Preoperative Evaluation: Risk Reduction (Part 2 of 2)
Once a patient has been cleared from a cardiac standpoint, the next step in the process is to reduce perioperative complications even further. Our goal should be to prevent postoperative infections, bleeding, and minimize the length of stay.
What are the indications for perioperative Beta Blockers? • One of the most controversial perioperative topics • Perioperative Ischemic Evaluation (POISE) Trial (2008) -> RCT of >8000pts comparing initiating Extended Release Metoprolol vs placebo immediately preoperatively -> Reduction in non-fatal MI and cardiac death, but overall mortality and stroke risk increased
• 2009 ACCF/AHA Recommendations 1. Class I Rec: Continue beta-blockers for those already taking them. 2. Class IIa Rec: Beta blockers titrated to HR 60 – 65 for intermediate risk surgeries, vascular patients with known CAD, cardiac ischemia defined in preoperative testing, and more than one cardiac risk factors (CAD, CHF, CVA, DM, CRI.) 3. Otherwise, the usefulness is uncertain
How are postoperative pulmonary complications reduced? • Early Incentive Spirometry has been shown to decrease complications of atelectasis and pneumonia by >50% • Smoking Cessation 4 – 8 weeks prior to surgery • BiPAP post operatively may reduce need for re-intubation if required • Optimize chronic lung disease (i.e. COPD) • Pulmonary Function Testing and ABG Analysis are NOT routinely useful
How are postoperative thromboembolic complications reduced? • Elastic Stockings pre- and post operatively • Early Ambulation post operatively
Who needs Endocarditis Prophylaxis Preoperatively? • Only required in HIGH RISK PROCEDURES and HIGH RISK CONDITIONS • High Risk Conditions = All prosthetic valves, Previous history of endocarditis, Congenital heart disease (Unrepaired cyanotic CHD), Repaired congenital heart disease with in 6 months of repair • NOT HIGH RISK DISEASE: Mitral Stenosis, Aortic Stenosis, Mitral Valve Prolapse, and Hypertrophic Obstructive Cardiomyopathy • HIGH Risk Procedures = Anything that is likely to cause bleeding and induce bacteremia • NOT HIGH RISK PROCEDURE: GI or GU procedures
What are some medications you should be aware of preoperatively and why? • Aspirin: Continue for all minor surgeries; Should stop taking 5 to 10 days before moderate and high risk surgery; can restart 1 – 2 days after • Anticoagulants: Can be continued for all minor surgeries (DO NOT DISCONTINUE) • Warfarin or Anticoagulant Therapy: Will need “bridge therapy” with heparin (1/2 life of heparin is about 90 minutes so discontinue 6 hours before major surgery) • Sulfonylureas and Metformin: Stop 1 – 2 days before surgery; Maintain glucose control with insulin (Typically reduce long-acting insulin by 50% and hold short acting day of surgery)
What are some disease processes you should be aware of preoperatively and why? • HTN: Diastolic BP >110mmHg is associated with increased perioperative risk; Goal BP should be <160/100mmHg • CAD: Consider beta blocker therapy as discussed above; Continue Statins • Recent Coronary Stent Placement: At risk of stent thrombosis -> for bare metal stents risk reduces at 4 – 6 weeks and for drug eluding stents risk reduces at 12 months; ALL elective procedures should be delayed accordingly • CHF: Decompensated failure is a major predictor of increased risk while compensated failure is an intermediate predictor of risk; Hold or decrease dose of ACEI and Diuretic the day of surgery to prevent hypotension
In my opinion, how this will affect your practice: • Continue Beta Blockers in patients already on them, consider adding them for patients with multiple risk factors for CAD • You may continue all NSAIDs, ASA, and anticoagulants for minor surgeries • Be sure to know what the HIGH RISK PROCEDURES and CONDITIONS are for endocarditis prophylaxis • Be aware of some specific medications and disease processes
References: 1. ACCF/AHA Task Force on Practice Guidelines et al. 2009 ACCF/AHA focused update on perioperative beta blockade incorporated into the ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery. JACC 2009 Nov; 54 (22): 13 – 118. PMID: 19926002 2. Laine C et al. In the Clinic: Preoperative Evaluation. Ann Intern Med 2009 Jul; 151 (1): 1 -16. PMID: 19581642 3. Lindenauer PK, Pekow P, Wang K, Mamidi DK, Gutierrez B, Benjamin EM. Perioperative beta-blocker therapy and mortality after major noncardiac surgery. N Engl J Med. 2005;353(4):349–361. PMID: 16049209
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.