Praxis Medical Insights

Incidence and Mechanism

Hydrothorax occurs in 1.0-5.1% of patients receiving peritoneal dialysis through pleuroperitoneal leaks, with the European Respiratory Society noting that it is almost always unilateral (88% right-sided) 1
The European Respiratory Society reports that hydrothorax can develop at any time: 50% occur within the first 30 days of starting peritoneal dialysis, 18% after the first year, and some as late as 8 years after initiation 1
Asymptomatic hydrothorax is found in 26% of cases, according to the European Respiratory Journal 1

The European Respiratory Society states that hemodialysis does not directly cause hydrothorax, but patients with end-stage renal failure on hemodialysis commonly develop bilateral pleural effusions from fluid overload (61.5% of cases) 2
The European Respiratory Journal notes that heart failure with associated cardiac comorbidity is another cause of bilateral pleural effusions in hemodialysis patients 3
Uremic pleuritis is a less common cause of pleural effusions in hemodialysis patients, as reported by the European Respiratory Journal 3

The European Respiratory Journal describes the pleural fluid in peritoneal dialysis-related hydrothorax as having a clear or straw-colored appearance 1
The pleural fluid is characterized as an extreme transudate with protein <1 g/dL, according to the European Respiratory Journal 1
The European Respiratory Journal notes that the pleural fluid has markedly elevated glucose (350-450 mg/dL or 19.4-25 mmol/L), reflecting dialysate glucose 1
A pleural fluid to serum glucose ratio >1.0 is diagnostic, as reported by the European Respiratory Journal 1

The European Respiratory Journal states that hemodialysis patients with bilateral effusions should be managed with intensified diuresis and optimized dialysis for fluid removal 3
The European Respiratory Journal and Praxis Medical Insights report that patients with end-stage renal failure who develop pleural effusions have a poor prognosis, with a 1-year mortality of 46% 2, 3