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Explain the pre-anesthetic concerns for patients with a transplanted heart.
Preoperatively, the primary concern is the transplanted heart’s function. Without rejection, the post-transplantation patient generally does not perceive any functional limita-tions and is classified as a New York Heart Association (NYHA) class I or II. However, ventricular function must be assessed preoperatively. Information regarding prior episodes of rejection (if any) and ventricular function is usually available from the managing cardiologist. This is especially important in patients who are a few years out from their transplant, because the post-cardiac transplan-tation patient is subject to accelerated atherosclerotic coronary disease (possibly the result of a vasculitis from low-level, subclinical rejection). The likelihood of signifi-cant coronary occlusion increases directly with time from transplantation. Post-transplant coronary occlusion is reported to occur at a rate of 10–20% incidence at 1 year, 25–45% incidence at 3 years, and a 50% incidence at 5 years.
While some benign dysrhythmias are common following transplantation (e.g., incomplete right bundle branch block, premature atrial contractions, occasional premature ventric-ular contractions, and first-degree AV block), more ominous rhythms may be signs of acute rejection. Given the propen-sity toward accelerated atherosclerotic disease, one should always consider that new perioperative dysrhythmias accompanied by hypotension may be a sign of ischemia.
During the preoperative evaluation, special attention should be paid to renal and hepatic function because impair-ment of these organs is a major side-effect of the immuno-suppressive medications cyclosporine and tacrolimus. Renal and/or hepatic impairment may predispose to acid-base and electrolyte derangements. A complete blood count should be reviewed for anemia and thrombocytopenia, as hemato-logic toxicity is a major side-effect of azathioprine.
Infection is a major source of morbidity and mortality for the immunosuppressed post-transplant patient, so aseptic technique is mandatory for all invasive procedures, including intravenous catheter placement. Prophylactic antibiotics are routinely employed where appropriate.
Many immunosuppressive regimens include fairly high dose corticosteroids, and unless the patient has recently been tapered off steroids, the issue of a preoperative “stress dose” should be discussed with the primary managing physician.
Finally, given the dependence of the graft on the Frank-Starling mechanism (discussed above), one must assure an adequate intravascular volume status prior to anesthetic induction.
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