Intended for healthcare professionals

Clinical Review

Spontaneous pneumothorax

BMJ 2014; 348 doi: (Published 08 May 2014) Cite this as: BMJ 2014;348:g2928

Re: Spontaneous pneumothorax

The Comprehensive review on Spontaneous Pneumothorax stated that the risk of primary spontaneous pneumothorax (PSP) is higher in tall men due to alveolar stretch. It appears that PSP appears to be due to a low thoracic index moulding the lung into a shape that causes an environment of high apical stress that leads to pleural buckling and fatigue, with resulting pleural tissue porosity and bulla formation [1]. There is a twenty-fold increase in pleural stress occurring in the apex of chests (x5 – x10 higher stress on finite element analysis testing), with the low thoracic index typically found in PSP patients further accentuating this (x4 stress) [1]. The increase in stress occurred especially in the area where the first rib caused lung indentations [2]. The mild differences in thoracic index found in females and occurring with age act to reduce pleural stress, explaining the predominant presentation in young male adults.

1. Casha AR, Manché A, Gauci M, Wolak W, Dudek K, Schembri-Wismayer P et al. Is there a biomechanical cause for spontaneous pneumothorax? Eur J Cardiothor Surg 2014;45:1011-1016.
2. Stephenson SF. Spontaneous pneumothorax: the sharp rib syndrome. Thorax 1976;31:369-72.

Competing interests: No competing interests

21 May 2014
Aaron R Casha
Cardiothoracic surgeon
Marilyn Gauci, Ruben Gatt, Joseph N Grima
Mater Dei Hospital, Malta
Attard Malta