 |
| Dialysis USA 3-2007 004 (Photo credit: jimforest) |
This question is asked more times than can be counted. A patient is informed that they have stage 4 kidney disease and they need to make a choice as to what modality of dialysis they prefer while they await transplantation.
The patient is usually confused and unsure, already overwhelmed with dealing with the reality of having to receive organ replacement therapy in the first place. Usually the decision is made without enough information and reflects the personal bias of the physician with whom the patient has the most trust.
Rarely will a patient have a preconceived idea as to what form of dialysis would best fit their lifestyle and rarely still does one find a busy nephrologist with the patience to explain in the detail the pros and cons of all modalities without introducing personal and professional preference.
If we were to take a moment to answer this question we would realize that thinking about the answer in a vacuum without a patient involved is difficult. It is difficult because there are patient specific factors which influence the modality of choice. Therefore the best way would be to examine the pro's and cons of each separate modality, giving the patient the power of choice empowered by knowledge.
The most established modality is haemodialysis dating back to 1945, physicians therefore have a great deal of experience with this modality it has stood the test of time and advanced rapidly with greater understanding of the processes of diffusion and osmosis as well as the development of plastics. Understanding the complex equations which determine membrane transport characteristics and hence dialysis adequacy are a badge of pride for nephrologists.
Peritoneal dialysis could be considered to be the older dialysis modality. It was first attempted in humans in 1923 and was partially successful. Between 1923 and 1928 surgeons performed several procedures which prolonged the life of patients using peritoneal dialysis, however adoption of this method was slow and to some extent marginalized during the development of haemodialysis.
Modern haemodialysis and peritoneal dialysis can be considered equal means of renal replacement therapy they each have their strengths and weaknesses.
HAEMODIALYSIS
Pros
- Treatment is rapidly effective at clearing toxins from the blood stream.
- Dialysis adequacy can be increased easily to match the needs of the patient.
- Treatment failure and withdrawl from haemodialysis is less common.
Cons
- Dialysis occurs across an artificial membrane which may cause allergic reactions.
- Blood stream access is necessary and most be maintained.
- Haemodialysis is expensive
- Low blood pressure occurs during haemodialysis more frequently
- Higher risk of bleeding due to the use of blood thinners like heparin.
PERITONEAL DIALYSIS.
 |
| Peritoneal dialysis (Photo credit: Wikipedia) |
Pros
- Uses a perfectly bio-compatible membrane, the bodies peritoneum.
- Dialysis is controlled by the patient.
- Dialysis can be done in a continuous manner.
- Low blood pressure is unlikely.
- Removal of excess body fluid is more easily accomplished in a gentle manner.
- Although the peritoneum is biocompatible it was never meant to be used for dialysis. Hence it has a set life time during which it will function as a dialysis membrane and becomes progressively more inadequate for the purposes of dialysis.
- Higher chance of treatment failure.
- Not suitable for very obese patients, patients with intrabdominal masses or hernia's
- Risk of peritoneal infection and discontinuation of dialysis.
- Not all patients may be trained to perform their own dialysis.
In terms of patient related factors, for peritoneal dialysis to be effective the patient must be highly motivated and trainable with clean suitable surroundings in which to perform exchanges. Patients have an advantage on peritoneal dialysis if they have a high peritoneal surface area to body surface area. Patients may choose peritoneal dialysis for the independence that it grants. Patients who have had previous myocardial infarction stroke or poor vascular tone are less likely to have episodes of low blood pressure on peritoneal dialysis that may result in another stroke or myocardial infarction.
Dialysis is a continuously changing process recent advances in haemodialysis and peritoneal dialysis are closing the gaps between the two. In fact recent reports suggest that nocturnal daily haemodialysis may be the closest to full replacement of renal function that we have yet seen. While development of new solutions and cyclers for peritoneal dialysis have removed some of the inherent drawbacks of peritoneal dialysis increasing benefit to patients who were previously unlikely to do well in peritoneal dialysis.
[...] Hemodialysis is a life saving therapy for patients with severe kidney disease. The therapy is well established and is the most readily available form of renal replacement therapy in the United States. Improving survival on dialysis is the aim of several ongoing studies. The largest of these studies is the Dialysis Outcomes and Practice Patterns study or (DOPPS). The investigators sought to determine detailed information about the association of various co-morbid and clinical characteristics of patients which may shed light on the causes of death and ultimately how to increase length and quality of life on dialysis. [...]
ReplyDelete