Pleural Effusion

Pleural Cavity and Space Visceral pleurae envelop all surfaces of the lungs, including the interlobar fissures. This lining is absent at the hilus, where pulmonary vessels, bronchi, and nerves enter the lung tissue. The mediastinum completely separates the right and left pleural spaces.

Pleural Effusion • Accumulation of fluid within the visceral and parietal layers of the pleura when there is an imbalance between formation and absorption in various disease states. • Normal amount 8.4 ml per hemithorax with a WBC count of 1700 per c.mm 75% of which are macrophages and 23% lymphocytes. • Protein concentration is low about 15% of plasma protein concentration

Development of Pleural Effusion pulmonary capillary pressure (CHF) capillary permeability (Pneumonia) intrapleural pressure (atelectasis) plasma oncotic pressure (hypoalbuminemia) pleural membrane permeability (malignancy) lymphatic obstruction (malignancy) diaphragmatic defect (hepatic hydrothorax) thoracic duct rupture (chylothorax)

Pleural Effusion Exudative Pleural Effusions : Neoplastic diseases Metastatic disease Mesothelioma • Infectious diseases Bacterial infections Tuberculosis Fungal infections Viral infections Parasitic infections

Clinical features Symptoms and signs of pleurisy often precede the development of an effusion especially in patients with underlying pneumonia, pulmonary infarction or connective diseases. Frequently the onset is insidious. Breathlessness is the only symptom related to the effusion depending on the size and the rate of accumulation of the fluid.

The physical signs [usually manifest when the pleural effusions exceed 300 mL] Reduced chest movement on the affected side. Absence or Decrease tactile vocal fremitus Absent or Decrease vocal resonance. Stony dullness on percussion. Absent or reduced breath sounds. Large effusion causes displacement of trachea and mediastinuim to the opposite side.

Pleural Effusion Clues in the physical Exam. to the common etiologies A- Distended neck veins, an S3 gallop, or peripheral edema suggests congestive heart failure. B- A right ventricular heave or thrombophlebitis and sinus tachycardia suggests pulmonary embolus. C- The presence of lymphadenopathy or hepatosplenomegaly may suggests neoplastic disease. D-Ascites may suggest a hepatic cause. E-Signs of consolidation above the level of the fluid in a febrile patient suggests parapneumonic effusion .

Investigations 1- Radiological examination shows dense uniform opacity in the lower and the lateral parts of the hemi thorax. Upper margin high in axilla in PA view *Upper margin high anteriorly and posteriorly in lateral view. This is just an illusion. The fluid some times loculated in the interlobular fissure or below the lower lobe (subpulmonary effusion) simulating an elevated diaphragm.

Pleural Effusion Role Of Imaging conventional radiographic methods used are frontal, lateral, oblique and decubitus radiographs. Because of gravity, fluid accumulates in subpulmonic location and then spills over into the costophrenic sulcus posteriorly, anteriorly, and laterally and then surrounds the lung forming a cylinder, seen as a meniscoid arc.

Pleural Effusion Role Of Imaging Amount of fluid – 75 mL-subpulmonic space without spillover, can obliterate the posterior costophrenic sulcus, 175 mL is necessary to obscure the lateral costophrenic sulcus on an upright chest radiograph 500 mL will obscure the diaphragmatic contour on an upright chest radiograph; 1000 ml of effusion reaches the level of the fourth anterior rib, On decubitus radiographs and CT scans, less than 10 mL, and possibly as little as 2 mL, can be identified

Right lateral decubitus X-ray showing a large pleural effusion

Pleural Effusion Role Of Imaging Role of CT scan – Visualization of underlying lung parenchymal processes that are obscured on chest radiographs by large pleural effusions. Role of ultrasonography free vs loculated pleural effusions, and loculated effusions vs solid masses. Thoracentesis of loculated pleural effusions is facilitated by ultrasound marking or guidance.

Pleural Effusion Role Of Imaging Role of MRI Can display pleural effusions, pleural tumors, and chest wall invasion. Can characterize the content of pleural effusions. Can determine the age of the hemorrhage.

Pleural effusion CTScan of thorax

Pleural aspiration and pleural biopsy 1-Pleural fluid aspiration provides the absolute prove for the presence of pleural effusion, for which 50ml of fluid should be with-drawn. Current guidelines recommend the use of a fine bore (21g green) needle and a 50 ml syringe to gather an adequate sample. In cases of pleural effusion of unknown aetiology all aspiration and biopsy sites should be marked with Indian ink, as local radiotherapy is recommended to prevent tumour invasion of the chest wall in patients who are subsequently diagnosed with malignant effusion.

Pleural aspiration Cont.. a- In suspected pulmonary tuberculosis a large volume of fluid should be aspirated and send for laboratory study. Pleural fluid usually send for cytological, bacteriological (e.g. mycobacteriumTB) and biochemical analysis

Pleural fluid aspiration cont.. b- The pleural fluid can be straw-coloured, blood-stained, purulent or chylous. c- The most useful indices are protein, lactate dehydrogenase, Glucose and PH. The predominate cell type [neutrophils, eosenophils, lymphocyte, red blood cell]. The fluid should also be examined for malignant cells.

Exudative pleural effusion 1-Pleural fluid/ serum protein ratio more than 0.5 . pleural fluid protein level of >30 g/ l 2- Pleural fluid/ serum LDH ratio more than 0.6 or Pleural fluid LDH more than two-thirds of the upper limit of normal serum LDH 3- Pleural fluid glucose is very low(<1.4).

The differential cell count in pleural aspirates A predominance of polymorphonuclear cells seen in effusion caused by; A parapneumonic effusion. In effusion caused by pulmonary embolus, tuberculosis and Benign Asbestos Pleural Effusion (BAPE).

The differential cell count in pleural aspirates An eosinophilic pleural effusion (>10% eosinophils) is of little use in differentiating aetiology. It is often associated with air or blood in the pleural space, and does not exclude malignancy as a possible cause. A lymphocytic pleural effusion is most often the result of tuberculosis or malignancy. Up to 10% of tuberculosis effusions are polymorph predominant. lymphocyte-rich exudates may also be caused by sarcoidosis, rheumatoid pleuritis and chylothorax.

Specific tests of pleural fluid Pleural fluid amylase levels are raised (pleural fluid levels higher than the normal range for serum or pleural-to-serum ratio >1) in oesophageal rupture, acute pancreatitis and malignancy (especially adenocarcinoma). Pleural fluid triglyceride and cholesterol levels should be measured in cases of suspected chylothorax and pseudochylothorax. Adenosine deaminase levels can be helpful in the diagnosis of tuberculous pleurisy

Transudate pleural effusion Ultrafiltrates of plasma in the pleura caused by a small, defined group of etiologies. Pleural fluid protein level is <30 g/l The following cause transudates ; Congestive heart failure Cirrhosis (hepatic hydrothorax) Atelectasis (which may be due to malignancy or pulmonary embolism) Hypoalbuminemia, Nephrotic syndrome, Peritoneal dialysis, Myxedema and Constrictive pericarditis

The pleural biopsies Should be taken after the pleural fluid sample is drawn. Diagnostic yield from pleural biopsy material are greater than that of pleural effusion examination alone. The pleural biopsy needle usually inserted in the intercostal space with the maximum dullness on percussion and at the maximum radiological opacity.

Other investigation a-Total & differential peripheral blood leucocyte count and ESR. b-Tuberclin test and sputum for AFB. c- Biopsy or aspiration of any mass lesion or regional lymph node enlargement. d-Bronchoscopy

Management of Pleural effusion Aspiration should not be performed for bilateral Pleural effusions in a clinical setting strongly suggestive of a pleural transudates, unless there are atypical features or they fail to respond to therapy. An accurate drug history should be taken during clinical assessment

Management ..Contin.. 1-Pleural Fluid aspiration often necessary especially to relieve breathlessness. 2-You should not remove more than one (I litre) litre in the first attempt ,because re-expansion pulmonary oedema may occurs. 3-Chest radiograph should be taken after aspiration to assess the size of the effusion and to check for secondary pneumothorax.

Management cont… 4-Para-pneumonic effusion requires complete aspiration of the effusion to avoid the development of Empyema. 5-Tuberculous pleural effusion should be aspirated as much as we can. To promote rapid absorption of the effusion prednisolone 20mg/daily by mouth for 4-6 weeks plus the usual course of anti- tubercolous treatment.

Management cont… 6-Malignant pleural effusion should be aspirated completely. a- To prevent the re-accumulation the fluid usually aspirated via chest tube b-Then the pleural space is obliterated by the injection of substances which cause sever inflammatory reaction and promote fibrosis (pleurodesis) e.g. Tetracycline.