Case presentation

1. Case presentation

2. consult from surgery- 51y female • 51y female with Traumatic Brain injury @ 12yo • Obese (BMI > 40) • HTN- well-controlled on lisinopril 40mg/d • OSA • Chronic cough + intermittent hemoptysis • Extensive pulmonary w/u normal to date (PFT+bronch) • Hx of left fem/pop DVT ~9mo ago • Recent Pap normal

3. What issues are pertinent to her surgery? • What tests need to be done now? • Should she be cleared for the surgery?

4. The Pre-operative evaluation August Hein, M.D. LtCol USAF, MC, SFS

5. Stratification • Patient factor • Different classification systems • Goldman 1977 • Detsky 1986 • Lee’s revised 1999 • Recognize similar key points • Surgical factors/risk • Low • Intermediate • High

6. Surgery classification • Invasiveness • Emergent / Routine

7. Surgical Stratification • Cardiac risk • High (> 5% risk of cardiac event*): • Emergent major operations, esp. in elderly • Aortic/ major vascular surgery • Peripheral vascular surgery • Anticipated large fluid shifts and/or blood loss *Cardiac event = fatal and non-fatal MI

8. Intermediate risk (< 5% risk of event) • Carotid endarterectomy • Head and neck surgery • Intraperitoneal and intrathoracic surgery • Orthopedic or Prostate surgery

9. Low risk (< 1% risk of cardiac event) • Endoscopic procedures • Superficial procedures • Cataract surgery • Breast surgery

10. Pulmonary risk • Definite factors • Upper abdominal surgery • Thoracic surgery • AAA repair • Surgery > 3hrs • Probable factors • General anesthesia • Emergency surgery

11. Patient Factors • Exercise Capacity • Medication use • Obesity • Age • Labs EKG CXR PFT

12. Source: http://uptodateonline.com/utd/content/image.do?imageKey=prim_pix/preop_pa.gif

13. Source: AAFP 15 April 2004

15. Exercise Capacity • Good capacity = 4 METs • Two level blocks without symptoms • One flight of stairs with two bags of groceries Poor exercise capacity: < four level blocks or two flights of stairs Expected Complications: Total: 20% vs 10% Cardiac: 10% vs 5% Pulmonary: 9% vs 6% (not statistically signif.)

16. Medication use • Back door route to forgotten medical hx • HTN • Hypothyroid • Asthma/COPD • May forget OTCs (aspirin, NSAIDS) • So ask!

17. Obesity • DESPITE • Reduced lung volume • V/Q mismatch • Relative hypoxemia • NOT a risk factor, but considered in pulmonary and upper abdominal surgery Studies that show increased RR tend to not use multivariate analysis

18. Age • Mortality risk • < 60 = 1.3% • 80-89 = 11.3% Multiple factors present, not a good sole criterion for withholding surgery

19. Labs • CBC • Asymptomatic anemia <1% prevalence • Surgically significant anemia is even lower • Mortality for surgery with expected blood loss • Hct >12  1.3% • Hct < 6  33% • Remainder of CBC not useful (wbc,plt) in asymptomatic individuals

20. Labs (cont’d) • Lytes • History/medication use more useful • BUN/Cr • Reasonable over 50 – recent emphasis on CRI • Major surgery • Hypotension expected • Nephrotoxic meds anticipated

21. Labs (cont’d) FBS/FBG/FSG – or just serum glucose Not recommended for surgical screening **Recent control hx imperative for diabetics** LFT – only if history/exam suggest disease PT/PTT – low correlation of abnl to postop comp. “perfectly unhelpful” predictor + likelihood ratio 0.0 - likelihood ratio 1.01

22. Labs (cont’d) • UA • ? id renal disease or UTI? • Serum Cr would id renal dz better • UTIs may contribute to 4-5 post-op infections/year • If UA for all non-prosthetic knee operations • $1.5 million per infection prevented! • Post-op infection adds ~$3000 to surgical costs

23. EKG • Low likelihood of changing management • Recent MI important to detect • Cardiac event risk increased by: • Non-sinus rhythm • PACs • >5 PVCs • No risk increase with BBB

24. EKG • Recommendations • Men > 45 Women > 55 • Known cardiac dz • H&P suggesting possibility of cardiac dz • Electrolyte imbalance risk (ie diuretic use) • DM/HTN • Candidates for major surgeries

25. CXR • Abnormalities not well associated with post-operative risk • 0.1% affected management • Routine use not recommended • 2 exceptions (by consensus) • >60y • Suspected cardiac or pulmonary disease

26. Pulmonay Function Test • No improvement over clinical eval • Where the money is: • Decreased breath sounds • Prolonged expiratory phase • Rales, rhonchi, wheezes • PFTs for unexplained dyspnea after good clinical eval

27. Minor risk predictors • Advanced age • Abnormal electrocardiogram • Left ventricular hypertrophy • Left bundle branch block • ST-T-wave abnormalities • Rhythm other than sinus rhythm (e.g., atrial fibrillation) • Low functional capacity: < 4 METs (e.g., inability to climb one flight of stairs holding a bag of groceries) • History of stroke • Uncontrolled systemic hypertension

28. Intermediate risk predictors • Mild angina pectoris • Previous MI based on the history or the presence of pathologic Q waves • Compensated or previous CHF • Diabetes mellitus, particularly insulin-dependent diabetes • Renal insufficiency

29. Major risk predictors • Unstable coronary syndromes • Acute (<7d) or recent (7-30d) MI w/ evidence of important ischemic risk by clinical symptoms or noninvasive study • Unstable or severe angina • Decompensated CHF • Significant arrhythmias • High-grade atrioventricular block • Symptomatic ventricular arrhythmia in the presence of underlying heart disease • Supraventricular arrhythmias with uncontrolled ventricular rate • Severe valvular disease

31. Indications for Ambulatory ECG for ischemia monitoring • Class I: None • Class IIa • Patients with suspected variant angina • Class IIb • Evaluation of patients with chest pain who cannot exercise • **Preoperative evaluation for vascular surgery of patients who cannot exercise** • Patients with known CAD and atypical chest pain syndrome • Class III • Initial evaluation of chest pain patients who are able to exercise • Routine screening of asymptomatic subjects source: http://www.americanheart.org/presenter.jhtml?identifier=1925

32. Pre-op eval “take home” • Screening questionnaire • Exercise tolerance • Blood pressure and pulse • Expand H & P if above abnl, pt >60y or major surgery • HCG for young women • HCT for bloody surgery • Serum Cr for major surg/ possible hypotension/ nephrotoxic meds/ pt > 50 • Beta-blocker for known Ischemic dz --> vascular surgery • Stress-testing if exercise capacity in question

33. ECG Men > 45 Women > 55 • Known cardiac dz • Eval suggesting possibility of cardiac dz • Electrolyte imbalance risk (ie diuretic use) • DM/HTN • Candidates for major surgeries

34. 2007 Dental update • Antimicrobial prophylaxis = FOUR cardiac conditions w/ highest risk of adverse outcome from endocarditis: • 1. Prosthetic cardiac valves • 2. Cardiac transplantation with subsequent valvulopathy • 3. Previous history of infective endocarditis • 4. Congenital Heart Disease (CHD), including only: • Unrepaired cyanotic CHD, including palliative shunts and conduits • Completely repaired congenital heart defects with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first six months after the procedure • Repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device (which inhibit endothelialization) • B. Dental Procedures for Which Endocarditis Prophylaxis is Recommended: “All dental procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa.”* • * No prophylaxis needed: routine anesthetic injections through non-infected tissue, taking dental radiographs, placement of removable prosthodontic or orthodontic appliances, adjustment of orthodontic appliances, placement of orthodontic brackets, shedding of deciduous teeth, and bleeding from trauma to the lip or oral mucosa. • C. What Antibiotic Regimens for a Dental Procedure? The same single dose antibiotic regimens from the 1997 Guidelines can be given 30 to 60 minutes before the procedure.

35. Case #2 • 76y male with debilitating Rt hip OA • Scheduled for Rt Total Hip • s/p inferior MI 1yr ago – TPA, resolution • No tobacco use • No CVD, no DM, EF wnl, Bun/Cr wnl • Walked 1-2 mi/day until 2mo ago – pain • Simvastatin, HCTZ, • Rx’d Atenolol, stopped after bronchitis 2 wks ago • BP 157/92; Exam wnl; ECG =inf Q waves

36. Lee's Revised Cardiac Risk Index Clinical variable Points High-risk surgery (i.e., intraperitoneal, intrathoracic, or suprainguinal vascular surgery) 1 Coronary artery disease 1* Congestive heart failure 1 History of CVD 1 Insulin for diabetes mellitus 1 Preoperative SCr > 2.0 mg/dL 1 Total:__1__

37. Interpretation of Risk Score • Risk class Points Complication* risk I. Very low 0 0.4% II. Low 1 0.9% III. Moderate 2 6.6% IV. High 3 +11.0% *- MI, PE, VF, cardiac arrest, or complete heart block.

38. Review • *Exercise tolerance • *Blood pressure and pulse • *Expand H & P if above abnl, pt >60y or major surgery • HCG for young women • *HCT for bloody surgery • *Serum Cr for major surg/ possible hypotension/ nephrotoxic meds/ pt > 50 • *Beta-blocker for known Ischemic dz --> vascular surgery or history of taking them • *Stress-testing

39. Summary • Pre-op eval is not “clearance” • Determine risks, then minimize • Let surgeon, anesthesia do the “clearing” • Screening Labs/Tests rarely useful alone • Should be driven by suspicions from eval/hx

40. Links • Articles • http://www.acc.org/clinical/guidelines/perio/update/periupdate_index.htm • http://www.aafp.org/afp/20040415/poc.html • http://www.americanheart.org/presenter.jhtml?identifier=1960 • Smetana, Gerald W. in:http://uptodateonline.com/utd/content • http://www.aafp.org/afp/20070301/656.html • http://circ.ahajournals.org/cgi/reprint/CIRCULATIONAHA.106.183095v1 • forms • http://www.aafp.org/afp/20040415/pocform.html • http://uptodateonline.com/utd/content/image.do?imageKey=prim_pix/preop_pa.gif