Hepatic Hydrothorax

Epidemiology

  • Pleural effusion usually occurs in presence of ascites (although ascites may detectable only by U/S)
  • Incidence of effusion in presence of  ascites: 6% of cases

Etiology

Percutaneous Transhepatic Procedures

  • Increased hepatic hydrothorax may occur in rare cases after transhepatic procedures: probably occurs due to inadvertent iatrogenic defect created in diaphragm -> leakage of ascitic fluid across diaphragm
  • Implicated Procedures
    • Post-Percutaneous Transhepatic Coronary Vein Occlusion: used to control bleeding esophageal varices/transdiaphragmatic, transhepatic injection of gelfoam into coronary vein (material lodges in esophageal veins)
    • Percutanous Transhepatic Cholangiogram: in addition to inducing hepatic hydrothorax, this procedure can also inadvertently result in cholethorax (see Pleural Effusion-Cholethorax)

Physiology

  • Transudation of ascitic fluid from peritoneal space across diaphragmatic defects into pleural space
  • India ink injection into ascitic fluid -> appears in pleural fluid
  • IV injection of radiolabelled albumin: appears in ascites first, only subsequently in the pleural fluid (injection of air in peritoneal space had same results, with PTX observed, due to observable defects in diaphragm at thoracoscopy)
  • Pleural pressure in cirrhosis-associated effusions are higher than in other transudates (due to fluid flowing down pressure gradient into pleural space from ascites)
  • Decreased plasma oncotic pressure only a secondary etiologic factor in cirrhotic effusions

Diagnosis

  • Pleural Fluid
     -Appearance: usually straw-colored but may be bloody in rare cases

    • pH:
    • LDH ratio:
    • Total protein ratio: pleural fluid protein is usually higher than ascitic fluid protein (but is still usually <3 g/dL)
    • Cell count/ diff ( may be PMN or lymphocyte-predominant): PMN count >500/mm3 strongly suggests spontaneous bacterial empyema from associated SBP
    • Gram stain/ culture:
    • Cholesterol:
    • Amylase: normal
  • CXR/Chest CT Patterns
    • Pleural effusion: may be large (occupying hemithorax): 67% are right-sided/ 16% are left-sided/ 16% are bilateral

Clinical

  • Symptoms/signs:
    • Signs of cirrhosis: usually dominate the clinical picture
    • Signs of pleural effusion (see Pleural Effusion-Transudate): dyspnea/ dullness to percussion/ decreased BS over area

Spontaneous Bacterial Pleuritis

  • May occur
  • Most, but not all, cases have associated SBP
  • Usually due to E.Coli
  • Chest tube does not appear to be necessary

Treatment

  • Treat Ascites (since effusion is simply an extension of the ascites)
    • Low sodium diet/ Lasix (start at 40 mg per day) + Aldactone (start at 100 mg per day)/ etc.
  • Therapeutic Thoracenteses
    • Contraindicated (fluid rapidly accumulates and protein depletion may occur)
  • Transhepatic Portosystemic Shunt (TIPSS)
    • May be required for refractory ascites
    • Complications: worsened hepatic encephalopathy, CHF (due to increased venous return to rich side of heart)
    • Contraindications: hepatic encephalopathy
  • Pleurodesis: may be required in some cases with persistent symptomatic effusion despite aggressive therapy of ascites
    • Monitor closely after chest tube placement, since amount of ascites can rapidly decrease (causing precipitous hypovolemia): inject Doxycycline as soon as lung is rexpanded (do not need to wait until drainage decreases)
    • May be done with thoracoscopic talc insufflation (or thoracoscopic placement of biological glue over diaphragmatic defect + talc insufflation)
  • Peritoneojugular Shunt: may control ascites but will not control effusion (since the fluid will preferentially move to the lower pressure pleural space over the central veins)
  • Thoracotomy: with repair of diaphragm and pleural abrasion (to effect a pleurodesis)
    • Not usually necessary
    • Post-op chest tube drainage may be excessive
  • Liver Transplantation: definitive treatment

References

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