Preoperative Cardiac Clearance: Making Sense of the Guidelines (Part 1 of 2)
As a senior resident, I was frequently asked to assess the preoperative risk of patients and currently do it on a daily basis as faculty. The goal is to identify procedures and patient factors that could significantly elevate the risk of intra- and peri-operative complications.
What is the Risk of Medical Complications of Surgery in “Healthy Patients?” • Less than 0.1% overall mortality • Warner MA et al looked at 38,598 “healthy patients” –> only 33 (0.08%) had major morbidity and mortality (Only 2 deaths at 30 days post-op, and both were due to myocardial infarctions)
What are the Perioperative Risk Classifications for Surgical Procedures? • High-Risk = >5% perioperative risk for death or MI (Aortic and peripheral vascular surgery) • Intermediate-Risk = 1 – 5% perioperative risk for death or MI (Intraperitoneal and intrathoracic surgeries, Carotid endarectomy, Head and neck surgery, orthopedic surgery, and prostate surgery) • Low-Risk = <1% perioperative risk for death or MI (Endoscopic and superficial procedures, cataract surgery, breast surgery, dental procedures, and ambulatory surgery)
What Underlying Chronic Conditions Influence the Risk of Medical Complications of Surgery? Conditions associated with higher perioperative risk 1. Ischemic heart Disease 2. Congestive Heart Failure 3. Cerebrovascular Disease 4. Diabetes Mellitus (Use of Insulin Therapy) 5. Renal Insufficiency (Serum Cr >2.0mg/dL)
What is a Revised Cardiac Risk Index (RCRI)?
Does Exercise Tolerance Influence the Risk for Perioperative Complications? • METs = Metabolic Equivalents • Excellent (>7 METs) = Jogging (10-minute mile), Scrubbing Floors, & Tennis • Moderate (4 – 7 METs) = Cycling, Climbing a Flight of Stairs, Walking 4mph, and Yardwork • Poor (<4 METs) = Vacuuming, Activities of Daily Living (Eating, Dressing, and Bathing), Walking 2mph, and Writing • Reilly DF et al determined that if a patient could not walk 4 blocks or climb 2 flights of stairs perioperative cardiac complications DOUBLED
How Soon After Smoking Cessation, are the Risks for Perioperative Complications Reduced? • Risk for pulmonary complications is reduced if smoking cessation is implemented as late as 4 to 8 weeks before surgery
What are the Essential Elements of Perioperative Risk Assessment? • History and Physical Exam • Lab Testing (History and Physical exam should guide this) • Smetana GW et al found that routine blood work before an operation in all patients without the use of history and physical altered perioperative care in 0 – 2.6% of cases • Charpak Y et al found that when use of history and physical exam were used to guide lab testing the yield of the lab tests increased from 4% to 81%
Should all patients have preoperative CXR and EKG Testing? • CXR : Age >50 years, known cardiac or pulmonary disease, symptoms or examination suggesting cardiac or pulmonary disease, or having major surgery • CXR : Not indicated in younger patients, normal history and physical exam, or if procedure does not carry high cardiopulmonary risk • 2012 ACP Choosing Wisely Recommendation: In the absence of cardiopulmonary symptoms, preoperative chest radiography rarely provides any meaningful changes in management or improved patient outcomes. • EKG : Men > 40 years and Women > 50 years, known coronary artery disease, diabetes mellitus, or hypertension • 2012 ACP Choosing Wisely Recommendation: In asymptomatic individuals at low risk for coronary heart disease (10-year risk <10%) screening for coronary heart disease with exercise electrocardiography does not improve patient outcomes.
When Should Clinicians Consider Preoperative Cardiac Stress Testing? • In general, indications for non-invasive stress testing is the same for patients undergoing surgery as for those who are not • Patients with active cardiac conditions (unstable angina, decompensated heart failure, severe valvular disease, or recent percutaneous coronary intervention) should have non-invasive testing before ALL procedures with the exception of urgent surgical procedures
What are the ACC/AHA 2009 Guidelines for Preoperative Assessment? In my opinion, how this affects your practice: • ACP also has an algorithm for cardiac risk assessment and it does not matter which algorithm you use, just pick one of them. • Follow a systematic, step by step process when evaluating your patients for perioperative risk of morbidity and mortality
References: 1. Charpak Y et al. Usefulness of Selectively Ordered Preoperative Tests. Med Care 1988; 26: 95 – 104. PMID: 3339918 2. Laine C et al. In the Clinic: Preoperative Evaluation. Ann Intern Med 2009 Jul; 151 (1): 1 -16. PMID: 19581642 3. Reilly DF et al. Self-Reported Exercise Tolerance and the Risk of Serious Perioperative Complications. Arch Intern Med 1999; 159: 2185 – 92. PMID: 10527296 4. Smetana GW et al. The Case Against Routine Preoperative laboratory Testing. Med clin North Am 2003; 87: 7 – 40. PMID: 12575882 5. Warner MA et al. Major Morbidity and Mortality Within 1 Month of Ambulatory Surgery and Anesthesia. JAMA 1993; 270: 1437 – 41. PMID: 8371443 _______________________________________________________________________________
Dr. Salim R. Rezaie is a physician at the University of Texas Health Science Center at San Antonio. He is double board-certified in Emergency Medicine and Internal Medicine.