Page 13 - JSOM Summer 2023

TABLE 2 Demographic and Measurement Values for Male Versus did not match that at the two civilian institutions with a higher
Females number of geriatric patients and obese patients, which man-
Males Females dated exclusion. We plan to conduct an additional study with
(n = 139) (n = 61) p-value equally matched patients and similar measurement protocol
Median Age, year in a military population to further contribute to this body of
(IQR) 26.0 (22.0–33.0) 29.0 (21.5–34.0) 0.76 literature.
Median BMI, kg/m
2
(IQR) 24.0 (21.5–27.4) 23.5 (19.7–26.6) 0.17 No matter which anatomical location is chosen, there are safer
Median Chest Wall alternative techniques that emphasize not advancing the nee-
Thickness, 2nd ICS 39 (32–45) 38 (32–47) 0.45 dle any deeper than entry into the pleural space. One method
MCL, mm (IQR) is attaching a half fluid filled syringe to the NCU. When ad-
Median Chest Wall vancing the needle through the tissues towards the lung, en-
Thickness, 5th ICS 29 (21–38) 34 (23–43) 0.07
AAL, mm (IQR) sure there is negative pressure in the chamber of the syringe
Median Skin by pulling backwards on the plunger. As the NCU enters the
to Pericardium 65 (53–79) 69 (59–80) 0.13 pleural space there is rapid identification of the presence of gas
Distance, 5th ICS (TPX) by the escaping gas bubbles that are immediately visible
AAL, mm (IQR) in the syringe, along with a release of negative pressure. At this
IQR = interquartile range, BMI = body mass index. point the catheter only may be advanced. This technique has
the benefit of both confirmation of the diagnosis of the PTX
females at 5th ICS AAL with 65-mm (IQR 53–79) versus and treatment, simultaneously. An alternative technique not
69-mm (IQR 59–80) (p =.13), respectively. requiring extra equipment is to advance the NCU no further
than half the length of the needle into the tissues, from which
point the catheter only is advanced, which is unlikely to cause
Discussion
damage. The size of the patient also needs to be considered,
This analysis indicates that there is a risk of cardiac injury with larger individuals having either greater muscle mass or
when treating a left-sided tension PTX in non-obese individu- more subcutaneous fat, and therefore more of the NCU may
als if an 83-mm NCU is used at the 5th ICS at the AAL. These be required to reach the pleural space. However, smaller indi-
data, obtained from a random sampling of 200 CT scans from viduals with less subcutaneous fat are at specific risk with the
urban trauma centers, demonstrated that the median distance current TCCC guidelines. In either setting, an 83-mm NCU
from the skin to the heart was 66-mm (2.5 in) in those with a is too long if “hubbed” to provide a distinct benefit for any
BMI of 24. Thus, the data indicate that in the non-obese pa- patient evaluated in this study and using the full length of the
tient, 75% of the time there could be a potential cardiac injury needle catheter unit should likely be reserved for obese pa-
with NDC of the left chest with an 83-mm NCU. tients with significant chest or flank tissue.

Our analysis does not demonstrate a difference between sexes Conclusion
when it comes to potential injury of the heart when a left-
sided NDC is performed; 75% of both males and females are Needle decompression for tension pneumothorax is a poten-
at risk for cardiac injury with an 83-mm needle. One of the tially lifesaving intervention. However, there is also a risk of
reasons that the left 5th ICS AAL was chosen by the CoTCCC harm from this procedure. Providers should attempt to mini-
was because this is an area with less muscle on the chest wall mize the risk of harm to the patient. The authors suggest that
and therefore a better chance of effective decompression of a the current TCCC guideline recommendation for “hubbing”
life-threatening T-PTX. Fully inserting, or “hubbing,” the NCU the NCU on the left lateral 5th ICS AAL position should be
as described in TCCC carries anatomic risk of injury to the reviewed with possible adjustments in technique to make the
heart at the 5th ICS AAL. procedure safer. The avoidance of harm to our patients should
remain our highest priority.
It should also be noted that as the TCCC procedure calls for
leaving the needle in, thus the cutting edge of the needle is in Author Contributions
place to cut or puncture cardiac structures. Further, there is PT and MB conceived the study concept and study design. AC
often a tissue plug picked up by the needle, and, unless this and EH performed data acquisition, and MB performed data
is expelled, the gas cannot escape through the needle as rec- analysis. JG, JB, SN, and DH provided operational support
ommended by TCCC. In this case, leaving the needle in place for data acquisition and analysis. PT, CB, JB, EG, JG, AH, DJ,
only serves to increase the risk of potential injury to the heart SN, GS, and MB provided critical revision and editing with all
while not allowing functional decompression of the pleural authors approving the final manuscript.
space. Disclaimer
The view(s) expressed herein are those of the author(s) and
There are several limitations to this study. First, this is a ret- do not reflect the official policy or position of Brooke Army
rospective review of CT imaging that was not collected in an Medical Center, US Army Institute of Surgical Research, the
identical fashion. While the overall CT scan protocols at both US Army Medical Department, the US Army Office of the Sur-
institutions are similar, they are not identical, and patient posi- geon General, the Department of the Army, the Department
tioning was not globally standardized. Next, while this popu- of the Air Force, or the Department of Defense, or the US
lation mirrors a military population, the patients are civilians. Government.
A dataset of military trauma center patients was examined
in preparation for this study. However, the dataset contained Disclosure
measurements at different levels, and the patient demographics None.

Risk of Harm in Needle Decompression | 11