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Med-Spot on Med-Source: Cardiac Clearance for Non-Cardiac Surgery

Med-Spot 6.24.07: Guidelines for Cardiac Clearance for Non-Cardiac Surgery

Case Scenario:
R.J. is a 76-year-old man who is scheduled for a right hip arthroplasty in two weeks. He presents at the request of his orthopedic surgeon for a medical consultation before surgery. He had an inferior MI one year ago for which he received antithrombolytic therapy with complete resolution of his symptoms. He has never smoked, has no history of cerebrovascular disease or diabetes, has a normal ejection fraction, and normal renal function. R.J. usually walks one to two miles in the morning, but his function has been severely limited over the past two months because of hip pain. He is taking hydrochlorothiazide (Esidrix) and simvastatin (Zocor). Although his primary care physician prescribed a beta blocker after his MI, R.J. stopped taking it after a bout of bronchitis two weeks ago. He is asymptomatic from a cardiac and respiratory standpoint. His vital signs are normal except for a blood pressure of 157/92 mm Hg. His physical examination is within normal limits, and electrocardiography demonstrates Q waves inferiorly. Should he undergo cardiovascular stress testing before surgery, and is he a candidate for perioperative beta blockade or other medical therapy?

To answer this question use the figure below referring to the 2 tables below the figure when necessary (see end of post for answer).




TABLE 1: Clinical Predictors of Increased Perioperative Cardiovascular Risk

Major

Unstable coronary syndromes

Acute or recent* MI with evidence of important ischemic risk by clinical symptoms or noninvasive study

Unstable or severe angina (Canadian class III or IV)

Decompensated heart failure

Significant arrhythmias

High-grade atrioventricular block

Symptomatic ventricular arrhythmias in the presence of underlying heart disease

Supraventricular arrhythmias with uncontrolled ventricular rate
Severe valvular disease

Intermediate

Mild angina pectoris (Canadian class I or II)

Previous MI by history or pathologic Q waves

Compensated or prior heart failure

Diabetes mellitus (particularly insulin-dependent)

Renal insufficiency

Minor

Advanced age (older than 75 years)

Abnormal electrocardiography results (e.g., left ventricular hypertrophy, left bundle branch block, ST-T abnormalities)

Rhythm other than sinus (e.g., atrial fibrillation)

Low functional capacity (e.g., inability to climb one flight of stairs with a bag of groceries)

History of stroke

Uncontrolled systemic hypertension



Table 2: Cardiac Risk Stratification for Noncardiac Surgical Procedures

High (reported cardiac risk often >5 percent)

Emergent major operations, particularly in patients older than 75 years

Aortic and other major vascular surgery

Peripheral vascular surgery

Anticipated prolonged surgical procedure associated with large fluid shifts and/or blood loss

Intermediate (reported cardiac risk generally 1 to 5 percent)

Carotid endarterectomy

Head and neck surgery

Intraperitoneal and intrathoracic surgery

Orthopedic surgery

Prostate surgery

Low (reported cardiac risk generally <1>

Endoscopic procedures

Superficial procedures

Cataract surgery

Breast surgery


Resolution of the Case:
Hip arthroplasty is an intermediate-risk surgery. Based on the Lee revised cardiac risk index (Table 3),11 the patient in the case scenario receives 1 point for CAD, putting him at low risk. Because his functional status was good before his recent hip problems and he is having no cardiovascular symptoms, after referring to Figure 12 and considering the results of the CARP study, the physician decides in collaboration with the patient that cardiovascular stress testing is not necessary. Because he was taking beta blockers before his recent illness and should remain on them because of his CAD whether or not he is having surgery, the physician chooses to resume them. However, the patient would not otherwise be a candidate for beta blockade. Continuing statin therapy would neither harm nor benefit him for his current surgery.


sources: AAFP (http://www.aafp.org/afp/20070301/656.html) , ACC, AHA

1 comment:

Clinical Cases and Images said...

You may find this summary useful:

Preoperative Care of Patients with Kidney Disease

http://clinicalcases.blogspot.com/2003/04/preoperative-care-of-patients-with.html

It is based on 8 cases of patients with kidney disease but most principles apply to many other patients.

Our medical students especially like the PASS/HIP mnemonics and the approach to reading EKGs:

http://note3.blogspot.com/2004/01/systematic-approach-to-reading-ekg.html