When to Refer a Patient with Kidney Disease
Kidney disease is a common problem in the United States. In adults, the most common causes of chronic kidney disease are diabetes mellitus, hypertension, glomerulonephritis and cystic kidney diseases. Currently, almost 400,000 people in the United States have end-stage renal disease (ESRD) requiring renal replacement therapy with some form of dialysis. That number continues to increase by approximately 5 percent each year. It has been estimated that as many as 5 million people in the United States have earlier forms of chronic kidney disease (CKD) that ultimately may progress to ESRD.
Kidney transplantation offers a distinct survival advantage over dialysis in the management of patients with ESRD. Transplantation has become the treatment of choice for patients who do not have concomitant medical problems that preclude successful transplant surgery or compliance issues that would interfere with the regimen of immunosuppressant medications that are required to prevent rejection of the transplanted kidney following the transplant operation.
Kidney transplants are performed using either living donors or deceased donors. Although the number of deceased donors has been increasing slowly over the past several decades, the number of patients waiting for a kidney transplant is growing much faster, thereby further increasing the waiting time for transplantation, extending over five years for many patients. In general, the long-term outcomes of kidney transplantation are better in recipients of living donor kidney transplants than in those of deceased donor transplants. Living donors can include either family members or unrelated individuals such as a spouse, friends or associates.
Absolute contraindications to kidney transplantation include active malignancy, active chronic infection, severe cardiovascular or pulmonary disease, and severe psychosocial problems that may preclude compliance. There is no absolute age limit, but patients over the age of 72 years are discouraged from transplantation unless they are in excellent health and have identified a suitable living donor. Obesity is also a relative contraindication to kidney transplantation. In general, patients with a body mass index (BMI) greater than 40 will be asked to lose weight before they are considered for transplantation.
The bulk of evidence suggests that duration of time on dialysis adversely affects the success of kidney transplantation. In fact, the best outcomes occur in patients who receive pre-emptive kidney transplants (i.e., before the need for dialysis). Patients interested in a deceased donor kidney transplant will be placed on the active waiting list when estimated glomerular filtration rate (measured by creatinine clearance or an accepted formula) is more than 20 ml/minute. However, patients can be referred for evaluation before renal function deteriorates to this level. Patients should be referred for living donor transplantation when estimated glomerular filtration rate has fallen below 30 ml/minute. This will allow the patient more time to assess their options for transplantation and perhaps have a living donor option.