Diagnosis Of Peritonitis In Patients Research Articles

Evaluation of a new rapid-diagnostic test for peritonitis in peritoneal dialysis: the PERIPLEX® device.

In 2017, the British company MOLOGIC developed a new rapid-diagnostic test (PERIPLEX®) for the diagnosis of peritonitis in patients undergoing peritoneal dialysis. This single-use test is based on the detection in dialysate of two biomarkers of bacterial infection: Interleukin-6 (IL-6) and matrix metalloproteinase-8 (MMP-8). The test was evaluated in a prospective multicenter study including 10 centers from the RDPLF (French Language Peritoneal Dialysis Registry). A total of 184 tests were performed; 86 tests were negative and 98 were positive. 85 peritonitis were confirmed. There were no false-negatives, and 13 false-positives. Of the 13 false-positives, 7 of them were for sepsis without peritonitis, or peritoneal inflammation. The performance of the test is considered excellent: sensitivity 100%, specificity 86.9%, positive predictive value 86.7%, negative predictive value 100%. In this study, a negative test can formally rule out the diagnosis of peritonitis.

Bacteriological sampling of peritoneal dialysis fluids. How to limit negative-culture peritonitis rate?

Peritonitis is a major and serious complication in terms of morbi-mortality for patients treated with peritoneal dialysis. Their microbiological diagnosis is challenging for both the detection of the etiological agents and in interpreting positive cultures.
 Many microorganisms can cause this infection; usual micro-organisms such as coagulase-negative staphylococci or Enterobacteriaceae, but also ‘atypical’ bacteria, which culture or detection, is more tedious can be found.
 To identify the responsible bacteria, molecular biology and culture techniques can be set up. Molecular biology (particularly the sequencing of the universal 16s rDNA gene) makes it possible to identify atypical agents, but antimicrobial susceptibility testing cannot be performed following these technics.
 The culture of peritoneal dialysis fluids remains the ‘gold-standard’ for the diagnosis of these infections. Nevertheless this must be optimized to enhance its sensitivity.
 The etiological diagnosis of peritonitis in patients treated with peritoneal dialysis may be difficult, but modern microbiology combined with a bacterioclinical discussion allow the identification of the microorganism responsible for the infection in the great majority of the cases.

Evaluation of different culture methods for the diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis

A total of 170 continuous ambulatory peritoneal dialysis (CAPD) fluids were processed by various culture methods, including direct inoculation of the centrifuged sediment, inoculation into automated blood culture bottles, water lysis, Tween-80 incorporated blood agar, and Triton-X treatment of the specimen. Of 170 CAPD fluids, 127 showed the growth of bacteria/fungi. Sixty-three fluids showed growth by all methods, the water lysis alone detected 24 additional positive cultures, while Tween-80 blood agar and Triton-X yielded 30 additional positive cultures. A combination of water lysis, Tween-80 blood agar and Triton-X treatment of the CAPD fluid is recommended for diagnosis of CAPD peritonitis in resource-limited settings.

The Diagnosis of Peritonitis in Patients on Continuous Ambulatory Peritoneal Dialysis

The Diagnosis of Peritonitis in Patients on Continuous Ambulatory Peritoneal Dialysis

Limulus amoebocyte lysate assay in the diagnosis of peritonitis in patients receiving continuous ambulatory peritoneal dialysis.

To evaluate the Limulus amoebocyte lysate (LAL) assay for differentiating Gram positive from Gram negative peritonitis in patients receiving continuous ambulatory peritoneal dialysis (CAPD). One hundred and six patients with suspected peritonitis were studied. LAL assay was performed by adding 0.1 ml of CAPD fluid to 0.1 ml of LAL reagent and incubating in a heating block for 60 minutes at 37 degrees C. The sensitivity of the reaction was determined by: (i) diluting endotoxin in distilled water and used (filter sterilised) peritoneal dialysis fluid; and (ii) diluting a broth culture of E coli used in peritoneal dialysis fluid. A positive LAL assay was defined as the constant stability of the clot through an inversion of 180 degrees. Compared with bacterial culture, the LAL assay had a sensitivity of 65% and a specificity of 98%. The sensitivity of microscopy compared with culture of Gram negative organisms was 76%; overall sensitivity of microscopy in comparison was 80%. The Gram stain was more sensitive than has previously been reported; the LAL assay was specific but insensitive for the diagnosis of CAPD peritonitis. There was a correlation between reduced leucocyte count and culture; this was reduced in cases from which Gram negative organisms had been isolated. It is recommended that laboratories evaluate their Gram stain procedure to improve its sensitivity because the LAL assay is not a satisfactory substitute.

Usefulness of peritoneal fluid amylase levels in the differential diagnosis of peritonitis in peritoneal dialysis patients.

Peritonitis continues to be a major cause of morbidity in peritoneal dialysis patients despite recent technological advances (Y systems) that have reduced peritonitis rates to much more acceptable levels. Most of the time when a peritoneal dialysis patient presents with peritonitis, it is infectious in origin. However, these patients occasionally develop other intra-abdominal pathology that requires more intensive medical care or, at times, surgical intervention. To help in the early differential diagnosis of the cause of peritonitis in these patients, peritoneal fluid amylase levels were prospectively obtained from 50 patients presenting to the hospital with peritonitis. Thirty-nine of them had typical infectious peritonitis, and their mean peritoneal fluid amylase level was 11.1 (range, 0 to 90). Six patients had pancreatitis and a mean peritoneal fluid amylase level of 550 U/L (range, 100 to 1,140 U/L). Five patients were found to have other intra-abdominal pathology, and their mean peritoneal fluid amylase level was 816 U/L (range, 142 to 1,746 U/L). In patients who did not respond to initial therapy, sequential peritoneal fluid amylase levels did not increase in patients with typical infectious peritonitis whereas it did increase in patients with other intra-abdominal pathology. In conclusion, it was found that peritoneal fluid amylase levels were helpful in the differential diagnosis of peritonitis in these patients. An elevated level (greater than 100 U/L) differentiated those patients with other intra-abdominal causes of peritonitis from those with typical infectious peritonitis.

Clinical and microbiological evaluation of four culture methods for the diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis.

A prospective study was performed to evaluate four culture methods for the diagnosis of bacterial peritonitis in patients on continuous ambulatory peritoneal dialysis. Peritonitis was present in 44 of 85 patient admissions (52%). The overall sensitivity of the culture methods in detecting peritonitis was 66%. The sensitivities of the individual methods were as follows: bag culture method, 61%; blood culture broth method, 51%; filter method, 54%; and plate method, 39%. Our broad definition of peritonitis resulted in lower sensitivities. A combination of the bag and blood culture broth methods detected all positive cultures.

Laboratory diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis.

The clinical course and laboratory diagnosis of peritonitis in patients undergoing continuous ambulatory peritoneal dialysis was studied in 32 consecutive episodes. Peritonitis was associated with a failure in aseptic technique in eight episodes and with an exit-site infection in four episodes. Intraperitoneal vancomycin and ceftazidime were safe, effective, and convenient. Most patients administered their antibiotics at home, and symptoms usually resolved by day 4. Culture of the deposit obtained by centrifugation of 50 ml of effluent after leukocyte lysis provided the best rate of recovery (84% culture positive) but was technically demanding. Filtration of the same volume without leukocyte lysis was simple to perform and almost as effective. Enrichment was less satisfactory (65% culture positive) owing to the presence of antibiotic or infection with fastidious microorganisms. Culture of 50 ml of effluent after concentration by a commonly used laboratory technique, centrifugation without leukocyte lysis, performed poorly (59% culture positive at 48 h), as this method caused sequestration and death of microorganisms within the leukocytes. Culture of nearly 1 liter of effluent from 33 asymptomatic patients by the same techniques yielded no microorganisms.

Novel plate culture method to improve the microbiological diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis.

A novel economical plate culture technique incorporating Tween 80 was used for the isolation of organisms from dialysis effluent in cases of continuous ambulatory peritoneal dialysis peritonitis. It was found to be convenient for routine laboratory use and increased the yield of positive plate cultures in specimens without antibiotics from 53 to 75% (P less than 0.01) and in specimens containing antibiotics from 24 to 38% (P less than 0.05). It allowed for the identification and susceptibility testing of isolates 24 h earlier than did broth culturing and a more ready appreciation of mixed cultures and contaminants.

Laboratory diagnosis of peritonitis in patients treated with continuous ambulatory peritoneal dialysis

Patients treated with continuous ambulatory peritoneal dialysis (CAPD) are constantly exposed to microbial invasion of the peritoneal cavity and rapid microbiological diagnosis of peritonitis is essential. Aseptic peritonitis is diagnosed in a high proportion of episodes when small volumes of dialysate are cultured. The aims of this study were to enumerate the microorganisms associated with clinical peritonitis and compare the efficacy of various culture systems for laboratory diagnosis of peritonitis. Four qualitative culture systems were compared: low (1 ml) volume and high (10 ml) volume inoculations of broth media, centrifugation (10 ml) followed by culture of the sediment and filtration (less than or equal to 100 ml) followed by culture of the filter. The pour plate and drop plate were the 2 quantitative methods used. Results of this study indicate that culture of 10 ml fluid volumes is comparable to culture of larger volumes sampled by filtration. Low volume cultures of fluid resulted in a lower proportion of positive cultures. The low numbers of viable microorganisms often found in dialysate from patients with peritonitis supports the concept of culturing a minimum of 10 ml of fluid.

Microbiological diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis.

The fast and accurate etiological diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis is essential. The concentration of larger volumes of peritoneal fluids may yield more isolates than conventional methods. The removal of antibiotics present in the fluids as a consequence of therapy by washing or using antibiotic-removing resins increases the yield considerably. The use of anaerobic culture media is justified if fecal organisms are suspected as the cause of the infection.

Laboratory diagnosis of peritonitis in patients undergoing continuous ambulatory peritoneal dialysis.

A simple laboratory method for culture of continuous ambulatory peritoneal dialysis (CAPD) fluids is described. Guidelines for antimicrobial therapy are discussed based on results from 18 patients studied over an 11-week period. Cephalosporins appeared to be a rational choice for therapy while awaiting laboratory results.

The Value of Dialysate Cell Count in the Diagnosis of Peritonitis in Patients on Continuous Ambulatory Peritoneal Dialysis

Dialysate white-cell count and differential was performed by a Cytospin technique in 38 control CAPD patients and serially in 24 patients with bacterial peritonitis and one patient with “peritoneal fluid eosinophilia”. Dialysate solutions of control patients have cell counts below 501 mm3, comprised mainly of mononuclear cells; these presumably repre