Acute renal failure after open heart surgery: newer concepts and current therapy.

Abstract

It is frequently stated that the best cure is prevention. Nowhere is this more appropriate than with the function of nine increases (Fig 1). This risk may be reduced with the addition of appropriate volume. the kidney in response to an insult like open heart surgery. It has Another area of patient preparation may lie in the use of been estimated that the frequency of renal failure in the setting calcium blockade,’ free oxygen radical scavengers,3 osmotic of open heart surgery ranges from 5% to 40%.’ The patients are diuretics such as mannitol,* diuretics with the site of action at frequently elderly, may have significant comorbid disease such the loop of Henle,5 and so-called “renal dose” dopamine infuas diabetes or peripheral vascular disease, may already show sions6 This combination tends to block the entry of calcium into signs of previous renal dysfunction, and are not infrequently the cell, thought to be one of the primary reasons for initial subject to long pump times because of intraoperative complica- cellular dysfunction, as well as promote a forced diuresis, tions, or extensive surgical requirements. It would seem, there- maintained renal plasma flow, and reduced metabolic demand fore, that appropriate patient preparation might be the first of the tubular cells. Thus, if the kidney is subjected to periods of step in their treatment. hypoxia, the cells might be more tolerant. The patient with postoperative failing renal function would obviously need the usual evaluation of causes for this dysfunction. This would necessitate a review of the pre-renal, postrenal, and intrinsic renal conditions that might give rise to the specific dysfunction. It is here where the stage is set for the subsequent therapeutic approach, given the diagnosis of the existing condition thought to be active. Therefore, a knowledge of the patterns of renal failure, and the interventions that would be appropriate, might salvage some function and facilitate later