Page 99 - JSOM Spring 2021

will develop into a tension pneumothorax. Many authors have were used. The PubMed search strategy was “recommen-
questioned why a potentially deadly tension pneumothorax dations OR guidelines AND sucking chest wound OR open
can be accepted as a complication in treating a nondeadly pneumothorax.” Google search terms were “guideline open
open pneumothorax or sucking chest wound. 26,27 pneumothorax,” “guideline sucking chest wound,” “guide-
line tactical medicine,” “Leitlinie penetrierende Thoraxver-
The goal of this article was to summarize the known evidence letzung,” “Leitlinie offener Pneumothorax,” and “Leitlinie
for using chest seals for treating the sucking chest wounds of taktische Medizin.” Guidelines related to combat medical care
adult patients in combat areas. The focus is on the efficacy or casualty care in an austere environment were included but
of the various vented and unvented chest seals in stabilizing did not result in the exclusion of more civilian-oriented guide-
patients with sucking chest wounds. Also extremely important lines. Per the exclusion criteria, guidelines in languages other
is the chest seal’s ability to prevent development of a tension than English, German, or French were excluded because of
pneumothorax. The literature review results are compared the language barrier. Guidelines older than 2010 were also ex-
with their recommended use within various guidelines, with cluded because they are not regarded as up to date. September
an emphasis on medical treatment in a tactical environment. 17, 2020, was the last day of literature searching.

Methods Results
The author reviewed publications using the PubMed database, Five studies testing the efficacy of various chest seals in treat-
but this paper is not registered as a systematic review. The ing sucking chest wounds were identified using the described
search was for open pneumothorax or sucking chest wound search strategy (Figure 1). Using hemopneumothorax swine
studies and their use of vented or unvented chest seals in adult models, Arnaud et al. in 2008 compared both the effec-
28
patients and animals. tiveness and adhesive qualities of two vented chest seals, the
Asherman (Chinook Medical Gear) and the Bolin (H&H
• The search words for publications, which also included Medical). They injected repetitive doses of air into the pleural
their word patterns, included Medical Subject Headings space until either a tension pneumothorax occurred or a max-
(MeSH) article titles and article abstracts: “chest seal imum of 1,500mL of air had been injected. Their definition of
OR vented chest seal OR unvented chest seal OR suck- a tension pneumothorax was a minimum heart rate increase of
ing chest wound OR open pneumothorax OR penetrat- 20% or a 20% minimum decrease in arterial pressure (MAP).
ing chest wound” (search strategy 1) and “chest seal” Their second step repeated the experiment upon application
(search strategy 2). of a chest seal. A third step was the injection of blood into the
• Publication inclusion and exclusion criteria for treating pleural space. They also tested the adhesive strength of each
chest wounds and prevention of, or stabilization of, a chest seal. With no chest seal applied, the MAP dropped >20%
tension pneumothorax are shown in Table 1. after 372 ± 260mL of air had been injected. With chest seal ap-
plication, no tension pneumothorax occurred with or without
TABLE 1 Inclusion and Exclusion Criteria the additional injection of blood. They compared the adhesive
Inclusion Criteria Exclusion Criteria parameters of both chest seals on dry skin and moist, bloody
• Chest seal efficacy, failure • Studies of devices other than skin. The Asherman chest seal was significantly less adhesive
rate, clinical results for chest seals on moist, bloody skin. 28
treating open pneumothorax
or sucking chest wounds Kotora et al. in 2013 reported a comparative testing of
29
• Human and animal studies • Treatment for non-traumatic vented chest seals in a hemopneumothorax swine model. They
pneumothorax tested the effect of repetitive injections of air with and with-
• English, French, and German • No primary data provided out applying one of three different chest seals: HyFin (North
papers (e.g., reviews or books) American Rescue), SAM (SAM Medical Products), and Senti-
• Full text available—free of • Studies reporting data on nel (QuadMed). Their definition of a tension pneumothorax
charge or purchased by the children 28
German Military Medical was the same as that of Arnaud et al. If no tension pneumo-
Service thorax occurred, the tests were repeated with additional injec-
• Insufficient information or tions of blood into the chest cavity. A tension pneumothorax
missing abstracts. developed after 29.0mL air/kg bodyweight with no chest seal
application. After application of these tested chest seals, and
This author did not read the full text of an article if an exclusion continuing the injections of air, the authors prevented the de-
criterion was met by reading the title and/or abstract of a search velopment of tension pneumothorax in 20 of 24 swine mod-
result. If an article fit one of the inclusion criteria, the full text els. However, their criterion of a tension pneumothorax was
was read, when available. Other inclusion criteria were then ad- reached in 4 of 24 swine models. Discontinuing the injection
dressed. The findings were analyzed for evidence related to the of air resulted in stabilization. Upon final measurement, there
use of the various chest seals in the treatment of sucking chest was no significant difference reported in the 20 cases. Addi-
wounds or open pneumothorax and their ability to prevent the tional blood injections led to no further destabilization. The
development of a tension pneumothorax. Studies were also as- authors recommended the use of vented chest seals. 29
sessed regarding their implications for chest seal use in treating
battlefield sucking chest wounds. No statistical analysis (e.g., In 2013, Kheirabadi et al. compared the effectiveness of
30
meta-analysis) of the reported findings was performed. the Halo unvented chest seal (Medical Devices) to the Bolin
vented chest seal in an open pneumothorax swine model us-
Regarding the search words and strategy for international guide- ing repetitive infusions of air. Their definition of a tension
lines, PubMed database, Google, and professional knowledge pneumothorax was an intrapleural pressure ≥1mmHg and

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