What is Peritoneal Dialysis? How does it compare to Hemodialysis?
Peritoneal dialysis (PD) and hemodialysis are two different types of dialysis used to filter wastes and excess fluid from the blood when the kidneys are not functioning adequately. Here is a comparison:
How PD Works:
- A catheter is surgically inserted into the patient's abdomen and dialysis solution (dialysate) is infused into the peritoneal cavity
- The peritoneal membrane lining the cavity acts as a filter between the blood and dialysate
- Waste products and water move from the blood across the peritoneal membrane into the dialysate based on diffusion and osmosis
- After several hours, the waste-rich dialysate is drained out of the abdomen and fresh dialysate is infused to continue the process - this is called an exchange
- Exchanges are done 4-5 times per day either manually or using a cycling machine at night
How Hemodialysis Works:
- Blood is removed from the body via an IV access or catheter and pumped through an artificial kidney machine (dialyzer)
- On the other side of the dialyzer's semipermeable membrane is dialysis solution
- As the blood flows along one side of the membrane and dialysis fluid flows along the other, waste products and extra fluid move from the blood into the dialysate based on diffusion and osmosis
- The clean blood is then returned to the patient's body
- Hemodialysis treatments last ~3-4 hours and are done 3x a week
So in summary, PD uses the patient's peritoneum as a natural filter while hemodialysis uses an artificial membrane. PD is done daily and is slower while hemodialysis is longer but done less frequently. But both clean the blood!
What are the advantages of PD vs Hemodialysis?
Some of the main advantages of peritoneal dialysis (PD) compared to hemodialysis include:
Flexibility - PD allows more flexibility in treatment schedules since it does not require going to a dialysis center 3 times per week for several hours at a time like hemodialysis. Exchanges can be done at home on one's schedule.
Quality of Life - Many patients report an improved quality of life because PD allows them to avoid the dietary restrictions, difficult medication regimens, and post-dialysis fatigue associated with conventional hemodialysis.
Preservation of Residual Kidney Function - Hemodialysis is harder on the kidneys and residual function tends to decline faster than with PD. Preserving residual function is associated with better patient outcomes.
Avoidance of Damaging Hemodynamic Shifts - The rapid fluid and electrolyte shifts that occur with intermittent conventional hemodialysis can damage the cardiovascular system over time. The more gradual ultrafiltration of PD avoids these shifts.
Lower Cost - Once the patient is set up and trained, administering home-based PD is generally cheaper for healthcare systems than paying for thrice weekly hemodialysis treatments in a dialysis clinic.
Disadvantages: The main disadvantages are the higher risk of peritonitis, the need for good eyesight and dexterity to perform exchanges, and the fact that some patients eventually may need higher clearance rates only achievable with hemodialysis. But for many, PD offers a better quality of life.
Why is Peritoneal Dialysis penetration low?
Penetration rate of PD
Country
Dialysis patients. (‘000)
PD Penetration Rate (in %)
Country
Dialysis patients. (‘000)
PD Penetration Rate (in %)
1
USA
378,800
7%
2
Japan
277,500
3.3%
3
China
114,300
14%
4
Brazil
83,800
11%
5
Germany
66,700
4.8%
6
Mexico
62,400
65.8%
7
Taiwan
53,200
9.3%
8
Turkey
46,200
12.5%
9
South Korea
41,300
19%
10
Italy
36,100
9.6%
11
France
31,400
7.5%
12
India
26,500
24.5%
13
UK
24,700
17%
14
Argentina
24,400
3.9%
15
Spain
22,800
9.6%
16
Canada
22,200
18%
17
Thailand
21,800
5.5%
18
Colombia
17,700
36.6%
19
Iran
16,900
6.8%
20
Bangladesh
16,800
1.6%
21
Malaysia
16,700
12.5%
22
Chile
12,800
5%
23
Australia
9,600
23%
24
Greece
9,000
8.3%
25
Indonesia
8,800
9.7%
26
Philippines
7,500
12.7%
27
Belgium
7,200
9%
28
Tunisia
6,700
3%
29
Romania
6,500
19.2%
30
Pakistan
6,100
0.7%
31
Vietnam
6,100
16.4%
32
The Netherlands
6,000
20.1%
33
Peru
5,100
16.7%
34
Morocco
5,000
0.6%
35
Hong Kong
4,300
79.4%
36
Austria
4,000
8.8%
37
South Africa
4,000
29%
38
Singapore
3,800
18.8%
39
Sweden
3,600
23.8%
40
El Salvador
2,900
76.5%
41
Switzerland
2,900
9.3%
42
Croatia
2,800
8.7%
43
Uruguay
2,600
8.9%
44
Denmark
2,600
22.8%
45
Egypt
2,300
2%
46
New Zealand
2,100
36%
There are no rows in this table
There are a few situations where peritoneal dialysis (PD) may not be able to adequately replace standard hemodialysis:
Heart failure - PD is not ideal for patients with severe congestive heart failure. The extra fluid from the PD exchanges can put too much strain on an already compromised heart. Hemodialysis is better for acute removal of fluid.
Hyperkalemia - PD removes potassium more slowly than hemodialysis, so may not be sufficient to treat acute severe hyperkalemia that carries cardiac risks. Hemodialysis would be needed urgently.
Fluid overload - Patients who develop significant fluid overload issues and pulmonary edema may need the rapid fluid removal capability of hemodialysis if the condition becomes acute.
Inadequate solute clearance - Over time on PD, the peritoneal membrane can start thickening and patients may see reductions in adequacy of blood toxin clearance. They may then need to transition to hemodialysis.
Recurrent peritonitis - Some patients on PD may experience repeated episodes of peritonitis. If the infections become resistant, are unable to be cleared, or the peritoneum is significantly damaged, switching to hemodialysis may become necessary.
So while PD can effectively replace hemodialysis for many patients, those with advanced heart disease, fluid overload issues, or recurrent infections may end up needing hemodialysis instead if their conditions can no longer be managed well with PD alone.
Does PD improve life expectancy for patients with kidney disease compared to hemodialysis?
Here is a summary of the burden kidney diseases and dialysis place on public health:
- Chronic kidney disease (CKD) is a major public health problem that affects over 10% of the global population. As kidney function declines, the risk of kidney failure, cardiovascular disease, and premature death rises dramatically.
- Kidney failure requiring dialysis or transplantation for survival affects over 750,000 people in the United States. This number has been gradually increasing over time.
- Dialysis is an intensive, expensive therapy - the Medicare costs for dialysis in the US exceeded $35 billion in 2016. Patients typically require dialysis 3 times per week, placing major restrictions on work and lifestyle.
- Mortality rates for dialysis patients remain very high, with only about 40% surviving 5 years. Dialysis is therefore a heavy burden not just economically, but on patients and families.
- CKD and end-stage renal disease risk factors like diabetes and hypertension are becoming more prevalent globally. This is projected to drive up rates of kidney failure and dialysis needs further in the coming decades, especially in developing countries.
In summary, kidney diseases already affect a large population worldwide, carrying risks of serious complications and early death. As CKD risk factors spread, dialysis utilization and costs are steadily increasing over time. This growing burden has heavy public health, economic, and human implications needing urgent attention.
Reimbursements for Peritoneal Dialysis vs Hemodialysis
Peritoneal dialysis (PD) as a modality is underutilized in most parts of the world today despite several advantages, including the possibility of it being offered in the remotest of locations and being significantly more affordable than hemodialysis (HD) in most cases. In this article, we will compare the cost of HD and PD in several countries to demonstrate that PD is less than, or at least as expensive as, HD. A thorough literature survey of EMBASE and PUBMED was conducted; 78 articles which compared the annual PD and annual HD costs were finally selected. Careful attention was paid to the methodology followed by each study and the year it was published in. Our final calculations included 46 countries (20 developed and 26 developing). We found that the cost of HD was between 1.25 and 2.35 times the cost of PD in 22 countries (17 developed and 5 developing), between 0.90 and 1.25 times the cost of PD in 15 countries (2 developed and 13 developing), and between 0.22 and 0.90 times the cost of PD in 9 countries (1 developed and 8 developing). From our analysis, it is evident that most developed countries can provide PD at a lesser expense to the healthcare system than HD. The evidence on developing countries is more mixed, but in most cases PD can be provided at a similar cost where economies of scale have been achieved, either by local production or by low import duties on PD equipment. [Note: the