Pre-operative Assessment

1. Pre-operative Assessment Rami Baddredine, MD (Anticoagulation) Miriam Jacob, MD (Anticoagulation and diabetes) Karen Joynt, MD (Pulmonary) James Yau, MD (Cardiovascular) Edited by Amy Shaheen, MD

2. Learning Objectives • At the completion of this presentation, the learner should be able to: • Describe appropriate pre-operative cardiovascular evaluation • Describe appropriate pre-operative pulmonary evaluation • Manage anticoagulation in the peri-operative period • Manage diabetes in the peri-operative period • Locate resources related to the above topics on the internet

3. Presentation Outline • Cardiovascular evaluation • Pulmonary evaluation • Management of anticoagulation • Management of diabetes • Online resources • Quiz • References

4. Cardiovascular Pre-op evaluation

5. Cardiac Preoperative Evaluation • Epidemiology • The prevalence of cardiovascular disease increases with age. • Estimated that the number of people >65 in the US will increase by 25-35% over next 30 years. • This is the same population in which the most surgical procedures are performed. • Number of noncardiac surgeries may increase from 6 million per year to 12 million per year; some of which have been associated with significant periop cardiac morbidity and mortality.

6. Cardiac Preoperative Evaluation • ACC/AHA Guideline on Perioperative Cardiovascular Evaluation for Noncardiac Surgery • http://www.acc.org/clinical/guidelines/perio/update/pdf/perio_update.pdf • First developed by ACC/AHA Task Force on Practice Guidelines in 1996. • Updated in 2002. • Provides framework for considering cardiac risk in noncardiac surgeries. • Provides tables and algorithms for quick reference and decision making.

7. Cardiac Preoperative Evaluation • Purpose • Not to give “medical clearance”. • Perform an evaluation of the patient’s current medical status. • Make recommendations concerning the evaluation, management, and risk of cardiac problems over the entire perioperative period • No test should be performed unless it will influence patient treatment. • Must be carefully tailored to the patient and the circumstance.

8. Cardiac Preoperative Evaluation Need for noncardiac surgery Urgent or elective emergency Coronary revascularization Within 5 years? YES Operate (OK for surgery) Recurrence of symptoms NO NO Recent coronary evaluation Within 2 years? YES Recent stress test or Coronary angiogram favorable results YES NO CLINCAL PREDICTORS (see next set of algorithms) Unfavorable results

9. Cardiac Preoperative Evaluation • Next step is to evaluate the patient’s risk and the inherent riskiness of the surgery • Patient’s risk is determined by clinical predictors and functional capacity • Surgery riskiness is determined by the type and site of surgery • Once patient’s risk and surgery’s risk are known, additional algorithms can be used to determine the appropriate course of action

10. Cardiac Preoperative Evaluation: Clinical predictors ٭acute (within 7 days) or recent (7-30 days) MI or class III or IV symptoms #high grade AV block, symptomatic ventricular arrhythmia with underlying heart disease, or SVT with uncontrolled ventricular rate †LVH, LBBB, ST-T abnormalities

11. Cardiac Preoperative Evaluation: Functional capacity • Functional capacity is also an important part of the algorithm and relies on “METs”, or metabolic equivalents, to rate a patient’s functionality • 1 MET is equivalent to a metabolic rate consuming 3.5 milliliters of oxygen per kg of body weight per minute or 1 kilocalorie per kg of body weight per hour • In a treadmill test, actually measuring METs requires that the person being tested wear a mask in order to measure his or her oxygen consumption (and the carbon dioxide exhaled) • However, METs can be estimated as follows: • 1-4 METs: daily activities, walking 1-2 blocks on level ground at 2-3 mph, light housework • 4-10 METs: climbing stairs or hill, jogging short distance, heavy housework, bowling, dancing, golf, swimming • 10-14 METs: running (at least an 8-minute mile), downhill skiing, rock climbing, etc.

12. Cardiac Preoperative Evaluation: surgical riskiness ٭combined risk of cardiac death and nonfatal myocardial infarction

13. Cardiac Preoperative Evaluation Patient with MAJOR CLINICAL PREDICTORS Consider delaying or canceling non-cardiac surgery Consider coronary angiography Medical management and risk factor modification Subsequent care* dictated by findings and treatment results *subsequent care may include delay or canceling surgery, coronary revascularization followed by non-cardiac surgery, or intensified care.

14. Cardiac Preoperative Evaluation Patient with INTERMEDIATE CLINICAL PREDICTORS Poor functional capacity (<4 METS) Mod or excellent (>4 METS) high surgical risk Intermediate surgical risk low surgical risk Low risk Operate Noninvasive testing High risk Consider coronary angiography Subsequent care dictated by findings and treatment results

15. Cardiac Preoperative Evaluation Patient with NO OR MINOR CLINICAL PREDICTORS Poor functional capacity (<4 METS) Mod or excellent (>4 METS) high surgical risk Intermediate or low surgical risk Low risk Operate Noninvasive testing High risk Consider coronary angiography Subsequent care dictated by findings and treatment results

16. Pulmonary Pre-op evaluation

17. Pulmonary evaluation • Currently no published guidelines are available for the general surgical patient • Existing literature focuses on: • Evaluation of the lung cancer patient prior to lung resection • Evaluation of risk for post-operative pneumonia • General guidelines are reportedly forthcoming this year

18. Evaluation of the lung cancer patient prior to lung resection • 30,000 lung resections are performed annually • Mortality rate from lung resection surgery is 7-11% • Accurate pulmonary evaluation can predict risk of operative mortality and help stratify patients in terms of treatment options (Beckles 2003, Datta 2003)

19. Preoperative evaluation • Staged, stepwise assessment to evaluate risk of complications (Beckles 2003, Datta 2003), starting with careful history and physical examination and then proceeding to objective testing • Stage I assessment • Spirometry / DLCO measurement, +/- ABG • If FEV1>80% predicted or >2L, MVV is >55% predicted, and DLCO is >60% predicted, pt is suitable for resection including pneumonectomy without further evaluation • If pt does not meet these criteria, proceed to stage II testing • Stage II assessment • Quantitative V/Q scan or differential lung scan • If predicted postoperative (ppo) FEV1 is >40% predicted and ppo DLCO is >40% predicted, pt is suitable for resection including pneumonectomy • If pt does not meet these criteria, proceed to stage III testing

20. Preoperative evaluation continued • Stage III assessment • Exercise testing • If VO2 max is greater than 20 mL/kg/min, pt is suitable for surgery • If VO2 max is less than 10 mL/kg/min (roughly the ability to walk up one flight of stairs), pt is at greatly increased risk of complications and death from surgery and non-surgical management should be pursued • Alternative algorithm (Wyser 1999) • If FEV1 or DLCO <80% predicted, proceed directly to exercise testing • If VO2 max >20, proceed to surgery • If VO2 max 10-20, undergo quantitative V/Q and calculate ppo values as before

21. Evaluation of risk for post-operative pneumonia • Why is post-op PNA important? • Pneumonia is the 3rd most common postop complication (after UTI, wound infection) (Garibaldi 1981) • Pneumonia occurs in 10-40% of patients in the post-op period and carries a mortality of 30-46% (Brooks-Brunn 1997) • 25% of deaths occurring within 6 days of surgery are pulmonary in etiology (Brooks-Brunn 1995)

22. Risk Assessment for Post-op PNA • Risk index developed in a sample of 10 VA hospitals using data from the Department of Veterans Affairs National Surgical Quality Improvement Program (NSQIP) • 160,805 patients in derivation cohort, 1997-1999 • 155,266 patients in validation cohort, 1995-1997 • 2,466 patients developed pneumonia (1.5%), compared with myocardial infarction in only 0.4% • Patients with post-op PNA had a 30-day mortality of 21%, compared with only 2% of the remaining patients

23. PNA Predictors • Most important predictors (Odds Ratios, OR, listed for those predictors with OR for development of PNA of greater than 1.5): • Type of surgery • AAA, OR=4.29 • Thoracic surgery, OR=3.92 • Upper abdominal surgery, OR=2.68 • Neck surgery, OR=2.30 • Neurosurgery, OR=2.14

24. PNA Predictors, continued • Age • >80, OR=5.63 • 70-79, OR=3.58 • 60-69, OR=2.38 • Functional status prior to surgery • Totally dependent, OR=2.83 • Partially depentent, OR=1.83 • Weight loss > 10% in last 6 months, OR=1.92 • History of COPD, OR=1.72 • General anesthesia, OR=1.56 • “Impaired sensorium,” OR=1.51

25. Development of Risk Index • Predictors were then turned into a scoring system, based on strength of association, to allow prospective grading of post-operative risk • Scoring system (“risk index”) was then validated on an independent cohort • Notable study limitations: veteran population, very few women, many comorbidities, no data about PFTs was included, no correction for prophylactic antibiotics was possible

26. Postoperative PNA Risk Index From Arozullah et al 2001

27. Risk Index and Outcomes

28. Pre-op evaluation of coagulationandPeri-op management of anticoagulation

29. Management of bleeding risk • Management of bleeding risk in the peri-op period requires consideration of risk of bleeding • Defining the level of hemostatic risk for the proposed surgery is essential • Low Risk surgery: -nonvital organs are involved -surgical site is exposed -limited degree of surgical dissection -local hemostatic measures are likely to be effective -the site does not have local fibrinolysis

30. Risk assessment, continued • Moderate / High risk surgeries • Vital organs are involved, with deep or extensive dissection • The site is associated with local fibrinolysis (eg, prostatic surgery, tonsillectomy, oral or nasal surgery) • Local hemostatic measures are ineffective (eg, closed liver or kidney biopsy) • The surgical procedure or the underlying condition is expected to induce a hemostatic defect (eg, cardiopulmonary bypass, brain injury, extensive malignancy) • Bleeding complications are frequent and/or are likely to compromise the surgical result

31. Pre-op workup • For low risk surgeries : if the history and physical exam do not suggest bleeding then no more tests are needed • For high risk surgeries : Hx , Physical , platelet count, PT and PTT must be done • If Hx/ PE or Coags suggest high risk bleeding then more sophisticated tests should be obtained ( heme consult would not hurt) • A “ Bleeding Time “ is NOT warranted pre-op because it does not predict severity of bleeding

32. Patients already on anticoagulation • Patients might be on prophylactic or treatment anticoagulation preoperatively • Factors to consider when evaluating risk of bleeding with surgery: Age, comorbidities, type of surgery, anticoagulant regimen/ duration and degree of monitoring

33. Venous Thromboembolism ( VTE) • Temporal relation of VTE to surgery is key • Within the first month after DVT patients must receive both pre and post-op anticoagulation • Between 2-3 months, pre-op anticoagulation is only needed for high risk patients but post-op anticoagulation is recommended to all patients • After 3 months, the risk of bleeding is more than the benefit of anticoagulation so only prophylactic pre and post-op anticoag. is recommended

34. Arterial Thromboembolism (ATE) • The risk of bleeding is similar pre and post-op in patients with ATE • Continue anticoagulation preop for all patients • Continue post-op anticoagulation only if the surgery is minor • High risk ATE patients (Like anticoagulation for prosthetic valves): a heparin bridge is recommended and restart anticoagulation ASAP post-op

35. General Recommendations • Always weigh the risk of thrombosis against risk of bleeding • Patients on oral AC , allow INR to reach 2 pre-op unless high risk bleeding ( INR< 1.5) • Bridge with Heparin if high risk re-thrombosis

36. Peri-op management of diabetes

37. Diabetes- Preoperative Management • Why do we care? • Increased risk of pre-operative infection • Increased post-operative cardiovascular morbidity and mortality • Focus is on cardiopulmonary risk assessment and management • History • Laboratory Studies

38. Diabetes- Preoperative Management • History • Long term complications of DM (i.e. retinopathy, nephropathy, neuropathy, CHD, PVD) • Baseline glycemic control (freq of monitoring, average BS) • Hypoglycemia (frequency, severity, awareness, timing) • Therapy (pharmacologic and non-pharmacologic) • Surgery • Major vs. Minor surgery • When to stop eating • Duration of procedure • Type of Anesthetic – epidural vs. general

39. Diabetes- Preoperative Management • Laboratory Studies • Baseline EKG, renal function • Baseline glucose levels • Use this to assess risk for postoperative wound infections • In case-control study of post-CABG patients, multivariable analysis found patient with preoperative glucose >200 mg/dL had OR of 10.2 for deep sternal wound infections (independent risk factor)2.

40. Diabetes- Preoperative Management Baseline HbA1c – Not recommended Study of cardiothoracic surgeries – pt with sternal wound infection had mean HbA1c of 8.44 vs. 7.80 in those without infection but was not statistically significant (p=0.09)3 Non-invasive cardiac testing dependent on risk stratification Preoperative Glycemic Control – Goals • Avoid hyperglycemia and hypoglycemia • No consensus about how “tight” the control must be (there is data in ICU and post-MI patients not in surgery patients- unsure if this translates)

41. Diabetes- Preoperative Management • Type 2 – Diet modification only • Check BG preoperatively and after • Type 2 – Oral agents • Discontinue agent on morning of surgery • Supplemental sliding scale insulin • Type 1 or 2 – Insulin Therapy • For short procedures, continue SQ regimen • 1-2 day before, may switch from long-acting to intermediate acting insulin • May reduce night time intermediate insulin if pt has borderline hypoglycemia

42. Diabetes- Preoperative Management • If in AM and lunch will be eaten- convert as follows • Once daily intermediate in AM  2/3 dose • Twice daily  ½ total dose as intermediate • If pt misses lunch as well – less AM insulin • Once daily  ½ total dose as intermediate • Twice daily  1/3 total dose as intermediate • Multiple short and intermediate  1/3 total dose as intermediate • Multiple short acting  1/3 pre-meal short-acting • Continuous insulin  continue basal infusion, use SSI prn • Later in the day – less AM insulin and start dextrose containing IVF • Long, complex surgeries – use IV Insulin (less variability in BG than with SQ regimen), start early in AM, closely monitor electrolytes. No optimal regimen has been found, based on experience and expert opinion. No particular regimen has been found to affect morbidity, mortality, or length of stay.

43. Online resources for further info • Cardiovascular evaluation • http://www.acc.org/clinical/guidelines/perio/clean/I_definition.htm • Pulmonary evaluation • http://www.thoracic.org/ • Management of diabetes • http://www.diabetes.org

44. Quiz • Question One: • Question: A 76 year-old man with history of CAD s/p CABG (3 years ago), HTN, DM2, CVA, CRI, and newly diagnosed lung mass was sent to the cardiology clinic by the surgeon for “cardiac clearance” for resection of the mass. Patient reports that he had been doing well and in his USOH, and the mass was discovered on a recent CXR. What is the most appropriate recommendation for this pt? • A) Pt will need at least a noninvasive test prior to the surgery • B) Pt may proceed with the surgery without further cardiac evaluation • C) Pt will need a coronary angiogram prior to the surgery • D) The surgery should be delayed until he is on optimal medical regimen • Answer: B. Pt may proceed with the surgery without further cardiac evaluation. Pt had recent revascularization procedure (within 5 years – CABG 3 years ago), and has not had recurrence of symptoms. Therefore, he can proceed to noncardiac surgery without any further cardiac evaluation. Pt still need to continue medical therapy and postoperative risk stratification and risk factor modification.

45. Quiz continued • Question Two: • Question: As the cardiology consult resident, you are seeing a 72 year-old woman with history of DM2, COPD, and on-going tobacco abuse who was admitted with a fractured pelvis after a fall at home. The patient is a resident at an ALF and fell when she tripped over some furniture. She reports that she has had some difficulty with worsening fatigue and DOE, and she can barely walk across the room because of her symptoms. What is the most appropriate recommendation for this pt awaiting an orthopedic procedure? • A) Pt will need at least a noninvasive test prior to the surgery • B) Pt may proceed with the surgery without further cardiac evaluation • C) Pt will need a coronary angiogram prior to the surgery • D) The surgery should be delayed until she is on optimal medical regimen and has stopped smoking • Answer: A. Pt should have at least a noninvasive cardiac evaluation given that she has at least one intermediate clinical predictor (DM) and poor functional capacity (METS<4). If low risk on the noninvasive test, then she may proceed to the OR; but if high risk, she may need more invasive testing such as coronary angiography.

46. Quiz continued • Question Three: • You are asked to evaluate Mr. L, a 65 year old male with known COPD, in pre-op clinic preceding planned resection for a 2 cm right upper lobe nodule. Which of the following statements is FALSE: • A) If Mr. L’s FEV1 is 40% predicted, he should undergo quantitative V/Q scanning and possibly exercise testing prior to surgery • B) If Mr. L’s FEV1 is 50% predicted, he can proceed to surgery without further testing so long as lobectomy is not planned • C) If Mr. L’s FEV1 is 90% predicted with a normal DLCO and MVV, he can proceed to surgery including lobectomy without further testing • D) If Mr. L’s FEV1 is 2.2L, but his DLCO is only 40% predicted, he should undergo further testing prior to surgery • Answer: B – If Mr. L has an FEV1 of 50% predicted, he shouldn’t go directly to surgery – instead, he should undergo quantitative V/Q testing and possibly exercise testing prior to surgery for further risk stratification

47. Quiz continued • Question Four: • Question: Which of the following is NOT a significant risk factor for the development of postoperative pneumonia, based on the VA study outlined above? • A) Thoracic surgery • B) Age greater than 70 • C) History of inhaler use • D) Receipt of general anesthesia • Answer: C – there is no evidence that a history of inhaler use is directly related to risk for post-op PNA, although COPD has been shown to be a risk factor in various smaller studies.

48. Quiz continued • Question Five: • Question: Mr Green is a 69 yo healthy male scheduled to have CABG in 2 weeks. You are asked to asses his bleeding risk. How would you asses him? • A) History alone • B) History and physical exam • C) PT/PTT/platelets • D) All of the above • Answer: D. CABG is a high-risk surgery, so he will need a thorough evaluation prior to the procedure.

49. Quiz continued • Question Six: • Question: Mr. Smith is a 68 year old male on Coumadin for a prosthetic mitral valve. He is scheduled to have an inguinal hernia repair. How would you manage his coumadin pre/post-op? • A) Stop Coumadin 3 days pre-op, no need for bridge. Restart Coumadin 3 days post-op • B) Stop Coumadin 3 days preop, bridge with heparin when INR<2.5, restart heparin ASAP post-op, and then restart Coumadin • C) Continue Coumadin through surgery • D) Stop Coumadin one day prior to surgery and do not resume until 1-2 weeks post-op • Answer: B. This patient is at high risk for ATE despite the low-risk nature of the surgery and needs a heparin bridge for his procedure.

50. Question Seven: • Question: Ms. Apple is a 28 year old female undergoing thyroidectomy in one week. Pre-op labs show a PTT of 68, INR of 1.1, and a normal CBC. She give no history of abnormal bruising or bleeding. Your next step is: • A) Proceed with surgery • B) Consult hematology for further workup • C) Proceed with surgery after 4 units FFP • D) Proceed with surgery after 5 mg of Vitamin K SQ x1 • Answer: B. This patient has a high-risk surgery (head and neck) and therefore needs further workup (i.e. mixing study, etc.).