Evaluation And Management Of Peritoneal Dysfunction

1. Mechanism and causes of peritoneal dysfunction

The peritoneum is composed of a single layer of mesothelial cells and the connective tissue space underneath. In this connective tissue space, there are colloids, mucopolysaccharides, capillaries, lymphatic vessels and lymphocytes. The greatest resistance to solute and fluid transport comes from capillaries and the matrix around the capillary wall. The transport of solutes and fluids from capillaries to the peritoneal cavity requires passing through diffusion barriers, including the fluid layer in the peritoneal capillary cavity, vascular endothelial cells, endothelial cell basement membrane, peritoneal stroma, mesothelial cell layer, and peritoneal fluid layer. The peritoneal capillary wall is the key barrier to transport, and the transport of solutes and water through the capillary wall is achieved with the help of three "holes" of different sizes.

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The decline of peritoneal function is mainly caused by four factors: one is the use of bio-incompatible peritoneal dialysis fluid; the second is the decline of residual renal function; the third is repeated episodes of peritonitis; and the fourth is the increase in dialysis age. Long-term exposure of the peritoneum to a high-sugar, hyperosmotic environment can lead to neovascularization, inflammation, and fibrosis.

2. Definition and classification of peritoneal dysfunction

Peritoneal dysfunction is mainly manifested as ultrafiltration failure. In 2021, the International Society of Peritoneal Dialysis (ISPD) changed the term "ultrafiltration failure" to "ultrafiltration insufficiency", focusing on the detection of ultrafiltration capacity. Its specific definition is: when the net ultrafiltration of the 4-h peritoneal equilibrium test (PET) is <400 mL (3.86% glucose/4.25% dextrose) or <100 mL (2.5% glucose/2.27% dextrose), ultrafiltration insufficiency should be suspected; and all patients who have difficulty maintaining adequate fluid removal.

Based on the detection of peritoneal dysfunction by PET, peritoneal dysfunction can be divided into two categories: (1) Rapid peritoneal solute transfer rate (PSTR): including inherent rapid PSTR (individual differences exist at the beginning of peritoneal dialysis) and acquired peritoneal ultrafiltration insufficiency (related to long-term peritoneal dialysis, peritonitis, etc.). (2) Low glucose permeability (OCG): including inherent peritoneal ultrafiltration dysfunction (individual differences exist at the beginning of peritoneal dialysis) and acquired peritoneal ultrafiltration dysfunction (related to progressive peritoneal fibrosis, vascular damage, etc.).

III. Main evaluation methods and diagnosis of peritoneal dysfunction

1. Diagnosis of rapid PSTR

The International Society of Peritoneal Dialysis (ISPD) guidelines recommend that 4-hour PET be performed using peritoneal dialysis fluid with 2.5%/2.27% or 4.25%/3.86% dextrose/glucose, and creatinine be used as the index solute to evaluate PSTR. It is required to be performed early in dialysis treatment (6-12 weeks) and then repeated when clinically indicated, such as when the patient's fluid status worsens or ultrafiltration changes significantly.

PSTR mainly reflects the peritoneal diffusion function and can be expressed by the mass transfer area coefficient. The clinical significance of rapid PSTR is: (1) It is associated with low survival in peritoneal dialysis patients (1A). (2) It is partly due to reduced ultrafiltration when PSTR is higher than the average. It can be treated by shortening the residence time of glucose peritoneal dialysis fluid, using icodextrin peritoneal dialysis fluid and/or using peritoneal dialysis fluid with higher glucose concentration (1A). (3) Compared with glucose peritoneal dialysis fluid, the use of icodextrin peritoneal dialysis fluid can improve the patient's volume status and reduce volume overload (1A). (4) APD and icodextrin peritoneal dialysis fluid can reduce the risk of death associated with rapid PSTR.

2. Diagnosis of ultrafiltration insufficiency

Ultrafiltration insufficiency should be suspected in the following situations: (1) When the net ultrafiltration of 4 h PET is <400 mL (3.86% glucose/4.25% dextrose) or <100 mL (2.27% glucose/2.% dextrose). (2) All patients who have difficulty maintaining adequate fluid removal. In addition to peritoneal dysfunction, ultrafiltration insufficiency may also be caused by mechanical problems, leakage, or reabsorption of peritoneal dialysis fluid.

Peritoneal osmotic conduction to glucose is an intrinsic property of the peritoneum, reflecting the intrinsic property of the peritoneum to transport water under the action of the glucose crystal osmotic gradient (ultrafiltration). OCG is the product of the ultrafiltration coefficient and the reflection coefficient. According to low OCG, it can be divided into intrinsic peritoneal ultrafiltration insufficiency (low OCG appears at the beginning of peritoneal dialysis, which may be related to genetics) and acquired peritoneal ultrafiltration insufficiency (related to peritoneal injury and interstitial fibrosis). Acquired peritoneal ultrafiltration insufficiency, sodium difference <5 mmol/L or sodium sieving ratio <0.03, is a high risk factor for encapsulated peritoneal sclerosis.

3. Diagnosis of peritoneal ultrafiltration insufficiency (UF) caused by intrinsic peritoneal dysfunction (manifested as low OCG)

When UF is suspected, in addition to 4 h PET. 3.86% glucose/4.25% dextrose peritoneal dialysis solution should be used for 1 h to measure the decrease in sodium concentration for diagnosis. When the sodium concentration decreases ≤5 mmol/L and/or the sodium sieving ratio ≤0.03 at 1 h, UF is indicated.

IV. Intervention and management of peritoneal dysfunction

1. Use peritoneal dialysis fluid with good biocompatibility

Currently, lactate dialysis fluid with different concentrations of glucose as osmotic agent is commonly used in China. The peritoneum is immersed in peritoneal dialysis fluid containing low pH, high sugar, lactate and glucose degradation products for a long time, which changes the original physiological state of the peritoneal cavity, reduces the defense function of the peritoneal cavity, and damages the peritoneal mesothelial cells, eventually leading to the occurrence of peritoneal fibrosis. The larger the dialysis fluid dose and the higher the glucose concentration, the more obvious this damage effect is. The use of peritoneal dialysis fluid with good biocompatibility, such as icodextrin dialysis fluid and neutral pH peritoneal dialysis fluid, is conducive to protecting peritoneal function.

2. Protect residual renal function

With the decline of residual renal function, the clearance rate of solutes and water by the residual kidney decreases. In order to maintain the body's volume balance and adequate toxin removal, the clinical practice is often forced to increase the dose and concentration of dialysis fluid, which aggravates the damage of bio-incompatible dialysis fluid to the peritoneum. The presence of residual renal function can reduce the level of oxidative stress in peritoneal dialysis patients and reduce the generation of lipid peroxides. Incremental peritoneal dialysis can be used. A large amount of clinical data suggests that exposure to hypertonic glucose peritoneal dialysis fluid is an important cause of peritoneal ultrafiltration failure. Davies' clinical control study showed that patients exposed to hypertonic glucose had ultrafiltration failure 2 years earlier than the control group. Selgas also found that hypertonic glucose peritoneal dialysis fluid and diabetes would accelerate the occurrence of ultrafiltration failure. Hypertonic glucose can induce peritoneal oxidative stress response, thereby causing vascular hyperplasia and peritoneal fibrosis. The use of antioxidants can reduce the occurrence of damage. During peritoneal dialysis treatment, the principle of dose escalation should be followed, that is, a smaller dose should be given at the beginning of dialysis, and attention should be paid to the control of water and salt. Then, the dialysis dose should be gradually increased according to the loss of residual renal function. This can reduce the exposure to glucose peritoneal dialysis fluid, protect residual renal function, and prevent excessive ultrafiltration.

3. Avoid peritonitis

Inflammation can lead to progressive peritoneal fibrosis, angiogenesis, damage peritoneal function, and can lead to permanent peritoneal ultrafiltration insufficiency.

4. Automated peritoneal dialysis

Automated peritoneal dialysis and icodextrin peritoneal dialysis fluid can improve the volume status of PSTR peritoneal dialysis patients, reduce volume overload, and reduce mortality. Studies have shown that the use of icodextrin peritoneal dialysis fluid can improve volume status and reduce the occurrence of volume overload compared with the use of glucose peritoneal dialysis fluid.

5. Peritoneal rest

Temporarily stop peritoneal dialysis for a period of time, usually 2 to 4 weeks or longer. During this period, patients may need to switch to other renal replacement therapies such as hemodialysis to allow the peritoneum to fully rest and recover.

It should be noted that the specific plan for peritoneal rest should be adjusted and implemented according to the individual situation of the patient, under the guidance and close monitoring of the doctor. At the same time, the doctor will also evaluate whether the patient is suitable for restarting peritoneal dialysis in the future and when to start.

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V. Summary

Finally, Professor Chen Menghua concluded that effectively protecting peritoneal function is an important prerequisite for improving the survival rate of peritoneal dialysis technology and patient survival rate. The use of bio-incompatible peritoneal dialysis fluid, hypertonic glucose peritoneal dialysis fluid, glucose degradation products, residual renal function impairment, peritonitis, etc. are the main causes of peritoneal function impairment. The classification and evaluation of peritoneal function according to pathophysiology is of great significance for the adjustment of peritoneal dialysis prescriptions and prognosis.

How Does Cistanche Treat Kidney Disease?

Cistanche is a traditional Chinese herbal medicine used for centuries to treat various health conditions, including kidney disease. It is derived from the dried stems of Cistanche deserticola, a plant native to the deserts of China and Mongolia. The main active components of cistanche are phenylethanoid glycosides, echinacoside, and acteoside, which have been found to have beneficial effects on kidney health.

Kidney disease, also known as renal disease, refers to a condition in which the kidneys are not functioning properly. This can result in a buildup of waste products and toxins in the body, leading to various symptoms and complications. Cistanche may help treat kidney disease ase through several mechanisms.

Firstly, cistanche has been found to have diuretic properties, meaning it can increase urine production and help eliminate waste products from the body. This can help relieve the burden on the kidneys and prevent the buildup of toxins. By promoting diuresis, cistanche may also help Reduce high blood pressure, a common complication of kidney disease.

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In conclusion, cistanche is a traditional Chinese herbal medicine used for centuries to treat kidney disease. Its active components have diuretic, antioxidant, anti-inflammatory, immunomodulatory, and regenerative effects, which help improve renal function and protect the kidneys from further damage. , cistanche has beneficial effects on other organs and systems, making it a holistic approach to treating kidney disease.