NMS Q&A Family Medicine

Preoperative Clearance 233example, atenolol and metoprolol, and clonidine, analpha 2 agonist, have been shown significantly to reducesuch perioperative risk. In addition, 45 days of a statin,such as atorvastatin, beginning 2 weeks before surgery hasalso an effect, a markedly reduced perioperative coronarydisease risk status. Smoking cessation not only reducesmorbidity and mortality in dozens of ways but alsoreduces respiratory complications in anesthesia in a relativelyshort time before surgery.8. The answer is C. Postpone surgery for 2 months. AnMI within 3 to 6 months poses a significant risk of perioperativecardiovascular mortality and morbidity. If theplanned surgery is elective, delaying the operation is thecorrect strategy, rather than instituting risk-reducingagents, effective although they may be.9. The answer is B. One should proceed with evaluationfor coronary revascularization. This is another example ofa high-cardiovascular-risk situation in that the patient hasclass III angina, according to the Canadian CardiovascularSociety system (see the discussion of Question 2), that isnow accelerating. Although there have been some recentlypublished data that might shed doubt on correcting stablecoronary artery disease before elective noncardiac surgery,all agree that patients with clear-cut indications for a revascularizationprocedure without regard for contemplatedsurgery must have such a procedure before proceedingwith elective surgery. Nitroglycerin and long-acting nitrateshave their place in maintaining the patient’s stability.10. The answer is D. The patient will be at increased riskfor pulmonary edema but not for other cardiac events.This applies specifically to patients who have a history ofCHF but are well.11. The answer is D. The patient will be at increased riskof CHF on the basis of the preoperative ejection fractionof 50%. Such patients have 4 times the chance of CHF(12% vs. 3%) compared with those patients with ejectionfractions 50%.12. The answer is A. Continue the current medications,including the dose(s) that is due on the day of surgery,and proceed with the surgery. Current thinking and inferencesfrom certain studies suggest that mild to moderatehypertension does not pose a significant cardiac risk inthe perioperative period. By the same token, however, it isfelt that antihypertensive medications should be continuedup to the day of surgery and postoperatively asrequired for control of the blood pressure.13. The answer is B. Delay surgery and take more aggressivesteps to control the blood pressure, such as adding acalcium channel blocking drug; proceed with surgerywhen the blood pressure is consistently below 140/90.One should put this or another effective method of loweringthe blood pressure into play before allowing the operationto proceed. This is the thinking of experts forrepeated blood pressure readings 180/110.14. The answer is A. The contribution of the lobe beingconsidered for resection must not exceed 1,400 mL. This isbased on the fact that the postoperative FEV 1 must be atleast 800 mL. Thus, as the preoperative FEV 1 was 2.2 L, thecontribution of the tissues to be resected being greater than1,400 mL would leave less than 800 mL after the surgery.(One may encounter a more liberal opinion, i.e., that theFEV 1 may be as low as 500 mL after surgery.) MI or death is8% to 30%; after 6 months, such risk falls to 3.5% to 5%.15. The answer is D. Preoperative Child–Turcotte–Pughclassification score is an indicator for postoperativehepatic status in a patient with lever disease. This score isa combination of graduated scores regarding several manifestationsof cirrhosis. Five conditions are listed (below),each of the five with a score from 1 point to 3 points (1 isnormal, 2 is moderately abnormal, and 3 is severely abnormal).Thus, normal risk is defined as no more than 1 pointin each of the 5 categories (ascites, encephalopathy, bilirubinelevation, serum albumen insufficiency, and elevationof prothrombin international normalized ratio [INR]time), and maximum risk denoted by overscore in the5 categories of 15. The risk of postoperative hepaticcomplications is reasonably directly related to the Child–Turcotte–Pugh score. The following table is a representationof the Child–Turcotte–Pugh scoring.Numerical ScoreParameter 1 2 3Ascites None Slight Moderateto severeEncephalopathy None Slight tomoderateModerateto severeBilirubin (mg/dL) 2 2–3 3Albumin (g/dL) 3.5 2.8–3.5 2.8PT (secondsincreased)1–3 4–6 6The table is modified from Friedman (2006); used with permission.16. The answer is C. Measure of 8 g/dL is the acceptedlevel below which the Hgb should be corrected beforeelective surgery in those patients with no major risk factorsfor coronary artery disease or factors of age, nutrition,or alcohol. However, for those with baseline risk factors,risk of coronary disease perioperatively is significantly increasedif the Hgb falls below 10 g/dL. In addition, Hgb 10 g/dL is associated with an increased risk of postoperativedelirium.