I have been part of an international group of experts in non-cancer palliative care (PCAND – Palliative Care for advanced Non malignant diseases), for more than two years now, and while there have been ferocious discussions on the suitability of peritoneal drains in our online group, there continues to be a lack of consensus.

NICE guidance supports indwelling peritoneal catheter drainage systems for treatment resistant, recurrent ascites on the basis of favorable clinical effectiveness, low complication rate, ease of use, ease of early and frequent drainage in the community. It is important to remember that non-tunnelled catheters like pigtail, repurposed central venous catheters are considered single episode devices with bacterial colonization developing up to 18 days after insertion, drain related infection a further 14.5 days after colonization and 1 in 5 patients developing drain related infection.

A recent discussion about a geriatric patient with endometrial cancer with peritoneal metastases who was being drained to dryness necessitated a review of existing guidance on diagnosis of infection in this setting and recalibration of the risks and benefits.

Procalcitonin (PCT) guided antibiotic cessation is usually advised at less than 0.5 ng/ml, fall of 80 percent from the baseline in pulmonary infections.
Bacterial infection, AKI (Renal dysfunction), Recent instrumentation or procedure, or substantial tissue injury, paraneoplastic production as seen in medullary thyroid cancer and neuroendocrine tumours (small cell type) might be causes leading to its elevation.

The utility of C-reactive protein as a marker of sepsis is confounded by the presence of inflammation associated with advanced cancer, and its immortalization as a prognostic rather than a diagnostic marker (in the Glasgow prognostic score), points towards the same. CRP is also suppressed disproportionately by dexamethasone.

Diagnostic standard for catheter related bacterial peritonitis is PMN count in the drain fluid, gram staining and bedside inoculation of culture bottles. PMN count of more than 250 cells/mm3, the diagnostic standard for SBP in the setting of a cirrhotic liver, might not be much suited to this setting, especially in the setting of an indwelling catheter. Addition of percentage threshold of 35 percent to the leucocyte count might increase the diagnostic specificity.

Prophylactic antibiotics to prevent spontaneous bacterial peritonitis are usually not indicated in the setting of malignancy as it is the drain which is the primary source of infection. Continuing drainage at 48 hours after insertion or late in the disease trajectory should prompt investigation for a diuretic responsive element, possibly contributed by underlying hepatic decompensation (which might occur in metastatic liver disease).

Interpretation of biomarkers in the presence of advanced disease, instrumentation and prognostic uncertainty in the absence of a diagnostic algorithm becomes the real challenge. Colonization may also occur in the absence of infection. Both serum biomarkers might not be reliable in this setting, and a PCT kinetics might provide a better clue about the status of infection.

With each passing day, whether to drain fluid and incur further protein deficit and haemodynamic burden in advanced disease is a question that assumes added significance for the Palliatrist.

References

Gregoriano, C., Wirz, Y., Heinsalo, A., Annane, D., Reinhart, K., Bouadma, L., Christ-Crain, M., Kristoffersen, K. B., Damas, P., Nobre, V., Oliveira, C. F., Shehabi, Y., Stolz, D., Verduri, A., Müller, B., & Schuetz, P. (2024). Procalcitonin-guided antibiotic treatment in patients with cancer: A patient-level meta-analysis from randomized controlled trials. BMC Cancer, 24, 1467. https://doi.org/10.1186/s12885-024-13160-2

National Institute for Health and Care Excellence. (2015). Procalcitonin testing for diagnosing and monitoring sepsis (HTG386). NICE.

National Institute for Health and Care Excellence. (2022). PeritX peritoneal catheter drainage system for vacuum-assisted drainage of treatment-resistant, recurrent malignant ascites (HTG282). NICE.

Stukan, M. (2019). Malignant ascites drainage with indwelling abdominal catheters: Can we predict and prevent infection complication? Annals of Palliative Medicine, 8(5), 626–632. https://doi.org/10.21037/apm.2019.08.02

Wang, S. S., Lu, C. W., Chao, Y., Lee, M. Y., Lin, H. C., Lee, S. D., Tsai, Y. T., Chen, C. C., & Lo, K. J. (1994). Malignancy-related ascites: A diagnostic pitfall of spontaneous bacterial peritonitis by ascitic fluid polymorphonuclear cell count. Journal of Hepatology, 20(1), 79–84. https://doi.org/10.1016/S0168-8278(05)80470-2

Yeo, M., Cho, I. R., Lee, S. H., Kang, H., Jang, E. S., Ahn, J., Jang, M. J., Choi, J. H., Paik, W. H., & Ryu, J. K. (2026). Characteristics of Pancreatic Cancer-associated Ascites and Redefined Criteria for Bacterial Peritonitis. Pancreas, 55(5), e471–e480. https://doi.org/10.1097/MPA.0000000000002606

Cite as

Arora, R. D. (2026). Conceptual Engineering (CE 10) Malignancy related ascites and PCT kinetics – diagnosing infection with an indwelling ascitic drain. Zenodo. https://doi.org/10.5281/zenodo.21993978

Disclaimer

Every attempt has been made to safeguard the identity of patients referred to in the vignettes, and any untoward circumstances arising out of this academic treatise are completely unintended on the part of the author. The author does not intend to cause any harm to another individual’s or organisation’s reputation and has tried his level best to ensure that identities are fiercely protected.

Artificial intelligence tools, primarily Claude (Anthropic), have been employed for evidence synthesis and language refinement. They do not replace critical scholarship, clinical experience, or editorial judgment. Final responsibility for all interpretations, factual accuracy, originality of synthesis, and the quality of the published material rests entirely with the Founder and Editor.