Pleural Effusion Flashcards
Form when there is ↑ capillary hydrostatic pressure or ↓ osmotic pressure
occurs when SYSTEMIC FACTORS that influence the formation and absorption of pleural fluid are altered
TRANSUDATES
CAUSES
• CHF (left heart failure) – MC cause
• hypoalbuminemia
• cirrhosis
• nephrotic syndrome
Result of inflammation
occurs when LOCAL FACTORS that influence the formation and absorption of pleural fluid are altered
EXUDATES
CAUSES
parapneumonic effusion - MCC
malignancy – 2nd MC cause
empyema – exudate w/ pus
hemothorax – fluid that has a hematocrit that is >50% of the blood hematocrit
chylothorax – w/ ↑ triglycerides or cholesterol
Diseases that usually produce BILATERAL EFFUSIONS
Congestive heart failure
If there are markedly different amounts in each hemithorax, suspect a parapneumonic effusion or malignancy on the side with the greater volume of fluid
lupus erythematosus usually produces bilateral effusions, but when UNILATERAL - LEFT-SIDED
Diseases that can produce effusions on EITHER SIDE (but usually unilateral)
• tuberculosis and other exudative effusions associated with infectious agents, including viruses
• pulmonary thromboembolic disease
• trauma
Diseases that usually produce LEFT-SIDED EFFUSIONS
• pancreatitis
• distal thoracic duct obstruction
• Dressler syndrome
Diseases that usually produce RIGHT-SIDED EFFUSIONS
• abdominal disease related to the liver or ovaries (some ovarian tumors can be associated with a right pleural effusion and ascites [MEIGS SYNDROME]
• rheumatoid arthritis - can produce an effusion that remains unchanged for years
• proximal thoracic duct obstruction
Light’s Criteria
- pleural fluid protein/serum protein >0.5
- pleural fluid LDH/serum LDH >0.6
- pleural fluid LDH > 2/3 the normal upper limit for serum
Light’s Criteria
EXUDATIVE pleural effusions MEET AT LEAST ONE of the following criteria, whereas transudative pleural effusions meet none:
- pleural fluid protein/serum protein >0.5
- pleural fluid LDH/serum LDH >0.6
- pleural fluid LDH > 2/3 the normal upper limit for serum
if one or more of the exudative criteria are met and the patient is clinically thought to have a condition producing a transudative effusion, the difference between the protein levels in the serum and the pleural fluid should be measured
if this gradient is >31 g/L (3.1 g/dL), the exudative categorization by these criteria can be ignored because almost all such patients have a TRANSUDATIVE pleural effusion
IF A PATIENT HAS AN EXUDATIVE PLEURAL EFFUSION, THE FOLLOWING TESTS ON THE PLEURAL FLUID SHOULD BE OBTAINED:
description of the appearance of the fluid
glucose level
differential cell count
microbiologic studies
cytology
The MC cause of pleural effusion
left ventricular failure
Diagnostic that the effusion is secondary to congestive heart failure
pleural fluid N-terminal pro-brain natriuretic peptide
(NT-proBNP) >1500 pg/mL
pleural effusions occur in ~5% of patients with cirrhosis and ascites
Hepatic Hydrothorax
direct movement of peritoneal fluid through small openings in the diaphragm into the pleural space – predominant mechanism
effusion is usually right-sided
frequently is large enough to produce severe dyspnea
Associated with BACTERIAL pneumonia, LUNG ABSCESS, or BRONCHIECTASIS
the MC cause of exudative pleural effusion (US)
Parapneumonic Effusion
FACTORS INDICATING THE LIKELY NEED FOR A PROCEDURE MORE INVASIVE THAN A THORACENTESIS (in increasing order of importance)
• loculated pleural fluid
• pleural fluid pH <7.20
• pleural fluid glucose <3.3 mmol/l (<60 mg/dl)
• positive Gram stain or culture of the pleural fluid
• presence of gross pus in the pleural space
the 2nd MC type of exudative pleural effusion
Effusion Secondary to Malignancy
