T2 L18: Pleural and chest wall disease

• What is the pleura?

  delicate serous membrane

  arranged as a sac

  enclosing the lungs at lines of the thoracic cavity

  • Visceral: covers surface of lungs and goes into fissures; attached directly to lungs
  • Parietal: lines inner chest wall

  
• What is the intrapleural space and what are its properties?

  space between visceral and parietal pleura

  contains 10 to 20 mL of fluid as lubricant

  continuously produced and absorbed by the lymphatic system

  
• What is pleural effusion?

  accumulation of fluid in intrapleural space exceeding physiological amounts (10-20mL)

  pathophysiology: changes in fluid & solute homeostasis. Mechanism determines if:

  • exudate (leaky vessels) or
  • transudate (intact vessel)

  may present as primary manifestation or secondary (complication)

  
• What is the epidemiology of pleural effusion?

  relates to underlying disease thus present at all ages
• What is the clinical presentation of pleural effusion?

  depends on fluid volume (small volume can be asymptomatic)

  symptoms: breathlessness, chest pain
• How is pleural effusion diagnosed?

  Examination: dullness to percussion (stony dull) & decreased breath sounds

  Thoracic imaging: Chest X-Ray, CT, thoracic ultrasound, thoracocentesis, thoracoscopy, biopsy
• What does this image show?

  chest X-ray

  left pleural effusion

  
• What does this image show?

  CT thorax

  1. Pleural mass
  2. Loculated left pleural effusion

  
• What does this image show?

  ultrasound

  pleural effusion

  
• What is transudative pleural effusion?

  caused by fluid leaking through intact blood vessels

  causes:

  increased hydrostatic pressure (eg cardiac failure)

  decreased plasma oncotic pressure (eg liver cirrhosis)
• What is exudative pleural effusion?

  Fluid accumulation in the pleural space due to inflammation or injury through leaky blood vessels / lymphatics

  Causes:

  • increased capillary permeability due to localised ruptures
  • decreased absorption eg lymphatic blockage
• What is Light's criteria?

  for exudative effusion. Has 1 or more of:

  1. Pleural fluid protein/serum protein >0.5
  2. Pleural fluid LDH/Serum LDH > 0.6
  3. Pleural fluid LDH >2/3 the upper limit of normal of serum LDH

  98% sensitive and 83% specific
• What are the possible causes of transudate pleural effusion?

  cardiac failure

  cirrhosis

  nephrotic syndrome
• What are the possible causes of exudate pleural effusion?

  malignancy

  pneumonia

  tuberculosis

  mesothelioma

  rheumatoid arthiritis
• What is pleural infection?

  bacteria enter pleural space:

  • direct eg pneumonia
  • indirect eg blood borne infection

  Confirmed on: microbiology, Light's criteria

  males more likely
• What is empyema?

  severe pleural infection

  symptoms: breathlessness, chest pain, persistent fever

  Pleural tap:

  • appearance frank pus
  • pleural fluid pH <7.2
  • only 20% will get an organism

  Management: chest drain and antibiotics for at least 6 week

  
• What is Haemothorax?

  blood in chest

  if occurs with pneumothorax: haemopneumothorax

  presents with breathlessness & chest pain

  history of trauma or malignancy

  treatment: chest drain & thoracoscopic surgery

  
• What is Pneumothorax?

  air in intrapleural space

  primary spontaneous:

  • no underlying lung disease
  • age <50 years
  • no smoking history

  secondary spontaneous:

  • underlying lung disease
  • Age >50 years
  • Smoker

  symptoms: shortness of breath, chest pain

  Clinical features: reduced/no air entry on affected site, hyperresonant to percussions, tracheal shift (tension Px)

  Management: conservative, aspiration, chest rain

  
• What is respiratory muscle weakness?

  Consequence of neuromuscular diseases (E.g. Amyotrophic lateral sclerosis, Guillian-Barre syndrome, Duchenne muscular dystrophy)

  Symptoms: nonspecific (fatigue, poor concentration, dyspnoea, orthopnoea)
• How is respiratory muscle weakness examined?

  Physical examination: increased resp rate, alternate ribcage/abdominal breathing, accessory muscle use, unable to clear mucus, impaired swallow

  Pulmonary function testing: preserved total lung capacity, elevated residual volume, reduced vital capacity
• How is respiratory muscle weakness managed?

  long-term non-invasive positive pressure ventilation
• What is kyphoscoliosis?

  abnormal curvature of spine

  cause - various

  respiratory implications: restrictive lung defect / respiratory failure