The peritoneum is a good biological semi-permeable membrane with good diffusion, permeation, secretion and absorption functions. In adults, the peritoneal area is approximately 2.2 m2, which is larger than the 1.5 m2 surface area of the glomerular capillaries of the bilateral kidneys. When the condition requires, the peritoneum can be used as a dialysis membrane, through dialysis with the blood in the peritoneal surface vessels, the metabolites and excess electrolytes accumulated in the body can be excreted with the dialysis fluid, thus achieving the purpose of eliminating toxic substances in the body and regulating water, electrolyte and acid-base balance.
The peritoneum has different ability to remove various solutes, with urea being removed faster, potassium, chloride, sodium and creatinine second, uric acid and carbonate slower, and calcium and magnesium the slowest. Generally, a dialysis of 8000~10000ml as a course of treatment can make the urea nitrogen decrease by 3.3~7.8mmol/L per day on average and bring out about 500~1500ml of water; applying potassium-free dialysis solution, potassium can be removed by 7.8~9.5mmol/L per day.
[Indications]
1. Acute renal failure, which can be used after the diagnosis is clear. In early stage, it can be used as prophylactic dialysis with good efficacy; in severe condition, it can also stabilize the disease at a certain level; in very severe condition, it needs to be combined with hemodialysis, and for acute renal failure with shock, cardiac insufficiency, and patients with severe bleeding tendency, peritoneal dialysis therapy is preferred.
2, chronic renal failure.
3.Acute drug intoxication and severe edema, water intoxication and heart failure caused by any cause.
4, Others It can also treat certain patients with acute liver failure, acute pancreatitis and multiple myeloma.
[Contraindications]
1, limited peritonitis should be contraindicated; diffuse peritonitis should be considered only as a last resort.
2, Recent major abdominal surgery with abdominal drainage, extensive peritoneal adhesions and pregnancy.
3, severe chronic respiratory failure.
4.Patients in critical condition, hypotension or poor cardiovascular function should be treated first and peritoneal dialysis should be used only after the condition improves.
[Dialysis tubing]
At present, the commonly used peritoneal dialysis tubing in clinical practice is Tenckhoff tubing with two polyester velvet rings for fixation, which is suitable for all patients on peritoneal dialysis. Other types of tubing, such as convoluted double cannulae, are all modified versions of Tenckhoff tubing, mainly modified for the intra-abdominal section of Tenckhoff tubing.
[Anesthesia].
Local anesthesia.
[Surgical method]
The placement of peritoneal dialysis tubing is closely related to the effect of peritoneal dialysis. The surgery requires that the peritoneal dialysis tubing be placed in the cysto-rectal fossa (utero-rectal fossa) to ensure unobstructed drainage.
1. Position, incision The patient lies supine. The skin is incised 0.5-1 cm to the right of the midpoint of the line connecting the pubic symphysis and the umbilicus, the layers of the abdominal wall are separated, the peritoneum is incised, the dialysis tube is delivered to the cystorectal fossa, the dialysis tube is flushed with heparin saline to prove patency, and the peritoneum is sutured [Figure 1 ⑵]; a subcutaneous tunnel is made under the skin, outside the muscle layer, 2-3 cm from the incision, and the dialysis tube is passed out of the abdominal wall, and two polyester fleece rings are fixed separately to close the abdominal wall.
2.Dialysis mode
(1) Intermittent peritoneal dialysis (IPD): standard IPD protocol, manual operation, dialysate 2L/time, 8-10 consecutive exchanges per dialysis day, 1 hour each time, 4-5 dialysis days per week, total dialysis hours of 36-42 hours.
(2) Continuous ambulatory peritoneal dialysis (CAPD): standard CAPD protocol with 4 daily exchanges of dialysate at 2 L each. exchange times, 8 a.m., 12 noon, 5 p.m., and 10 p.m.; dialysate selection, 3 times during the day with dialysate containing 1.5% sugar and at night with dialysate containing 4.25% sugar.
(3) Continuous cyclic peritoneal dialysis (CCPD): CCPD standard protocol, exchange dialysate 5 times a day, 2 L each time; exchange time, starting at 10 p.m. and shutting down at 8 a.m. the next morning; exchange every 2.5 hours at night, 4 times in total; feed 10 minutes, stay 2 hours, release 10 minutes, and keep 11 hours during the day; dialysate selection, 1.5% sugar-containing dialysate for each time at night and 4.25% sugar-containing dialysate at night. During the daytime, the dialysis solution containing 4.25% sugar was used.
Different dialysis methods and dialysis levels with different sugar concentrations are selected for different patients, and changes in blood biochemical data should be monitored daily during the dialysis process to avoid excessive water and electrolyte excretion.
[Complications]
Although the effect of peritoneal dialysis is good, there are some complications that should be paid attention to and prevented.
1. Peritonitis used to have a high incidence, but it is no longer common after the adoption of intermittent dialysis and certain preventive measures. The preventive measures are to improve the aseptic operation technique and to add appropriate amount of antibiotics to the dialysis solution.
Injury to internal organs Injury to the intestinal canal is a serious and rare complication; it can be avoided by paying attention to gentle operation during intubation.
3.Bleeding A large amount of progressive bleeding is mostly caused by injury to internal organs, and dialysis should be stopped and treated appropriately; a small amount of bleeding should be closely observed, and dialysis can still be continued.
4.Leakage of dialysis fluid can be leaked from around the dialysis tubing during the operation or from the incision after the operation; it is common that the peritoneal packet is not sutured tightly, and the dialysis tubing is placed too shallowly or moved outward; if leakage from the incision is found, it should be sutured and bandaged immediately; if the leakage is serious, the tubing should be placed again.
5, poor drainage Mostly due to adhesions or intestinal tubing, large omentum blocking the dialysis tubing hole, should be changed to dialysis tubing with fine holes or repeated flushing with heparin saline; if still ineffective, dialysis should be stopped.
[Dialysis fluid]
At present, dialysis fluid are bags of commercial peritoneal dialysis fluid, there are several different packages such as 500ml, 1000ml, 2000ml; its basic components; if the condition is urgent and there is no ready-made peritoneal dialysis fluid, you can refer to Table 2 to prepare clinical dialysis fluid to save the patient’s life.