Page 25 - JSOM Summer 2018

with death from respiratory, not cardiovascular, arrest.” Suspect a tension pneumothorax and treat when a casualty
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Waydas states, “Experimental studies indicate that, in the has significant torso trauma or primary blast injury and one
awake patient, respiratory dysfunction and arrest due to hy- or more of the following:
poxia in the respiratory center precede the circulatory arrest, – Severe or progressive respiratory distress
and that hypotension appears to be a late sign with circulatory – Severe or progressive tachypnea
arrest being the last occurrence in a series of events.” 30 – Absent or markedly decreased breath sounds on one side of
the chest
The protocol for the Vanderbilt LifeFlight service calls for – Hemoglobin oxygen saturation less than 90% on pulse
finger or tube thoracostomy if there is one or more of the oximetry
following: “evidence of thoracic trauma such as ecchymosis, – Shock
abrasions, crepitus, diminished/absent breath sounds, pene- – Traumatic cardiac arrest without obviously fatal wounds
trating wounds, and/or presence of subcutaneous emphysema.
The patient must also have an injury pattern that is consistent *Note: If not treated promptly, tension pneumothorax may
with the development of tension pneumothorax such as a pen- progress from respiratory distress to shock and traumatic car-
etrating injury or blunt trauma to the thorax. Other clinical diac arrest.
findings in the protocol are vital sign or clinical findings in-
dicating severe hypoxia and/or hypotension, especially in the What should be the initial treatment of a suspected tension
setting of trauma arrest. The protocol also calls for finger or pneumothorax?
tube thoracostomy to be performed on patients with multisys-
tem injury or thoracoabdominal penetrating injury who are in If a chest seal is present
trauma arrest.” 53 The TCCC Guidelines currently state that when a casualty
who previ ously had an open pneumothorax—and who now
If tension pneumothorax is not relieved by NDC or tube tho- has a chest seal in place—is suspected of having a tension
racostomy early in its evolution, it may progress to life-threat- pneumothorax, the first step is to “burp” the chest seal. That
ening hypotension and traumatic cardiac arrest. There have is—lift up the edge of the seal. This will allow the accumulated
been two recent deaths noted during the monthly JTS/AFMES air in the pleural space that is responsi ble for the increased
Mortality Conferences in which postmortem CT scan demon- intrapleural pressure to escape.
strated blood and air in the hemithorax with mediastinal shift
and no definite evidence of attempted NDC. The amount of Based on the work done by Kheirabadi and Kotora and their
blood in the hemothoraces was not enough to have caused colleagues, 59,60 TCCC began to recommend the use of vented
lethal hemorrhagic shock and the autopsies did not demon- chest seals in 2013 to prevent the potential development of a
strate any other lethal injuries (Lt Col Edward Mazuchowski, tension pneumothorax when a chest seal is used to treat an
unpublished data). Additionally, a 2008 report from the Ca- open pneumothorax. However, recent reports from the bat-
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nadian military discussed opportunities for improvement in tlefield indicate that most of the chest seals now being used for
TCCC and reported that seven casualties had presented to US combat forces continue to be the nonvented type. Even
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medical treatment facilities with no vital signs but without when vented chest seals are used, they may at times clog with
having had prehospital NDC. The lesson learned from both blood and not function effectively to relieve intrapleural ten-
2
the US and the Canadian casualties described above is that the sion physiology. 63
combat medical providers must be aware that tension pneu-
mothorax is a reversible cause of traumatic cardiac arrest and Recommendation:
that additional emphasis in TCCC training must be placed on
this point. A similar issue has been reported in the civilian – If the casualty has a chest seal in place, burp or remove the
sector with a recent study noting that the most common error chest seal.
in the management of prehospital cardiac arrest in trauma pa-
tients is failure to treat for a possible tension pneumothorax; Pulse oximetry monitoring
the incidence of tension pneumothorax in 144 traumatic car- The next step in the treatment sequence is to establish mon-
diac arrest patients was found to be 9.7%. 58 itoring of hemoglobin oxygen saturation (Spo ) by placing a
2
pulse oximeter on a finger of the casualty. This will provide
The TCCC Guidelines already recommend that a combat casu- the treating combat medical provider with a baseline for Spo ,
2
alty with torso trauma or polytrauma who suffers a traumatic which will be important both to determine whether hypoxia
cardiac arrest before reaching a medical treatment facility is present and to provide a baseline with which to judge the
should have bilateral NDC performed prior to discontinuing success or failure of further treatment.
resuscitation efforts, but this clinical scenario is currently ad-
dressed only in the cardiopulmonary resuscitation section near Recommendation:
the end of the Tactical Field Care (TFC) section of the Guide-
lines. Moving it up to the Respiration section to add extra – Establish pulse oximetry monitoring.
emphasis on considering tension pneumothorax in a casualty
with a traumatic cardiac arrest will help to increase awareness How should the casualty be positioned for NDC?
that bilateral NDC should be performed on combat casualties Since tension pneumothorax may be accompanied by hemo-
with tho racic trauma or polytrauma who suffer a traumatic thorax, attempts at needle decompression may be unsuccessful
cardiac arrest. if the tip of the needle rests in a blood-filled portion of the
pleural space rather than an air space. This indicates that that
Recommendation for when to treat for suspected tension optimal positioning of the patient may be important to ensur-
pneumothorax: ing successful needle decompression.

TCCC Guidelines Change 17-02 | 23