A 60-Year-Old Man Who Requires Splenectomy

Elective splenectomy has been scheduled for a 60-year-old man with severe idiopathic thrombocytopenic purpura (ITP) that has responded poorly to treatment. His current platelet count ranges from 5000/μL to 10,000/μL despite several months of aggressive therapy, including 2 courses of high-dose corticosteroids and 2 courses of intravenous immunoglobulin.

HISTORY

The patient has no history of congestive heart failure (CHF), angina pectoris, ischemic heart disease, diabetes mellitus, or stroke. He does have severe degenerative joint disease (DJD) in his knees, which precludes stair climbing and limits his ability to walk long distances. Before ITP was diagnosed, he used NSAIDs; but he currently takes only acetaminophen for symptom relief. A careful review of systems confirms the absence of symptoms of either ischemic heart disease or CHF.

PHYSICAL EXAMINATION

This well-appearing, appropriately thin man is in no acute distress. Blood pressure is 115/70 mm Hg; heart rate, 88 beats per minute and regular; and respiration rate, 14 breaths per minute. No carotid bruits are detected. Chest is clear. Heart rhythm is regular, with normal S₁ and S₂ and no murmurs or additional heart sounds. Neurological examination results are normal. Scattered ecchymoses are evident on the skin; they are most marked on the extremities.

LABORATORY AND IMAGING STUDIES

Blood glucose levels are normal. Significant abnormalities found are a platelet count of 9000/μL and a serum creatinine level of 2.2 mg/dL. A routine ECG shows normal sinus rhythm and no evidence of left ventricular hypertrophy or cardiac ischemia.

CORRECT ANSWER: E

A variety of excellent studies and subsequent practice guidelines are available

that help physicians evaluate and advise patients who require surgery.^1,2 According to the most current guidelines (2007) from the American College of Cardiology and the American Heart Association, the following are key elements of risk stratification for perioperative cardiovascular evaluation of patients who require noncardiac surgery.² These elements allow a decision pathway:

• Step 1: Emergency surgery.

• Step 2: Active cardiac conditions.

• Step 3: Risk level of surgery.

• Step 4: Functional capacity of the patient.

• Step 5: Presence of clinical risk factors in the patient.

• Step 6: Whether testing and preoperative intervention will change management.

Emergency surgery. If emergency, noncardiac surgery (eg, ascending cholangitis) is required, the patient should undergo surgery with perioperative surveillance and postoperative risk assessment. Emergency surgery should not be delayed for preoperative cardiac evaluation.

Active cardiac conditions. Next to be considered is the presence of active cardiac conditions, which are defined as unstable coronary syndromes, decompensated CHF, significant arrhythmias, or severe valvular disease. If any of these conditions are present, they need to be evaluated and treated before surgery. In this patient, the results of a thorough history taking, physical examination, and ECG showed no evidence of active cardiac conditions.

Risk level of surgery. The next step is to assess the degree of medical risk of the procedure. Surgical procedures have been grouped by risk category for perioperative complications. Low-risk procedures include endoscopy, superficial procedures, and cataract and breast surgery. If a patient has reached this step and requires one of these procedures, surgery can be performed. If the procedure is more formidable (as in this patient, who requires a splenectomy), then functional capacity is evaluated.

Functional capacity. The patient's functional capacity can be evaluated by asking whether he or she can perform 4 METs (a metabolic energy expenditure unit) without cardiac symptoms. Commonly used items are the ability to walk up 1 flight of stairs holding a bag of groceries or the ability to walk on level ground at 4 miles per hour (or 1 mile in 15 minutes). If the patient has good functional capacity (4 METs or higher) without symptoms, an intermediate-risk procedure, such as splenectomy, can proceed without further evaluation. If the patient has symptoms or if functional capacity cannot be properly evaluated (as in this case, in which DJD precludes adequate ambulation and step climbing), the next step is to evaluate clinical risk factors.

Clinical risk factors. These include a history of ischemic heart disease, compensated or previous CHF, or cerebrovascular disease; diabetes; and renal insufficiency. Only the last risk factor is present in this patient (serum creatinine level, 2.2 mg/dL). When 3 or more are present, a variety of pathways of cardiovascular testing and perioperative management come into play²; when none are present, surgery can be performed. When 1 or 2 risk factors are present, noninvasive testing can be considered if it will change management.

Testing and preoperative intervention. This patient has refractory severe ITP. If the results of a noninvasive stress test were positive, cardiac catheterization (choice D) with subsequent coronary artery bypass grafting (CABG) or stent placement would be relatively contraindicated in light of his dangerously low platelet count. Severe thrombocytopenia essentially contraindicates a major heart operation; moreover, both CABG and stent placement require antiplatelet therapy.

Thus, all interventions are either not required or are not able to be done safely. The patient's inability to exercise because of DJD eliminates choices A and B. The discussion above makes pharmacological stress testing (choice C) and cardiac catheterization (choice D) moot as well. He can and should proceed with his required, yet elective intermediate-risk surgery. He may be a candidate for perioperative β-blocker therapy, but this decision would be based on empirical findings rather than on results of preoperative cardiovascular testing.³

Outcome of this case. The patient received metoprolol during the perioperative period with close monitoring of heart rate and blood pressure. He then underwent a complication-free laparoscopic splenectomy. At 3 months, he is doing well; his platelet count is 90,000/μL, and he does not require any hematological or cardiac medications.

FOR MORE INFORMATION:

Fleisher LA, Beckman JA, Brown KA, et al. 2009 ACC/AHA focused update on perioperative beta blockade incorporated into the ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: a report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. Circulation. 2009;120:e169-e276.