Tension pneumothorax
From Wikipedia, the free encyclopedia
| Spontaneous tension pneumothorax | |
|---|---|
| Classification and external resources | |
Chest X-ray of Left-sided Tension Pneumothorax (seen as dark space within ribs on viewer's right side). | |
| ICD-10 | J93. |
| ICD-9 | 512.0 |
| DiseasesDB | 31862 |
| MedlinePlus | 000090 |
| eMedicine | med/2793 emerg/470 |
A tension pneumothorax is a life-threatening condition that results from a progressive deterioration and worsening of a simple pneumothorax, associated with the formation of a one-way valve at the point of a rupture in the lung.[1] Air becomes trapped in the pleural cavity between the chest wall and the lung, and builds up, putting pressure on the lung and keeping it from inflating fully.
Upon inspiration, when the pressure inside the chest and pleural cavity falls as a result of the respiratory muscles increasing chest dimensions, air is sucked in through the one way valve, into the pleural space. Because exhalation is a passive process, there is an insignificant amount of pressure created to force the air back out of the pleural cavity. This condition over time results in a gradual accumulation of air to the degree that it begins to put pressure on the mediastinum, compressing the heart and decreasing cardiac output due to the reduced amount of diastolic filling of the ventricles, and also putting pressure against the trachea, causing it to move away from the midline (the center). Because of the increased thoracic pressure, venous return to the heart is decreased, causing a backup of blood into the venous system, as evidenced by distended jugular veins.[1]
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Signs and symptoms
- Decreased or absent breath sounds on the affected side
- Tracheal deviation towards unaffected side[1] (late sign)
- Hyperresonance on percussion[1]
- Unequal chest rise[1]
- Dyspnea (difficulty breathing)
- Tachypnea (rapid breathing)[1]
- Tachycardia (rapid heart rate)[1]
- Hypotension (low blood pressure)[1]
- Hypoxia (deficiency in the amount of oxygen reaching the tissues)[1]
- Pale, cool, clammy skin
- Subcutaneous emphysema (air trapped beneath the skin)
- Cyanosis (bluish color of skin)
- Jugular venous distension (enlarged jugular veins; late sign)
Differentiation
| Cardiac tamponade | Pneumothorax | |
|---|---|---|
| Breath sounds | Equal on both sides | Decreased or absent on affected side |
| Trachea | Midline | Deviated away from affected side |
| Percussion | Normal resonance | Tympanic (Hyperresonant) |
| Pulse | Affected by breathing | Normal |
A tension pneumothorax is a condition whose signs and symptoms resemble very closely those of a condition called pericardial tamponade. A chest x-ray will distinguish the two. On physical exam, the differentiating factors are listed in the table at right. The sign that occurs in pericardial tamponade in which the pulse is affected by breathing is called pulsus paradoxus, or simply paradoxical pulse.
Treatment
Initial treatment involves the insertion of a large bore cannula or needle into the second intercostal space on the mid-clavicular line (known as "needle thoracostomy", or more commonly, "needle decompression"), thereby releasing the pressure in the pleural cavity and converting the tension pneumothorax to a simple pneumothorax, which is then treated at the earliest opportunity by inserting a chest tube.[1]
Tension pneumothorax represents a medical emergency which cannot often accommodate the time spent waiting for the capture and interpretation of a chest radiograph. Consequently, the decision to proceed with needle decompression must be made clinically (i.e., "at the bedside") by observing the acute presentation and reviewing relevant history. There is some debate on the topic of needle thoracostomy. There are risks associated with the process such as lung laceration, especially if no tension pneumothorax condition is present, and that relieved tension may reaccumulate undetected if the needle thoracostomy becomes dislodged. There is also the possibility that the cannula will not reach the pleural cavity due to a thick chest wall, especially in overweight individuals. Traditionally needle decompression has been attempted using a 4.5 cm (2") to 5 cm catheter. However,previous studies have shown a failure rate of up to 40% using this technique. Based on the clinical findings and failure rates, it is recommended that a 3.25" 14 gauge needle should be used in order to address the issue of the needle not reaching the pleural space.
Once the needle is placed, a chest tube is inserted. Almost always there is a rush of air released from the pleural space when the chest is entered, then the tube is slipped into the pleaural space to drain the air and re-expand the lung. Nearly always, there will be a large air leak that will generally resolve over the subsequent days. If the chest tube becomes clogged or kinked, the tension pneumothorax will reoccur. This can be a life threatening event, especially when unrecognized. Chest tubes are prone to clogging with fibrinous material or blood clot. Chest tube clogging can occur in the external portion of the chest tube, where it can be seen. Milking and stripping of the tubes is not recommended to re open or keep open the tubes. Stripping the tubes can cause a negative pressure in the chest tube system. Another option is to create a sterile field, open the chest tube and the connection to the drainage tubing, and introduce a external suction catheter to try to suck out the clogged chest tube. This has the disadvantge of breaking the sterile field, and air can be sucked back into the chest. If the chest tube clogging cannot be cleared, the tube has to be replaced. Often physicians will place large bore chest tubes or multiple chest tubes with the hope of minimizing the potential for chest tube clogging. Chest tube clogging can also occur in the non visible portion of the tube inside the chest, and go unrecognized.[2] In the setting of ongoing air leak this can result in a return of the tension pneumothorax, which can be lethal if unrecognized.
The US Military has made considerable advances into research involving needle decompressions. Medic kits are available with a small 14 gauge needle and catheter contained within a pen-sized container. [6]
References
- ^ a b c d e f g h i j "Chest Trauma Pneumothorax - Tension". Trauma.org. March 22, 2005. http://www.trauma.org/thoracic/CHESTtension.html. Retrieved September 7, 2006.
- ^ Shalli, Shanaz; Saeed, Diyar; Fukamachi, Kiyotaka1; Gillinov, A. Marc; Cohn, William E.; Perrault, Louis P.; Boyle, Edward M., Chest Tube Selection in Cardiac and Thoracic Surgery: A Survey of Chest Tube-Related Complications and Their Management. Journal of Cardiac Surgery, Volume 24, Number 5, September 2009 , pp. 503-509(7)
- ^ Zengerink I, Brink PR, Laupland KB, Raber EL, Zygun D, Kortbeek JB (January 2008). "Needle thoracostomy in the treatment of a tension pneumothorax in trauma patients: what size needle?". J Trauma 64 (1): 111–4. doi:. PMID 18188107. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?an=00005373-200801000-00017. Retrieved 2008-08-09.
- ^ Cullinane DC, Morris JA, Bass JG, Rutherford EJ (December 2001). "Needle thoracostomy may not be indicated in the trauma patient". Injury 32 (10): 749–52. doi:. PMID 11754880. http://linkinghub.elsevier.com/retrieve/pii/S0020-1383(01)00082-1. Retrieved 2008-08-09.
- ^ Britten S, Palmer SH, Snow TM (June 1996). "Needle thoracocentesis in tension pneumothorax: insufficient cannula length and potential failure". Injury 27 (5): 321–2. doi:. PMID 8763284. http://linkinghub.elsevier.com/retrieve/pii/0020138396000071. Retrieved 2008-08-09.
- ^ http://firemedicnerd.wordpress.com/2010/01/05/needle-decompression/
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