Airway/Breathing Problem

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Pneumothorax:

Massive hemothorax:

Tension pneumothorax should be diagnosed clinically during the primary survey before adjunct imaging is obtained. Classic signs of a tension pneumothorax are decreased breath sounds, tracheal deviation to the opposite side, hypotension, and distended neck veins, though not all of these may be present.$^{50}$ Identification of tension pneumothorax should prompt immediate needle decompression or chest tube placement. There is ongoing debate regarding the optimal location for needle decompression, whether it should be performed in the midclavicular line at the second intercostal space, or the fourth to fifth intercostal space at the anterior axillary line. A cadaveric study showed 100% success when placed at the fifth intercostal space compared to 58% at the second intercostal space, likely due to decreased chest wall thickness at that site.$^{55}$ This has been reiterated by a meta-analysis of 15 studies,$^{56}$ and the fifth intercostal space is now the site recommended by ATLS®.$^{23}$ Additional studies have shown that pigtail catheter placement is associated with decreased infection rates when compared to large-bore chest tubes, and there was no significant difference in mechanical ventilation and ICU days between chest tube and pigtail catheter use for traumatic pneumothorax.$^{57,58}$

For a patient with normal vital signs and a pneumothorax <2 cm on chest x-ray or <3.5 cm on CT scan, an observation period of 6 hours is reasonable in accordance with the Western Trauma Association guidelines published in 2021. They note only 10% of these patients ultimately require a thoracostomy tube.$^{60}$ Additionally, it has historically been taught that any patient with a pneumothorax who is also receiving positive-pressure ventilation should have a chest tube placed, regardless of the size of the pneumothorax, to avoid conversion to tension physiology. This practice is likely unnecessary, given a 2021 meta-analysis of 12 studies and 354 patients demonstrating a failure rate of only 24% (with only 2.8% resulting in tension pneumothorax).$^{61}$ This practice, of course, requires close clinical monitoring.

Emergent operative management may be indicated if the patient requires continued blood transfusion to maintain hemodynamics; if blood continues to drain at 150 to 200 mL/hr for 2 to 4 hours; or if there is >1500 mL blood output after chest tube placement. These data are based on a multicenter retrospective case series demonstrating that the risk for death increases linearly with total chest hemorrhage after thoracic injury, with the mortality of patients with initial output of 1500 mL being 3 times that of patients with an initial output of 500 mL.$^{62}$