Page 75 - JSOM Spring 2018

TABLE 1 Details of Ketamine Administration
Pain Level
Medications Pain Level Ketamine After Ketamine Ketamine Ketamine
Patient Age, y Sex MOI Before Pickup at Pickup Dose 1 Dose 1 Dose 2 Dose 3 Dose 4 Notes
Morphine
1 25 M Blast/IED 10mg IM Severe 50mg IM Severe N/A N/A N/A
Morphine
2 25 M GSW Moderate 50mg IM Mild N/A N/A N/A
10mg IM
Fentanyl
3 24 M Burns/IED Severe 50mg IM None N/A N/A N/A
800μg TM
Fentanyl
4 23 M Blast/IED Severe 25mg IM Unknown N/A N/A N/A
800μg TM
Fentanyl
5 21 M Burns/IED Moderate 25mg IM None N/A N/A N/A
800μg TM
6 25 M GSW None Severe 50mg IM Mild N/A N/A N/A
Morphine
7 20 M Blast/IED Severe 50mg IM Mild N/A N/A N/A
20mg IM
8 30 M Blast/IED None Severe 50mg IM Mild N/A N/A N/A
9 30 M Blast/IED None Moderate 50mg IM None N/A N/A N/A
Morphine
10 20 M GSW Moderate 25mg IM None N/A N/A N/A
10mg IM
GCS, Glasgow Coma Scale; GSW, gunshot wound; IED, improvised explosive device; IM, intramuscular; MOI, mechanism of injury; N/A, not
applicable; TBI, traumatic brain injury; TM, transmucosal.

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often, just a single dose was required, as opposed to the need of IV morphine or IV fentanyl are often required. Decreasing
for multiple doses of morphine or fentanyl, based on empiric or eliminating opioid use during TACEVAC may be beneficial
PJ experiences and observations. 20 to avoid known complications of opioids such as respiratory
depression, acute nausea and vomiting, and histamine-related
Ketamine was discovered in 1962 and was used successfully hypotension with morphine analgesia.
3
in the Vietnam conflict. Since that time, the drug has been
used as a general anesthetic; recently, ketamine has gained ac- Ketamine provides an additional benefit in combat rescue be-
ceptance in the medical community for off-label uses of anal- cause it is not only an effective analgesic but also an excellent
gesia and procedural sedation. Physicians have been using the induction agent for RSI, particularly in battlefield trauma: It
drug for approximately two decades for procedural sedation stimulates catecholamine release, increased cardiac output, in-
in children. The American College of Emergency Physicians creased mean arterial pressure, and cerebral blood flow. 24,25
has published a statement supporting its use in procedural In addition, ketamine decreases vascular nitric oxide, which
sedation. 21,22 prevents vasodilation that can promote increased blood return
to the heart. All are important factors in maintaining hemo-
The pharmacodynamics of ketamine are advantageous and dynamic stability in battlefield trauma patients who may have
versatile. Ketamine has a rapid onset of action and can be ad- lost significant quantities of blood. 26
ministered through various routes, including IM, IV, IO, in-
tranasal, and rectal. When given via the IV route, the onset Though the overall sample size in this study was small, the data
of action is approximately 30 seconds; the terminal half-life is we collected, in addition to the anecdotal evidence from many
5
longer than 150 minutes for the IM, IV, and IO routes. This providers from a wide array of medical specialties, seem to sup-
is much more rapid when compared with morphine, whose port the idea that ketamine is as efficacious as opioids for the
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full effects sometimes take longer than 30 minutes. When use of battlefield analgesia. Controlled trials in the prehospital
delivered via the IM route, ketamine’s time to clinical effects tactical setting would be helpful, but, at this time, ketamine
is 4 minutes. More importantly, ketamine has the benefit of appears to be a reliable battlefield and TACEVAC analgesic.
allowing the respiratory drive to remain intact. The versatil- Ketamine’s rapid onset of action and profound analgesic prop-
ity of administration routes combined with a wide therapeutic erties have helped it succeed where prior administration of opi-
window result in a very useful medication for the tactical pro- oids failed to provide adequate control of pain. Notably, none
vider. Quick administration and decreased risk of respiratory of the patients in this study had hallucinations or emergence
depression allow the tactical prehospital medic to multitask; phenomenon, which has been associated with the anesthetic in-
this is essential when returning enemy fire or caring for mul- duction doses of ketamine. These conclusions are supported by
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tiple patients may necessitate expedited medical care. findings of a recent study from Petz et al., who confirmed the
successful use of ketamine in the current Afghanistan conflict
The concurrent administration of ketamine with opiate medi- examining MERT, Pararescue, and US Air Medical Evacuation
cations produces a known synergistic effect due to ketamine’s team use of analgesic medications on the battlefield.
interaction at the δ and μ opioid receptors. This synergism
with opioids was proven clinically beneficial; Galinski and col- Our limited process improvement initiative does not have
leagues demonstrated a 26% decrease in morphine redosing enough data to make a strong determination about ketamine
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without significant adverse effects. This is important because safety and efficacy in the hands of PJs providing TACEVAC.
studies that evaluated opiate use for pain control in the prehos- However, it does indicate that the use of ketamine in this com-
pital setting have shown that as many as three repeated doses bat casualty care setting appears to be safe and effective. Our
Prehospital Ketamine Use During OEF | 71