Pleural Diseases

Pleural Diseases-

-Pleural Effusion-

-A pleural effusion is an accumulation of fluid between the lung and chest wall in the pleural space

-Pleural effusion can be transudative or exudative

-Transudate pleural effusion result from imbalances in the hydrostatic and oncotic pressures in the chest.  Common conditions responsible for this include CHF and nephrosis

-Exudate pleural effusions can result from disease in virtually any organ.  Common mechanisms are infection, malignancy, immunologic reactions, lymphatic problems, non infectious inflammation, iatrogenic causes, and movement of fluid from below the diaphragm

-Exudative pleural effusion most commonly result from lung inflammation or impaired lymphatic drainage from the pleural space

-Light's Rule for determining if pleural effusion is transudative or exudative (if one of the three is true, the fluid is exudative)
1.  Pleural fluid protein/serum protein ratio greater than 0.5
2.  Pleural fluid LDH/serum LDH ratio greater than 0.6
3.  Pleural fluid LDH greater than two thirds the upper limits of the labs normal serum LDH

-Indications for Thoracocentesis:
1.  Pleurisy
2.  Fever
3.  Bilateral pleural effusions that are markedly disparate sizes
4.  Absence of cardiomegaly on chest x ray
5.  ECHO not consistent with heart failure
6.  BNP levels not consistent with heart failure
7.  An A-a gradient larger than expected with heart failure
8.  The effusion does not resolve with diuresis

-Conditions that can be diagnosed by pleural fluid:
1.  Empyema
2.  Malignancy
3.  TB
4.  Fungal infection
5.  Chylothorax
6.  Cholesterol effusion
7.  Urinothorax
8.  Esophageal rupture
9.  Hemothorax
10. Extravascular migration of CVP catheter
11. Lupus
12. Rheumatoid disorders

-Exudative pleural effusions can be difficult to perform a thoracocentesis.  Sometimes require a VATS  (Video Assisted Thoracoscopy) for therapeutic removal of fluid.  May get some useful diagnostic information front the thoracocentesis.  The yield for producing malignant cells is low if cancer is suspected.


-Pneumothorax-

-A pneumothorax is an accumulation of air that causes a positive pressure in the pleural space.

-Pneumothoraces can be spontaneous or primary or from secondary causes

-Spontaneous pneumothorax usually occurs when the patient is at rest.  Presenting history and physical exam findings include decreased chest excursion on the affected side, diminished breath sounds on the effected side, and hyperresonant percussion on the effected side due to the increase in accumulation of air.  Patients may also complain of pain on that side. Subcutaneous emphysema may also be present.

-Evidence of hemodynamic compromise such as tachycardia, hypotension, labored breathing suggest the pneumothorax is under tension and warrants emergency decompression

-Findings on chest x ray for a pneumothorax include:  a white visceral line on the chest x ray where there is no pulmonary vessels beyond the pleural edge

-Findings suggesting tension pneumothorax on chest x-ray include tracheal deviation to the contralateral side.

-Risk factors for spontaneous pneumothorax include:  smoking, family history, Marfan's Syndrome, homocystinuria, and thoracic endometriosis

-Secondary Pneumothorax comes from a complication of an underlying lung disease

-Common causes of secondary pneumothorax include:  COPD, cystic fibrosis, primary or metastatic lung disease,  or necrotizing pneumonia

-Pneumothoraces can also come from blunt force trauma or barotrauma

-Treatment options include:  observation, supplemental oxygen, needle aspiration of air, chest tube insertion, and thoracoscopy

-Observation is appropriate for those patients who have stable vital signs, having their first spontaneous pneumothorax, and is small (less than 15%)

-Patients who are stable having their first spontaneous pneumothorax should undergo needle aspiration if it is greater than 15 percent.  If they fail, a chest tube should be inserted.

-Proper landmarks for needle aspiration is the second or third intercostal space in the mid-clavicular line

-Proper placement of the chest tube is the forth or fifth intercostal space in the anterior auxiliary line.

-Careful attention should be made to the neurovascular bundle beneath each rib.   The needle/tube should be inserted just above the rib below.

-A chest x ray should be taken after placement to ensure re-expansion