pleural effusion

Question 1

causes of transudate and exudate effusions?

Answer 1

transudate: HF, liver cirrhosis, nephrotic syndrome

exudate:
1. infections
-pneumonia (parapneumonic effusion)
-pulmonary TB
-empyema

2. malignancies
   -lung cancer
   -mesothelioma
   -metastatic breast cancer
   -ovarian cancer
3. pulmonary embolism (can cause both but commonly exudate)
4. autoimmune dx
   -SLE
   -RA

Question 2

symptoms?

Answer 2

dry cough
SOB
pleuritic chest pain
asthma - chest tightness, worse at night, wheeze on auscultation

physical exam:
-reduced chest expansion on effected side
-absent or faint breath sounds on area
-stony dull percussion note on area
-bronchial breathing ABOVE the effusion
-reduced tactile fremitus

Question 3

diagnosis?

Answer 3

chest xray
-homogenous opacity obliterating the costophrenic angle with meniscus sign

pleural tapping
-send for protein, LDH, pH (<7.2 in empyema), cell count, gram stain and culture, acid-fast bacili stain, cytology

CT with contrast if previous tests dont provide diagnosis

gold standard is pleural biopsy

Question 4

light’s criteria?

Answer 4

uses total protein and LDH to differentiate exudate from transudate effusions.

it’s exudate if:
pleural effusion proteins > 0.5 of serum
pleural effusion LDH > 0.6 of serum
pleural LDH is more than 2/3 upper limits of normal serum LDH
VERY HIGH LDH (>1000) suggests empyema or malignancy