به نام خدا

دكتر محمد امامي فوق تخصص ريه ومراقبتهاي ويژه هيات علمي دانشكده پزشكي

Clinical Manifestations And Diagnostic Approache Of Pleural Effusion

Clinical Manifestations Asymptomatic Pleurtic chest pain Cough Dyspnea dullness to percussion decreased breath sounds egophony at the upper level of the effusion decreased tactile fremitus

APPROACH TO PATIENTS WITH PLEURAL EFFUSION

A diagnostic thoracentesis should be performed on nearly every patient with free pleural fluid that measures more than 10 mm on the decubitus radiograph

Thoracentesis is a safe procedure when performed by an experienced operator

it can be safely performed in : patients with coagulopathies thrombocytopenia in patients on positive mechanical ventilation

ultrasound guidance for thoracentesis on small or multiloculated effusions in patients with poor lung function Bulous lung disease

The first question that should be answered with the diagnostic thoracentesis is whether the patient has a transudative or an exudative pleural effusion

Exudative pleural effusions meet at least one of the following criteria, whereas transudative pleural effusions meet none (1) pleural fluid protein–to–serum protein greater than 0.50 (2) pleural fluid LDH–to–serum LDH greater than 0.60 (3) pleural fluid LDH greater than two thirds of the upper normal limit for serum.

transudative pleural effusion If none of these criteria is met,

The previously discussed criteria may misidentify a transudative effusion as an exudative effusion in as many as 25% of cases. If a patient appears to have a transudative effusion clinically, additional tests can be assessed to verify its transudative etiology. If the difference between the protein concentration of serum and the pleura exceeds 3.1 gm/dL, the patient in all probability has a transudative effusion.

TRANSUDATIVE PLEURAL EFFUSIONS Congestive heart failure Pericardial disease Hepatic hydrothorax Nephrotic syndrome Peritoneal dialysis Urinothorax Myxedema Fontan procedure Central venous occlusion Subarachnoid-pleural fistula Veno-occlusive disease Bone marrow transplantation Iatrogenic

CHF and cirrhosis are responsible for almost all transudative pleural effusions.

EXUDATIVE PLEURAL EFFUSIONS Neoplastic diseases : Metastatic disease Mesothelioma Primary effusion lymphoma Pyothorax-associated lymphoma

Infectious diseases : Pyogenic bacterial infections Tuberculosis Actinomycosis and nocardiosis Fungal infections Viral infections Parasitic infections

Pulmonary embolism Gastrointestinal disease : Esophageal perforation Pancreatic disease Intra-abdominal abscesses Diaphragmatic hernia Postabdominal surgery

Collagen vascular diseases Rheumatoid pleuritis Systemic lupus erythematosu Drug-induced lupus Immunoblastic lymphadenopathy Sjýgren's syndrome Churg-Strauss syndrome Wegener's granulomatosis

Postcardiac injury syndrome Post–coronary artery bypass surgery Asbestos exposure Sarcoidosis Uremia Meigs’ syndrome Ovarian hyperstimulation syndrome Yellow nail syndrome

Drug-induced pleural disease Nitrofurantoin Dantrolene Methysergide Bromocriptine Procarbazine Amiodarone Dasatinib

Radiation therapy Electric burns Iatrogenic injury Hemothorax Chylothorax

Pneumonia, malignant pleural disease, pulmonary embolism, and gastrointestinal disease account for at least 90% of all exudative pleural effusions

Appearance of Pleural Fluid The gross appearance of the pleural fluid should always be described and its odor noted

If the pleural fluid smells putrid, the patient has a bacterial infection (probably anaerobic) of the pleural space. If the fluid smells like urine, the patient probably has a urinothorax.

If the pleural fluid is bloody, a pleural fluid hematocrit should be obtained. If the pleural fluid hematocrit is greater than 50% that of the peripheral blood, the patient has a hemothorax and the physician should strongly consider inserting chest tubes. If the pleural fluid hematocrit is less than 1%, the blood in the pleural fluid has no clinical significance. If the pleural fluid hematocrit is between 1% and 50%, the patient most likely has malignant pleural disease, a pulmonary embolus, or a traumatically induced pleural effusion.

The supernatant of the pleural fluid should be examined if the pleural fluid is turbid, milky, or bloody. If the pleural fluid is turbid when originally obtained, but the turbidity clears with centrifugation, the turbidity is due to cells or debris in the pleural fluid. If the turbidity persists after centrifugation, the patient probably has a chylothorax or a pseudochylothorax.

Pleural Fluid Protein The pleural fluid protein level tends to be elevated to a comparable degree with all exudative pleural effusions and is, therefore, not generally useful in the differential diagnosis of an exudative pleural effusion.

if the protein level is above 5.0 g/dL, the likelihood of the diagnosis of tuberculous pleurisy is increased. If the pleural fluid protein level is very low (<0.5 g/dL), the patient probably has: a urinothorax an effusion secondary to peritoneal dialysis, a leak of CSF into the pleural space, an effusion secondary to the misplacement of a central intravascular line.

When pleural fluid protein concentrations are in the 7.0 to 8.0 g/dL (70 to 80 g/L) range, Waldenström’s macroglobulinemia and multiple myeloma should be considered

Pleural Fluid Lactate Dehydrogenase LDH, as an intracellular enzyme degree of cell turnover and/or the degree of inflammation within the pleural space no utility in the differential diagnosis of exudative pleural effusion level of LDH in the pleural fluid reflects the degree of inflammation in the pleural space

Pleural fluid LDH levels above 1000 IU/L empyema rheumatoid pleurisy paragonimiasis malignancy.

Cholesterol Pleural cholesterol is thought to be derived from degenerating cells and vascular leakage from increased permeability

Pleural Fluid Glucose A low glucose concentration probably indicates the coexistence of two abnormalities: a thickened, infiltrated pleura leading to an impaired diffusion of glucose into the pleural space plus increased metabolic activity leading to increased glucose utilization within the pleural space

reduced pleural fluid glucose level (<60 mg/dL, 3.33 mmol/L) Parapneumonic effusion malignant effusion tuberculous effusion rheumatoid effusion hemothorax paragonimiasis Churg-Strauss syndrome

The lowest glucose concentrations are found in rheumatoid pleurisy and empyema, with glucose being undetectable in some cases

Pleural Fluid White Cell Count and Differential In the normal pleural space, the cell count has been reported to be 1700 cells/mm 3. In effusions, the cell count has limited diagnostic value. A pleural fluid white blood cell count of 1000/mm 3 roughly separates transudative from exudative pleural effusion

a pleural fluid white blood cell count above 10,000/mm 3 empyemas parapneumonic effusions pancreatitis pulmonary embolism collagen vascular diseases malignancy tuberculosis

The differential cell count on the pleural fluid is much more useful than the white cell count itself

Pleural effusions due to an acute disease process such as pneumonia, pulmonary embolization, pancreatitis, intra-abdominal abscess, or early tuberculosis contain predominantly polymorphonuclear leukocytes. Pleural effusions due to a chronic disease process contain predominantly mononuclear cells.

Lymphocytosis(>%80) tuberculous pleurisy lymphoma Sarcoidosis chronic rheumatoid pleurisy yellow nail syndrome chylothorax

Pleural fluid eosinophilia (≥10% eosinophils by differential count) air or blood in the pleural space traumatic hemothorax pulmonary embolism Pneumothorax idiopathic malignancy parapneumonic tuberculosis Benign asbestos pleural effusions

drug reactions Paragonimiasis Churg-Strauss syndrome Pulmonary infarction Fungal infection (coccidioidomycosis, cryptococcosis, histoplasmosis)

Small lymphocytes, when accounting for more than 50% of the white blood cells in an exudative pleural effusion, indicate that the patient probably has a malignant or a tuberculous pleural effusion

Pleural Fluid Cytology A pleural fluid specimen from every patient with an undiagnosed exudative pleural effusion should be sent for cytopathologic studies The first pleural fluid cytologic study is positive for malignant cells in up to 60% of the effusions caused by pleural malignancy. If three separate specimens are submitted, up to 90% of effusions due to pleural malignancy have positive cytopathology.

The frequency of positive pleural fluid cytologic tests is dependent on the tumor type. For example, less than 25% of patients with Hodgkin's disease have positive cytology whereas most patients with adenocarcinomas have positive cytology. The percentage of positive diagnoses is obviously dependent on the skill of the cytologist

Tumor markers Tumor markers No single pleural fluid tumor marker is accurate enough for routine use in the diagnostic evaluation of pleural effusion

Culture and Bacteriologic Stains Pleural fluid from patients with undiagnosed exudative pleural effusions should be cultured for bacteria (both aerobically and anerobically), mycobacteria, and fungi

Pleural Fluid pH and PCO 2 The pleural fluid pH can be reduced to less than 7.20 with 10 different conditions: (1) complicated parapneumonic effusion (2) esophageal rupture (3) rheumatoid pleuritis (4) tuberculous pleuritis (5) malignant pleural disease (6) hemothorax (7) systemic acidosis (8) paragonimiasis (9) lupus pleuritis (10) urinothorax

The decreased pleural fluid pH appears to result from lactic acid and carbon dioxide accumulation in the pleural fluid. The routine measurement of pleural fluid pH is recommended only in patients with parapneumonic effusions

In general, pleural fluids with a low pH also have a low glucose pleural fluid glucose can be used as an alternative to the pH measurement. When the pleural fluid pH is used as a diagnostic test, it must be measured with the same care as arterial pH. The fluid should be collected anaerobically in a heparinized syringe and placed on ice. If the sample is left open to air, a spuriously high pH value can be obtained because of the rapid loss of carbon dioxide.

Transudates generally have a pleural fluid pH in the 7.40 to 7.55 range, while the majority of exudates range from 7.30 to 7.45

Pleural Fluid Amylase esophageal perforation pancreatic disease malignant disease routine measurement of pleural fluid amylase is not indicated

Other rare causes of an amylase-rich pleural effusion include : pneumonia ruptured ectopic pregnancy hydronephrosis cirrhosis

Tests for Collagen Vascular Diseases About 5% of patients with rheumatoid arthritis and 50% of patients with SLE have a pleural effusion sometime during the course of their disease. At times, the effusions may be the first manifestation of the disease; therefore, these diagnostic possibilities should be considered in patients with undiagnosed exudative pleural effusion

Measurement of the ANA titer is the best screening test for lupus pleuritis, although it is now evident that a positive pleural fluid ANA is not specific for the diagnosis. Although all patients with lupus pleuritis have a positive pleural liquid ANA (>1 : 40), the finding of a positive ANA has been found in between 11% and 27% of other effusions. Neither the titer of ANA, the ratio of pleura- to-plasma ANA, or the pattern of staining has been found to increase the specificity for SLE. In fact, a positive pleural fluid ANA in patients without SLE may be associated with malignancy. In patients with SLE, the lack of ANA in pleural liquid may have a high negative predictive value

When a rheumatoid pleural effusion is suspected, the clinical picture usually establishes the diagnosis. If any question exists, the level of rheumatoid factor in the pleural fluid should be measured. Only patients with rheumatoid pleuritis have a pleural fluid rheumatoid factor titer equal to or greater than 1 : 320 and equal to or greater than the serum titer

Adenosine Deaminase a product of activated lymphocytes catalyzes the conversion of adenosine to inosine is important for normal immune function The pleural fluid ADA levels are elevated in almost all patients with tuberculous pleuritis

An occasional patient with empyema, lymphoma, or leukemia may have elevated pleural fluid ADA levels Because it is a highly sensitive test, the ADA can be a useful test to exclude the diagnosis of tuberculosis when the ADA level is low (<40 U/L).