So Bored I Popped a Lung – Tension Pneumothorax

It’s Friday night in Central Brooklyn, and it’s your 6th night shift in a row. It’s surprisingly quiet in the critical care/resuscitation unit, and that notification phone still hasn’t rung. Just when you sit down, corner deli coffee in hand, trying to figure out if it’s actually Friday or Saturday, morning or night-time, EMS runs into the trauma bay, “Doc, didn’t you get the note? 35 year-old male, stab wound to the right chest”.

You take the information as you help roll this guy off the backboard and recite your dogma in your head, ABCs, IV, O2, MONITOR.

“35 year-old male, history unknown, GCS 13, stabbed in the right chest on Utica Avenue about 15 minutes ago, VS HR 103, RR 20, BP 110/72, O2 95% on room air.”

As you are working through the primary survey, he is talking to you, eyes open, and you breathe a sigh of relief. There are two 2-3 cm stab wounds to the anterior mid-chest at about the 4th intercostal space (ICS) and no other visible injuries.

You’ve deemed his airway is stable at present, and it’s hard for you to tell if breath sounds are equal bilaterally with the commotion in the room. But you think so. While you are helping get a second line, and your colleagues are working on the secondary survey and FAST, your patient begins to crash.

His vital signs are now HR: 130, BP 86/55, RR 35, Sat 76%. He’s obtunded and has distended neck veins, minimal movement of his chest with respiration, and reduced breath sounds on the right. While your colleague is getting the airway, your senior calls out for additional equipment.

What are the top 3 things on your differential?
  1. Tension Pneumothorax
  2. Hemothorax
  3. Cardiac Tamponade

 

So, what exactly is a tension pneumothorax?
A pneumothorax, is a build up of air between the potential space between the lung’s parietal and visceral pleura, aka the pleural cavity. A tension pneumothorax occurs when the build up of air occurs under pressure. This often happens due to injury to the underlying lung tissue, which then forms a one way valve. This allows air to enter the pleural space, but not to escape. The pressure build-up shifts the mediastinum, and decreases venous return to the heart to cause hemodynamic compromise.

 

How do you diagnose it?
Remember, tension pneumothorax should be a bedside diagnosis. Your eyes, ears, and stethoscope are your best bet. Classic signs include hypotension, tachycardia, respiratory compromise, distended neck veins, absent breath sounds unilaterally (or at times bilaterally), deviation of the trachea to the opposite side, and hyper-resonance to percussion.

You may not always see these signs, but consider tension pneumothorax in patients with unexplained hemodynamic compromise – especially in patients receiving positive pressure ventilation with developing tachycardia, hypotension, and rising airway pressures.

 

Who gets them?
Basically, anything that causes air to enter the pleural space without a way out can cause a tension pneumothorax. Typically, it is caused by communication from the chest wall due to trauma or barotrauma from positive pressure ventilation.

 

How do you fix it?
Immediate needle decompression followed by a chest tube is the most accepted method.

Needle Decompression

The most common approach is with a 14 gauge needle/catheter placed in the anterior mid-clavicular line in the second ICS. Theoretically you should hear a large gush of air – then you have now converted this tension pneumothorax into a simple/open pneumothorax.

http://www.nejm.org/doi/full/10.1056/NEJMvcm1111468?af=R&rss=currentIssue&

Phew, you threw a catheter in there, and you think there was a gush of air. But you’re not sure. Is your work done?

No. At best, needle decompression is temporizing. There is even some data that it might not be successful in many cases. You’ve got to place a chest tube.

How do you do that?

Historically, chest tubes equal to or greater than 32 french are recommended, especially in cases like this, in which you might also be suspecting a hemothorax.

Traditionally you enter the 5th ICS, midclavicular line, which is the nipple line in men, and at the level of the inframammary crease in women. For a bit more on technique, and how to place a chest tube – check out this awesome article from LITFL: Own the Chest Tube, LITFL

For some more great reading on chest tubes vs. needle aspiration, check out Dr. Kelson’s article on our very own blog: It’s not the size, it’s how you use it (when it comes to chest tubes) – Clinical Monster 

 

What kind of complications should you look out for?
 Re-expansion lung injury although rare, can be seen and can usually be treated with oxygen and observation. Also consider things like bleeding from intercostal vessels, injury to the lung tissue itself, empyema and chest tube malfunction such as an air leaks.

Your astute, so you didn’t wait for an X-Ray. (A chest X-ray ideally should not be used to diagnose a tension pneumothorax – remember if you see it, treat it). But lets say your patient was stable, and you got one prior to recognition, what would you see?http://www.radiologymasterclass.co.uk/gallery/chest/pneumothorax/pneumothorax_b

  • Air in the left pleural cavity
  • Collapsed left lung
  • Tracheal deviation to the left
  • Shift of the heart border to the right
  • Depression of the left hemidiaphragm

What would you see if you were looking for a pneumothorax on ultrasound?

A literature review of studies on the detection of pneumothorax by lung ultrasound by ED physicians on blunt trauma patients from 1965-2009 (Wilkerson and Stone, 2010) showed a sensitivity of 86-98% and specificity of 97-100%, in comparison to chest radiography, which has a sensitivity of 28-75% and specificity of 100%.

You can look for an absence of signs of a normal lung-pleural interface (“lung sliding”), and absence of B line with only A lines. You may see a lung point, the point at which the visceral and parietal pleura make contact (they are separated when a pneumothorax is present), which is the most specific and pathognomonic sign. You may also see a “bar-code” sign on M mode, and a heart point sign.

hhttp://epmonthly.com/article/soundings-the-rest-is-history-and-physical/ttp://epmonthly.com/article/soundings-the-rest-is-history-and-physical/

 

Check out these great resources for views of these other signs of pneumothorax, and technique:

Rebel EM – Ultrasound Detection of Pneumothorax

LITFL – Pneumothorax Ultrasound

 

 

Phew, breathe a sigh of relief. You may have peed your scrubs a little, but the patient’s vitals have stabilized. Good job! You pat yourself on the back, thinking you are one great resident…

https://i2.wp.com/2.bp.blogspot.com/-SWF_lDcuT-c/U5Y6RrtJFKI/AAAAAAAAAIQ/C--ZZ05Er78/s1600/NOTGONNAHAPPEN.gif?resize=400%2C300

Until you realize you now have 5 patients lined up in the hallway. But don’t you worry, that’s why you got that corner deli coffee old friend. Get yourself to work! (Trudges along…)

Special thanks to Dr. deSouza, Dr. Birnbaum, and Dr. Zonnoor.

 

References:

Brims, Fraser. Tension-Pneumothorax, An Alternative View. LITFL: Life in the Fast Lane Medical Blog. Retrieved from

Brohi, K. Tension Pneumothorax. 2006. Trauma.Org. Retrieved from http://www.trauma.org/index.php/main/article/199/

Brunett PH, Yarris LM, Cevik A. Brunett P.H., Yarris L.M., Cevik A Brunett, Patrick H., et al.Chapter 258. Pulmonary Trauma. In: Tintinalli JE, Stapczynski J, Ma O, Cline DM, Cydulka RK, Meckler GD, T. Tintinalli J.E., Stapczynski J, Ma O, Cline D.M., Cydulka R.K., Meckler G.D., T Eds. Judith E. Tintinalli, et al.eds.

Pneumothorax: Practice Essentials, Background, Anatomy. Emedicine.medscape.com. Retrieved from < http://emedicine.medscape.com/article/424547-overview>

Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7e New York, NY: McGraw-Hill; 2011.

Sharma, A., & Jindal, P. (2008). Principles of diagnosis and management of traumatic pneumothorax. Journal of Emergencies, Trauma and Shock, 1(1), 34–41. http://doi.org/10.4103/0974-2700.41789

Wilkerson, G., Stone M. (2010). Sensitivity of Bedside Ultrasound and Anteroposterior Chest Radiographs for the Detection of Pneumothorax After Blunt Trauma. Academic Emergency Medicine, 17(1), 11-17

 

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Delna

PGY2 Clinical Monster in Training

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