Page 25 - Journal of Special Operations Medicine - Winter 2014

The use of ketamine for procedural sedation in the was 16.6% and was significantly higher for wounded
combat setting was used in a single patient to control Servicemembers, with a rate of 31.8%. 18,19 Ketamine is
hemorrhage from facial and right eye injuries. In this thought to be associated with a decreased prevalence of
same patient, a cricothyroidotomy was contemplated PTSD. There are no studies that conclude that prehos-
but subsequently aborted secondary to rapid transport pital ketamine can decrease PTSD in severely injured
time. It was the impression of the treating medic that patients, but it has been shown to decrease the amount
ketamine would have provided adequate sedation had of PTSD in patients when ketamine is given periopera-
the procedure been necessary. It may be used more fre- tively. Another study showed use of an analgesic was
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quently as evacuations become longer in the current associated with a lower incidence of PTSD. There is an
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combat setting. opinion among military providers that ketamine’s rapid
onset of effective analgesia in the prehospital setting
As evacuation time and care in the field become pro- could help decrease the prevalence of PTSD. Of the nine
longed during future operations, wound care by the US Servicemembers who received ketamine at the POI,
medic may be necessary and can be extremely painful. only two were subsequently diagnosed with PTSD. We
Ketamine is an optimal drug for procedural sedation in compared the injuries and scenarios surrounding the in-
the combat setting: its relative short effects, safety pro- juries of nine other Soldiers assigned to the 75th Ranger
file, and wide therapeutic index allow for all necessary Regiment with similar injuries. We compared past medi-
procedures and wound management without worry cal and behavioral health history along with the medi-
about airway or vascular compromise. Ketamine has cal records surrounding the injuries. We were limited
been shown to be as effective as other agents for rapid to the medical records available in electronic medical
sequence intubation. Other options for pain manage- record. In that group, six of the nine had PTSD. Even
13
ment include regional blocks, but these are technically though this was a small group, when compared to other
challenging in the field setting and have been associated severely injured Soldiers with similar injuries from the
with a risk of systemic toxicity, mostly due to an inad- 75th Ranger Regiment, ketamine appeared to decrease
vertent intravascular injection. There is also a small the incidents of PTSD.
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risk of peripheral nerve damage. In addition to the risks
of both regional and local anesthesia, another issue is
the ability to carry an adequate amount of anesthetic Limitations
when all medical supplies must be carried on the back Due to the small size of this retrospective study, it is dif-
of the medic. 2 ficult to draw any definitive conclusions about higher
doses of ketamine being administered in the prehospital
Ketamine has long been thought to worsen TBIs, and setting. In addition, other narcotic and sedative agents
fears of elevated ICP have limited its use in trauma pa- given with ketamine confound results, especially regard-
tients. Many combat trauma patients who suffer pen- ing ketamine’s effectiveness. The data from the patient
etrating trauma from improvised explosive devices also questionnaire are based on answers given up to 3 years
suffer TBI. Three of the patients in this case series were after the injury; recall on pain levels can be skewed in
exposed to overpressure that could cause a TBI, yet this population. The PHTR is very thorough but reliant
there were no adverse outcomes from the ketamine ad- on the medic filling out the casualty card and writing the
ministration. Recent data show that the historical con- report for input reliably. Certainly, there could be errors
traindication for use with TBI seems overreaching and on medication doses and the times they were given.
that ketamine decreased ICP in children by 30%. 15,16

Increased intraocular pressure (IOP) is another histori- Conclusion
cal concern with the administration of ketamine in the
presence of an eye injury, but recent studies have shown Ketamine appears to be a safe and effective as a dissocia-
that doses less than 4mg/kg are not associated with in- tive agent and an analgesic in the pre-hospital setting.
creased IOP when there is no globe injury. Although It has a superior safety profile when used in a combat
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patient 8 had penetrating shrapnel wounds to his eye trauma setting, with none of the undesirable side effects
and TBI, he was administered ketamine with no adverse of opioids. Despite the small population of the study,
effects or increased morbidity. Of the concerns regard- the results are promising. This small group appeared to
ing laryngospasm with ketamine use, there were no re- tolerate the larger doses well with few side effects. As
ported cases in this small group. with all other controlled substances, clear protocols and
proper training at all levels, as outlined in the fourth
A 2006 study showed posttraumatic stress disorder edition of the RMHB, are the keys to proper and suc-
(PTSD) rates for Servicemembers who deployed to Iraq cessful use of ketamine. With these promising results,

Prehospital Analgesia With Ketamine for Combat Wounds 15