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