Page 23 - Journal of Special Operations Medicine - Spring 2015

obtained vital signs. A cardiac rhythm strip showed decrease gas bubbles in tissue. Lactated Ringer’s or
12
normal sinus rhythm, with heart rate, 84 beats/min; Plasma­Lyte (Baxter International Inc; www.baxter.com)
®
blood pressure, 138/66mmHg; respiratory rate, 16/min; is recommended due to the hyperchloremic acidosis as­
oxygen saturation on room air, 98%; and temperature, sociated with administration of hyperphysiologic 0.9%
98.0ºF by mouth. An 18­gauge, peripheral intravenous sodium chloride solutions. A Foley catheter may need
(IV) catheter was placed in the left antecubital fossa on to be placed in obtunded casualties. If there is concern
first attempt. A 12­lead electrocardiogram indicated for AGE, the casualty can also be placed in the Tren­
some degree of benign early repolarization but no evi­ delenburg position (bed angled downward toward the
dence of acute pathology. Physical examination showed head) to put the right ventricular outflow inferior to the
a healthy appearing and alert male who appeared his right ventricle, allow air to migrate superiorly, and help
stated age and was in no acute distress. Head, eyes, restore forward blood flow. If aeromedical evacuation is
ears, nose, and throat examination was unremarkable, required, it is recommended to maintain as low an alti­
neck veins were flat, lung sounds were clear, heart tones tude as possible: altitude of 500 feet above the departure
were normal, abdomen was soft and nontender, and point has been cited as a preferred limit. 14
his extremities were without tenderness to palpation. A
neurologic examination showed no abnormalities to in­ SOF Considerations
clude sensation, strength, rapid alternating movements,
coordination (heel­to­shin, finger­to­nose), and reflexes DCS is made more likely in SOF missions where mul­
bilaterally. tiple risk factors are comingled—a single mission may
require both a high­altitude parachuting as well as div­
ing. While there is risk with either activity, there is a syn­
Treatment
ergistic effect that is more likely to result in DCS. SOF
The definitive treatment of DCS Type II is recompres­ medical personnel anticipating the possibility of DCS
sion with a hyperbaric oxygen (HBO) chamber. HBO during a mission should know the location of the near­
12
is considered both therapeutic and diagnostic for DCS. est available HBO chamber and develop an evacuation
13
The highest priority must be placed on evacuation of the plan. Prolonged evacuation times are to be expected in
casualty to this capability. HBO is typically provided by the environments in which SOF personnel operate.
major medical centers and is not available at all hos­
pitals. The nearest location of a hypobaric chamber A dual­cylinder portable resuscitator/inhalator/aspirator
worldwide can be found by calling the Divers Alert Net­ setup similar to the Flynn Series III (O­Two Systems;
work at +1­919­684­9111. BAMC does not have a hy­ otwo.com) pictured in Figure 1 and commonly issued to
perbarics service; any patient requiring HBO treatment Dive Medical Officers (NSN 6515­01­061­7811) is ideal
is referred to Wilford Hall Ambulatory Surgical Center to provide uninterrupted high­concentration oxygen and
(WHASC) at nearby Lackland Air Force Base, Texas.

Figure 1 Flynn Series III Dual Cylinder Portable Resuscitator
Immediate stabilizing treatment primarily consists of de­ NSN: 6515-01-061-7811.
livering the highest concentration of oxygen possible.
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In many settings, this consists of the nonrebreather
mask, which delivers a variable concentration reported
to be as low as 60%, depending on many factors. These
include flow rate, mask seal, and the presence/absence
of check valves on the mask ports. For this reason, the
demand valve resuscitator (also known as a manually
triggered ventilator or flow­restricted, oxygen­powered
ventilatory device) or the Oxylator (CPR Medical De­
®
vices Inc; www.cprmedic.com) device carried in the SOF
medical set (used in automatic or manual mode only)
are the preferred methods. These devices allow a high
flow rate and delivered oxygen concentration of up to
100% with a good mask seal. Additionally, these devices
only use gas on demand, not on “free flow,” like a non­
rebreather mask or bag­valve mask, and thus conserve
limited oxygen resources in a prolonged evacuation.

IV fluids should be administered to ensure good urine
output of 1–2mL/hr; hydration is theorized to help

Case Report: DCS Following Altitude-Chamber Training 13