Pleural Disease

Pleural Disease

·        Common problems:

o  Effusion

o  Empyema

o  Pleural pain

o  Pleural disease

o  Pneumothorax.

·        Usually presents with pain related to breathing: cough, deep inspiration

·        Investigations:

o  CXR: PA, lateral and lateral decubitus (does pleural opacity move with gravity)

o  Pleurocentesis

o  Pleural biopsy

o  US for septa or cysts

o  CT.  MRI rarely superior to CT

·        Pleural space:

o  Usually 0.4 mls of fluid

o  If ­ then either ­ production or ¯ clearance (eg Tb or malignancy blocking lymphatics)

·        Pleural fluids:

o  Takes 300 – 500 ml before visible on CXR

o  Transudate:

§  Pleural membrane not diseased

§  Due to change in hydrostatic or osmotic pressure due to distant disease

§  Eg nephrotic syndrome, cirrhosis or CHF

o  Exudate:

§  Protein rich (> 30 – 40 g/L)

§  Due to pleural disease: Parapneumonic effusion, empyema, malignancy, Tb, SLE/RA, asbestosis, drug induced

o  Empyema:

§  = Collection of purulent material (with or without bugs) in any body site: usually refers to pleural space

§  Commonly associated with underlying pulmonary parenchymal infection

§  Low pH differentiates it from effusion, as does growth of organism on culture

§  Strep pneumoniae and Staph aureus are the main pathogens

§  Closely related to lung abscess (necrotising pneumonia)

§  Symptoms: fever, sweats, cough, dyspnoea, weight loss, pleurisy

§  Signs: stony dullness to percussion, ¯breath sounds, maybe quite localised, fluid in costophrenic angles on X-ray

§  Need to drain.  Reduced antibiotic penetration, especially if loculated

§  Usually heals with pleural fibrosis

o   If blood in a pleural tap then:

§  Hit an artery

§  Haemothorax (need to evacuate. NB can bleed 3 litres into one side of the chest ® profound shock)

§  Blood in an effusion (eg Tb/cancer). To differentiate from a haemothorax measure the haematocrit

·        Testing pleural fluid:

o   Total protein

o   Albumin:  If (effusion albumin)/(serum albumin) > 0.5 then transudate

o   LDH: ­ in exudates

o   pH < 7.2 Þ empyema

o   Amylase.  Normally none.  If present then oesophageal rupture or pancreatitis

o   Cytology for malignancy

o   Microscopy and culture: low sensitivity. Organisms causing empyema are hard to culture (eg anaerobes, Tb, fungi, etc)