Renal Transplant Patients in the ED
When renal transplant patients present to the ED it may be for any number of presentations. Clearly renal issues are always on the table and these manifest typically with an increase in serum creatinine level as you might expect. Parenchymal dysfunction has many causes, and the differential diagnosis must be approached systematically, again as with any ED patient. Anything that affects the native kidneys and renal tract can affect the transplant i.e. exclude correctable prenal and post renal factors.
Improvements in surgical technique and the advent of more potent immunosuppressive agents have reduced early complications of renal transplantation. Greater emphasis is now placed on preventing late complications. This is accomplished in the outpatient setting through routine assessment of patients who have received transplants.(1)
Chronic systemic immunosuppression is a double-edged sword. The same immunosuppressive effects that prevent rejection of the allograft pose a risk for development of malignancy and infectious diseases. Routine cancer surveillance is mandatory to assure rapid diagnosis and treatment of any malignancy.(1)
The critical transplant specific considerations are:(1)
Rejection - delayed graft function immediately after transplantation is usually due to acute tubular necrosis (ATN). The frequency is variable among the different transplant centers and is approximated at roughly 20-30% of deceased donor transplants.
Nephrotoxicity of medications - nephrotoxicity of the calcineurin inhibitors cyclosporine and tacrolimus is dose-related. Occasionally, performing a renal allograft biopsy is necessary if the serum creatinine level does not respond to a reduction in dose. Haemolytic uremic syndrome (HUS) and thrombotic microangiopathy (TMA) may occur in the setting of endothelial injury associated with calcineurin inhibitors and the development of CMV infection. Nephrotoxic agents e.g. aminoglycosides should usually be avoided. A systemic process reveals anemia, reduced haptoglobin levels, rising lactic dehydrogenase (LDH) levels, and a peripheral blood smear with schistocytes, all of which are consistent with the diagnosis. At times, HUS and TMA are confined to the kidney and do not give rise to any systemic findings.
Recurrence of native kidney - in renal kidney transplant recipients accounts for fewer than 2% of all graft losses, though it affects as many as 10% of recipients. A few diseases are associated with a high risk of renal allograft loss, including focal segmental glomerulosclerosis, HUS oxalosis, and membranoproliferative glomerulonephritis. Diabetic nephropathy can recur in renal allografts, but the time to onset is similar to that seen in native kidneys, and in general, this condition is an uncommon cause of graft loss.
For a more detailed discussion go to the medscape article which covers in great depth these issues. Renal transplant patients who present to the ED require vigilance in four areas:
Immediate resuscitation requirements
Renal specific issues
Immunocompromised context in terms of risk of infection and malignancy
Underlying pathology which led to renal disease in the first place
Involve your renal referral partners early please.
References
(1) Medscape paper: Assessment and management of the renal transplant patient