Pathophysiology
Pleural fluid is secreted by the parietal layer of the pleura and reabsorbed by the lymphatics in the most dependent parts of the parietal pleura, primarily the diaphragmatic and mediastinal regions. Exudative pleural effusions occur when the pleura is damaged, e.g., by trauma, infection, or malignancy, and transudative pleural effusions develop when there is either excessive production of pleural fluid or the resorption capacity is reduced. Lights criteria can be used to differentiate between exudative and transudative pleural effusions. Diagnosis
A pleural effusion is usually diagnosed on the basis of medical history and physical exam, and confirmed by a chest X-ray. Once accumulated fluid is more than 300 mL, there are usually detectable clinical signs, such as decreased movement of the chest on the affected side, dullness to percussion over the fluid, diminished breath sounds on the affected side, decreased vocal resonance and fremitus (though this is an inconsistent and unreliable sign), and pleural friction rub. Above the effusion, where the lung is compressed, there may be bronchial breathing sounds and egophony. A large effusion there may cause tracheal deviation away from the effusion. A systematic review (2009) published as part of the Rational Clinical Examination Series in the Journal of the American Medical Association showed that dullness to conventional percussion was most accurate for diagnosing pleural effusion (summary positive likelihood ratio, 8.7; 95% confidence interval, 2.2–33.8), while the absence of reduced tactile vocal fremitus made pleural effusion less likely (negative likelihood ratio, 0.21; 95% confidence interval, 0.12–0.37).
A standard fatty meal (usually a high fat milk shake) is then given and more imaging is performed for another hour so that the response to the fatty meal by the gall bladder can be shown. The gall bladder should respond and begin emptying into the duodenum, the amount of bile ejected can then be calculated as an ejection fraction (EF). An EF < 35% is considered to be diagnostic of biliary dyskinesia and suitable for cholecystectomy to be considered. Treatment
Laparoscopic cholecystectomy has been used to treat the condition when due to dyskinesia of the gallbladder. Prognosis
Symptoms may persist after cholecystectomy, and have been linked to the use of proton pump inhibitors. See also
Bile acid malabsorption, an entry of the bile acid into a large intestine due to malabsorption the bile in the ileum, which may cause chronic  diarrhea. References


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