Pulmonary infiltrates and Effusions Flashcards
Definition of infiltrate?
Filling of air spaces within an area of lung with fluid, inflammatory exudates, or cells
What can cause a localized infiltrate?
Infection - bacterial
Hemorrhage
PE
Malignancy
Atelectasis
Foreign body
What can cause diffuse infiltrates?
Infection - viral
Tuberculosis
Fibrosis
Silicosis
Asbestosis
Coal Worker’s Pneumoconiosis
Hypersensitivity pneumonitis
Define physiologic pleural fluid
5-15mL of fluid is considered normal; functions to lubricate the space between the pleura and precent friction during respiration
Define pleural effusion
Abnormal accumulation of fluid within the pleural space
What are the symptoms of a pleural effusion?
Pleuritic chest pain
Dyspnea
Cough
Referred pain
-Shoulder
-Upper abdomen
What are the signs of pleural effusion?
Decreased breath sounds
Pleural friction rub
Dullness of percussion
+Egophony
Decrease/absent tactile fremitus
Deviation of trachea (away)
Tachypnea
What are the radiologic signs of pleural effusion on CXR?
Dependent locations of pleural space best seen on upright CXR
-loss of normal costophrenic angle blunting
-effusion will present as radiopaque or increased density
How much fluid must accumulate to appear on lateral view?
75-100mL in posterior costophrenic sulcus/recess
What much fluid must accumulate to appear on frontal view?
175-200 mL in lateral costophrenic angle/sulcus
What are the 5 types of pleural effusions?
Transudate
Exudate
Empyema
Hemothorax
Chylothorax
Define transudate
Increase production of fluid due to increased hydrostatic pressure or decreased oncotic pressure; intact capillaries
Define exudate
Increased production of fluid due to abnormal capillary permeability; decreased lymphatic clearance; “leaky capillaries”
What are causes of transudative effusions?
CHF
Nephrotic syndrome
Myxedema
Cirrhosis
What are causes of exudative effusions?
Pneumonia
Malignancy (breast and lung esp)
Pulmonary embolism
Rheumatoid arthritis
Other infection (fungal, viral, TB)
Describe an empyema
Infection in the pleural space with purulent material
Can occur as complication of pneumonia, thoracotomy, abscess, or trauma
What can happen as empyema infection persists?
fluid thickens and creates fibrous tissue
-decortication: removal of fibrous tissue overlying lung to allow lung to expand
Describe a hemothorax
bleeding into pleural space usually due to trauma
May result from coagulopathy, blood vessel rupture, malignancy
Hematocrit of pleural fluid will be >50% of peripheral crit
Describe a chylothorax
Accumulation of chyle in pleural cavity due to disruption of the thoracic duct
-lymph formed in digestive system called chyle accumulates due to either disruption or obstruction of the thoracic duct
What findings indicate a chylothorax?
large pleural effusion
Thoracentesis: milky fluid with triglyceride level >1.2mmol/L
How is pleural effusion diagnosed?
CXR (PA, lat, and LD)
CT of chest
US
Thoracentesis (diagnostic and therapeutic)
What should be analyzed in pleural fluid?
Gross appearance
Specific gravity
Cell differential count
Protein, LDH, Glucose
Bacterial or other specialized cultures
What will be found with transudative fluid analysis?
Clear
low protein, LDH, albumin
few cells present
What will be found with exudative fluid analysis?
Cloudy fluid
high protein, LDH, albumin
increased cell count
How are pleural effusions treated?
Thoracentesis
underlying pathology
Pleurodesis if chronic friction
-treat chronic malignant pleural effusions
