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Perioperative Medicine

Perioperative Medicine. Thomas W. Barrett, MD Portland VA Medical Center Assistant Professor of Medicine Oregon Health and Science University Oregon ACP Scientific Meeting November 5, 2004. Goals & Audience. Define Perioperative Medicine Review best predictor of outcomes

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Perioperative Medicine

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  1. Perioperative Medicine Thomas W. Barrett, MD Portland VA Medical Center Assistant Professor of Medicine Oregon Health and Science University Oregon ACP Scientific Meeting November 5, 2004

  2. Goals & Audience • Define Perioperative Medicine • Review best predictor of outcomes • Review options for decreasing risk after surgery • Practice Paradigms for Perioperative Medicine • Current State of Perioperative Medicine • Challenges • Future

  3. Definition • The use of medicines, techniques, or devices to improve outcomes after surgery. • Less heart attack, stroke, renal failure, pneumonia, ileus, delirium, VTE Dz, disability, and death. • Multidisciplinary: Surgery, Anesthesiology, Internal Medicine, Nursing, Pharmacy, Physical Therapy, Occupational Therapy, Speech Therapy, Nutrition, Social Work

  4. Significance • 100,000 patients undergo surgery daily in the US, 33 million annually, 10% of population • Cost $ 450 Billion annually, average $ 13,000 per treatment, 40% of the healthcare budget • 1 million patients have adverse events per year, costing $ 45 Billion annually • Within next 2 decades, surgical patients will increase by 25%, cost by 50%, in-hospital complications by 100%, as population ages Mangano, J Cardiothorac Vasc Anesth. 2004 Feb;18(1):1-6.

  5. Population Pressor • At present, 10,000 “baby boomers” are turning 58 each day • The present surgical burden may become a surgical crisis • Biggest impact on above would be to address the best predictor of outcomes

  6. Best Predictor of Outcomes? • 3 fold increase in odds of adverse cardiac outcome (CHF,VT),and 9 fold increase in odds of clinical ischemia event (USA, non fatal MI, Cardiac death), up to 2 years after surgery • 70% of adverse outcomes (CHF, VT, MI, USA, Cardiac death) associated with it

  7. Best Predictor? • Preoperative Demographics • Results of risk indices • Stress test results • Intraoperative events • Perioperative ischemia

  8. Perioperative Ischemia • More predictive of adverse outcomes than preoperative demographics, stress test results, or intraoperative events • Post op day 0-2: if no ischemia then rare adverse outcome (CHF, VT, MI, USA, Cardiac death) 6 v 17% over 2 yrs., if positive ischemia, 2.2 fold increase odds, if infarction, 20 fold increase Mangano et al., 1990s

  9. Perioperative Ischemia • Perioperative ischemia defined by three lead Holter monitor, lasting at least one minute, >0.1 mV ST depression, or>0.2 mV ST elevation • Known CAD and pts with 2 CAD RFs (age>65, HTN, DM, Hyperlipidemia, tobacco) are equally likely to have ischemia, p=0.60; incidence 27% and 27% • Ischemia most common post op day 0-3 • Persists up to 7 days after surgery Mangano et al., 1990s

  10. Perioperative Ischemia • Silent 84-97% • Anesthesia and surgery are not associated with an increase in ischemia • Mean ST change pre/intra/post op, 1.5/ 2/ 2.6 • Duration of ischemia 69/ 45/ 207 minutes • Area under the curve: 88/ 74/ 383 mm.min • Postoperative ischemia is related to HR, Mean HR; 76/ 71/ 92; with 57% ischemia in HR>100, some studies had a threshold of 80. Mangano et al., 1990s

  11. Pathophysiology of the Perioperative State • Hyperadrenergic state with excitotoxic, inflammatory, thermic, thrombogenic stressors • Tachycardia, increased myocardial contractility, increased myocardial O2 demand, changes in endothelium, clotting factors, and plaque stability • Critical fixed obstructive coronary lesions • Coronary vulnerable plaque disruption • May not manifest for weeks or months

  12. Interventions to Decrease Risk • Perioperative b-blockers • a2-agonists • Statins • ASA

  13. Perioperative b-Blockers • Retrospective observational cohort • Case control • Randomized Clinical Trials • Meta-analysis • Systematic review • AHRQ Quality marker

  14. Perioperative b-Blockers Decrease • Perioperative ischemia • Postoperative myocardial infarction • Postoperative mortality, especially in vascular surgery, but also other noncardiac surgery • Not studied in CABG as it is standard care

  15. Guidelines • ACC/AHA 2002 update: Perioperative beta-blockers are Class I for symptomatic angina, arrhythmia, hypertension,or positive ischemia on stress test and undergoing vascular surgery. • Class IIA for untreated HTN, known CAD, or major RF for CAD • ACP 1997 Author’s addendum: For all patients, determine eligibility for Beta blocker use.

  16. Perioperative b-Blockers: Mechanism of Action • Decreases tachycardia, inotropy, arrhythmias, and ventricular wall stress • Redistributes coronary blood flow • Potentiates minimum alveolar concentration for volatile anesthetics, which are cardioprotective • Decreases central nociception, so patients have less pain, and therefore less adrenergic stim. • Decreases inflammatory cytokines

  17. Perioperative b-Blockers: Quality • Perioperative b-Blockers are utilized about 40% of the time, which is c/w ambulatory use of b-Blockers for patients c CAD • Very rare to have patients not already taking b-Blocker, started on it for surgery • Noncardiac surgery one institution, PBB incidence 37%, full use of PBB would have prevented 62-89 deaths and saved $ 318,000 to $ 463,000 annually

  18. Perioperative b-Blockers: Quality • Canadian anesthesiologists self reported 57% usage of PBB, but 97% agreed it was useful • VA survey: 71% self report, 87% agreed helpful in known CAD, 72% for RFs, only 30% PBB efficacious for nonvascular, noncardiac surgery • A systems improvement involving FP, internists, and anesthesiologists in Canada resulted in a 69% incidence of PBB.

  19. Perioperative b-Blockers: Subjective Suggestions • Start 7 days before surgery, continue for 7 days after surgery. • If known vascular disease do not stop • Titrate to goal HR of 65 postop • If HR>65 and SBP>100 double dose • If HR<55 or SBP<100 hold dose

  20. Perioperative b-Blockers • Controversial? • Large RCT of perioperative b-Blockers in a multi-center, international design is ongoing, POISE (Perioperative Ischemic Evaluation) in Canada will enroll 10,000 patients. • Medico-legal implications

  21. a2-agonists • Retrospective observational cohort • Case control • Randomized Clinical Trials • Meta-analysis • Systematic review • Centrally acting sympatholytic

  22. a2-agonists • Decrease perioperative ischemia, myocardial infarction, and mortality after vascular surgery • Decrease perioperative ischemia and mortality for up to 2 years after noncardiac surgery, study design questions • Decrease perioperative ischemia after CABG • Still controversial, and considered second line to b-Blockers. Not everyone can tolerate bB

  23. Statins • 1 Case control • 2 Observational cohort • 1 RCT • Pleotrophic effects

  24. Statins • Case control vascular surgery, reduced in-hospital mortality by a factor of 4.5 • Observational cohort: 780,000 patients. Reduced in-hospital mortality after noncardiac surgery by 38%, but mortality 2.13% v 3.05% • Observational cohort CABG, 323 patients, decreased death, MI, USA, arrhythmia

  25. Statins • Vascular surgery RCT: 100 patients, atorvastatin 20 mg, 30 days before surgery, f/u 6 months • Composite of death, nonfatal MI, USA, stroke • Incidence 8% v 26%, p=0.031 • Event free survival at 6 months 91% v 74%, p=0.018 • More studies needed

  26. ASA in CABG • Prospective observational cohort of 5,022 patients surviving 2 days post CABG • Compared patients receiving ASA within 48 hrs of CABG to those not • 30 day mortality 1.3 v 4%, p<0.001 • 48% reduction in MI • 50% reduction in stroke Mangano, NEJM 2002;347(17):1309-17

  27. ASA in CABG • 74% reduction in renal failure • 62% reduction in bowel infarction • Risk of bleeding, gastritis, impaired wound healing, and infection was not increased • No other drug explained benefit • Kind of study that changes management Mangano, NEJM 2002;347(17):1309-17

  28. Current State of Perioperative Medicine: Traditional • Local system of care defines patient responsibilities • Traditional: PCP sees patient before surgery and assesses risk and need for risk stratification or intervention? • Anesthesiologist meets patient for the first time minutes before surgery, up to discharge from PACU

  29. Current State of Perioperative Medicine: Traditional • Surgeon schedules surgery, then addresses all postoperative issues until discharge. If there is a problem, then gets subspecialty consultation • Surgeons can take 1-2 days longer to realize there is a medical problem (Anecdotal) • If wait until there is a problem, then it is too late. We want to prevent problems.

  30. Current State of Perioperative Medicine: Co-Management • New practice paradigm • An Internist (Hospitalist) sees patient several weeks before surgery for a preoperative consultation. Systems care • Risk assessment is done for all organ systems: CNS, Lung, Heart, GI, VTE Dz, Heme • Risk stratification performed • New risk reduction drugs initiated • Patient is seen every day in the hospital until d/c

  31. Current State of Perioperative Medicine: Co-Management • Regions of country that having been doing this for > 20 years • Hospitalist academic community started this ~5 years ago, and are amassing data • Private practice model, resident resistance • Sound business model • One study published to date: HOT 526 patients undergoing total hip or knee replacement

  32. Hospitalist Orthopedic Trial • Decreased minor complications such as: electrolyte abnormalities, fever, UTI, 30 v 44% • Unadjusted LOS same • Adjusted for care facility taking patient: 0.5 day less • Costs the same • Nurses, Orthopedic faculty and residents preferred the co-management model • More studies are needed Huddleston et al., Ann Intern Med 2004 Jul 6;141(1):28-38

  33. Current State of Perioperative Medicine: Research • NIH NHLBI Working Group Statement Feb. 2004 • Drs. Claude Lenfant and Dennis Mangano organized, 18 months, 45 experts from surgery, anesthesiology, general medicine, subspecialties, critical care, government and health economics • Topics included risk profiling, preventable and treatable complications, and multispecialty guidelines Mangano, J Cardiothorac Vasc Anesth. 2004 Feb;18(1):1-6.

  34. NHLBI Working Group Recommendations • There is an impending surgical crisis • Total numbers of surgeries will increase, adverse events will increase, in-hospital and discharge plans will become more challenging • Risk profiling, multispecialty paradigms, patient education before surgery, and discharge risk profiling needed more attention Mangano, J Cardiothorac Vasc Anesth. 2004 Feb;18(1):1-6.

  35. NHLBI Working Group Recommendations • Non vascular, noncardiac surgery and elderly populations need more attention • Assessment and reporting of complications varies across specialties • No consistent approach to informed consent is standard • A comprehensive, national database with multispecialty, multi-center, and agreed upon components would best address this variability. Mangano, J Cardiothorac Vasc Anesth. 2004 Feb;18(1):1-6.

  36. NHLBI Working Group Recommendations • National Perioperative Initiative (Funding) • Perioperative Medicine Advisory Board at NHLBI • Involvement of specialty societies are crucial • Current guidelines of preoperative assessment have much in common, but without widespread recognition and implementation of a general paradigm by the multiple specialties, a unified approach will not be realized Mangano, J Cardiothorac Vasc Anesth. 2004 Feb;18(1):1-6.

  37. Other Challenges • Common adverse events involving the CNS, renal, pulmonary, GI, heme are not addressed by the current guidelines • Interventions to decrease perioperative risk are few, and when existent not used in over 50% of high risk patients (Perioperative b-Blockers) • Drug and technology development that is tailored to the unique perioperative physiologic state is non existent at present

  38. Other Challenges • Long term outcome data are few. A couple 1-2 year studies with a few hundred patients • Customary window to follow is 30 days • If we had robust long term data, then we may be able to identify high risk population that would benefit from other interventions, e.g. drugs. • Effectiveness of Risk Indices and Guidelines? Ease of use v. efficient systems care. Audience?

  39. Proposed Actions for Clinicians • Look at your system of care and assess interest in establishing a Perioperative Medicine program.: Internists (Hospitalists), surgeons, anesthesiologists. • Benefits: Financial, variety, patient satisfaction • Consider a Perioperative b-Blocker protocol, which will require active involvement if it is to work.

  40. Proposed Actions for Researchers • Establish fruitful multispecialty collaborative relationships • Assist government to prioritize Perioperative Medicine with the help of societies • Hospitalists need to enter the Perioperative Medicine debate (Youth) • Multidisciplinary skills may be helpful

  41. Future • Systems of care that have highly evolved multispecialty co-management programs do not want to go back • Quality of life for PCP, surgeon, anesthesiologist • Data will cement the co-management model, which will become standard of care everywhere

  42. Future • Multispecialty research will advance drug and technology development to give our patients undergoing surgery the safest, most robust system of care available, thus averting the impending surgical crisis.

  43. Thank you • Please email me if you wish to have a copy of this presentation or a list of references. • Look for the SHM Supplement on Perioperative Medicine barretth@ohsu.edu

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