Medical Consultation and Preoperative Evaluation

Medical Consultation and Preoperative Evaluation Diane Doerner MD PhD University of Washington Medical Center Ten Commandments for Effective Consultations • Determine the question being asked 1. Determine the question being asked. 2. Establish the urgency of the consult. 3. Gather primary data. 4. Communicate as briefly as possible. 5. Make specific recommendations. Goldman, L et al. Arch Int. Med (1983), 143: 1753 Ten Commandments for Effective Consultations • Determine the question being asked 6. Provide contingency plans. 7. Understand your role in the process. 8. Offer educational information. 9. Communicate recommendations directly. 10. Provide appropriate follow-up. Goldman, L. et al. Arch Int. Med (1983), 143: 1753 • One study looking at patterns of consultation among internists showed that 67% of consultations were for preoperative evaluation. In 12% of cases, the findings of the consultation resulted in a significant change in perioperative management; in 7%, surgery was delayed; a decision was made to cancel surgery altogether in 2% of cases. » Mollema, et al (2000) Neth J Med 56:7 Why Preoperative Evaluation? • 10 percent of the United States population undergoes non-cardiac surgery annually. • Over 8 million have known CAD or cardiac risk factors. • Over 50,000 will suffer a perioperative myocardial infarction. • The economic burden of these complications has been estimated at more than $20 billion annually. “The purpose of preoperative evaluation is not to give medical clearance, but rather to 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; and provide a clinical risk profile that the patient, primary physician, anesthesiologist, and surgeon can use in making treatment decisions…” » Kim A. Eagle, FACC, Chair, ACC/AHA Task Force on Practice Guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery Steps to Preoperative Evaluation 1. Surgical Risk Factors 2. Patient Risk Factors 3. Preoperative Testing 4. Perioperative Management Case 1 • A 74-year old man is referred to you for preoperative evaluation prior to undergoing a right total hip replacement. He is severely limited due to his osteoarthritis and can ambulate only limited distances in the home. His medical history is notable for CAD, for which he underwent an uncomplicated 3-vessel CABG 2 years ago. He has been symptom-free since. He has mild HTN and chronic renal insufficiency with a creatinine of 2.0 at baseline. Other than his CABG, he has no surgical history. His current medications include aspirin and lisinopril, 10 mg daily. His vital signs are notable for a BP of 140/87, HR 88. Examination is essentially normal. – What are his surgical and medical risk factors? Risk: Type of Procedure ACC/AHA Guidelines • High risk (reported risk of adverse cardiac event >5%) – Emergency surgery – Aortic procedures – Peripheral vascular surgery – Prolonged surgical procedures associated with large volume shifts or high EBL Risk: Duration of Anesthesia Reilly, et al. (1999) Arch Int Med 159:2185 70 60 50 Percent Complications 40 30 20 10 0 0 - 3.9 4 - 7.9 8 - 11.9 12 - 15.9 16 + Duration (hours) Risk: Type of Procedure ACC/AHA Guidelines • Intermediate Risk (reported cardiac risk < 5%) – Carotid endarterectomy – Head and neck surgery – Intraperitoneal and Intrathoracic – Orthopedic surgery – Prostate surgery Risk: Type of Procedure ACC/AHA Guidelines • Low risk (reported cardiac risk < 1%) – – – – Endoscopic procedures Superficial procedures Cataract surgery Breast surgery Case 1 • A 74-year old man is referred to you for preoperative evaluation prior to undergoing a right total hip replacement. He is severely limited due to his osteoarthritis, and can ambulate only limited distances in the home. His medical history is notable for CAD, for which he underwent an uncomplicated 3-vessel CABG 2 years ago. He has been symptom-free since. He has mild HTN and chronic renal insufficiency with a creatinine of 2.0 at baseline. Other than his CABG, he has no other surgical history. His current medications include aspirin and lisinopril, 10 mg daily. His vital signs are notable for a BP of 140/87, HR 88. Examination is essentially normal. – What are his surgical and medical risk factors? Steps to Preoperative Evaluation 1. 2. 3. 4. Surgical Risk Factors Patient Risk Factors Preoperative Testing Perioperative Management Patient Factors: Exercise Tolerance • McPhail, et al (1988) J Vasc Surgery 7:60 – 100 patients requiring vascular reconstructive surgery were evaluated preoperatively with treadmill testing or arm ergometry. – Patients able to achieve 85% of their maximal predicted heart rate had a 6% cardiac complication rate, whereas patients unable to achieve 85% MPHR had a 24% rate of complications (p = 0.04) – Patients who had a positive stress test but achieved > 85% MPHR had fewer cardiac complications. 1 MET: the oxygen consumption (VO2) of a 70 kg, 40 y.o. man at rest…3.5 cc/kg/min Duke Activity Status Index < 4 METS: Baking Slow dancing Golfing with a cart Playing a musical instrument Walking 2 – 3 mph > 4 METS: Ice skating Moderate cycling Walking 4 mph Heavy housework Skiing Risk: Patient Factors Major Clinical Predictors ACC/AHA Guidelines • Unstable coronary syndromes • Decompensated CHF • Significant arrhythmias • Severe valvular disease Risk: Patient Factors Intermediate Clinical Predictors ACC/AHA Guidelines • Mild angina pectoris • Prior MI • Compensated or prior CHF • Diabetes mellitus • Renal insufficiency Risk: Patient Factors Minor Clinical Predictors ACC/AHA Guidelines • • • • • • Advanced age Abnormal ECG Rhythm other than NSR Low functional capacity History of CVA Uncontrolled HTN Case 1 • A 74-year old man is referred to you for preoperative evaluation prior to undergoing a right total hip replacement. He is severely limited due to his osteoarthritis, and can ambulate only limited distances in the home. His medical history is notable for CAD, for which he underwent an uncomplicated 3-vessel CABG 2 years ago. He has been symptom-free since. He has mild HTN and chronic renal insufficiency with a creatinine of 2.0 at baseline. Other than his CABG, he has no other surgical history. His current medications include aspirin and lisinopril, 10 mg daily. His vital signs are notable for a BP of 140/87, HR 88. Examination is essentially normal. – What are his surgical and medical risk factors? – What preoperative testing is indicated? Steps to Preoperative Evaluation 1. Surgical Risk Factors 2. Patient Risk Factors 3. Preoperative Testing: • • Who How 4. Perioperative Management Cardiac Testing: Resting ECG • Class I (definite indication) – Recent ischemic symptoms – Major / intermediate clinical predictors and high or intermediate risk procedure • Class II (probably warranted) – – – – Asymptomatic diabetics History of cardiac revascularization Asymptomatic man > 45 yo or woman > 55 yo Prior hospitalization for cardiac causes • Class III (not indicated) – Asymptomatic patient; low risk procedure Echocardiography • Class I (definite indication) – Current or poorly-controlled CHF unless prior studies have documented severe ventricular dysfunction Class II (probably warranted) – Prior CHF and no recent evaluation – Dyspnea of unknown etiology – Evidence of significant valvular disease Class III (not indicated) – Routine testing of ventricular function in asymptomatic patients without a prior history of CHF • • Need for non-cardiac surgery emergency N Y Recurrent S/sx? O. R. elective Recent cardiac revascularization ? N Y Favorable result? Recent cardiac evaluation? N Unfavorable result or change in sx? Clinical Predictors ACC/AHA Guidelines Clinical Predictors Major Clinical Predictors? Intermediate or Minor Clinical Predictors? Further evaluation Exercise Tolerance? Poor Exercise Tolerance: < 4 METS Good Exercise tolerance: > 4 METS Minor or No Clinical Predictors Poor Exercise Tolerance: < 4 METS Good Exercise tolerance: > 4 METS High risk procedure Intermediate or low risk procedure Non-invasive cardiac testing High risk Further evaluation Low risk O. R. Intermediate clinical predictors Poor Exercise Tolerance: < 4 METS Good Exercise tolerance: > 4 METS High risk procedure Intermediate risk procedure Low risk procedure Non-invasive cardiac testing High risk Low risk O. R. Further evaluation Preoperative Stress Testing:** Major clinical predictors? N Y Further evaluation 2 or more of the following: * Intermediate clinical predictors * Poor exercise tolerance < 4 METS * High risk surgery Y N O.R. Patient ambulatory and can exercise? ** Test ONLY if outcome will impact management Patient ambulatory and can exercise? N Bronchospasm? Second degree AV block? Theophylline dependent? Valvular dysfunction? Y Male, normal ECG at rest? N ETT Echo or Perfusion scan Y ECG ETT Y N Prior symptomatic arrhythmia? Poor Echo window? Extreme blood pressure? Hx Arrhythmias? Severe HTN? N Pharmacological Echo or Perfusion Scan Persantine or Adenosine Perfusion Scan Y N Dobutamine Echo or Perfusion Scan Y Further evaluation Perioperative Management: Percutaneous Intervention (PCI) • No randomized trials have demonstrated benefit of balloon angioplasty or stenting in decreasing cardiac risk before non-cardiac surgery. • Posner KL, et al (1999) Anesth Analg 89:553 – Retrospective cohort study comparing patients undergoing preoperative PTCA, patients with known CAD that did not undergo PTCA preoperatively, and normal controls (no known CAD). – No reduction in early postoperative MI or death in patients who underwent PTCA. – Study was not controlled for severity of CAD, differences in medical management between the groups, or comorbidity. Case 1 • A 74-year old man is referred to you for preoperative evaluation prior to undergoing a right total hip replacement. He is severely limited due to his osteoarthritis, and can ambulate only limited distances in the home. His medical history is notable for CAD, for which he underwent an uncomplicated 3-vessel CABG 2 years ago. He has been symptom-free since. He has mild HTN and chronic renal insufficiency with a creatinine of 2.0 at baseline. Other than his CABG, he has no other surgical history. His current medications include aspirin and lisinopril, 10 mg daily. His vital signs are notable for a BP of 140/87, HR 88. Examination is essentially normal. – What are his surgical and medical risk factors? – What preoperative testing is indicated? – What measures would you initiate preoperatively to optimize his risk? Steps to Preoperative Evaluation 1. Surgical Risk Factors 2. Patient Risk Factors 3. Preoperative Testing: • • Who How 4. Perioperative Management Perioperative Management: Beta-Blockers Poldemans D, et al (1999) NEJM 341:1789 – 112 patients identified to be at increased cardiac risk (positive dobutamine Echo) preoperatively were randomized to treatment with bisoprolol or placebo. – Cardiac complications and cardiac death was significantly less in the treatment group (p=0.02): • Bisoprolol • Placebo 3.4 % 17.0 % Wallace A, et al (1998) Anesthesiology 88:7 – 200 patients undergoing general surgery were randomized to 7 day treatment with Atenolol or placebo. – Patients treated with Atenolol had significantly fewer episodes of ischemia by continuous monitoring (p=0.03) Perioperative Management: Cardiac Devices • Pacemakers: – Current generated through use of electrocautery can interfere with function of implantable devices: • Temporary reset to a VVI mode • Increase in pacing rate due to activation of rate-responsive sensor • Failure to sense or capture Recommendations: *Obtain information preoperatively regarding the pacer manufacturer, model and serial number, battery status, and most recent interrogation. *If the pacer is programmed in a rate-responsive mode, this feature should be inactivated preoperatively. *If a patient is pacer-dependent, temporary reset to a non-sensing mode preoperatively may be indicated. *Operative techniques to minimize stray current (short electrocautery strokes, placement of electrocautery grounding pad away from pacer pocket). Perioperative Management: Cardiac Devices • Implantable Defibrillators: – Can fire due to activation by stray electrical current from electrocautery use – Must be programmed OFF preoperatively and then reactivated postoperatively – Place defibrillator patches intraoperatively – Telemetry monitoring is indicated postoperatively until the AICD has been reactivated. Perioperative Management: Blood Thinners • • • • • • • • Aspirin (general indication) Aspirin (TIA / CVA / MI) NSAIDS Cox II inhibitors Clopidogrel (Plavix) Persantine Coumadin Herbal remedies (Gingko, Ginseng, Garlic, Feverfew) 14 days 7 days 3-7 days -------4-7 days 7 days variable 14 days Perioperative Management of Selected Drugs: Drug Beta-blockers Clonidine Preoperative Continue including day of surgery (DOS) Continue including DOS Long NPO period Substitute IV form Substitute transdermal form Calcium channel blockers ACEI Continue including DOS HTN (-) CRI: Continue on DOS. CHF or CRI: Hold on DOS Hold on DOS Substitute IV form for arrhythmia. Substitute Hydralazine / NTP Use IV diuretic prn Diuretics Oral contraceptives and HRT Hold 4-6 weeks preop for Hold 4-6 weeks preop for surgery with high risk of surgery with high risk of thrombosis. thrombosis. Case 2 • A 60-year old woman is referred to you for preoperative evaluation prior to undergoing a right femoral-popliteal bypass procedure. She develops symptoms of claudication at about 1 block but states she can walk 2 blocks if need arises. Her medical history is otherwise notable for obesity, hyperlipidemia and type II diabetes, diagnosed 6 years ago and well controlled on oral medications. ROS is significant for infrequent atypical CP. Her current medications include glucophage and atorvastatin and cilostazol. Her vital signs are normal. Examination is only remarkable for a cool right lower extremity with a non-palpable dorsalis pedis pulse. Cardiopulmonary examination is normal and there are no bruits. – What are her surgical and medical risk factors? – What preoperative testing is indicated? – What measures are needed perioperatively? Preoperative management of diabetics: • General anesthetic produces relative insulin hyposecretion and resistance due to changes in neuroendocrine balance (increased production of ACTH, catecholamines, GH, and glucagon). Postoperative factors such as inability to eat or absorb oral medications, use of steroids, hyperalimentation or tube feeds can affect glycemic control. Perioperatively: – Assess glycemic control preoperatively. – Oral hypoglycemics can generally be continued up until the time of surgery but should not be taken on the morning of the procedure. Metformin should be held for 48 hours postoperatively, and then restarted only if renal and hepatic function are stable. – The dose of intermediate and long-acting insulins should be reduced on the night prior to surgery. – For long or complicated procedures in patients requiring insulin, intravenous insulin should be used in the immediate perioperative period. For short procedures, it may be possible to either delay the use of morning insulin, or use a fraction of the normal dose of intermediate-acting insulin. • • THANKS