Anesthesia for Renal Transplantation

RENAL TRANSPLANTATION

The success of renal transplantation, which is largely due to advances in immunosuppressive therapy, has greatly improved the quality of life for patients with end-stage renal disease. With modern immu-nosuppressive regimens, cadaveric transplants have achieved almost the same 80–90% 3-year graft sur-vival rate as living-related donor grafts. In addition, restrictions on candidates for renal transplantation have gradually decreased. Infection and cancer are the only remaining absolute contraindications.

Preoperative Considerations

Current organ preservation techniques allow ample time (24–48 h) for preoperative dialysis of cadaveric recipients.

Living-related transplants are performed electively with simultaneous donor and recipientoperations. The recipient’s serum potassium concentration should be below 5.5 mEq/L, andexisting coagulopathies should be corrected.

Intraoperative Considerations

Renal transplantation is carried out by placing the donor kidney retroperitoneally in the iliac fossa and anastomosing the renal vessels to the iliac vessels and the ureter to the bladder. Heparin is adminis-tered prior to temporary clamping of the iliac vessels. Intravenous mannitol administered to the recipient helps establish an osmotic diuresis following reper-fusion. Immunosuppression is initiated on the day of surgery with combination medications which may include corticosteroids, cyclosporine or tacro-limus, azathioprine or mycophenolate mofetil, anti-thymocyte globulin, monoclonal antibodies directed against specific subsets of T lymphocytes (OKT3), and interleukin-2 receptor antibodies (daclizumab or basiliximab). The anesthetist should discuss in advance with the surgery team the timing and dos-age of any immunosuppressive agents which will need to be given perioperatively. Recipient nephrec-tomy (with a failed transplant) is performed for intractable hypertension or chronic infection.

A. Choice of Anesthesia

Most renal transplants are performed with general anesthesia, although spinal and epidural anesthesiaare also utilized. All general anesthetic agents have been employed without any apparent detrimen-tal effect on graft function. Cisatracurium and rocuronium may be the muscle relaxants of choice, as they are not dependent upon renal excretion for elimination. Vecuronium may be used with only modest prolongation of its effects.

B. Monitoring

Central venous cannulation may be useful for ensuring adequate hydration while avoiding fluid overload, particularly in patients with impaired cardiac status. Central lines are also useful portals for the various infusions that these patients require in the first few days after transplant. Normal saline is commonly used. A urinary catheter is placed preoperatively, and a brisk urine flow following the arterial anastomosis generally indicates good graft function. If the graft ischemic time was prolonged, an oliguric phase may precede the diuretic phase, in which case fluid therapy must be appropriately adjusted. Administration of furosemide or addi-tional mannitol may be indicated in such cases. Hyperkalemia has been reported after release of the vascular clamp following completion of the arterial anastomosis, particularly in pediatric and other small patients, and release of potassium con-tained in the preservative solution has been impli-cated as the cause of this phenomenon. Donor kidney washout of the preservative solution with ice-cold lactated Ringer’s solution just prior to the vascular anastomosis may help avoid this problem. Serum electrolyte concentrations should be moni-tored closely after completion of the anastomosis. Hyperkalemia may be suspected from peaking of the T wave on the ECG.