The culture from peritoneal dialysis catheter enhances yield of microorganism identification in peritoneal dialysis-related peritonitis

Empyema associated with peritoneal dialysis peritonitis

A 65-year-old woman on peritoneal dialysis (PD) was admitted due to abdominal pain with cloudy PD effluent. The white blood cell count in PD effluent was 5860/µL with 85% polymorphonuclear neutrophils. Therefore, she was clinically diagnosed with peritonitis. The cultures of PD effluent were negative. Initial abdominal computed tomography did not find suggest any intraabdominal pathology. The patient was treated with empirical intraperitoneal antibiotics. Because abdominal pain with cloudy PD effluent persisted, the PD catheter was removed eventually. The culture of the removed PD catheter grew Klebsiella pneumoniae. However, intermittent fever was noted over the following days and empyema developed approximately 2 weeks after PD catheter removal. The culture of pleural fluid also grew K. pneumoniae. Another computed tomography revealed multiple intraabdominal abscesses that was assumed to come from a complication of PD-associated peritonitis. We postulate that the empyema might be caused by transdiaphragmatic extension of the intraabdominal abscesses into the pleural space.

The application of metagenomic next-generation sequencing for detection of pathogens from dialysis effluent in peritoneal dialysis-associated peritonitis

BACKGROUND

Metagenomic next-generation sequencing (mNGS) can improve pathogen identification in infectious diseases.

METHODS

A prospective parallel control study was undertaken to evaluate the clinical significance of mNGS in identifying pathogens in dialysis effluent of patients with peritoneal dialysis-associated peritonitis (peritonitis). Dialysis effluent specimens were detected both by peritoneal dialysis effluent culture and mNGS. The positive rates and coincidence rates of the two methods were compared.

RESULTS

From April 2020 to March 2021, 30 patients presenting with peritonitis were enrolled in this study. The positive pathogen detection rate of mNGS was significantly higher than that of the traditional culture method (86.67% vs. 60.00%; p = 0.039). Fifteen specimens were positive for both of the methods, while 11 specimens were negative for culture but positive for mNGS. Three specimens were positive for culture but negative for mNGS; all of them were streptococcus mitis. One specimen was negative for both methods. The culture method detected one type of pathogen in all specimens; however, two or more types of pathogens were detected in eight specimens by mNGS. In addition to common pathogens, additional pathogens detected by mNGS included Coxiella burnetii, human herpesvirus type 5, human herpesvirus type 6B and Mortierella.

CONCLUSION

The pathogen detection rate of mNGS in dialysis effluent of peritonitis patients was significantly higher than that of traditional culture. The mNGS is advantageous in diagnosing the pathogens that are difficult to be cultured. However, mNGS did not demonstrate sensitivity to streptococcus mitis. Results from this study show that mNGS, combined with traditional culture, has potential application for detecting pathogens in peritoneal dialysis patients with peritonitis.

ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment

Peritoneal dialysis (PD)-associated peritonitis is a serious complication of PD and prevention and treatment of such is important in reducing patient morbidity and mortality. The ISPD 2022 updated recommendations have revised and clarified definitions for refractory peritonitis, relapsing peritonitis, peritonitis-associated catheter removal, PD-associated haemodialysis transfer, peritonitis-associated death and peritonitis-associated hospitalisation. New peritonitis categories and outcomes including pre-PD peritonitis, enteric peritonitis, catheter-related peritonitis and medical cure are defined. The new targets recommended for overall peritonitis rate should be no more than 0.40 episodes per year at risk and the percentage of patients free of peritonitis per unit time should be targeted at >80% per year. Revised recommendations regarding management of contamination of PD systems, antibiotic prophylaxis for invasive procedures and PD training and reassessment are included. New recommendations regarding management of modifiable peritonitis risk factors like domestic pets, hypokalaemia and histamine-2 receptor antagonists are highlighted. Updated recommendations regarding empirical antibiotic selection and dosage of antibiotics and also treatment of peritonitis due to specific microorganisms are made with new recommendation regarding adjunctive oral N-acetylcysteine therapy for mitigating aminoglycoside ototoxicity. Areas for future research in prevention and treatment of PD-related peritonitis are suggested.