revised cardiac risk index (would have been by other risk evaluations as well), but illustrates why it is not a clearance, but a risk evaluation.

Perioperative Risk Evaluation

• Several factors go into the determination of the perioperative risk evaluation. – Patient specific risk factors– Surgery risk factors– Functional status– Urgency of the surgery– Determination if patient is having ACS– Need for further testing– Other perioperative considerations

Patient Risk Factors

• Main predictors– History of CAD

– History of CHF

– History of TIA/Stroke

– History of Diabetes on insulin

– History of CKD with Cr over 2.

– Emergent surgery

– PAD (CAD equivalent?)

• Other predictors– Atrial fibrillation/arrhythmia with uncontrolled ventricular rate

– Obesity

– Pulmonary hypertension

– Aortic stenosis

– Recent PE

– Diabetes (not on insulin)

– Others (multiple)

Cardiac Risk Stratification for Noncardiac Surgical Procedures

High risk (reported risk of cardiac death or nonfatal myocardial infarction [MI] often greater than 5%)

•Aortic and other major vascular surgery

•Peripheral artery surgery

Intermediate risk (reported risk of cardiac death or nonfatal MI generally 1 to 5%)

•Carotid endarterectomy

•Head and neck surgery

•Intraperitoneal and intrathoracic surgery

•Orthopedic surgery

•Prostate surgery

Low risk (reported risk of cardiac death or nonfatal MI generally less than 1%)

•Ambulatory surgery

•Endoscopic procedures

•Superficial procedures

•Cataract surgery

•Breast surgery

Fleisher, LA. et al. Journal of American College of Cardiology 2007; 50:159.

Functional Status

• Functional status can be expressed in metabolic equivalents (1 MET is defined as 3.5 mL O2 uptake/kg per min, which is the resting oxygen uptake in a sitting position).– Can take care of self, such as eat, dress, or use the toilet (1

MET)– Can walk up a flight of steps or a hill or walk on level ground

at 3 to 4 mph (4 METs)– Can do heavy work around the house such as scrubbing

floors or lifting or moving heavy furniture or climb two flights of stairs (between 4 and 10 METs).

– Can participate in strenuous sports such as swimming, singles tennis, football, basketball, and skiing (>10 METs)

Cohn, SL, Fleisher, LA. UpToDate 2014.

Duke Activity Status Index (DASI)

Hltaky MA Boineau RE et al. Am J Cardio. 1989; 64: 651-654.

Duke Activity Status Index (DASI)

• Duke activity status index = Sum (values for Yes for 12 questions)

• Estimated peak oxygen uptake (VO2 peak) in mL/kg/min = (0.43 X (Duke Activity Status Index)) + 9.6

• METS = VO2 peak / 3.5 mL/kg/min• Somewhat cumbersome to ask all these questions. • Looked at an easier way, a sum of 10.2 or higher is 4

METS or higher. – If yes for questions1-4 (or yes to question 10 in place of 4),

they have 4 or greater METS.

Example: Case 3

• 50 year old male with significant past medical history of emphysema, tobacco abuse who presents with worsening right arm/leg pain and weakness.– Surgery is time sensitive intermediate risk surgery.

– At risk for worsening neurologic deficits and paralysis if not done.

– Functional status is limited due to his weakness, but was not having SOB/CP prior to this with exertion, and as recently as 2 months ago could exert himself to 4 or more METS.

– Pre op risk evaluation - revised risk score likely 0, possibly 1 if considered that could have had a stroke (listed in history, but symptoms more explained by cervical stenosis).

– Either way risk is 0.4-0.9% of major adverse cardiac event, and is low cardiac risk for surgery.

– No further cardiac workup recommended prior to surgery.

Risk Calculators

• Common Risk Calculators Used– Revised Cardiac Risk Index (RCRI)– American College of Surgeons National

Surgical Quality Improvement Program Risk Calculator (ACS-NSQIP)

– Gupta Myocardial Infarction/Cardiac Arrest Risk Calculator (MICA)

Revised Cardiac Risk Index (RCRI)

Six independent predictors of major cardiac complications

High-risk type of surgery (examples include vascular surgery and any open intraperitoneal or intrathoracic procedures)

History of ischemic heart disease (history of MI or a positive exercise test, current complaint of chest pain considered to be secondary to myocardial ischemia, use of nitrate therapy, or ECG with pathological Q waves; do not count prior coronary revascularization procedure unless one of the other criteria for ischemic heart disease is present)

History of HF

History of cerebrovascular disease

Diabetes mellitus requiring treatment with insulin

Preoperative serum creatinine >2.0 mg/dL (177 µmol/L)

Rate of cardiac death, nonfatal myocardial infarction, and nonfatal cardiac arrest according to the number of predictors

No risk factors - 0.4 percent (95% CI: 0.1-0.8)

One risk factor - 1.0 percent (95% CI: 0.5-1.4)

Two risk factors - 2.4 percent (95% CI: 1.3-3.5)

Three or more risk factors - 5.4 percent (95% CI: 2.8-7.9)

Revised Goldman cardiac risk index (RCRI)

Lee TH, Marcantonio ER, Mangione CM, et al. Circulation 1999; 100:1043. Devereaux PJ, Goldman L, Cook DJ, et al. CMAJ 2005; 173:627.

Lee Revised Cardiac Risk Index

• 1. High-risk surgical procedures– Intraperitoneal– Intrathoracic– Suprainguinal vascular

• 2. History of ischemic heart disease– History of myocardial infarction– History of positive exercise test– Current complain of chest pain considered secondary to myocardial ischemia– Use of nitrate therapy– ECG with pathological Q waves

• 3. History of congestive heart failure– History of congestive heart failure– Pulmonary edema– Paroxysmal nocturnal dyspnea– Bilateral rales or S3 gallop– Chest radiograph showing pulmonary vascular redistribution

• 4. History of cerebrovascular disease– History of transient ischemic attack or stroke

• 5. Preoperative treatment with insulin• 6. Preoperative serum creatinine > 2.0 mg/dL

Lee TH, Marcantonio ER, Mangione CM, et al. Circulation 1999; 100:1043.

Lee Revised Cardiac Risk Index

• RISK OF MAJOR CARDIAC EVENT• Points Class Risk

– 0 I 0.4%

– 1 II 0.9%

– 2 III 6.6%

– 3 or more IV 11%

• Similar to rates of the Goldman Revised Risk Index, slightly higher risk than Goldman Revised Risk Index for those with 2 or more points.

Lee TH, Marcantonio ER, Mangione CM, et al. Circulation 1999; 100:1043 .

Surgery Risk Calculator (ACS-NSQIP)

• ACS-NSQIP– Consists of 20 patient factors plus the surgical procedure.

– More comprehensive than other risk calculators.

– Much more involved, not as quick to do at the bedside.

– Not externally validated (as compared to RCRI)

© 2007 - 2015, American College of Surgeons National Surgical Quality Improvement Program.

Gupta Risk Calculator (MICA)

• Evaluates risk of Perioperative Myocardial Infarction or Cardiac Arrest (MICA) using several variables.– Age

– American Society of Anesthesiology (ASA) Class

– Preoperative Creatinine

– Preoperative Functional Status

– Procedure

American Society of Anesthesiology Classification

• ASA Classification:– 1. A normal healthy patient.

– 2. A patient with mild systemic disease

– 3. A patient with severe systemic disease

– 4. A patient with severe systemic disease that is a constant threat to life.

– 5. A moribund patient who is not expected to survive without the operation.

– 6. A declared brain dead patient whose organs are being removed for donor purposes.

Example: Case 4

• 61 year old female with significant past medical history of 80 pack year smoking history who presents with a lung mass and a L frontal brain lesion (CT with edema, minimal midline shift).– Pre op risk evaluation No personal history of CAD, MI, DM, CKD,

stroke, CHF, arrhythmia, DVT. No symptoms of OSA. Mother with MI at 70. No cancer history.

– Able to walk more than 4 blocks, more than 2 flights of stairs without issues. No limitations due to SOB/CP. No current SOB/CP.

– Low cardiac risk (revised risk score 0), with risk about 0.4% for major adverse cardiac events.

– Good functional status (over 4 METS), can do 4+ blocks, 2 or more flights of stairs.

– Surgery likely intermediate risk. Time sensitive surgery. – EKG without ischemia. No cardiac history of symptoms. – No further cardiac workup recommended at this time

2007 ACC/AHA Guidelines

Fleisher, LA. et al. Circulation 2007; 116:1971-1996

Example: Case 5

• 75 year old male with history of CHF, Diabetes (on insulin) ESRD who presents for right hip arthroplasty. Due to pain, really cannot ambulate nor do stairs (METS under 4). – Surgery intermediate risk. Elective. – Functional status poor by history (difficult to determine due

to functional limitations)– Elevated cardiac risk (revised risk score 3) with risk of

MACE of 11%. – EKG with non specific T wave changes (stable from

previous)– Should we do further testing?

• If so, what testing would you like?

Example: Case 6

• 75 year old male with history of CHF, Diabetes (on insulin) ESRD who presents with acute traumatic right hip fracture while ambulating to commode. Due to pain, really cannot ambulate nor do stairs at baseline (METS under 4). – Surgery intermediate risk. Urgent surgery– Functional status poor by history (difficult to determine due

to functional limitations)– Elevated cardiac risk (revised risk score 3) with risk of

MACE of 11%. – EKG with non specific T wave changes (stable from

previous)– Should we do further testing?

• If so, what testing would you like?

2014 Updates to 2007 ACC/AHA Guidelines

• Algorithm for assessing cardiac risk• Definitions of urgency and risk

– Emergency procedure:• Need for OR in < 6 hours

– Urgent procedure:• OR in 6-24 hours

– Time-sensitive procedure:• Delay of > 1-6 weeks (for workup) will negatively affect outcome

– Elective procedure: • Can be delayed up to 1 year

• Determination if patient is having Acute Coronary Syndrome (ACS)

• Simplification of risk into low risk or elevated risk.

2014 Perioperative Guideline

Fleisher, LA. et al. Journal of the American College of Cardiology 2014;64(22):e77.

Stepwise Approach

• Emergent surgery– Proceed to surgery

• Perioperative risk factor treatment/optimization especially post op.

• Urgent/Elective surgery– Is patient having ACS

• If yes, Cardiology evaluation

• Estimate risk of major adverse cardiac events (MACE)

• Definitions changed from low, intermediate and high risk to low and elevated. Most intermediate risk patients were being treated the same as high risk.

Stepwise Approach

• Low risk – Proceed to surgery

• Elevated risk– Evaluate functional status

• Functional status moderate to excellent (at least 4 METS)– Proceed to surgery

– Functional status poor or unknown• Determine if testing will affect management

• If testing will change management, then stress testing is reasonable

• Further testing usually means stress test, but occasionally could also mean echocardiogram.

Example: Case 7

• 74 year old male with past medical history of HTN, DM (on insulin), HLD, Prostate cancer, seizures, Left ischemic CVA (right hemiparesis) who presented with acute on chronic SDH. Was on ASA/Plavix, had a fall. Now with worsening lethargy.– Subfalcine herniation, right sided lesion has enlarged and is

exerting significant mass effect– Surgery is urgent/emergent (to be done that day per

surgeon)– Revised risk score 2 or 3 (3 if emergent surgery), elevated

cardiac risk. – Functional status poor (right hemiparesis)– EKG without ischemia/previous infarction– Other testing indicated?

• If so, what testing?

Example: Case 8

• 76 year old female with lung cancer, DM type 2 (on insulin) HTN, portal vein thrombus, admitted with lethargy, dizziness from ICH, possible hemorrhagic metastasis. Symptoms improving on dexamethasone.– Patient low cardiac risk for surgery with Revised risk score 1 (DM

on insulin), corresponding to a risk of major adverse cardiac events of 0.9%.

– Surgery intermediate risk, and time sensitive given neurologic changes related to bleeding (which are a bit better on steroids).

– Functional status over 4 METS.

– EKG sinus bradycardia without ischemia. Possible infarction noted on previous EKG's. Stress test done 2 months ago without ischemia.

– No further cardiac workup recommended prior to surgery.

2014 Perioperative Guideline

Fleisher, LA. et al. Journal of the American College of Cardiology 2014;64(22):e77.

Perioperative EKG

• Not all patients going for surgery need an EKG. • Commonly done on just about all patients.

– No standard age or risk factor cutoff to determine when it is needed.

– Ideal timeframe prior to surgery when checked is not known.• General consensus is somewhere within 3 months prior to surgery.

– Minimal benefit in asymptomatic patients going for low risk surgery.

– Reasonable to check in patients with known CAD, PAD, arrhythmia, strokes, structural heart disease or going for elevated risk surgery.

Perioperative Echocardiogram (TTE)

• Minimal benefit for routine evaluation of left heart function/Ejection fraction (EF).

• Reasonable to check when:– Moderate to severe stenosis or regurgitation suspected with no

recent (likely 1 year) or a new change in clinical status or physical since last evaluation.

– Dyspnea of unknown origin.

– Patient with CHF with a change in clinical status or worsening dyspnea.

• Consider if known left heart dysfunction and last evaluation over a year.

Example: Case 9

• 73 year old female with significant past medical history of DM type 2 not on insulin), HTN, GERD, OA, renal cell cancer, breast cancer who presents with worsening LE pain, weakness and back pain. – Revised risk score 0. Risk of MACE about 0.4%

– Surgery (tumor metastases resection) intermediate risk.• Probably time sensitive (possibly elective) as pain and weakness worsening and

progressive, but no cord compression nor acute fracture.

– Stress 2/2014 which was normal, and showed normal LV function at that time.

– The main current abnormality is unexplained DOE, present for 1-2 years.

– Reports of orthopnea, but she has no signs of CHF on her exam with clear lungs, no LE edema, no JVD.

– No murmur nor symptoms to suggest aortic stenosis.

– Further testing?• What test would you like if any?

Other Perioperative Considerations

• OSA– Suspected OSA can be evaluated by the STOP BANG

score.– If known, continue patients CPAP.– Elevate head of bed for patient when sleeping if not on

CPAP.

OSA Risk, STOP BANG Score

• Height ___________ Weight _________ Age __________ Male / Female ___________

• STOP-BANG Sleep Apnea Questionnaire

• STOP – Do you SNORE loudly (louder than talking or loud enough to be

heard through closed doors)? Yes No

– Do you often feel TIRED, fatigued, or sleepy during daytime? Yes No

– Has anyone OBSERVED you stop breathing during your sleep? Yes No

– Do you have or are you being treated for high blood PRESSURE? Yes No

• BANG – BMI more than 35kg/m2? Yes No

– AGE over 50 years old? Yes No

– NECK circumference > 16 inches (40cm)? Yes No

– GENDER: Male? Yes No

• TOTAL SCORE – High risk of OSA: Yes 5 – 8

– Intermediate risk of OSA: Yes 3 - 4

– Low risk of OSA: Yes 0 - 2

Example: Case 10

• 75 year old male with significant past medical history of OSA, PE, HTN, hypothyroidism, HLD who presents with acute onset of weakness over the past week with inability to ambulate well due to recurrent falls. No history of MI, CAD, CHF, arrhythmia, CKD, DM type 2, stroke. Able to do 4 blocks and 2 flights of stairs prior to this event.– Patient low risk for intermediate risk surgery by revised risk index. RCRI

score 0, corresponding to 0.4% risk of major adverse cardiac events. – Surgery (severe spinal stenosis), intermediate risk. Time sensitive if

causing his symptoms. – Functional status over 4 METS (until weakness in past few days), no

active cardiac complaints. No SOB/CP. – EKG essentially normal, unchanged from previous (from 3 months ago

when had previous surgery). – no further cardiac testing recommended prior to surgery– continue CPAP post op

Other perioperative considerations

• Pulmonary hypertension– Can be associated with higher complication rate.

– Evaluation of RV function prior to surgery reasonable.

– Evaluation by pulmonary HTN specialist recommended if any significant RV dysfunction or high pulmonary artery pressures.

• Chronic steroid use or adrenal insufficiency– Stress dosing of steroids recommended

• Hypothalamic pituitary access can be affected by steroids even taken just a week, and time of affect is unpredictable. (days to months)

• For any chronic use of 20 mg prednisone (or equivalent) for 3 or more weeks.

• Not needed for doses of prednisone 5 mg or lower daily.

• No consensus for doses in between 5-20 mg, but typically will receive stress dosing for doses over 5 mg prednisone daily.

Other perioperative considerations

• Anticoagulation– A challenging topic– Main question is if therapy interrupted for surgery, is bridging

necessary?

• Liver disease– In patients with cirrhosis, risk of perioperative morbidity and

mortality much higher than risks calculated based on cardiovascular risk.

– If evaluating patient with cirrhosis, recommend having hepatology involved given the risks.

• Most elective surgeries are not recommended in setting of decompensated cirrhosis.

Other Perioperative Considerations

• Conduction abnormalities– Generally without advanced heart block, most do not progress to

complete heart block perioperatively.

– Can be concerning in some cases

• Case 11– 85 year old male with history of DM type 2, stroke, CAD with MI, CABG,

CKD, HTN, gout who presents with HA. Found to have cerebellar lesion– Patient with 1 degree AV block, 2nd degree type 1, RBBB, and LAFB

(Trifasicular block).– Bradycardia (into 20’s) and dropped beats, – During stress had accelerated idioventricular rhythm. – Appeared to have a few 8-10 beat runs of V tach on monitor.– EP evaluation (patient received transvenous pacer prior to surgery)

Questions?

References

• Bilimoria KY, Liu Y, Paruch JL. et al. J Am Coll Surg. 2013 Nov;217(5):833-42.• Chung, F. Yegneswaran, B. et al. Anesthesiology 2008; 108:812-821.• Cohn, SL, Fleisher, LA. UpToDate 2014. Accessed September 2015.• Devereaux PJ, Goldman L, Cook DJ, et al. CMAJ 2005; 173:627.• Fleisher, LA. et al. Circulation 2007; 116:1971-1996. • Fleisher, LA. et al. Journal of American College of Cardiology 2007; 50:159. • Fleisher, LA. et al. Journal of American College of Cardiology 2014;64(22):77.• Gupta, P. et al. Circulation 2011;124(4):381-387. • Hltaky MA Boineau RE et al. Am J Cardio. 1989; 64: 651-654.• Lee TH, Marcantonio ER, Mangione CM, et al. Circulation 1999; 100:1043.• Shaw, M. Cleveland Clinic Journal of Medicine 2002; 69 (1): 9-11.