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Abstract: PO1315

Between Gradients and Ratios

Session Information

Category: Trainee Case Report

  • 703 Dialysis: Peritoneal Dialysis


  • Bohra, Nidrit, Reading Hospital, Reading, Pennsylvania, United States
  • Sullivan, Abigayle, Reading Hospital, Reading, Pennsylvania, United States
  • Chaudhary, Haseeb, Reading Hospital, Reading, Pennsylvania, United States

Hydrothorax due to peritoneal dialysis is a rare but known outcome from dialysis mainly in continous ambulatory peritoneal dialysis [CAPD]. Around 80% cases are due to a pleuroperitoneal fistula (PPF), an abnormal communication between the pleural and peritoneal space allowing leak of dialysate. A pleural fluid glucose to serum glucose gradient of >50 mg/dl is 100 % specific for detecting the leak of glucose rich dialysate via the fistula.

Case Description

A 63-year-old man with history of heart failure with reduced ejection fraction and end stage renal disease [ESRD] on continuous cyclic peritoneal dialysis [CCPD] for 3 months, presented with recurrent hydrothorax. CXR showed worsening right sided hydrothorax despite a recent paracentesis. He continued CCPD as his initial pleural to serum [PF-S] glucose gradient was normal at 21 mg/dl. However, PF-S glucose ratio was >1 raising the clinical suspicion. For confirmation, a peritoneal scintigraphy with nuclear technetium 99 scan was performed that revealed a pleuroperitoneal fistula as the source of the recurrent hydrothorax.


Peritoneal dialysis can be complicated by development of a hydrothorax in both CAPD and CPPD. Hydrothorax development is often attributed to a pleuroperitoneal leak which can be congenital or acquired. Initial diagnosis can be supported by increased PF-S glucose gradient >50mg/dl , but in our case, this did not prove to be a reliable indicator.Literature suggests that the pleural effusion is unlikely to be due to a pleuroperitoneal communication with a low PF-S glucose gradient of <50 mg/dL. However, there is also evidence that supports that peritoneal leak as the only cause for pleural glucose to be higher than the serum, i.e. a PF-S glucose ratio >1.0.The PF-S glucose > 1.0 in our case also supports the higher sensitivity of this approach.