**3. Epidemiology and pathology of pneumothorax**

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

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

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**Figure 1.**

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

**4. Classification and treatment**

the UK the male-to-female ratio is 3:1 [7].

*Single apical bulla, a common cause of primary spontaneous pneumothorax.*

pleural space without any of the above breaches.

drain must be inserted, before obtaining a chest X-ray.

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

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

Eighty percent of pneumothoraces are secondary to trauma, and 20% spontaneous without provocation. Two big categories of spontaneous pneumothorax (SP) exist, with bimodal age distribution: primary SP 15–35 years of age and secondary SP +55 years of age. Pneumothorax is distinctly rare among children less than 15 years. Wilcox et al. reported 17 cases in 12 years [11]. Primary SP occurs on a background of normal lungs, whereas secondary SP is associated with diseased lungs, such as emphysema, chronic obstructive pulmonary disease (COPD), lung fibrosis and cystic fibrosis. Secondary SP is strongly related to cigarette smoking and associated with a higher morbidity and mortality compared to primary SP. Primary pneumothorax has been associated with rupture of apical bullae or blebs (**Figure 1**) and has a 54.2% chance of recurring after the first episode [12]. In

The British Thoracic Society (BTS) has published an updated summary of the management of pneumothorax in 2010 [10]. Similar guidelines were published earlier by the American College of Physicians in 2001 [13] and later by the European Task Force in 2015 [14]. Breathlessness and the size of pneumothorax influence the management of SP. There is a general consensus that conservative management should be tried in the first episode, as conservative management of small pneumothoraces has been shown to be safe [10, 15]. Surgery proved that recurrence is less, and video-assisted
