*Controversies in Pneumothorax Treatment DOI: http://dx.doi.org/10.5772/intechopen.87141*

*Pneumothorax*

their statement that "although thoracic surgeons are the best trained physicians to manage chest tubes and pleural problems, they often do not speak the same language or recommend similar treatment algorithms even to each other" [5].

The pressure in the pleural space is determined by the difference between the lung elastic recoil and volume changes of the semi-rigid chest wall. The rib cage moves in three dimensions; the girdle handle movement of the ribs increases the anteroposterior and the lateral dimensions of the chest, whereas the piston-pump movement of the diaphragm leads to an increase in the vertical dimension of the chest cavity. The chest and diaphragm movements create a physiological negative pressure within the pleural space that forces the lung to change shape and volume with the respiratory cycle, resulting in inflation and deflation. Neutralising this negative pressure in the pleural space leads to lung collapse, as the elastic structure of the lung favours its collapse (recoil). Pneumothorax or air in the pleural space invariably leads to lung collapse. A thin film of fluid exists between the parietal and visceral pleurae to lubricate the sliding of these two structures, roughly 15 mls in a 70 kg adult person. The fluid is a microvascular filtrate produced by the parietal pleura and is cleared also by the parietal pleural lymphatics, a process similar to that in any other body organ.

The term "pneumothorax" was first coined by Itard (1803), but it was Laennec (1819) who described its clinical picture [6]. The term refers to "air in the pleural space". Pneumothorax is a significant global health problem ranking high on the list of common medical conditions, especially in the emergency department. In the United Kingdom (UK), the overall person consulting rate for pneumothorax (primary and secondary combined) was 24 per 100,000 each year for men and 9.8 per 100,000 each year for women. Hospital admissions for pneumothorax as a primary diagnosis occurred at an overall incidence of 16.7 per 100,000 per year for men and 5.8 per 100,000 per year for women. Mortality rates were 1.26 per million per year

How does air gain access to the pleural space? Well, there are several mechanisms for this to happen. Communication between atmospheric air and the pleural space can result from trauma, penetrating injuries, impalements, stabs, bullets and ammunition. Fractured ribs puncturing the lung is a common cause for traumatic pneumothorax, recorded in our accident and emergency department (58 patients between January 2007 and 2018). Pneumothorax could also occur spontaneously and unprovoked due to a puncture in the visceral pleura, allowing air to pass from the open alveoli or small bronchi directly into the pleural space. Air can gain access to the pleural space from holes or tears in the aero-digestive system, such as neck stabs to the trachea, or a bronchopleural fistula due to tuberculosis or oesophageal rupture. Iatrogenic pneumothorax is caused by interventional procedures such as central line access, bronchoscopy, oesophagoscopy, insertion of stents, etc. Air in the peritoneal cavity can gain access to the chest through holes (fenestrations) in the diaphragm. This is one of the explanations of catamenial pneumothorax [8, 9]. Pneumothorax following substance abuse and recreational drugs, especially cocaine, cannabis and marijuana, has been associated with bullous disease and pneumothorax. However, many is the time bullae are absent and the pneumothorax is associated with pneumomediastinum or pneumopericardium. In these instances, air leak

**2. The physiology of respiration and pneumothorax**

**3. Epidemiology and pathology of pneumothorax**

for men and 0.62 per million per year for women [7].

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does not track to the lung surface, but instead it tracks into the connective tissue separating the lung segments and heads towards the hilum. To be comprehensive one should not forget about gas producing organisms which might generate air in the pleural space without any of the above breaches.

One-way valve motion of air from the lung to pleural space is a dreaded complication. It could lead to life-threatening tension pneumothorax. In this complication, not only the ipsilateral lung collapses, but the mounting pressure on the mediastinum pushes the central structures and restricts movement of the contralateral lung. Dislocation of the heart to the contralateral side might reach a critical degree that kinks the vena cavae and severely restricts venous return to the heart. This could result in hyperacute heart failure and death [10]. Cyanosis, sweating, severe tachypnoea, tachycardia and hypotension may indicate the presence of this medical emergency. Diagnosis of tension pneumothorax is clinical, and a needle or chest drain must be inserted, before obtaining a chest X-ray.
