Page 48 - Journal of Special Operations Medicine - Winter 2014

different patient populations. This study only includes We also found that there were more LSIs in cricothy-
patients who were transported to a combat hospital. It rotomy patients than noncricothyrotomy patients. This
is therefore possible that we missed a group of patients has not been previously reported but is likely to be a
with cricothyrotomies performed prehospital who died surrogate for injury severity (i.e., more unwell patients
and were subsequently not transported to hospital. This require a greater number of interventions). This effec-
would introduce a survivor bias and potentially improve tively means that the task burden on prehospital medics
both the success rate and the survival rate associated is very high when caring for patients who require a sur-
with this procedure. gical airway (Table 4).

Four cricothyrotomy patients had a GCS score of 8 or Due to its relatively low frequency and emergency na-
higher on arrival at the combat hospital, and an addi- ture, airway management is often not suitable for ran-
tional six patients had a GCS score between 4 and 7. The domized controlled trials. Most reports have been
7
rate of survival to combat hospital discharge in these two retrospective and, thus, success rates may not be accu-
groups combined (of those with known outcomes) was rate and complications may be missed. Our study was
80%. However, those with a GCS score of 3 only had prospective and observational. The data were captured
a 23% survival rate. This low GCS is likely to represent on return to the combat hospital, with verification of
confounders of nonsurvivable head injuries and profound procedural success judged by in-hospital physicians.
hypovolemia manifesting in unconsciousness. None of This creates the possibility for recall and observation
the patients with a GCS score higher than 3 had any pre- biases. However, data capture was performed within
hospital or en route analgesia or sedation recorded. While minutes to hours after the transport (depending on op-
it is possible that the medications were not accurately erational needs), limiting these biases. In addition, we
recorded or that these patients were unconscious at the were not able to obtain data on ISSs from the avail-
time of the cricothyrotomy, it suggests that some of these able medical data sources and there were limited data
patients might not have received adequate analgesia. recorded of prehospital provider type undertaking the
LSIs. Also, most of the patients had a blast injury, which
The reasons for failure of cricothyrotomy in our study is uncommon in US civilian settings. Finally, prehospital
are consistent with those previously described. 8,14,16,19 cricothyrotomy is uncommon and, thus, our sample size
The patient who received a main stem bronchus intuba- is small, limiting other analyses of the data.
tion survived to hospital discharge, but no further in-
formation was available on his outcome, so the impact In our prospective, multicenter study evaluating crico-
of this “failure” is unknown. A failure or complication thyrotomy in combat, procedural success was higher
rate of 18% is comparable to both pooled civilian data than previously reported. In addition, the majority of
3
and combat data. The reason that significantly more cricothyrotomies were performed by the evacuation
16
cricothyrotomies were performed by helicopter-borne helicopter medic rather than the prehospital combat
medics may reflect their higher level of training, fre- medic. Future training of prehospital combat medics
quent exposure to this procedure, or a greater ability in this lifesaving skill should include the following:
to recognize the clinical situation that requires an in- decision-making skills to undertake the procedure; rec-
vasive advanced airway (i.e., more developed decision ognition that the greatest survival is associated with
making). The number of cricothyrotomies performed by conscious patients (and, therefore, a need to deliver ap-
ground medics (n = 6), however, is too small to mean- propriate analgesia or sedation); that head, face, and
ingfully compare their success and complication rates. neck injury is a common injury pattern indicating po-
tential airway compromise; and that these patients are
The training level and experience of Army flight medics likely to require a number of prehospital interventions
vary across units. While most active duty Army flight (commonly, intravascular access, warming blankets,
medics during the study period were only required to and wound packing).
be current EMT-Bs, some flight medics, especially those
in the National Guard and Army Reserve, were expe-
rienced and practicing National Registry Paramedic Presentation
(NRP) and Flight Paramedic Certified (FP-C) as their Part of these data was presented in May 2014 at the
primary civilian employment. Since this study period, Society for Academic Emergency Medicine conference
the Army has adopted NRP certification with an addi- in Dallas, Texas.
tional 2 months of intensive training in critical care as
their new flight medic training standard. This decision
was based on a previous study that showed improved Funding
patient outcomes using National Guard critical care– This study received funding from the US Air Force Sur-
trained paramedics during medevac. 20 geon General’s Office (AFMSA-EM-I-12-00).

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