Sweet hydrothorax: A PD complication

Acute hydrothorax is an uncommon but a well-recognized complication of peritoneal dialysis. No single test is definitive for diagnosis. Diagnosis becomes a challenge.

Peritoneal dialysis-(PD) related hydrothorax was first reported in 1967 by Edward and Unger in JAMA( see attached). Transudative pleural effusion develops, more commonly involving the right side, and usually occurs immediately after starting PD or a few days later. The patients may remain asymptomatic or have sudden dyspnea, decrease in ultrafiltration, or pleuritic chest pain.

How do we diagnose it?

Presence of high pleural-fluid glucose concentration.

Pleural fluid concentration of glucose >300mg/dl might be diagnostic.

Others have hypothesized that, given dynamic movement of dialysate, an absolute glucose-concentration level cannot be used to diagnose PD-related hydrothorax. The pleural fluid-to-serum glucose concentration gradient of greater than 2.77 mmol/L (50 mg/dl) was proposed as the cut-off to diagnose the condition.

In general, any pleural-fluid glucose concentration greater than serum is considered to be highly supportive of PD-related hydrothorax.

Imaging:

1.Radionuclide scan (for example, Tc-99 m DTPA) is associated with sensitivity of 40% to 50%.
2.The methylene blue test has been used where its injected and dye is traced from the peritoneum to the pleura. In one study showed no sensitivity and is associated with a risk of chemical peritonitis.

Some case report examples in literature

http://www.pdiconnect.com/content/27/3/296.full.pdf

http://www.sciencedirect.com/science/article/pii/S1755001708001103

Check out this powershow that reviews the management of this entity.