Tension pneumothorax (TP) is defined as a progressive build-up of air within the pleural space, generally due to a laceration of the lung.
The clinical presentation of tension pneumothorax is very similar to that of pneumothorax, even though it is much more pronounced. The classical signs include hypotension and hypoxia, the absence of sounds from the affected hemithorax and the deviation of the trachea away from the side of the affected chest. Furthermore, it is possible to observe hyperresonance in the thorax, tachycardia and a characteristic distension of the jugular veins.
The diagnosis of tension pneumothorax is largely based on the use of imaging studies, which should be performed promptly to avoid further complications of this medical emergency. If the use of radiography is considered, the time to obtain imaging studies should be balanced against the expected clinical course. Findings usually include increased thoracic volume, trachea deviation and ipsilateral lung collapse. Moreover, the intercostals spaces appear widened and heart border flattened on the affected side.
CT scan is very reliable as diagnostic technique, but it is not recommended for routine use. Anyway, it provides a series of advances, such as the possibility of distinguishing a large bulla from a case of pneumothorax, underlying the presence of emphysema or emphysema-like changes, or determining the side of the pneumothorax. It can also be used to detect the presence of concomitant pulmonary diseases, because of the greater quality of the images provided by it. Ultrasonography, instead, can be used as a valid alternative to CT scan for patients with very unstable conditions, without compromising the sensitivity, specificity, and effectiveness of the diagnosis itself.
The classical treatment for tension pneumothorax is the chest decompression through needle thoracostomy, performed by inserting an intravenous cannula into the second rib space in the mid-clavicular line. The needle is pushed down until air can be aspirated into a syringe attached to the needle itself. Once the needle is withdrawn leaving the cannula opened, a rush of air comes out of it indicating the presence of the condition. With the pressure gradually decreasing dueto this maneuver, tension pneumothorax slowly turns into simple pneumothorax. In any case, many experts suggest that this methodology might be ineffective, and tension might even re-accumulate after the clinical procedure. Furthermore, the formation of air embolism from the lung laceration is highly possible. For these reasons, it is strongly recommended to wait for the diagnostic results before carrying out this clinical procedure.
Frequently used as definitive treatment for tension pneumothorax is chest tube placement. This procedure is often preferred by clinicians, because it is very rapid and allows a controlled intervention much safer than the blind needle thoracostomy, even though it takes a little bit longer to complete. These surgical procedures are also coupled with pharmacotherapy whose main purpose is to reduce morbidity and prevent complications. The main medications employed include anesthetics, analgesics, and antibiotics.
The prognosis of tension pneumothorax depends of the promptness of treatment. In fact, if not recognized and treated on time, tension pneumothorax swiftly progresses to respiratory insufficiency, cardiovascular collapse and finally death. This is the reason why immediate treatment is paramount, to be performed before the appearance of any signs of hemodynamic instability.
The etiological factors of tension pneumothorax can be both iatrogenic and related to a trauma, such as an explosion or a penetrating traumatic event, which then causes the disruption of the pleura usually in association with a rib fracture. Other possible situations from which tension pneumothorax can occur might also include:
Tension pneumothorax often occurs in a hospital setting, especially when subjects are under intensive care treatment undergoing ventilation with positive pressure.
There is not a validate estimate regarding the incidence of tension pneumothorax, and its value still has to be officially determined. In any case, experts believe that this condition occurs in 5% of those affected by a chest trauma, and under control in a pre-hospital setting, and from 1% to 3% of adults under intensive care    . According to a retrospective cohort study, the mechanically ventilated patients affected by tension pneumothorax have a risk of death which is around 38 times higher than those who are not affected  and show no sign of possible chest over-tension.
It is difficult to determine the incidence of tension pneumothorax outside hospital settings. A possible estimate could be given by the review of military deaths from thoracic trauma, which seems to suggest that up to 5% of the combat casualties showing thoracic trauma showed this condition at the moment of death . In any case, these data come from a setting of war, which do not necessarily represent a “normal” situation.
As previously said, tension pneumothorax usually occurs after a traumatic event which causes a laceratio, such as the already mentioned explosion, barotrauma secondary to positive-pressure ventilation, pneumoperitoneum, thoracic spine fractures, acupuncture, and colonoscopy. Other possible causes include:
Furthermore, tension pneumothorax is particularly frequent among those requiring ventilatory assistance or undergoing meconium aspiration, since aspirated meconium might work as a 1-way valve causing the condition. It is also particularly interesting to notice the presence of acupuncture among the etiological factors, which is responsible of around 1 over 5000 cases of tension pneumothorax .
The most important preventive measure to avoid tension pneumothorax is to stop smoking, so that the occurrence of an underlying episode of pneumothorax can be prevented. If a patient show a history of pneumothorax or tension pneumothorax, he/she is also strongly recommended to avoid scuba diving, which might cause dangerous pressure changes. Furthermore, it is recommended to wear seatbelt when driving or being in a motor vehicle, so that accident-related trauma can be prevented as much as possible.
The word pneumothorax refers to the presence of gas or air within the pleural space. In the case of tension pneumothorax (TP), air escapes from the lung into the pleural space, creating an increasingly higher pressure in what can be defined as a one-way-valve effect. The progressive build-up of air and pressure pushes the mediastinum to the opposite hemithorax, creating the conditions for obstructing venous return to the heart. The possible outcome is a circulatory instability which then results in traumatic arrest. Although there are many definitions, experts tend to consider TP as the condition in which pneumothorax leads to significant impairment of respiration, blood circulation and possibly death .
The classical signs of this life-threatening condition is an over-expanded chest that moves very little with respiration, together with depression of the hemidiaphragm and an alarmingly increased percussion note. Moreover, it is also possible to observe a deviation of the trachea away from the side affected by the tension. Patients usually appear tachycardic, tachypnoeic, and possibly hypoxic. After the appearance of these first signs, it is also possible to observe circulatory collapse with hypotension and subsequently traumatic arrest showing pulseless electrical activity (PEA).
Tension pneumothorax might develop especially in the presence of positive pressure ventilation, and after a while it is not difficult to appreciate how the circulatory functions are compromised by this tension. In the end, the condition causes steadily worsening oxygen shortage and low blood pressure, which might result in death. For these reasons, it can be considered as a life-threatening emergency requiring immediate clinical attention .
Tension pneumothorax is defined as a continuous build-up of air within the pleural space between the lungs and the chest, creating an increasing pressure in the chest. The possible outcome of this pathological condition are circulatory instability, respiratory and cardiac problems, which if not promptly treated might cause the death of the affected subject.
The classical signs of this life-threatening condition are an over-expanded chest that moves very little with respiration, together with depression of the hemidiaphragm (the muscle separating the chest cavity from the abdomen). Common symptoms are an increase heart rate (tachycardia), an increased breathing rate (tachypnea) as well as a serious reduction of oxygen supply (hypoxia). If the conditions lasts for long enough it might finally result in circulatory collapse, hypertension, traumatic arrest and death. For these reasons tension pneumothorax is considered a life-threatening emergency requiring immediate clinical attention.
The classical cause of tension pneumothorax is a traumatic event, such as a motor-vehicle accident or a surgical procedure like colonoscopy or acupuncture. The treatments for this condition include the aspiration of air with the help of a needle (needle thoracostomy) or with the help of a tube (chest tube placement). The latter is more frequently used because it is much safer and much more rapid, even though it takes a little bit longer to complete. Several medications are also used to avoid further complications like infection, and these include anesthetics, analgesics, and antibiotics.
The most important preventive measure to avoid tension pneumothorax is to stop smoking, so that the occurrence of an underlying episode of pneumothorax can be prevented. If a patient show a history of pneumothorax and tension pneumothorax, he/she is also strongly recommended to avoid scuba diving, which might cause dangerous pressure changes. Furthermore, it is recommended to wear seatbelt when driving or being in a motor vehicle, so that accident-related trauma can be prevented as much as possible.