Traumatic Tension Pneumothorax: A Tale of Two Pathologies.

Pneumothorax resulting from injury is a common phenomenon in both civilian and military trauma. A pneumothorax or simple pneumothorax is defined as air in the pleural space. A tension pneumothorax can evolve from a simple pneumothorax if there is a continued air leak from the lung without mechanism for egress. This occurs due to an expanding air volume and pressure in the pleural space. The tension pneumothorax results in obstructive shock that may be a life-threatening emergency. All types of pneumothorax can occur in patients who are non-positive pressure ventilated as well as those receiving positive pressure ventilation. Positive pressure ventilation changes the dynamics of pneumothoraces in that it can exacerbate an air leak, resulting in a simple pneumothorax evolving into a tension pneumothorax. The pathophysiology and clinical presentation of these traumatic conditions represent two differing sub-pathologies, and, although they share the same underlying physiological process in the opinion of the authors, a different approach should be adopted when considering treatment. The objective of this manuscript is to discuss the etiology, incidence, and clinical significance of simple and tension pneumothoraces. This paper will propose a uniform description of pathophysiology and diagnostic elements as well as treatment strategies. The intent is to provide a standardization of the nomenclature as well as an understanding of the physiology and clinical significance of the spectrum of pneumothoraces. Finally, we conclude with the author groups 16-point position statement on traumatic tension pneumothorax, its definition and management. The main author position is: - In spontaneously breathing pneumothorax, because of the risk of harm, suspected low incidence, high rate of misdiagnosis, and low rate of procedural success, a conservative approach is advised. - In positive pressure ventilated tension pneumothorax, the incidence is greater and the time to severe physiological impact shorter; thus a more aggressive approach is advised.