CLINICAL PRESENTATION, MICROBIOLOGICAL DATA AND OUTCOME OF PERITONITIS IN PATIENTS UNDERGOING PERITONEAL DIALYSIS IN A TERTIARY CARE HOSPITAL: A TEN-YEAR RETROSPECTIVE STUDY.

Introduction:

Peritoneal dialysis (PD) is a preferred starting modality for patients with end-stage renal disease (ESRD) which is a growing problem in India accounting for up to 150 million cases per year. Many patients in developing countries die even before they are started on renal replacement therapy because of resource poor economies.[1]

PD is administered as a chronic therapy used in 20-29% cases in different states of India. PD helps in preserving residual renal function. Due to its increasing use, there are many advancements in its administration and technique. It can be performed in a manual way known as “continuous ambulatory PD (CAPD),” or using a cycler, known as “automated PD (APD).” Developed countries have observed a surge in the APD since it better suits the patient in term of transportation. However, in a developing country like ours, its use is restricted due to financial constraints and limited government supported PD programs.[2-4]

Barriers to policy implementation in healthcare, particularly concerning dialysis modalities like PD are linked to several factors. These include government policies, economic considerations, the education and training of healthcare providers, specific factors related to each dialysis modality, and patient-related factors such as preferences and awareness. Notably, the success of policies that favor PD is often inversely related to the extent of hemodialysis (HD) infrastructure in a country. This means that countries with a well-established HD infrastructure may find it more challenging to implement PD-favored policies due to existing investments, economic dependencies, and familiarity with HD among both providers and patients.[5]

Be it APD or CAPD, this procedure is inherently limited by infectious complications (peritonitis). So, PD many a times have been switched over to HD because of refractory, fungal and pseudomonal peritonitis, and catheter loss.[4,6]

PD peritonitis has been linked with certain patient characteristics like socio-demographic status, co-morbidities in addition to procedure itself and the occurrence of other complications like “catheter tunnel infection or exit site infection.[7] However, the risk associated with such parameters has not been completely elucidated in the literature.

Peritonitis increases the failure rates and adverse outcomes.[4,6,7] Thus it is warranted to diagnose it early and manage with suitable antibiotics as per the cultured organism. The causative organisms vary in different parts of the world, and in different states of our country.[7-9] The evidence in the present literature is mainly based on short term follow up of the patients, thus demanding further research in different institutes of the nation doing PD on a large subset of patients.

Hence this study was planned where we retrospectively reviewed the data of patients undergoing PD over the last 10 years at our institute with an objective to ascertain the mode of PD used, complications associated with PD with the inciting organism (with their antibiotic sensitivity profile) and factors affecting the switch over to HD.

Methods:

A retrospective observational study was conducted in the department of Nephrology of Christian medical college & hospital, Ludhiana (Punjab, India) during which the previous 10-year records were screened. Any patient who underwent peritoneal dialysis during that period was included in the study. The exclusion criteria were: History of peritonitis in the last 1 month before enrolling for PD, patients receiving antibiotics within 7 days prior to enrolment, patients on immunosuppressants (barring topical steroids) and presence of any malignancy.

In the study, a total of 154 patients were included in the study over ten years. The demographic characteristics such as age, gender and the clinical conditions were recorded. The follow up records of the patients till date were recorded for the type of PD, failure of PD, catheter removal, shift to HD, incidence of peritonitis (based on clinical evaluation, peritoneal fluid cytology, acid fast bacilli or culture positivity) and occurrence of other complications. The culture reports of PD and their antibiotic sensitivity patterns were also obtained. 

Culture methods employed were manual inoculation and plating on media like blood agar, McConkey agar, chocolate agar and thioglycolate broth. BACTEC was used for processing and reporting the test samples. The outcome measures were peritonitis related mortality and the factors affecting it. The peritonitis related mortality was considered for deaths occurring in the hospital after 14 days of detection of peritonitis.

Statistical analysis

The data was collected and recorded in an EXCEL sheet and analyzed using Statistical Package for Social Sciences (SPSS) software, IBM manufacturer, Chicago, USA, Ver 21.0. The qualitative variables such as gender, underlying kidney disease, mode of peritoneal dialysis, complications, PD fluid culture, causative organism, outcome, cause of death and sensitivity of various antifungal and antibiotics were expressed as n(%). Quantitative variable such as age was expressed as mean ± SD. Univariate logistic regression was used to find out significant risk factors of mortality and conversion to hemodialysis. P value <0.05 was considered as statistically significant.

Results:

Total study population screened is 154 patients. Out of which 79 patients had complications. PD-related peritonitis was recorded in 68 (86.08%) patients, with 13 (16.45%) and 4 (5.06%) of the patients getting exit site infection and tunnel infection respectively. Two of exit site and tunnel infections each converted to peritonitis. Two of exit site infections converted to tunnel infection. PD peritonitis rate in this facility during that period was 0.36 episode per patient year. It is fulfilling ISPD guidelines of PD peritonitis rate should be less than 0.4 episodes per patient year.[9] 

The mean (SD) age of the patients in the study was 61.86 (+10.4) years with a predominant male population (M:F=2.02:1). The underlying kidney disease leading to ESRD was diabetic nephropathy (59.5%), chronic interstitial nephritis (35.44%), chronic glomerulonephritis (2.53%) and CAKUT (2.53%).

Of the 154 participants on PD, majority [150 (97.4%)] were on CAPD mode and only 3 (1.94%) were on APD. A single case was shifted from APD to CAPD.

Among 79 cases with complications, 5(6.32%) were positive for fungus, 34(43.04%) showed positivity for bacterial culture among which gram positive and negative bacteria were distributed equally. 40(50.63%) cases were sterile. The commonest gram negative organisms were Pseudomonas Aeruginosa, E. coli and Klebsiella Pneumoniae; while the common gram positive organisms were Enterococcus, Staphylococcus aureus and Streptococcus viridans.(Table 1) Among the sterile cases, one was found positive for tuberculosis effusion. The distribution of organisms in our study was equivalent with respect to gram stain reaction (50% gram positive and 50% gram negative). Literature review shows conflicting incidences with some studies showing more of gram-positive organisms.[8] While some are showing more gram-negative organisms.[10-12] Among gram-negative bacteria, Pseudomonas Aeruginosa was the commonest organism against E. coli in the study by Sharma et. al.[11]

The index study showed a culture negativity rate of 50% which was higher than suggestion of ISPD (<15%). However, studies in India and other developing countries have shown a similar range of culture negativity (18-70%).[10-13] As this study, one study from south Indian study reported a similar rate of 50%.[8] The variation in the reported culture positivity has been associated with the technique of culture in the laboratory vs automated systems and conventional systems; and different companies of culture media. A higher growth of microorganisms was observed when automated method, centrifugation before inoculation, enrichment media and large volume of PD effluent was used.[14,15] But one recent study showed no difference in culture positivity between BACTEC vs. conventional.[16]

The primary outcome has been shown in Figure no 1. 58(73.4%) showed complete resolution of peritonitis and continued CAPD. Total 13 patients were shifted to hemodialysis (HD). Out of which 9 patients survived and continued HD. 4 patients died while on HD. 8 patients continued CAPD and showed resistance to conversion to HD and died ultimately. CAPD catheter removal was done in total 15 patients. Out of which 13 patients shifted to HD. Remaining two had catheter reinsertion. The causes of 12 deaths have been shown in Table 2.

Candida albicans was sensitive to only Amphoterecin B while non-candida albicans was sensitive to all antifungal drugs: Clotrimazole, Ketoconazole, Fluconazole, Itraconazole and Amphoterecin B.(Table 3) Fungal peritonitis was observed in 7.4% cases against the Indian literature ranging from 7-15%.[8,11] This holds relevance as: first, fungal infections may increase the rate of hospitalization and remain undiagnosed in bacterial cultures; second, the concurrent administration of antifungal prophylaxis can decrease the incidence of candida infection. Currently ISPD guidelines recommend adding antifungal prophylaxis whenever patients receive antibiotic course. Because antibiotic treatment increases the chances of fungal peritonitis.[9]

For the antibiotics, the sensitivity pattern of gram-negative organisms and gram-positive organisms has been shown in Table 4 and 5. In the present study, Ciprofloxacin, Gentamicin, Amikacin, Piperacilin-tazobactum and Ceftazidime were the most sensitive drugs for gram negative organisms; MRSA was most sensitive to Vancomycin and Cotrimoxazole; Staphylococcus viridans was sensitive to Vancomycin, Penicillin, Ceftriaxone and Cefotaxime; and enterococcus was most sensitive to Gentamicin, Vancomycin, Penicillin and Ampicillin.

Regression analysis showed that none of the risk factors (age, gender, mode of PD, complications) significantly affected the mortality. Conversion to hemodialysis showed the highest OR of 3.222, (95% C.I 0.802 to 12.944) but it failed to cross statistical significance (p=0.099). (Table 6) To further know the risk factors of conversion to hemodialysis. Regression analysis was done that showed none of the risk factors (age, gender, mode of PD, complications) significantly affected it. The presence of complications was the strongest risk factor OR 5.595, 95% C.I (0.274 to 114.343) but it failed to cross statistical significance (p=0.263).(Table 7)

Conclusion

In conclusion, PD is a technique for end stages of renal disease for preserving the kidney functions artificially. Compared to the developed countries, CAPD is a common method applied in the developing countries as India. Currently, the modality holds no differences in the outcomes for PD. PD as a modality shows good resolution in patients, however it is prone to complications which are the prime reasons for failure or mortality or switch over to HD. The organisms causing peritonitis remains wide- predominantly bacteria, with some cases of fungus and tuberculosis. The use of empirical antibiotics such as vancomycin and third generation cephalosporins holds importance based on the local sensitivity patterns. Due to various confounders, none of the factors (age, gender, modality, complications rate and switch over to HD) showed an independent association with mortality.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.