The Patient with Anuric Renal Failure Undergoing Nontransplantation Surgery

Fluid management of the patient with anuric renal failure for nontransplantation surgery (see Chapter 54 ) should avoid excessive intravascular fluid administration and ECF volume expansion and should maintain or correct electrolyte and acid-base status. The clinical anesthesiologist should also attempt to prevent precipitating conditions that would require dialysis during the immediate postoperative period (e.g., hyperkalemia, pulmonary edema, metabolic acidosis). Dialysis is difficult or impossible in the hemodynamically unstable patient, and anti-coagulation may be strongly contraindicated for several hours postoperatively. Patients with chronic renal failure often present with hypertension, diabetes, and vascular disease. Avoidance of hypotension may be indicated to maintain coronary or cerebral perfusion pressure. In patients with acute renal failure, hypotension may worsen ischemic renal injury. This contrasts with the lack of concern for an adverse effect on renal function in the patient with chronic renal failure. Recent dialysis often induces acute electrolyte shifts, hypovolemia, and acidosis. The best compromise appears to be dialysis 12 to 24 hours preoperatively. If dialysis is performed close to the time of surgery, volume removal should be minimal. Patients with renal failure are often malnourished, have hypoproteinemia, are anemic, and have poor glucose tolerance.

Hemodynamics should be closely monitored. If hypovolemia develops, colloid should be used early, but the physician should avoid producing vascular overexpansion. Likewise, interstitial fluid overload should be avoided because it would require acute postoperative dialysis. Crystalloid replacement of third-space losses should be limited to 1 to 2 mL/kg/hour, whereas blood loss should be replaced with colloid or RBCs. Correction of sodium, potassium, and acidosis can be achieved by the use of isotonic fluid without potassium, with reduced amounts of chloride, and increased amount of buffer, respectively. Initially, an infusion of 30% of calculated maintenance fluid rate is important because approximately 70% of normal fluid requirements are used in excreting solute through the kidney, a route no longer available. The pH and levels of sodium, potassium, bicarbonate, and glucose should be monitored at regular intervals.