PERIOPERATIVE RISK ASSESSMENT AND EVALUATION FOR NONCARDIAC SURGERY Consultative Medicine Jayne Barr, MD, FACP, FAAP.

PERIOPERATIVE RISK ASSESSMENT AND EVALUATION FOR

NONCARDIAC SURGERY

Consultative Medicine

Jayne Barr, MD, FACP, FAAP

Outline

Role of consultantIntroductionRecommendations

Cardiac risk assessment Pulmonary assessment

MiscellaneousAlgorithm 2007

Introduction

In US, millions of patients undergo surgical procedures each year

Most morbidity & death occur in the post-op period & is of cardiac, pulmonary, neurologic, or infectious origin

MIs usually occurs w/in the first 4 days after surgery & is associated with a 15-25% mortality rate

Introduction

Nonfatal post-op MI is an independent risk factor for future infarction and death w/in 6 months after surgery

ACP guidelines similar to ACC/AHA except that ACP does not recommend use of exertional capacity (METs) to guage cardiovasc risk

Rationale for Perioperative Medicine Consultation

The cost of preoperative testing is estimated to be about $18 billion for the 30 million surgical cases performed annually in the US.

Average cost---$600 per casePreoperative clinic visits reduce the number

of tests ordered by approximately 55%

• Fischer S. 1996 Anesthesiology. Development and effectiveness of an anesthesisa preoperative evaluation clinic in a teaching hospital.

Perioperative Medical Assessment Goals

Efficient utilization of the sources and eliminating unnecessary tests and consults.

Reduce the length of stay and morbidityOptimizing the patient before surgery well in

advanceImproves the quality of perioperative careImproves surgical outcomesFamily and patient satisfaction

Role of the Consultant

Evaluate and optimize patient’s medical status

Treat modifiable risk factorsOffers opinions about operative risk and

perioperative managementRecommend measures to minimize

perioperative complicationsFocus over the entire perioperative periodLong term patient outcomes

What Not to Do

Recommend for or against surgeryTell anesthesiologist how to do their jobRecommend the obvious“clear” the patientSay nothing

Purpose of the Guidelines

Goal is not to “medically clear” ptProvide a risk profile based on pt’s medical

status and make recommendations concerning the management and risk of cardiac problems over the entire perioperative period

Methodology and Evidence

ACC/AHA conducted literature searches in PubMed, MEDLINE, and Cochrane Library from 2002-2007

Searches limited to English language and human subjects

Applying Classification of Recommendations and Level of Evidence (LOE)

Class I- Evidence that procedure is beneficial, useful, and effective

Class II- Conflicting Evidence Class IIa- Weight is in favor of usefulness/efficacy Class IIb- Efficacy is less well established

Class III- Evidence that procedure is not useful and may be harmful

Applying Classification of Recommendations and Level of

Evidence

Level of Evidence A- Data from multiple, randomized, clinical trials or meta-analysis

Level of Evidence B- Data from single-randomized trial or large non-randomized trial

Level of Evidence C- Only consensus opinion of experts, case studies, or retrospective studies, standard-of-care

ACC Guidelines—Clinical Risk Factors

Major Clinical Predictors

Unstable coronary syndromes ACS unstable angina

Recent MIAcute

decompensated HF

Significant arrhythmias VT Bradyarrhythmias High grade AV blocks Paced rhythms Uncontrolled SVT

Severe valvular disorders AS -- mean pressure gradient

> 40 mmHg or valve area < 1.0 cm2, or symptomatic

Symptomatic MS

Intermediate Predictors

Minor Clinical Predictors

History of prior MI History of

compensated or prior heart failure

History of CVADMRenal

insufficiency/CKD

Advanced ageAbnormal ekg

LVH, LBBB, ST-T abnormalities

Rhythm other than sinus rhythm

Low functional capacity

ACC Guidelines—Clinical Risk Factors

Cardiac Risk Stratification for Surgical Procedures

High (cardiac risk > 5%)

Intermediate(cardiac risk 1-5%)

Low(cardiac risk <1%)

Aortic and major vascular surgery

Peripheral vascular surgery

Emergent major operations, esp in elderly

Prolonged surgeries associated with large fluid shifts or blood loss

Intraperitoneal or intrathoracic surgery

Carotid endarterectomy

Head and neck surgery

Orthopedic surgery Prostate surgery

Endoscopic procedures

Superficial procedure

Cataract Breast surgery Ambulatory

procedure

Cardiac Risk Evaluation

Surgery induces changes that predispose to ischemia Anemia Hypotension Hypothermia Increased catecholamine levels

The revised cardiac risk index is helpful to stratify risk

Revised Cardiac Risk Index6 factors that indicate increased risk

Ischemic heart diseaseCompensated or prior heart failureCerebrovascular diseaseDiabetes mellitusRenal insufficiency (creatinine > 2 mg/dL)High risk surgical procedure

Intraperitoneal/intrathoracic, vascular

Based on 4315 pts undergoing elective major surgery. Lee, TH et al, Circulation 1999, 100:1043-1049

Risk of Major Cardiac Event(Lee Criteria)

POINTS(# of risk factors)

CLASS RISK(%

complication)

0 I 0.4%

1 II 0.9%

2 III 6.6%

≥ 3 IV 11%“Major Cardiac Event” includes MI, pulm edema, vfib, cardiac arrest, complete heart block

Recommendations- Who needs these tests prior to surgery?

EKGCXRAssess LV function--echocardiogramNoninvasive stress testingPre-op coronary revascularizationBeta-blocker therapy

Who needs it? Relevant data

CAD or other CAD risk factors

Hypertension, diabetes

History of arrhythmia

? men > 40? Women > 50

ArrhythmiasIschemic changesProlonged QTc

EKG

Recommendations for Pre-op EKG

Class I & II 0-1 clinical risk factor & vasc surgery (LOE: B) 1 risk factor & intermediate risk surgery (LOE: B) Abnormal preoperative ekgs added no benefit in

predicting postoperative cardiovascular complications compared to a properly performed medical history.

Class III Not indicated in asymptomatic persons & low risk

procedure (LOE: B) Preoperative routine ekg testing in asymptomatic

patients undergoing low risk surgical procedures was found to be not only not useful, but harmful in some cases

Who needs it? Relevant data

ACTIVE pulmonary process

?? History of pulmonary disease

Highly overutilized!

Can have implications for anesthesia and/or prognosis

Facilitate peri-operative medical management

CHF

Chest Xray

Recommendation for Noninvasive Evaluation of LV

function

Class IIa Dyspnea of unknown origin (LOE: C) Current or prior HF with worsening dyspnea or other

change in clinical status (LOE: C) Rest echo for LV assessment should be considered in

patients undergoing high risk surgeryClass IIb

Stable cardiomyopathy may not need (LOE: C)Class III

Routine echo in pts not recommended (LOE: B)

Recommendations for Noninvasive Stress Testing

Stress testing has a very high negative predictive value for postoperative cardiovascular events (between 90-100%, but a low positive predictive value between 6-67%)

Stress testing is more useful for reducing estimated risk if negative (or normal) than for identifying patients at very high risk when positive

Less established evidence for the preoperative stress tests: Patients with at least one clinical risk factor and poor functional

capacity who are scheduled for intermediate risk surgery when such testing will change the management

Patients with at least one clinical risk factor and good functional capacity who are scheduled for vascular surgery.

Recommendations for Noninvasive Stress Testing

Class I Active cardiac conditions should be treated prior to

surgery (LOE: B)

Class IIa 3+ clinical risk factors & < 4 METS who require

vascular surgery (LOE: B) Stress testing considered when such testing will

change the management

Energy Requirements

1 MET Take care of self Eat, dress, use toilet

2-3 METs Walk indoors around the house Walk a block

4 METs Light housework like dusting or washing dishes

Energy Requirements

4-5 METs Climb stairs, walk up a hill

6-9 METs Run a short distance Heavy housework Moderate recreational activities

10 METs Strenuous activities (swimming, tennis, skiing)

Recommendations for Noninvasive Stress Testing

Class IIb- considered for: 1-2 clinical risk factors & < 4 METS & intermediate

risk surgery 1-2 clinical risk factors & > 4 METS & vascular

surgeryClass III

Not needed if no risk factors & intermediate surgery Not needed if low risk procedure

What stress test to order

Depends on the expertise of facilityExercise ekg

Sensitivity 74%, specificity 69%

MPI, mostly dipyridamole stress Sensitivity 83%, specificity 49%

Dobutamine echocardiography Sensitivity 85%, specificity 70%

Recommendations for Pre-op Revascularization with CABG or

PCI

Class I Stable angina & left main stenosis Stable angina & 3 vessel disease Stable angina & 2 vessel disease (prox LAD

stenosis) & either EF < 50% or ischemia on stress test

High risk unstable angina or NSTEMI Acute STEMI

PCI: angioplasty

Delay surgery for > 14 days to allow healing of vessel injury

Should continue aspirin perioperatively (vs bleeding risk)

PCI: bare-metal stent

Delay surgery for 4-6 wks to allow for at least partial endothelialization

Clopidogrel usually not needed after 4 wksShould continue aspirin perioperatively (vs

bleeding risk)

PCI: Drug-eluting stents

Delay surgery for 12 months due to risk of in-stent thrombosis

Should continue aspirin perioperatively (vs bleeding risk)

Thrombosis may occur up to 1.5 years after implantation, particularly in the context of discontinuing antiplatelet agents before surgery

Why perioperative Beta Blockade

Perioperative myocardial ischemia may be caused by an activation of sympathetic nervous system.

Beta blockade limits the increase in heart rate and myocardial contractility, prevents the imbalance of myocardial oxygen supply and demand

Diastolic time reduces rapidly above 75 bpm, as left ventricular coronary perfusion occurs predominately during the diastole

Beta blockers have antiarrhythmic and antirenin effects.

Perioperative Beta Blockade con’t

Perioperative increase in catecholamine and cortisol level contribute to increased oxygen demand and endothelial dysfunction mediated by a rise in the BP, HR

Beta blockers limit activation of inflammatory responses in the myocardium and systemic circulation

Beta blockers affects leukocyte chemotaxis and recruitment, metalloproteinase activity and monocyte activation.

Beta-blockers

Since 2002, few randomized trials have not demonstrated efficacy of beta-blockers but weight of evidence still suggests benefit esp high-risk pts

Should be started 7-10 days before elective surgery and continue up to 30 days

Long-acting agents may be better than short-acting ie metoprolol, atenolol

Beta-blocker therapy

Class I Continue if already on beta-blocker Vascular surgery & high cardiac risk (ischemia on pre-

op testing)Class IIa- probably recommended for:

Vascular surgery & coronary disease Vascular surgery & > 1 clinical risk factor Intermediate surgery & > 1 clinical risk factor

Beta-blocker therapy

Class IIb- uncertain for: Intermediate/high risk surgery & 1 clinical risk factor High risk/Vascular surgery & no clinical risk factors

Class III Do not use with Contraindication to beta-blockers Routine administration of high-dose beta blockers w/o

dose titration is not useful and may be harmful to pts

not currently taking beta blockers (POISE trial)

Poise Trial Results

0

1

2

3

4

5

6

30d nonfatal mi all cause mort cva

Placebometoprolol

Reduction in nonfatal mi; significant hypotension, bradycardia; increase mortalityEvidence does not support the use of beta blocker for the prevention of perioperative clinicaloutcomes in patients having noncardiac surgery.

Decrease IV Trial

Beta blocker group had a lower incidence of perioperative cardiac death and nonfatal MI

Beta blocker group had significant reduction of 30 day cardiac death and nonfatal MI

Use of statins showed a trend for improved outcome

Beta-blockers

Accumulating evidence suggests HR target is 60-80 beats/min

Should continue beta-blocker therapy through peri-op period & titrate to tight HR control

Start at a low dose and gradually up-titrate in a week.

Follow conventional dosing and holding parameters Hold if HR< 50 bpm; Systolic BP< 100

ACC/AHA 2007 Guidelines

How do we risk stratify?

ACC Algorithm for 2007

Misc Points

Pre-op labsMedicationsPulmonary issuesCerebrovascular issueChronic anticoagulationDVT prophylaxisCode status

Pre-op lab testing

Order fewer selective, evidence based tests30-60% of abnormalities found on pre-op

tests are generally ignored anywayLab tests normal in last 4 months and no

clinical change probably do not require repeat tests

Labs Studies: Hematology

H/H Anemia suspected. High surgical blood loss possible

WBC Clinic signs of infections *usually of little value

Platelets History of bleeding. High risk if surgical blood loss occurs (intracranial, spinal)

PT/PTT/INR History of bleedingSuggestive history (liver disease)High risk of surgical bleeding.

Lab Studies: Chemistry

Electrolytes Medications that can affect this (bp meds, diuretics)Dehydration: other clinical signs

BUN/Cr Clinical history with risk of renal diseaseCardiac or pulmonary disease

Glucose Poorly controlled diabetes

Liver function tests

Suggestive clinical historyAlbumin is part of pulmonary risk model

Urinalysis Clinical signs of infection*usually of little value

Medications

Continue beta-blockers, oral nitrates, & most antihypertensives until the morning of surgery

Suggest holding ACE-I & ARBs on morning of surgery to decrease risk of renal dysfunction Inhibition of ACE may prevent events related to

myocardial ischemia and LV dysfunction Perioperative treatment with ACE inhibitors may have

beneficial effects on post-operative outcomes Noted increase risk on renal failure in patients

undergoing CV surgery

Diuretics

Hypertensive patients -- discontinue diuretic on the day of surgery and resume orally when possible

Heart failure patients -- Continue use up to the day of surgery, resume intravenously perioperatively, and continue orally when possible

Correct electrolytes before surgery

Other Medications

Aspirin, aggrenox, clopidogrel- stop 7 days prior

Cilastazol, COX-1 inh cause reversible platelet inhibition- stop 2-3 days prior

COX-2 inh do not affect platelets

Other Medications

NSAIDS affect renal function- stop 1-3 days prior

SSRIs increase bleeding by depleting serotonin stores- stop days prior depending on half-life

Hormones, Raloxifene, Tamoxifen increase risk of thromboemboli

Anti-convulsant/psychotic/depressant meds should be continued

Metformin held to reduce lactic acidosis

Herbal Medications

Supplements or herbal meds- stop 1 wk prior Ginger, ginkgo, ginseng, garlic, & feverfew can cause

bleeding Ginseng assoc w/ hypoglycemia Garlic assoc w/ hypoglycemia, hypotension Kava, echinacea assoc w/ hepatotoxicity

What about statins?

Several observational studies suggest benefit from peri-operative statins.

Randomized trials less clearBottom line-prescribe only if statin is

indicated regardless of surgery

Endocarditis prophylaxis

Revised recommendations have limited indications Prosthetic valve Previous endocarditis Cardiac transplantation with valvulopathy Certain congenital heart diseases

Cyanotic, recent use of prosthetic material, residual defects

Indicated only for Dental, respiratory, skin/soft-tissue/muscular

procedures Not for GI/GU

Preoperative Pulmonary Assessment and

Postoperative Risk Reduction

Patient Factors Advanced Age Poor functional status COPD CHF Tobacco abuse OSA Low albumin, high BUN

Surgical Factors Aortic, thoracic, upper

abdominal Prolonged surgery General anesthesia Emergency surgery Routine NG tube placement

Preoperative Pulmonary Function Testing

Indicated for all lung resection patientsFail to consistently predict pulmonary complications

Abnormal exam, CXR, and Goldman risk index more predictive Low rate of complications in patients with severe obstruction Use the “if they walked into my office” principle

Evaluate unexplained dyspnea Establish baseline for patients with known lung disease

Reducing Postoperative Pulmonary Complications

Incentive SpirometerSelective NG decompression after general surgeryCigarette cessation*Medically optimize COPDAvoid sedating medsNeuraxial anesthesia

No clear benefit with Nutritional supplementation Pulmonary arterial catheterization

*If pt stops smoking for <8 weeks prior to surgery, rates of pulm complications may be higher than not stopping at all.

Cerebrovascular risk evaluation

Vascular and cardiac surgery pose greatest risk of stroke

Principle risk factor is symptomatic carotid stenosis

Carotid revascularization should strongly be considered in these pt’s prior to vascular/cardiac surgery Unclear benefits of stenting vs surgery or other types

of surgeryNo evidence of benefit for asymptomatic

carotid stenosis

CHADS2 score

1 pt each Heart failure (EF < 30%) HTN age ≥ 75 yrs diabetes

2 pts Prior stroke

Low Bleed Risk

Continue warfarin (can consider lower INR of 1.3-1.5) Cataract Endoscopy, colonoscopy, ERCP w/o sphincterotomy Superficial dermatologic Dental procedures Joint and soft tissue aspirations or injections Minor podiatric procedures (nail avulsions)

Low risk- bridging not advised

One remote VTE (>6 months ago)Intrinsic cerebrovascular disease (carotid

atherosclerosis) w/o recurrent stroke or TIAAtrial fib w/o multiple risks for cardiac

embolism (CHADS2 1-2)Newer model mech valve in aortic position

(St. Jude)

High Risk- Bridging advised

DVT/PE or arterial thromboemboli < 3 moThromboembolic event + hypercoaguable problem

(i.e. protein C or S def…)Recurrent arterial or idiopathic VTERheumatic atrial fibAcute intracardiac thrombusAtrial fib + mech heart valve in any positionOlder mech valves in mitral position (single disk or

ball-in-cage)Recently placed mech valve (<3 months)Atrial fibrillation with h/o cardioembolism

Intermediate Risk- Bridging on case-by-case basis

Newer model mech valve in mitral position (St. Jude)

Older model mech valve in aortic positionAtrial fib w/o cardioembolism but with

multiple risks for cardioembolism (CHADS2 ≥ 3)

VTE > 3-6 months ago

DVT prophylaxis

DVT riskUp to 30% in general

surgeryUp to 60% in

orthopedic surgery Especially hip fracture

surgery

2008 ACCP guideline VTE prophylaxisNon-orthopedic surgery

Pharmacologic prophylaxis with UH, LMWH, or fondaparinux should be considered for all but the lowest risk ambulatory surgical patients

Add mechanical compression for those at highest risk

Continue until discharge Consider continuing LMWH for 28 days after discharge

in highest risk

Prophylaxis may be omitted in entirely laparoscopic procedures without other risk factors.

2008 ACCP guideline VTE prophylaxisOrthopedic surgery

Procedure Prophylaxis Duration

Total hip replacement LMWH 10 – 35 days

Total knee replacement

LMWH, fondaparinux therapeutic warfarin

10 – 35 days

Knee arthroscopy (uncomplicated)

Ambulation N/A

Knee arthroscopy (complicated)

LMWH until discharge

Hip fracture surgery LMWH, fondaparinux, therapeutic warfarin

10 – 35 days

Mechanical compression

Use alone if high bleeding risk and in combination for very high risk patients.

What to do with a DNR?

Anesthetic or surgical techniques may be considered resuscitative

Some procedures cause asystoleCounsel patients on how to manage the DNR

peri-operativelyInstitutional policies may dictate

OSU recommends suspending the DNR until leaving the PACU or for 24 hours in SICU

Conclusions

Successful peri-operative evaluation and management requires careful teamwork

Use of noninvasive and invasive pre-op testing should be limited to circumstances in which the results will affect pt management

Goal is to make recommendations to lower immediate peri-operative cardiac risk

References

Fleisher, LA, et al., ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery: Executive Summary, Circulation, Oct 23, 2007, 1-26.

Beckman, JA, et al., ACC/AHA 2006 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery: Focused Update on Perioperative Bets-Blocker Therapy, JACC, Vol. 47.

Lee, TH, et al., Derivation and prospective validation of a simple index for prediction of cardiac risk in major noncardiac surgery. Circulation 1999;100:1043-1049.

Geerts, WH, et al. Prevention of venous thromboembolism: American college of chest physicians evidenced-based clinical practice guidelines (8th edition). Chest 2008; 133: 381S-453S.

King MS. Preoperative evaluation. Am Fam Physician. 2000; 62:387-396.

Review questions

Which of the following must occur before EVERY surgery can safely be performed?

a. The patient must be medically “cleared” by their physician

b. The patient must undergo EKG and basic labs testsc. The patient must have a discussion of the risks and

benefits of the surgery and provide informed consent

d. Both a and c

Which of the following patients should receive beta-blockers before elective surgery?

a. 50 year old male scheduled for inguinal hernia repair who has past medical history of hypertension

b. 34 year old female scheduled for hysterectomy with history of poorly controlled type 1 dm, ckd with cr 3, and well controlled asthma on steroid inhaler and albuterol.

c. 55 year old female scheduled for lumpectomy for breast cancer with history of stroke at age 40 due to inherited thombophilia and takes warfarin

d. None of the above.

Which of the following patients should hold their respective anti-hypertensive on the morning of surgery?

a. 50 year old with hypertension and history of MI on metoprolol

b. 35 year old female with dm, ckd taking lisinopril

c. 78 year old male with CHF and EF 25% taking losartan whose dose was decreased recently due to low bp

d. Both b and c.

Which of the following patients should undergo stress testing prior to surgery?

a. 75 yo scheduled for hemicolectomy for colon ca with history of RCA stent 18 months ago. Able to walk and swim without anginal symptoms

b. 65 yo female with dm, htn, cad scheduled for lumpectomy. Wheelchair bound due to obesity and lymphedema. No chest pain or dyspnea

c. 80 yo with dm, htn scheduled for total hip replacement. No chest pain or dyspnea with walking.

d. 40 yo with no pmh scheduled for abdominoplasty. Reports over the past 1-2 months chest tightness while running that is increasingly precipitated by less activity.

For questions or comments contact:Jayne Barr, MD FACP FAAPEmail: [email protected]

Survey

We would appreciate your feedback on this module. Click on the button below to complete a brief survey. Your responses and comments will be shared with the module’s author, the LSI EdTech team, and LSI curriculum leaders. We will use your feedback to improve future versions of the module.

The survey is both optional and anonymous and should take less than 5 minutes to complete.

Survey