This is a case of 56 year-old-female who was diagnosed to have diabetes mellitus for 38 years. Her uncontrolled diabetes has taken its toll on his other systems such as the urinary and cardiac systems. She has just underwent Coronary Artery Bypass Graft to treat her 3-vessel disease. Before that, she was diagnosed to have Chronic Kidney Disease secondary to Nephropathy and has not been urinating normally for years (anuric). She has been created with arteriovenous fistula (AVF) on her left antecubital area for hemodialysis about 1 ½ months ago. Right now she is on peritoneal dialysis for three years with her own dialyzer machine. Her caregiver is doing the peritoneal dialysis for her with the order she got directly from her nephrologist.
So what is the difference between peritoneal dialysis (PD) and hemodialysis (HD)?
Dialysis is the process of removing waste products and water from the bloodstream. Necessary elements include a semipermeable membrane, dialysate solution, and a surgically created access. Blood is separated from dialysate solution by a semipermeable membrane. Because the dialysate solution contains physiologic amounts of electrolytes and buffers, exposure to blood across the membrane allows diffusion to begin. Solutes dissolved in the blood, such as blood urea nitrogen (BUN) and creatinine, cross the membrane from an area of greater to an area of lesser concentration. Osmosis is the other process at work, whereby water moves across the membrane into the dialysate, which by virtue of its composition has a lesser concentration of water molecules. (Levy, Morgan, & Brown, 2001). Both HD and PD rely on these basic principles of osmosis and diffusion.
During hemodialysis, the blood is pumped into a machine to be filtered and then returned to the body. On the other hand, PD process include the infusion time, dwelling time and the drain time.
In PD, a soft tube called a catheter is used to fill the abdomen with a cleansing liquid called dialysis solution. The walls of the abdominal cavity are lined with a membrane called the peritoneum, which allows waste products and extra fluid to pass from the blood into the dialysis solution. The solution contains a sugar called dextrose that will pull wastes and extra fluid into the abdominal cavity. These wastes and fluid then leave the body when the dialysis solution is drained. The used solution, containing wastes and extra fluid, is then thrown away. The process of draining and filling is called an exchange and takes about 30 to 40 minutes. The period the dialysis solution is in the abdomen is called the dwell time. A typical schedule calls for four exchanges a day, each with a dwell time of 4 to 6 hours. Different types of PD have different schedules of daily exchanges.
Patients who are ambulatory, work, want independence, live a distance from the nearest dialysis unit, like to travel, and like to participate in their care are apt to choose PD. Often, patients who are severely limited in mobility or who live in a nursing home will opt for PD because someone else is available to perform the therapy. Medical reasons to use PD include failed vascular accesses and severely compromised cardiac function.
A particular advantage of PD is that because of its continuous nature, potassium is not nearly as restricted in the diet as it is on HD, nor is fluid. In fact, it is not uncommon to find hypokalemia and dehydration in certain PD patients.
In HD, a nurse or a technician cares for the patient during treatment. The PD patient performs self-care, with the support and encouragement of the PD team. (Source: Findarticles.com)
One of the biggest adjustments you must make when you start hemodialysis treatments is following a strict schedule. Most patients go to a clinic-a dialysis center-three times a week for 3 to 5 or more hours each visit.
One important step before starting hemodialysis is preparing a vascular access, a site on your body from which your blood is removed and returned. A vascular access should be prepared weeks or months before you start dialysis. It will allow easier and more efficient removal and replacement of your blood with fewer complications. (Source: National Kidney & Urologic Diseases Information Clearinghouse (NKUDIC))
In a nutshell, the PD can be performed anywhere by a person who was taught to perform it while HD is done in dialysis centers performed by a dialysis nurse or any trainged healthcare personnel.