1. Consultative Medicine
Perioperative Risk Assessment and Evaluation for Noncardiac Surgery
Jayne Barr, MD, FACP, FAAP

2. Role of consultant Introduction Recommendations Miscellaneous
Outline
Role of consultant
Introduction
Recommendations
Cardiac risk assessment
Pulmonary assessment
Miscellaneous
Algorithm 2007

3. 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

4. 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

5. 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 case
Preoperative clinic visits reduce the number of tests ordered by approximately 55%
Fischer S Anesthesiology. Development and effectiveness of an anesthesisa preoperative evaluation clinic in a teaching hospital.

6. Perioperative Medical Assessment Goals
Efficient utilization of the sources and eliminating unnecessary tests and consults.
Reduce the length of stay and morbidity
Optimizing the patient before surgery well in advance
Improves the quality of perioperative care
Improves surgical outcomes
Family and patient satisfaction

7. Role of the Consultant Evaluate and optimize patient’s medical status
Treat modifiable risk factors
Offers opinions about operative risk and perioperative management
Recommend measures to minimize perioperative complications
Focus over the entire perioperative period
Long term patient outcomes

8. What Not to Do Recommend for or against surgery
Tell anesthesiologist how to do their job
Recommend the obvious
“clear” the patient
Say nothing

9. Purpose of the Guidelines
Goal is not to “medically clear” pt
Provide 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

10. Methodology and Evidence
ACC/AHA conducted literature searches in PubMed, MEDLINE, and Cochrane Library from
Searches limited to English language and human subjects

11. 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

12. 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

13. ACC Guidelines—Clinical Risk Factors Major Clinical Predictors
Unstable coronary syndromes
ACS
unstable angina
Recent MI
Acute 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

14. ACC Guidelines—Clinical Risk Factors
Intermediate Predictors
Minor Clinical Predictors
History of prior MI
History of compensated or prior heart failure
History of CVA DM
Renal insufficiency/CKD
Advanced age
Abnormal ekg
LVH, LBBB, ST-T abnormalities
Rhythm other than sinus rhythm
Low functional capacity

15. 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

16. 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

17. Revised Cardiac Risk Index 6 factors that indicate increased risk
Ischemic heart disease
Compensated or prior heart failure
Cerebrovascular disease
Diabetes mellitus
Renal 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:

18. Risk of Major Cardiac Event (Lee Criteria)
POINTS
(# of risk factors)
CLASS
RISK
(% complication) 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

19. Recommendations- Who needs these tests prior to surgery?
EKG
CXR
Assess LV function--echocardiogram
Noninvasive stress testing
Pre-op coronary revascularization
Beta-blocker therapy

20. EKG Who needs it? Relevant data CAD or other CAD risk factors
Hypertension, diabetes
History of arrhythmia
? men > 40
? Women > 50
Arrhythmias
Ischemic changes
Prolonged QTc

21. 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

22. Chest Xray 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

23. 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 surgery
Class IIb
Stable cardiomyopathy may not need (LOE: C)
Class III
Routine echo in pts not recommended (LOE: B)

24. Recommendations for Noninvasive Stress Testing
Stress testing has a very high negative predictive value for postoperative cardiovascular events (between %, 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.

25. 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

26. Energy Requirements 1 MET 2-3 METs 4 METs 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

27. Energy Requirements 4-5 METs 6-9 METs 10 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)

28. 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 surgery
Class III
Not needed if no risk factors & intermediate surgery
Not needed if low risk procedure

29. What stress test to order
Depends on the expertise of facility
Exercise ekg
Sensitivity 74%, specificity 69%
MPI, mostly dipyridamole stress
Sensitivity 83%, specificity 49%
Dobutamine echocardiography
Sensitivity 85%, specificity 70%

30. 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

31. PCI: angioplasty
Delay surgery for > 14 days to allow healing of vessel injury
Should continue aspirin perioperatively (vs bleeding risk)

32. PCI: bare-metal stent
Delay surgery for 4-6 wks to allow for at least partial endothelialization
Clopidogrel usually not needed after 4 wks
Should continue aspirin perioperatively (vs bleeding risk)

33. 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

34. 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.

35. 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.

36. 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

37. Beta-blocker therapy Class I Class IIa- probably recommended for:
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

38. Beta-blocker therapy Class IIb- uncertain for: Class III
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)

39. Poise Trial Results
Reduction in nonfatal mi; significant hypotension, bradycardia; increase mortality
Evidence does not support the use of beta blocker for the prevention of perioperative clinical
outcomes in patients having noncardiac surgery.

40. 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

41. Beta-blockers
Accumulating evidence suggests HR target is 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

42. ACC/AHA 2007 Guidelines
How do we risk stratify?

43. ACC Algorithm for 2007

44. Misc Points Pre-op labs Medications Pulmonary issues
Cerebrovascular issue
Chronic anticoagulation
DVT prophylaxis
Code status

45. Pre-op lab testing Order fewer selective, evidence based tests
30-60% of abnormalities found on pre-op tests are generally ignored anyway
Lab tests normal in last 4 months and no clinical change probably do not require repeat tests

46. 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 bleeding
Suggestive history (liver disease)
High risk of surgical bleeding.

47. Lab Studies: Chemistry
Electrolytes
Medications that can affect this (bp meds, diuretics)
Dehydration: other clinical signs
BUN/Cr
Clinical history with risk of renal disease
Cardiac or pulmonary disease
Glucose
Poorly controlled diabetes
Liver function
tests
Suggestive clinical history
Albumin is part of pulmonary risk model
Urinalysis
Clinical signs of infection
*usually of little value

48. 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

49. 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

50. 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

51. 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

52. 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

53. What about statins?
Several observational studies suggest benefit from peri-operative statins.
Randomized trials less clear
Bottom line-prescribe only if statin is indicated regardless of surgery
Routine use of statins for perioperative cardioprotection not recommended.

54. 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

55. 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

56. Preoperative Pulmonary Function Testing
Indicated for all lung resection patients
Fail 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

57. Reducing Postoperative Pulmonary Complications
Incentive Spirometer
Selective NG decompression after general surgery
Cigarette cessation*
Medically optimize COPD
Avoid sedating meds
Neuraxial 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.
* If pt stops smoking for <8 weeks prior to surgery, rates of pulm complications may be higher than not stopping at all.

58. 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 surgery
No evidence of benefit for asymptomatic carotid stenosis

59. CHADS2 score 1 pt each 2 pts Heart failure (EF < 30%) HTN
age ≥ 75 yrs
diabetes
2 pts
Prior stroke

60. 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)

61. Low risk- bridging not advised
One remote VTE (>6 months ago)
Intrinsic cerebrovascular disease (carotid atherosclerosis) w/o recurrent stroke or TIA
Atrial fib w/o multiple risks for cardiac embolism (CHADS2 1-2)
Newer model mech valve in aortic position (St. Jude)

62. High Risk- Bridging advised
DVT/PE or arterial thromboemboli < 3 mo
Thromboembolic event + hypercoaguable problem (i.e. protein C or S def…)
Recurrent arterial or idiopathic VTE
Rheumatic atrial fib
Acute intracardiac thrombus
Atrial fib + mech heart valve in any position
Older mech valves in mitral position (single disk or ball-in-cage)
Recently placed mech valve (<3 months)
Atrial fibrillation with h/o cardioembolism

63. Intermediate Risk- Bridging on case-by-case basis
Newer model mech valve in mitral position (St. Jude)
Older model mech valve in aortic position
Atrial fib w/o cardioembolism but with multiple risks for cardioembolism (CHADS2 ≥ 3)
VTE > 3-6 months ago

64. DVT prophylaxis DVT risk Up to 30% in general surgery
Up to 60% in orthopedic surgery
Especially hip fracture surgery

65. 2008 ACCP guideline VTE prophylaxis Non-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.

66. 2008 ACCP guideline VTE prophylaxis Orthopedic surgery
Procedure
Prophylaxis
Duration
Total hip replacement
LMWH
10 – 35 days
Total knee replacement
LMWH, fondaparinux
therapeutic warfarin
Knee arthroscopy (uncomplicated)
Ambulation
N/A
Knee arthroscopy (complicated)
until discharge
Hip fracture surgery
LMWH, fondaparinux,
Mechanical compression
Use alone if high bleeding risk and in combination for very high risk patients.

67. What to do with a DNR?
Anesthetic or surgical techniques may be considered resuscitative
Some procedures cause asystole
Counsel patients on how to manage the DNR peri-operatively
Institutional policies may dictate
OSU recommends suspending the DNR until leaving the PACU or for 24 hours in SICU

68. 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

69. 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:
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 ; 62:

70. Review questions
Which of the following must occur before EVERY surgery can safely be performed?
The patient must be medically “cleared” by their physician
The patient must undergo EKG and basic labs tests
The patient must have a discussion of the risks and benefits of the surgery and provide informed consent
Both a and c

71. Which of the following patients should receive beta-blockers before elective surgery?
50 year old male scheduled for inguinal hernia repair who has past medical history of hypertension
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.
55 year old female scheduled for lumpectomy for breast cancer with history of stroke at age 40 due to inherited thombophilia and takes warfarin
None of the above.

72. Which of the following patients should hold their respective anti-hypertensive on the morning of surgery?
50 year old with hypertension and history of MI on metoprolol
35 year old female with dm, ckd taking lisinopril
78 year old male with CHF and EF 25% taking losartan whose dose was decreased recently due to low bp
Both b and c.

73. Which of the following patients should undergo stress testing prior to surgery?
75 yo scheduled for hemicolectomy for colon ca with history of RCA stent 18 months ago. Able to walk and swim without anginal symptoms
65 yo female with dm, htn, cad scheduled for lumpectomy. Wheelchair bound due to obesity and lymphedema. No chest pain or dyspnea
80 yo with dm, htn scheduled for total hip replacement. No chest pain or dyspnea with walking.
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.

74. For questions or comments contact:
Jayne Barr, MD FACP FAAP

75. 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