NMS. Casos Clínicos

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Part I ♦ Foundations factor from endothelial cells, and it increases the spreading and aggregation of platelets. Conjugated estrogens, which have a slow onset of action, may be effective for up to 2 weeks. Finally, postoperative hemodialysis may reduce the uremia and improve platelet function. The patient becomes hypotensive, with a BP of 80/60 mm Hg, in the operating room. There is no evidence of surgical bleeding. Q: In addition to the usual methods to correct hypotension, are there any special measures you might take in this patient? A: The hypotension must be explained; this condition has many causes. Although easy to for- get, glucocorticoid deficiency is one important cause of such low BP in many renal fail- ure patients who have previously taken steroids. The hypotension should be treated with hydrocortisone 25 mg intraoperatively, followed by 100 mg in the next 24 hours. You successfully replace the hip. In the recovery room, the postoperative potassium level returns to 7.1 mEq/L, and there is 10 mL/hr of urine. Q: How would you manage the patient? A: The patient has oliguria and hyperkalemia . After adequate hydration, high potassium concentration should be treated. Peaked T waves on the ECG suggest that the hyperkalemia is physiologically important and warrants immediate treatment . IV calcium gluconate should be given to stabilize cardiac membranes. IV insulin and glucose should be given to reduce potassium levels, but hemodialysis will probably also be necessary.

Case 1.9  Surgery in a Patient with Cardiac Valvular Disease You are asked to see a female patient who needs an elective cholecystectomy. She has known valvular heart disease.

Q: How would you manage the following preoperative conditions?

Case Variation 1.9.1. The patient has chronic mitral valve stenosis that is currently well compensated. ◆ ◆ Stenosis of the mitral valve leads to increased left atrial pressure, which may result in pas- sive pulmonary hypertension and right heart failure , leading to symptoms of fatigue, dyspnea on exertion, or hemoptysis. The distended atrium is susceptible to atrial fibril- lation or other arrhythmias . Many surgeons would obtain a cardiology opinion and an echocardiogram to evaluate cardiac function if there is any doubt about the patient’s cardiac status. The perioperative mortality for all patients with hemodynamically significant mitral stenosis is as high as 5%. ◆ ◆ Because this patient has well-compensated mitral valve stenosis, surgery could proceed. Intravascular volume should be maintained, and hypoxemia, hypercapnia, and acidosis, which all increase pulmonary vascular resistance, should be avoided. Tachycardia should also be avoided because it decreases diastolic filling time. Like all patients with valvular heart disease, this woman should also receive prophylactic antibiotics for the prevention of bacterial endocarditis. SAMPLE