med 610 clinical respiratory diseases & critcare med

Pleural Effusions

Case 2 Answers

A 45 year-old man with cirrhosis secondary to chronic alcohol abuse and Hepatitis C presents to clinic complaining of increasing dyspnea. He has had ascites for several months but his abdominal girth has not changed since his last clinic visit. A chest x-ray is obtained and shows a new right pleural effusion. Thoracentesis is performed and reveals LDH 95 (serum value 290, upper limit of normal for serum 180), total protein 2.2 (serum value 5.8). The gram’s stain is negative and there are no white blood cells in the fluid.

How would you interpret the results of the pleural fluid studies?

The LDH is less than 2/3 the upper limit of normal while the pleural fluid: serum ratio for LDH is 0.32 and the pleural fluid: serum protein ratio is 0.4. This effusion is, therefore, best classified as a transudative process

How do you explain the presence of the pleural effusion?

Given the underlying history of cirrhosis and ascites, it is likely that this patient has developed a problem known as hepatic hydrothorax, in which ascitic fluid tracks from the abdomen through small defects in the diaphragm into the pleural space. This is more common when patients have ascites but can also occur in the absence of significant intra-peritoneal fluid accumulation. You should be aware that just as patients can develop spontaneous bacterial peritonitis, it is possible to develop spontaneous bacterial pleuritis.

How can you confirm the diagnosis?

The diagnosis is usually apparent based on clinical history. If it is still unclear, you can do simultaneous taps of the pleural and ascitic fluid and show that the serum-ascites and serum-pleural fluid albumin gradients are both > 1.1. If there is still doubt, you can order a nuclear medicine study in which technetium-99m labeled sulfur colloid is injected into the peritoneal cavity and the patient is scanned to see if the radio-labeled material can be detected in the pleural space as well.

What can you do to manage this pleural effusion? Is there a role for placing a drain in his right chest to limit the accumulation of fluid in the pleural space?

Although the fluid can be drained to relieve symptoms, fluid reaccumulation is the norm and you will not achieve long-term relief of the problem. Placement of a chest tube or drain is generally contraindicated as the patient will continue to lose large amounts of fluid through either system and is at risk for developing worsening intravascular volume status due to fluid shifts as well as profound hypoalbuminemia. Instead of trying to drain the fluid, initial treatment should focus on controlling the development of the ascites through the use of a low-salt diet and a diuretic regimen. Patients who fail this conservative approach may require a transjugular intrahepatic portosystemic shunt (TIPS) procedure or, if they qualify, liver transplantation. If TIPS or liver transplantation is not possible, patients can be considered for surgical procedures to close the diaphragmatic defects. Pleurodesis is rarely successful, as you cannot drain the pleural cavity of fluid for a sufficient period of time to allow the pleural surfaces to adhere to each other.

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