Dialysis Modalities: What the Non-Nephrologist Needs to Know

Hospital Physician August 2006 11 D ialysis has been used as a life-saving technique for decades but has been universally available as a chronic therapy for only approximately 30 years. In the United States, there are currently more than 300,000 patients undergoing dialysis, and the prevalence of end-stage renal disease (ESRD) is growing yearly.1 Diabetes and hypertension, which are growing to epidemic status in some areas of the United States, account for more than 50% of new ESRD patients. For eligible patients, kidney transplantation is the best treatment for ESRD.2 Rarely, some patients are able to obtain a preemptive transplant and never need to start dialysis. However, most patients who start dialysis will need it for the rest of their lives or until they undergo kidney transplantation. For others, dialysis is needed acutely while waiting for renal function to recover from a specific injury. Physicians in all specialties should have a working knowledge of dialysis. Primary care physicians play a critical role in identifying patients at risk for ESRD. In addition, as more patients live longer on dialysis, physicians in all specialties need to be familiar with the basic elements of dialysis to assist in their care. Surgeons who are to operate on ESRD patients need to be familiar with dialysis to understand the importance of scheduling surgery around dialysis as well as the volume and electrolyte control options available postoperatively. This article will review dialysis modalities for patients on chronic therapy and briefly address modalities used in the acute setting. The modalities that are currently available to patients with ESRD are hemodialysis and peritoneal dialysis. A basic knowledge of the workings of each type of dialysis will help physicians guide patients to the most appropriate form of renal replacement therapy. A brief glossary of common dialysis terms is provided in Table 1.