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THE SEROSA
- SESROSAL MEMBRANES INCLUDE:
- Pleura – visceral and parietal – very small amount of fluid present, minimal amount of protein
- Peritoneum
- Pericardium
- Tunica vaginalis
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Pleura – visceral and parietal – very small amount of fluid present, minimal amount of protein; drainage
Drained by lymphatics, so have about 4 ml of fluid in the space, lymphatics allow for drainage in that surface to prevent fluid accumulation
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Pneumothorax definition:
- Pneumothorax is a collection of air in the pleural cavity. Air may arise from outside the chest, from the lung or esophagus: . or collapse of lung..
- Most common cause is some iatrogenic injury
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Classification of Pneumothorax
- Traumatic or iatrogenic
- Spontaneous ( without apparent antecedent cause)
- Primary ( no apparent underlying lung pathology)
- Secondary (underlying lung pathology): emphysema, interstitial lung disease, etc.. rupture of the esophagus into pleural space, etc.
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Pneumomediastinum definition
- Pneumothorax in which the air leaks into the mediastinal space
- Because of the orientation of the facial planes, the air dissects into the neck, face and subcutaneous tissues of chest
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Diseases associated with secondary pneumothorax (not that important to know yet)
- TB
- Pneumonia
- Asthma, COPD, emphysema
- CF
- Interstitial lung disease
- Marfan syndrome
- Lymphangioleimatosis
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Pneumothorax treatment
- Watch and wait
- Needle aspiration of air
- Chest tube placement – to evacuate the air in the pleural space to allow for re-expansion of the lung
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Pleuritis definition
- Often used synonymously with pleuritic pain
- Is the inflammation of the pleura
- Often associated with the accumulation of extra fluid in the space between the two layers of pleura (pleural effusion)
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Pleuritis Symptoms
- Pain in the chest made worse with breathing
- Shortness of breath
- “stabbing” sensation, “catching” in the chest with breathing in
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Causes of pleurisy
- Infections
- Cancer
- And many other causes for a pleural effusion
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Evaluation of pleuritic chest pain
- Characteristics, onset, etc. :
- Other history: oral contraceptives, recent immobility, or long car or plane travel (PE risk); TB, or asbestor exposure
- Review of systems, find out what symptoms accompany the pain that might suggest a respiratory infection, PE, or malignancy
- Pleural fluid analysis can help determine the cause of the pleurisy
- Get travel history too
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Physical exam
- Focused
- Vital signs
- Dullness to percussion suggests pleural effusion
- Auscultation, a pleural friction rub is the only sigh of pleurisy
- LOOK AT THE PATIENT and excursion..
- Examination frequently normal
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Pleural effusions
- Estimated annual incidence of pleural effusion in the US is estimated to be 1.5 million
- Approx 200,000 are due to malignancy
- Etiology of effusion can be established in maj. Of cases with physical exam, and ..
- Lab evaluation examination of the fluid!!
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Common causes of pleural effusions*** know these
- CHF
- Bacterial pneumonia – with estension into the pleural space
- Cancer
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Pleural effusion pathogenesis
- Increased interstitial fluid (inflammation)
- Increased venous pressure (CHF)
- Decrease oncotic pressure (low proteins)
- Decreased pleural pressure (atelectasis of lung)
- Movement of the fluid from peritoneal cavity
- Obstruction of the lymphatic channels
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Imaging studies for pleural effusion
- Chest x-ray: PA and lateral views – blunting of costophrenic angles
- Lateral decubitys – identifies free flowing pleural fluid
- CT scan: currently most frequently used; can distinguish empyema from lung abscess; can detect pleural masses; can outline loculated fluid collections
- Ultrasound: useful in guiding placement for a needle in getting fluid out
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Findings in pleural effusion: signs and symptoms
- Many patients don’t have any symptoms
- Pleuritic chest pain – inflammation of the parietal pleura
- Other symptoms dry, nonproductive cough and dyspnea
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When withdraw fluid – what do you do?
- Examine it!!!
- If clear – good sign
- If hard, and hard to get out – major problem
- If gross blood, NOT GOOD! – probably need a chest tube or thoracic surgery
- Milky, opalescent fluid – chylothorax – blockage of lymphatics..
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Thoracentesis
Should be performed for new and unexplained pleural effusions when sufficient fluid is present
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Pleural fluid classification
- Exudate: inflammatory – high in proteins
- Or Transudate: 9/10 times not very inflammatory, not high in proteins
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Pleural fluid laboratory examination: Criteria for Exudate vs Transudate
- Ratio of pleural fluid protein to serum protein greater than 0.5
- OR ratio of pleural flid lactate dehydrogenase (LDH) to serum LDH greater than 0.6
- OR pleural fluid LDH greater than two thirds the upper limit or normal for serum LDH (a cutoff value of 200 IU/L was used previously)
- Pleural fluid is an exudate if it meets any of the three criteria
- It is a transudate if it does NOT meet any of these criteria
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Basic Lab Tests in pleural effusion
- Fluid protein
- Fluid LDH
- Fluid WBC with diff
- Gram stain
- pH, glucose
- possible Cytology – save some! Amylase – sometimes
- Serum LDH and Serum Protein
- Fluid description***!!!
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Exudative Effusion causes – very long list
- Bacteria, viral, Tb, fungus, parasite
- Malignancy
- Collagen vascular disease
- PE
- Other diseases, trauma, drugs
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Transudative pleural effusuions
- Narrows Dx to:
- CHF
- Hypoalbuminemia – cirrhosis
- Nephrotic syndrome
- Protein losing enteropathy
- All have protein ratio < 0.5, LDH ratio < 0.6
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Evaluation of parapneumonic effusion
- An accumulation of a pleural effusion in association with pneumonia.
- Protein ratio >0.5; LDH ration>0.6
- Means EXUDATIVE EFFUSION: .
- To drain the effusion or not depends on: bacteriology and chemistry (pH) of pleural fluid
- If high pH – probably can watch
- If low pH – might really need to drain (pH<7.20); positive chest x-ray or gram stain – low fluid pH probably is complicated and needs aggressive removal
- pH, cell count, gram stain, cultures
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Cell count
- Pleural fluid with lymphocytes greater than 85% of the total nucleated cells, suggests:
- TB,
- lymphoma,
- chronic rheumatoid (arthritis) pleuricy,
- (or chylothorax)
- So cell count can be very helpful
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Empyema
- Very infected pleural space
- Positive culture coming out of the pleural space
- A very low pleural glucose concentration (i.e. <30 mg/dL) indicates rheumatoid pleurisy or empyema: .
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Pleural Fluid cytology
- Mesothelial cells greater than 5% of total nucleated cells makes a Dx of TB unlikely (metastatic cancer?)
- Suspect palignancy in patients with known cancer or with lymphocytic, exudative effusions, especially when bloody
- Direct tumor involvement of the pleura is diagnosed most easily by performing pleural fluid cytology
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Other diagnostic modalities
- Pleural Biopsy: Abrams needle pleural biopsy of the parietal pleura is now used less with abailability of serum markers and thoracoscopy; not used any more
- Thoracoscopy – VATS, can look at pleural surface, and can direct biopsy to the abnormal surface
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Pleural effusions in specific diseases
- Rheumatoid effusions have low glucose level (<25 mg/dL)
- Measurement of RF in pleural fluid is not useful, because it can be elevated in other inflammatory states
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Chylothorax
- Leakage of chyle from a disruption of the thoracic duct leads to a chylothorax.
- Milky pleural effusion, disruption of the lymphatic channels, high triglycerides (>110 mgm/dL): .
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Hemothorax
Most important thing – need to evacuate it!
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Chronic effects of many inflammatory effusions
Can result in fibrosis of pleural surface
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Benign pleural reaction in asvestor Induced pleural disease
90-95% of all asbestos used in the US chrysotile.
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Four types of benign pleural reactions occur:
- Pleural effusions: .
- Plaques, local areas of fibrosis o fhte parietal pleura: .
- Diffuse pleural fibrosis, extensive visceral pleural fibrosis, with fusion of parietal and visceral pleural surfaces: .
- Rounded atelectasis that occurs when visceral pleural fibrosis extends into the parenchyma and renders a portion of the lung airless .
- Can also get a mesothelioma!
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Pleural mesothelioma
- Rare cancer of the membranes linng the thoracic and abdominal cavities and surrounding organs
- Virtually all cases of mesothelioma are linked to asbestos exposure and is life threatening.
- Symptoms of mesothelioma are shortness of bteath pain in the lower back or side of the chest, coughing, and weight loss
- Mesothelioma is NOT caused by cigarette smoking!
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Mesothelioma relation to pleura
Because malignant mesothelioma arises from the mesothelial cells of the serosal membrane, it can be found in any serosal membrane including the pleura, peritoneum, and pericardium: .
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Characteristic CT findings of Malignant mesothelioma
- Unilateral pleural effusion
- Thickening of the mediastinal pleura
- Circumferential and nodular pleural thickening of greater than 1cm
- Localized vs. diffuse (invariably malignant!!)…
- To diagnose need to look at histology!! Need biopsy
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Drug-induced pleural disease
- Drug-induced pleural disease may present as pleural effusion, fibrosis, toxic or allergic manifestation during the use of a particular class of drugs
- A detailed review of drug intake often reveals the cause for the pleural pathology
- Management: usually, discontinuatin of the drug resolves the pleural process
- In some cases, addition of corticosteroid therapy is helpful
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Pleural effusions
- Transudate vs. exudate
- Description of fluid
- Lab studies for fluid
- Direct biopsy
- Therapy
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