Thursday, September 30, 2010
Photo: our Ricky enjoys the overnight cycler. I was going to use this picture for the article in the newspaper, had it all cropped, formatted, and ready to go, then changed my mind because I spotted something in the picture that I didn't think we needed to put in the paper. See if you can spot what it is. Much more private posting the picture on the web, right?
Part three of a series on the treatment of renal failure. Why? Because a year ago my husband's kidneys blinked out like a couple of light bulbs, and renal failure has been the center of our lives since. Writers are always told to “write what you know,” so – renal failure. Part 3:
Peritoneal dialysis (PD) is a way of cleansing the renal patient's blood by putting dialysate, a fancy word for dextrose solution (sugar water), into the peritoneum of the renal patient, letting the solution sit there for a few hours (this is called the “dwell”) pulling toxins and extra fluid across the peritoneal membrane, and then draining the dialysate and putting in fresh dialysate and starting over. No bloodletting involved.
The peritoneum is the cavity in your torso where your vital organs and your intestines live. The cavity is lined by the peritoneal membrane, a sac that holds everything together and is rich in blood vessels.
The problem when PD was first used was that the abdomen had to be freshly punctured (this would be bloodletting) for each dialysis procedure, in effect putting the patient through surgery once or twice a week. Attempts to leave catheters in place were not successful because the site of the puncture or the peritoneum became infected.
PD was being used and improved during the same years as hemodialysis, starting before World War II, but was not used commonly until the 1980s. This was because Henry Tenckhoff designed a catheter that would not cause infection.
Dr. Henry Tenckhoff began working with Belding Scribner at the UW, that hotbed of dialysis research, in 1963. When Tenckhoff began working with PD patients, he had to go to their homes twice a week to perform the minor surgery of inserting a catheter into the patient's abdomen.
Dr. Tenckhoff observed that PD worked well and that PD patients did better in many ways than patients on hemodialysis. Eventually he developed what is now known as the Tenckhoff catheter, which could be placed into a patient's abdomen and left there, and with proper care would not become infected.
The Tenckhoff catheter is a piece of tubing which enters the patient's abdomen and has a coil inside the peritoneum. This inner bit has little holes in it, like drain field pipe on a much smaller scale. The holes facilitate the entry and exit of the dialysate. The outer bit of the catheter is a length of tubing with a connection on the end for attaching a tube to drain and fill the peritoneum.
Once patients have a Tenckhoff catheter placed in their abdomens and they have healed from the surgery, they are trained on how to do PD and then they do it at home, with frequent monitoring by a PD nurse. Testing is done frequently to monitor how the patient is doing and whether dialysis is working. Sterile dialysate is delivered to the patient's home about once a month.
There are two kinds of PD: manual, and machine assisted.
In the manual variety, the patient typically does four exchanges a day in which dialysate is drained from the peritoneum, and fresh dialysate is put in and left in – the “dwell” - for four hours or so, and then drained and replaced. An exchange takes 30 to 40 minutes.
In machine assisted PD, the patient hooks up to a cycler machine at night which does exchanges while the patient sleeps. Unfortunately the machines set off alarms if anything isn't quite right – not enough dialysate draining is the most frequent problem. So these patients might not get much sleep at night.
My husband started on manual PD, which turned out to be a full time job, but now he's on the overnight cycler machine. He feels and looks better than he has since he became ill over a year ago. We like PD, alarms and all.
Not everyone can do PD, but it's an excellent way to go if you can.
Next time: Kidney transplants