Page 30 - JSOM Summer 2018

space is the use of an NCD device with CO detector. This Recommendation:
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technique has been shown to improve the accuracy of deter-
mining NDC success in an animal model. This type of device A needle decompression procedure should be considered suc-
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is not, however, carried by most US combat medical personnel cessful if:
at the time of this writing. The Mayo clinic report on NDC de- – Respiratory distress improves, or
fined success as “. . . documented improvement in respiratory – There is an obvious hissing sound as air escapes from the
status (increased oxygenation, decreased respiratory rate, or chest when NDC is performed (this may be difficult to ap-
an improvement in ventilator requirements) or cardiovascular preciate in high-noise environments), or
status (normalized heart rate and/or blood pressure or a return – Hemoglobin oxygen saturation increases to 90% or greater
of pulses), or a documented “general improvement” in the pa- (note that this may take several minutes and may not hap-
tient’s condition as per provider after NT was performed.” 9 pen at altitude), or
– A casualty with no vital signs has return of consciousness
As exemplified in the scenario presented at the start of this re- and/or radial pulse.
port and another recently published combat casualty care case
report, it is not uncommon to see combat casualties undergo What should be done if the initial NDC is not successful?
multiple NDC procedures during their prehospital care. In The TCCC Guidelines do not at present include a sequence
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some cases, this may occur because the symptoms of respira- of steps to be undertaken if NDC fails to relieve the signs and
25
tory distress are caused by a condition other than a tension symptoms of a suspected tension pneumothorax.
pneumothorax in which NDC does not produce improvement
(eg, pulmonary contusion, hemothorax, or bronchial injury). As noted previously, there are some casualties in whom symp-
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In other cases, however, the multiple attempts may have been toms of respiratory distress, hypoxia, and/or shock are not re-
undertaken because because the current TCCC Guidelines do lieved by NDC and multiple NDC attempts are undertaken by
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not clearly state what constitutes success in NDC and do not the treating combat medical provider—7 in one case and 14
provide recommendations about what to do if NDC is not in the scenario presented at the beginning of this report.
successful in relieving the casualty’s respiratory distress. In the
casualty scenarios referenced above, the treating corpsman and Animal models have demonstrated that immersion of the tip of
medic observed improvement of their casualties’ respiratory the needle in a hemothorax is one cause of NDC failure. If the
distress with each NDC procedure followed by subsequent de- initial NDC was performed on a casualty in the supine position,
terioration. Such scenarios indicate that additional clarification blood would be expected to have pooled at the posterior aspect
is needed in the TCCC Guidelines, both about what constitutes of the chest, so a reasonable next step if the initial NDC was per-
success in NDC and how to proceed after the initial procedure. formed at the lateral site would be to perform the next attempt
at the anterior site, where the tip of the needle would be less
What are the indications that NDC has been successful? A likely to be occluded by blood. Another cause of failed NDC is
partial list of the potential clinical improvements includes: failure to penetrate the pleural space, possibly due to an unusu-
– Subjective improvement in the casualty’s respiratory dis- ally thick chest wall or a technical error in performing the NDC.
tress or an observed decrease in his or her respiratory rate. Therefore, if the first decompression was attempted at the ante-
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– Oxygenation improves, as indicated by hemoglobin oxygen rior site, the second attempt should be made at the lateral site.
saturation increasing to 90% or greater (note that this may
take several minutes after the NDC to happen.) Recommendation:
– Air escaping from the overpressurized pleural space creates a If the initial NDC fails to improve the casualty’s signs/symp-
hissing sound as air escapes from the chest during NDC. (This toms from the suspected tension pneumothorax:
may be difficult to appreciate in high-noise environments and – Perform a second NDC—on the same side of the chest—at
may not always be appreciable even in less noisy settings whichever of the two recommended sites was not previously
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[MSgt Shawn Anderson, personal communication] 2017. used. Use a new needle/catheter unit for the second attempt.
– Hemodynamic improvement—a reduction in the signs of – Consider—based on the mechanism of injury and physical
shock or a return of vital signs in a casualty with a trau- findings—whether decompression of the opposite side of
matic cardiac arrest. the chest may be needed.
If the above clinical findings are noted, it is likely that the What should be done if the initial NDC is successful, but signs/
tension pneumothorax has been successfully treated, but, since symptoms subsequently recur?
the leak of air into the pleural space may persist, the tension A positive response to the first NDC indicates that a tension
pneumothorax may recur, so the casualty must be constantly pneumothorax was present on the side of the chest that was
re-assessed. If some respiratory distress persists but oxygen- decompressed. After the initial successful NDC, following
ation, and heart rate are within the normal range and there needle removal, the catheter may subsequently kink, become
are no signs of shock, it may not be necessary to repeat NDC. occluded, or migrate out of the pleural space, thereby allowing
the re-accumulation of air in the pleural space with a subse-
If improvement in signs/symptoms is not seen after the NDC quent recurrence of tension pneumothorax.
procedure, other causes must be considered. In penetrating
thoracic trauma, respiratory distress and hemodynamic insta- In this instance, the initial treatment should be repeated—on
bility may also be caused by a hemothorax; in blunt trauma, the same side of the chest—using a new needle/catheter unit.
pulmonary contusions, flail chest, or pain from rib fractures
may also cause respiratory distress in the absence of a tension In a review of the treatment rendered to casualties in the battle of
pneumothorax. The symptoms of respiratory distress caused Mogadishu in 1993, Dr. Ken Zafren noted: “I did find research
by these conditions will not be relieved by NDC. that showed that needle thoracostomies were likely to remain

28 | JSOM Volume 18, Edition 2/Summer 2018