Page 46 - Journal of Special Operations Medicine - Winter 2014

The importance of training military medics in cricothy- Secondary outcomes included complications and rea-
rotomy has been previously highlighted. 13,14 The ma- sons for cricothyrotomy failure, associated LSIs per-
jority of military medics are trained to the emergency formed, type of provider performing the procedure, and
medical technician-B level with an additional 7 hours of survival to combat hospital discharge.
cricothyrotomy instruction, which includes at least 12
insertions on a plastic mannikin. Military medics are
14
taught this single advanced airway technique because it Data Analysis
can be used in nonparalyzed patients and requires less For this descriptive analysis, non-normally distrib-
training and equipment than orotracheal intubation. uted data are reported as a median (interquartile range
[IQR]). The Wilcoxon test (nonparametric) was used for
Combat cricothyrotomies between 2007 and 2009 have data comparisons and the chi-square test for equal pro-
been described in a case series. However, this study was portions was used for individual group data compari-
16
retrospective and did not include procedures performed son; significance was set at p < .05 for both tests.
en route to a combat hospital. Therefore, we performed
an up-to-date prospective review of prehospital and en
route combat cricothyrotomy with the aim of describing Results
the survival rate, complications, and associated lifesav- Of the 1,927 patients enrolled in the LSI study, 34
ing interventions to better inform future training and (1.8%) were recorded as having had a prehospital or
practice. en route cricothyrotomy. The median age of cricothy-
rotomy patients was 24 years (IQR: 22.5–25.0 years)
and 97% were male. Blast injury was the predominant
Methods
mechanism of injury, present in over three-quarters of
This study is part of a large, prospective, multicenter, these patients (Table 1). Major head, face, and neck in-
observational study at combat hospitals in Iraq and jury was recorded in 83% of cricothyrotomy patients,
Afghanistan that collected data on prehospital and significantly more than the patients who had not under-
en route life-saving interventions in combat (the Life- gone cricothyrotomy (43%; p < .0001).
Saving Intervention [LSI] database). The study proto-
17
col was approved by the Brooke Army Medical Center
Institutional Review Board (No. 363512). Table 1 Demographics, Patient Classifications, and
Mechanism of Injury
Criteria for enrollment included any patient with com- Demographics No. %
bat trauma who was transferred from the point of injury Range: Median: 24
to one of six combat hospitals between January 2009 Age, years 20–31 (IQR 22.5–25.0)
and October 2013. Trained on-site study investigators Male 33 97
recorded LSIs performed in the field and en route using
a standardized data collection form as the patients ar- Female 1 3
rived at the hospital. LSIs were predefined and included Iraq 0 0
cricothyrotomy, endotracheal intubations, chest tubes, Afghanistan 34 100
and applications of hemorrhage-control limb tourni- Patient classification
quets, among other LSIs. Successful application of each
LSI was determined by the on-site physician and investi- US military 19 56
gation team at the receiving combat hospital. Afghan security forces 11 32
Local civilian 3 9
We analyzed all patients in the LSI database who had a Coalition military 1 3
prehospital or en route cricothyrotomy. These patients
were then cross-referenced with the Department of De- Mechanism of injury
fense Trauma Registry (DoDTR) to provide data on hos- Blast 27 79
pital outcomes. The DoDTR (formerly the Joint Theatre Penetrating 6 18
Trauma Registry) is a performance-improvement mili- Blunt 1 3
tary medical database of combat casualties treated in
Iraq, Afghanistan, and other deployment areas. 18 Note: IQR = interquartile range.

The median Glasgow Coma Scale (GCS) score on arrival
Primary and Secondary Outcomes
to the combat hospital was 3 (IQR: 3–7.5) and four pa-
The primary outcome of this study was the success rate tients had a GCS score of 8 or higher (Table 2). Only
of prehospital and en route combat cricothyrotomy. four patients were recorded as having received sedating

36 Journal of Special Operations Medicine Volume 14, Edition 4/Winter 2014