Overview of Peritoneal Dialysis
Peritoneal dialysis-associated peritonitis is a complication in which the patient develops peritonitis manifestations such as abdominal pain, fever, or turbidity of the dialysate during peritoneal dialysis. It is the most common complication of peritoneal dialysis and a common cause of peritoneal dialysis failure. Peritonitis can be broadly categorized into bacterial peritonitis, fungal peritonitis, sclerosing peritonitis, chemical peritonitis, and so on. Bacterial peritonitis is the major complication of peritoneal dialysis.
Etiology
1. The most important etiologic factor is contamination, which often occurs during peritoneal dialysis fluid exchange.
2. External infection can lead to tunneling and peritonitis, and the most common causative organisms are coagulase-negative Staphylococcus aureus and gram-negative bacteria.
3. Decreased resistance of the organism.
4. Constipation and enema can induce enterogenic peritonitis.
5. Bacteremia, dental manipulation, colonoscopy, dislodgement of the titanium connector of the peritoneal dialysis catheter or rupture of the catheter there can also cause it.
Symptoms
1. Symptoms
The main manifestations are cloudy peritoneal fluid and abdominal pain. Turbidity of the peritoneal fluid is the most common and the earliest symptom, and abdominal pain is mostly acute, with varying degrees of pain. A few patients may be accompanied by nausea, vomiting, abdominal distension, fever, chills and so on.
2. Physical signs
The most common signs are pressure pain and rebound pain, some patients have localized abdominal muscle tension and weakened bowel sounds.
Examination
1.Laboratory examination
(1) Routine examination of peritoneal transudate: in most cases, the drainage fluid is turbid in appearance, with increased protein content and leukocyte count, leukocyte count >100×106/L, and the proportion of neutrophils is more than 50%.
(2) Smear of peritoneal dialysis fluid: centrifuge 50~100ml of dialysis fluid and take the sediment for gram staining. It can show the presence of yeast, and thus start rapid antifungal treatment and timely extubation.
(3) Bacterial culture of peritoneal dialysis fluid: when there is a suspicious symptom of peritonitis, ascites culture and drug sensitivity test should be done immediately, and the correct culture method is extremely important for determining the pathogenic bacteria.
2.Imaging examination
X-ray examination, ultrasound examination or CT examination, if necessary, will help the diagnosis of peritoneal dialysis-related peritonitis.
Diagnosis
1. Peritoneal dialysis patients present with turbid dialysate, abdominal pain, fever, nausea, vomiting.
2. Dialysate culture reveals pathogens.
3. Routine examination of the dialysate with a white blood cell count >100×106/L and a neutrophil ratio of more than 50%.
The diagnosis can be confirmed if 2 of the above 3 items are met. Peritonitis should be highly suspected when peritoneal dialysis patients are found to have turbidity in peritoneal dialysis fluid in clinical practice, but care should be taken to identify non-infectious causes of turbidity in peritoneal dialysis fluid.
Differential diagnosis
It is important to identify non-infectious factors causing turbidity in peritoneal dialysis fluid, such as chemical irritation to the peritoneum, intraperitoneal hemorrhage due to various reasons, eosinophilia due to allergy, celiac ascites due to thoracic duct obstruction, and intraperitoneal tumors.
Treatment
1. Initial treatment
(1) The cause of peritonitis should be found as soon as possible, and detailed information should be obtained on whether there is a change in bowel habit, and whether there is a history of peritonitis or duct-related infection.
(2) Broad-spectrum, potent antibiotic therapy should be given as soon as cloudy drainage develops. In patients with cloudy drainage, the addition of heparin to the peritoneal dialysis fluid helps to prevent fibrin from obstructing the ducts. Empiric antibiotics must cover both gram-positive and gram-negative bacteria. Vancomycin or cephalosporins may cover gram-positive bacteria, and tertiary cephalosporins or aminoglycosides are used for gram-negative bacteria. In the treatment of peritonitis, peritoneal application of antibiotics is preferred to intravenous administration, and intermittent and continuous administration are equally effective; fluid changes must be left in place for more than 6 hours for intermittent administration. In the early stages of peritoneal dialysis, oral cephalosporin therapy is effective for mild peritonitis such as that caused by Staphylococcus epidermidis, but is not indicated for severe peritonitis. Continuous peritoneal lavage is usually used in patients with infectious shock and severe turbidity of the peritoneal dialysis drainage fluid.
2. Follow-up
Once culture results and drug sensitization are available, antibiotic therapy should be appropriately adjusted to a narrow spectrum. Within 48 hours of initial treatment, most patients will have great clinical improvement with a course of antibiotic use of 14-21 days. Drainage fluid should be observed daily to see if it becomes clear. If there is no improvement after 48 hours, a cell count examination and another bacterial culture should be done. The laboratory can treat the drainage fluid with antibiotic clearance techniques to try to obtain the best possible culture results. Patients with fungal peritonitis often require immediate extubation and continuation of antifungal therapy for at least 10 days, and it is recommended that reintubation be considered after 1 to 2 months. Patients with refractory peritonitis also need to be extubated as soon as possible, and systemic antibiotics should be used to continue infection control and, if necessary, to maintain dialysis treatment with the aid of hemodialysis, as failure to do so will lead to peritoneal failure and increase the risk of death.
Patients with recurrent peritonitis who have an ascites leukocyte count of 6/L can be extubated and a new tube can be placed in situ, which can avoid conversion to hemodialysis in many patients.
Prognosis.
Peritoneal dialysis-associated peritonitis generally has a favorable prognosis if detected and treated early. However, recurrent peritonitis can lead to peritoneal adhesions and thickening, which in severe cases can lead to peritoneal failure and failure of peritoneal dialysis.
Prevention
1. Strengthen monitoring and training
Carefully monitor all peritoneal dialysis-associated infections in the dialysis center for possible causative agents and culture results, and investigate the frequency of recurrence of peritonitis. Conduct an etiologic analysis and give necessary interventions to prevent recurrence of peritonitis.
2. Peritoneal dialysis modalities
Prophylactic antibiotics are given at the time of catheter implantation and at the time of the procedure to avoid formation of injury and hematoma. The catheter is implanted until the wound is completely healed and the outlet needs to be kept clean and dry. The catheter should be kept in place to avoid pulling and damaging the outlet to avoid infection.
3. Prevention of intestinal infection
Dialysis patients should keep the regularity of bowel movement and avoid constipation.
4. Prophylactic antibiotic use
Empty the peritoneal dialysis fluid between all abdominal or pelvic operations, etc. and use antibiotics prophylactically.
5. Prevention of fungal peritonitis
Centers with a high incidence of fungal peritonitis can take oral fluconazole or mycotoxin to prevent fungal peritonitis.