Pneumothorax

ie air in the pleural cavity with consequences and management dependent on the degree of lung collapse

  • spontaneous
    • associated with smoking (in some studies >100x more likely), chronic lung disease eg COPD
    • often taller patients
    • NOT associated with exercise
    • hereditary
    • others - abnormal connective tissue, related to distal airway inflammation, apical ischaemia, low BMI etc
  • iatrogenic
  • traumatic
  • catamenial
    • R sided pneumothorax, generally in women 30-40y with symptoms within 48/24 of menstruation
    • cause unknown but many have associated endometriosis
    • one theory suggest PGF2, which is elevated in ovulation, causes bronchoconstriction which may be associated with small ruptures

Presentation

  • may or may not present with pain, SOB
  • examination findings of reduced air sounds, hyper-resonance on percussion rarely
  • deviated trachea (with tension), subcutaneous emphysema and pneumo-mediastinum on CXR
  • associated physiological signs - tachycardia, hypotension, pulsus paradoxus, ↑JVP
  • clinical symptoms associated with secondary pneumothorax are generally more severe than a similar sized primary pneumothorax
  • CXR should not demonstrate tension pneumothorax!! - this is a clinical finding and should have been treated before CXR!

Management

BTS pleural disease guideline 2010
  • expiratory CXR no greater accuracy than inspiratory
  • size of pneumothorax generally not as important as clinical consequences, although 'large' is generally viewed as being >2cm at apex on PA CXR in UK and >3cm in USA
    • methods of estimation of size are debatable. CT is better but exact estimation not necessarily important
    • spontaneous resolution of primary spontaneous pneumothorax (PSP) - rate of ~2% per 24/24. Resolution 4x faster with O2 therapy and therefore reserved for IP Mx
Collins method - % = 4.2 + 4.7 (A + B + C)
A is the maximum apical interpleural distance
B is the interpleural distance at midpoint of upper half of lung
C is the interpleural distance at midpoint of lower half of lung

Insertion of Intercostal Drain

  • landmarks - ant to mid-axillary line, 5th ICS
  • remembering that neurovascular bundle lies 'below the rib above' with vein then artery then nerve. (VAN from above down)
  • 2-3cm transverse incision in line with superior border of rib, to avoid the main N/vasc bundle. (there are smaller collateral branches here though)
  • blunt dissection to pleura and finger then to 'probe' canal
  • using forceps clamped on end of drain, insert into space
  • connect to drain bag
  • suturing and dressing to ensure confident fixing of drain to chest wall


Inpatient management options
  • video assisted thoracoscopic surgery with pleurectomy and abrasion
  • chemical pleurodesis eg tetracycline, minocycline, doxycycline
  • graded talc
  • open pleurectomy

Spontaneous pneumomediatinum

References include: