Pleural+Disease

=Pathophysiology=
 * visceral pleura tightly adherent to lung
 * parietal pleura may be stripped
 * only parietal pleura has nerve endings
 * pleural space generally only potential space
 * negligeable amount of lubricating fluid

=Pleural Effusions=
 * Percussion is dull
 * trachea may be shifted to opposite side
 * breath sounds decreased or absent,
 * bronchial sounds may be audible
 * Possible pleural rub
 * Fremitus typically decreased, but may be increased near top of large effusion
 * A change in starling forces can cause accumulation of fluid in pleural space
 * 5 to 10 L move through pleural space per day
 * abnormalty of pressure causes **transudate**
 * abnormality of pleural integrity causes **exudate**
 * difference can be tested by protein content


 * **Empyema** is pus in peural cavity
 * most common is complication of pneumonia
 * commmon pathogens include S. aureus, S. pneumonia, GBS, anaeerobes
 * can be sequela of surgery, or trauma


 * **Hemothorax** is bloeeding into pleural space
 * diagnosis by pleural tap
 * due to trauma
 * can lose 30-40% of blood volume into thorax


 * **Chylothorax** is accumulation of lymph in pleural space
 * Trauma
 * surgery
 * malignancy
 * idiopathic

>* believed to be related to congenital malformation of lung >* usually from mechanical ventillation
 * **Pneumothorax** is....air in the lung!
 * Hypperresonant to percussion
 * Trachea may be shifted
 * Breath sounds decreased to absent
 * possible pleural rub
 * Fremiut decreased to absent
 * can be spontaneous, especially in tall males between 20 and 40
 * often secondary to trauma or surgery
 * can cause pneumomediastinum or cutaneous emphysema
 * **Tension Pneumothorax** is pneumothorax with air at higher than atmospheric pressure
 * results in severe compromoise to plmonary function
 * results in severe compromise to cardiac function


 * **Pleural thickening** and opacification
 * due to prior inflammation
 * may decrease lung volume

>* asbestos exposure, even secondary exposure, is risk factor >* smoking acts syngergistically to increase risk
 * **tumors**
 * mesothelioma is common

=Chest X-Ray Abnormalities= >* defined as lung markings medial but not distal to airspace
 * fluid causes shadow
 * 250-500ml fluid needed to see on PA CXR
 * fluid often has meniscus,track up lateral chest wall
 * lateral decubitous position can see less than 100ml
 * cannot distinguish between pleural effusion, hemothorax, chylothorax, empyema
 * pneumothorax should appear...
 * may be missed if patient supine
 * sometimes useful to take film w/ patient exhale
 * mesotheliomas and pleural thickening makes things 'weird'.

=symptoms= inflammation of peura
 * **pleuritis**
 * commonly viral in origin
 * can also come from plumonary emblism of connective tissue disease
 * fever
 * chest pain
 * often abrupt in onset
 * exacerbated by breathing movements
 * pain often excruciating, unilateral, localized
 * tidal volume slow, respiratory rate fast
 * often see 'splinting'--decreased expansion on one side
 * pleural rub audible with stethoscope


 * **pleural effusions**
 * generally assumptomatic,
 * large enough effusionwill cause dyspnea, imparied ventilation
 * decreased breath sounds
 * dullness
 * decreased fremitus
 * empyemic patients often febrile, tachcardic, tachypneic, toxic


 * **Pneumohorax**
 * actute onset without antecedent
 * dysnea
 * chest wall appear grossly larger
 * hyperresonant
 * vocal fremitus, breath sounds decreased
 * **Tension Pneumothorax**
 * also causes hypotension
 * hypoxemia
 * dysnea
 * possible tracheal shift

=Diagnosis= >* CHF, cirrhosis, nephrotic syndrome, acute glomerulonephritis, hypoproteinemia >* infectious diseases >>* Tuberculosis, pneumonia >>* neoplasm >>* autoimmune disease like lupus, RA >>* pulmonary emblism >>* pancreatitis, esophageal rupture, subphrenic abscess >>* trauma >* depressed glucose implies tuberculosis or rheumatoid effusion >* amylase implies pancreatitis or esophageal ruputre >* falling pH may indicate empyema and indicate a chest tube >* bateriological examination >* lipid analsys confirms chylous effusion
 * **PLeural Effusion **
 * CXR and physical exam
 * pleural tap is mandatory
 * transudative pleural effusions come from imbalance in starling forces
 * exudateive pleural effusions
 * Other tests: WBC cound, RBC count of fluid


 * **Cope Needle Biopsy**
 * if pleural tap unrevealing,
 * biopsy of pleural material
 * helpful to diagnose TB, malignancy

>* any release of pressure useful
 * **Pneumothorax**
 * depends on mechanism, degree of respratory alteration
 * small can jst be watched, unless on PEEP, then chest tube is neeed
 * large require chest tpe
 * two or more recurrences of spontaneous pneumothorax are treated wtih horacotomy with obliteration of pleuralspace
 * tension pneumothorax is emergency


 * **Mesothelioma**
 * poor prognosis: 8-12 months
 * surgery, radiation, chemo unsuccessful
 * prevention by proper asbestos handling
 * prevention by reduction of cigarrette smoking