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compromise brings into question the effectiveness of the pro- between injury and ND, endotracheal intubation and mechan-
cedure in patients with the late sequelae of tension physiology. ical ventilation, and tourniquet placement. Furthermore, al-
Martin et al. demonstrated similar findings with swine mod- though the procedure setting was a recorded variable, we were
29
els in cardiac arrest resulting from tension pneumothorax. In unable to determine whether assessment of success was per-
their study, ND failed to restore perfusion in 64% of cases. formed on the ground or midflight. The change in atmospheric
pressure at varying altitudes can have implications on the suc-
Another area of debate is centered around catheter type and cess of ND. Collectively, these variables likely contributed to
the role of the performing provider. Various studies involving post-procedure hemodynamic parameters; however, we were
cadavers, along with ultrasound and CT findings, comment unable to perform a matched analysis to determine whether
on catheter length as a factor in ND success. 30–32 Ball et al. ND was independently associated with clinical improvement.
17
demonstrated a notably higher rate of failure when catheters In addition, without postmortem findings, we could not re-
<4.5cm in length were used. We were unable to detect a sig- liably identify patients who suffered cardiopulmonary arrest
nificant difference in catheter length between successful and from blunt cardiac injury rather than tension pneumothorax.
unsuccessful ND attempts, although in both groups, the mean Finally, we make no mention of complication rates or location
catheter length was >7cm. Similarly, catheter bore size did of needle placement on the chest because these data were not
not significantly affect success rates. This is in contrast with available.
other studies, which found that smaller-gauge catheters were
unable to adequately decompress the chest. Cadaver, ultra- Early identification and treatment of a tension pneumothorax
33
sound, and computed tomography studies have also brought by prehospital providers is critical for improving trauma pa-
into question whether ND success depends on catheter tient outcomes. Success in military settings demonstrates the
length. 30–32,34,35 The differences in findings are likely the result feasibility of ND, and the results of this study demonstrate
of variability in body habitus as well as location of placement that when performed on civilians in select circumstances, a
(i.e., midaxillary vs. midclavicular lines). As of the most re- high rate of success can be achieved. More specifically, when
cent ATLS recommendations, catheters between 5 and 8cm in performed for hypoxia rather than for cardiopulmonary col-
length should be considered for axillary placement at the fifth lapse, a larger proportion of patients will show improvement.
intercostal space. Regarding the role of the performing pro- Nonetheless, this should not deter providers from attempting
36
vider, we found no significant difference in success rate; both ND in all clinically indicated scenarios. Lastly, the success rate
paramedics and registered nurses were able to perform the of prehospital ND does not appear to be related to catheter
procedure with similar efficacy. Both sets of providers receive size used or the role of the performing provider.
basic training on ND as part of their certification process. 37,38
Previous Presentation
Aside from training, one factor that may improve success rates This paper was presented at the Clinical Congress of the
among prehospital providers is increased availability of porta- American College of Surgeons Annual Scientific Meeting; San
ble imaging equipment. While the detection of pneumothorax Francisco, CA; October 2019.
by Extended Focused Assessment with Sonography in Trauma
(eFAST) has gained acceptance as an adjunct during trauma Conflict of Interest
resuscitation in the emergency department, portable ultra- None of the authors has any conflict of interest to disclose.
sound has yet to become standard for prehospital personnel.
If made universally available, it may help decrease the number Financial Disclosure
of unnecessary prehospital decompressions and increase the Neither internal nor external financial support was used for
number of successful field interventions. 39 this study.

There are several limitations to this study, one of which is its Author Contributions
retrospective design. Because there are no standardized indi- The literature review was performed by RH, CG, AG, CPF,
cations for prehospital ND across all institutions, we were and AS. The study design was by RH, CG, AG, ME, CPF,
forced to rely on self-reported indications by the performing DEB, KI, and AS. Data collection was by RH, CG, AG, ME,
providers. Air Evac Lifeteam, the company responsible for op- CPF, DEB, KI, and AS. Data analysis/interpretation was per-
erating the helicopter fleet, does not standardize clinical indi- formed by RH, AG, KM, HT, and AS. All of the authors con-
cations or the setting for ND. These decisions are made by the tributed to the writing and critical revision of the manuscript.
regional emergency medical service directors. We attempted
to use predefined objective clinical criteria (e.g., vital signs, References
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