The Preoperative Medical Evaluation

1. The Preoperative Medical Evaluation Jennifer E. Guss, MD Baylor College of Medicine

2. The Preoperative Medical Evaluation • The internist is often called upon to “clear” a patient for surgery. These days, the goal in terms of standard of care and medical-legal implications is not to “clear” the patient but instead to establish a patient’s risk and propose a plan to reduce the risk in the perioperative period. • This lecture focuses on evaluating patients and stratifying their risks prior to surgery.

3. The Preoperative Medical Evaluation • The Healthy Patient • The Unhealthy Patient • Preparing for Noncardiac Surgery • Preparing for Cardiac Surgery-most usually evaluated by the cardiologist This lecture will not address evaluating the patient for cardiac surgery

4. Preop Evaluation-Healthy Patient • Stepwise approach-not every patient needs an extensive evaluation-studies have shown that nothing extra is gained in risk reduction by extra work up • Clinical Evaluation • Step 1:Questionnaire of general health • Step 2:Exercise capacity evaluation • Step 3:Medication use • Step 4:BP and HR measurements • Step 5:History and Physical Exam • Lab evaluation-done based on clinical evaluation results and other factors used to evaluate pt’s perioperative risk • Blood work • EKG • CXR • PFT’s

5. Clinical Evaluation- Step 1 is to stratify the risk with a questionnaire. Ask ALL patients. No additional benefit is gained by an H+P, labs, or further studies in patients who answer no to these questions. Preoperative patient questionnaire Do you feel unwell? Have you ever had any serious illnesses in the past? Do you get any more short of breath on exertion than other people of your age? Do you have any coughing? Do you have any wheezing? Do you have any chest pain on exertion (anginal type)? Do you have any ankle swelling? Have you taken any medicine or pills in the last three months (including excess alcohol)? Have you any allergies? Have you had an anesthetic in the last two months? Have you or your relatives had any problems with a previous anesthetic? Observation of serious abnormality from "end of bed" which might affect anesthetic? What is the date of your last menstrual period? Preop Eval-Healthy Patient

6. Healthy Patient-clinical evaluation • Step 2-ask ALL about exercise capacity-important determinant of overall perioperative risk. • 4 METS=walking 2 blocks or carrying 2 grocery bags up one flight of stairs. Anyone unable to walk 4 blocks or walk 2 flights of stairs is defined as having poor exercise tolerance and has a significant increase (twice) in serious postoperative complications. Also twice (10% v 5%) cv complications in those with poor exercise tolerance. Difference in pulmonary complications is 9% v 6%.

7. Healthy Patient-Clinical Evaluation • Medication use-ask ALL patients • Take a thorough history • Include OTC and herbal meds • Ask specifically about medications which inhibit platelets e.g. Plavix, ASA, Ibu, Gingko Biloba. These medications need to be stopped about 1 week prior to surgery. Document in your note that you advised the patient to do this. The surgeon should ask about this again prior to beginning surgery.

8. Healthy Patient-Clinical Evaluation Age-probably IS an independent risk factor over age 70, however, very few patients over 70 have no other medical problems so it is difficult to assess age independently. Many of the recommendations use age cutoffs when advising for or against ordering studies. Obesity-not considered an independent risk factor, though some surgeons won’t do certain elective procedures on morbidly obese patients until they have lost weight as outcomes are better as shown in some studies, especially easier extubation. Esp. an issue with weight loss surgery e.g. gastric bypass, cosmetic surgery.

9. Healthy Patient-Clinical Evaluation-recap • Clinical Evaluation-all patient should have: • Questionnaire of general health • Exercise capacity evaluation • Medication use • BP and HR measurements • If one of these is abnormal, then a full H and P should be performed. If these are all normal and the patient is a woman <50yo or a man <45yo, no further studies are needed and the patient should proceed directly to surgery, unless “major” surgery.

10. Healthy Patient-Clinical Evaluation • History and Physical-should be performed in any patient with affirmative answers to the questionnaire, with poor exercise tolerance, with abnormal VS, or who takes daily medications. • Should also be performed in all patients over 60 yo b/c of theoretic increased risk associated with increased age, or in those patients undergoing major surgery.

11. Healthy Patient-Lab Evaluation • Lab evaluation • Blood work • EKG • CXR • PFT’s • None of these studies are routinely indicated. They should only be ordered in the “healthy patient” if there are clear indications.

12. Healthy Patient-Lab Evaluation • Pregnancy test-women who may be pregnant • Hct-all pts undergoing surgery with expected major blood loss, pts 65+ yo undergoing major surgery regardless of expected blood loss • Serum Cr-if major surgery, hypotension expected, nephrotoxic drugs will be used, or pt is >50yo

13. Healthy Patient-Lab Evaluation • Other labs e.g. lft’s, glu, lytes depending on the MD’s discretion based on patients comorbidities and potential risks.

14. Healthy Patient-Lab Evaluation • EKG-for all men >45 • For all women >55 • Pt’s with known cardiac dz • possible cardiac dz • systemic dz associated with heart • Pt having major surgical procedure ….unless this pt has had EKG within the last month.

15. Healthy Patient-Lab Evaluation • CXR-should not be routinely performed • Only for pt’s over 50yo who are having major surgery • Pt’s with suspected cardiac or pulmonary dz • Correlation between findings on CXR and periop morbidity are not well defined, but it is still considered reasonable to look for unanticipated findings since they are common.

16. Healthy Patient-Lab Evaluation • PFT’s-order for patients with dyspnea that is unexplained.

17. The Healthy Patient-Preoperative Evaluation • Once a patient has had a full evaluation, the assessment should be not “clearing” a patient for surgery, but rather expressing the patient’s risk in undergoing surgery. If a patient has perioperative risks, then recommendations should be made to reduce these risks.

18. The Healthy Patient-Preoperative Evaluation • The job of the internist is to weigh the benefits of surgery and the necessity of surgery against the possible risks of the procedure and the added risks based on the patient’s comorbidities. • Options:modifying risk factors with medications +/- lifestyle changes, additional w/u, electing not to undergo procedure.

19. Beta Blockers and the Preoperative Evaluation • POISE study-presented at the American Heart Association 2007 Scientific Sessions on the continued release beta blocker metoprolol (Toprol XL) in patients undergoing noncardiac surgery. Use of beta-blockers has been hailed over the last decade as important in reducing risk of perioperative MI. However, based on the POISE study, it now is thought to increase the risk of severe stroke and overall death. • The study suggests that for every 1000 patients treated, metoprolol CR would prevent 15 MIs, but there would be an excess of eight deaths and five severe disabling strokes. • Problem with the study: dose was titrated very fast, possible that complications were due to hypotension. • Experts feel that perioperative beta blockers are safe and essential for patients already on beta blockers who whose doctors plan to initiate beta blockers within 30 days of surgery. If giving beta blockers to elderly patients who do not fit in these criteria, then must maintain adequate SBP.

20. The Unhealthy Patient-Preoperative Evaluation • ACC/AHA have specific guidelines for evaluating patients with preexisting medical problems. • There are several different ways of classifying patients’ risks. The Revised Goldman Cardiac Risk Index is considered by many to be the best, but the ACC/AHA has their own Guideline Summary based on their own, albeit similar, risk stratification.

21. ACC/AHA guideline summary: Clinical predictors of increased perioperative cardiovascular risk (myocardial infarction, heart failure, death) Stratifies risks into major, intermediate, and minor predictors that increase perioperative morbitity and mortaliy. These classifications are later used in the convenient ACC/AHA nomogram for preoperative evaluation. • Major predictors that require intensive management and may lead to delay in or cancellation of the operative procedure unless emergent • 1.Acute myocardial infarction (within seven days) in patients with evidence of important ischemic risk as determined by symptoms or noninvasive testing. • 2.Recent myocardial infarction (within 8 to 30 days) in patients with evidence of important ischemic risk as determined by symptoms or noninvasive testing   • 3.Unstable angina    

22. ACC/AHA guideline summary: Clinical predictors of increased perioperative cardiovascular risk (myocardial infarction, heart failure, death) • 3.Severe Angina • 4.Decompensated heart failure • 5.High-grade atrioventricular block   • 6.Symptomatic ventricular arrhythmias in patients who have underlying heart disease   • 7.Supraventricular arrhythmias with a poorly controlled ventricular rate   • 8.Severe heart valve disease

23. ACC/AHA guideline summary: Clinical predictors of increased perioperative cardiovascular risk (myocardial infarction, heart failure, death) • Intermediate predictors that warrant careful assessment of current status • Mild angina (Canadian Cardiovascular Society class I or II) • Previous myocardial infarction as determined from the history or the presence of pathologic Q waves   • Compensated heart failure or a prior history of heart failure • Diabetes mellitus, particularly in patients who are insulin-dependent   • Reduced renal function, which is defined as a serum creatinine >2.0 mg/dL (177 µmol/L) or a 50 percent increase above an abnormal baseline concentration

24. ACC/AHA guideline summary: Clinical predictors of increased perioperative cardiovascular risk (myocardial infarction, heart failure, death) • Minor predictors that have not been proven to independently increase perioperative risk • Advanced age   • Abnormal ECG (left ventricular hypertrophy, left bundle branch block, ST-T abnormalities)   • Rhythm other than sinus rhythm (eg, atrial fibrillation)   • Low functional capacity (eg, inability to climb one flight of stairs with a bag of groceries)   • History of stroke   • Uncontrolled hypertension

25. Assessing cardiac Risk in Non-Healthy Patients:Goldman Index Revised Goldman cardiac risk index (RCRI) • Six independent predictors of major cardiac complications • 1.High-risk type of surgery (includes any intraperitoneal, intrathoracic, or suprainguinal vascular procedures) • 2.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) • 3.History of CHF • 4.History of cerebrovascular disease • 5.Diabetes mellitus requiring treatment with insulin • 6.Preoperative serum creatinine >2.0 mg/dL (177 mol/L)

26. Assessing cardiac Risk in Non-Healthy Patients:Goldman Index • 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 percent) • One risk factor - 1.0 percent (95% CI 0.5-1.4 percent • Two risk factors - 2.4 percent (95% CI 1.3-3.5 percent) • Three or more risk factors - 5.4 percent (95% CI 2.8-7.9 percent) • Rate of cardiac death and nonfatal myocardial infarction, cardiac arrest or ventricular fibrillation, pulmonary edema, and complete heart block according to the number of predictors and the nonuse or use of beta blockers   • No risk factors - 0.4 to 1.0 percent versus <1 percent with beta blockers • One to two risk factors - 2.2 to 6.6 percent versus 0.8 to 1.6 percent with beta blockers • Three or more risk factors - >9 percent versus >3 percent with beta blockers

27. AHA/ACC Guidelines:evaluating cardiac risk for noncardiac surgery

28. AHA/ACC Guidelines:evaluating cardiac risk for noncardiac surgery

29. AHA/ACC Guidelines:evaluating cardiac risk for noncardiac surgery

30. Bibliography Up To Date-Management of cardiac risk for noncardiac surgery Preoperative medical evaluation of the healthy patient Estimation of cardiac risk prior to noncardiac surgery Medscape-POISED to Change the Guidelines on perioperative Use of Beta Blockers?, Nainggolan, Lisa Practice advisory for preanesthesia evaluation:a report by by the American Society of Anesthesiologists Task Force on Preanesthesia Evaluation. Anesthesiology 2002 N Engl J Med 345:1677, December 6, 2001 Clinical Practice, Lowering Cardiac Risk in Non Cardiac Surgery N Engl J Med 356:706, February 15, 2007 Review Article , Perioperative Stroke N Engl J Med 353:412, July 28, 2005 Editorial , Beta-Blocker Therapy in Non Cardiac Surgery