patient was further assessed in the ambulance
and then flown by Carilion Clinic LifeGuard
to Carilion Roanoke Memorial Hospital, from
which he was released the next day.
Hypothermia is separated into three phases:
mild, moderate and severe.1 Mild hypothermia begins when the core body temperature,
which normally varies among individuals
from 98–100° F, drops below 95° F. 2
As core temperature drops, several physiologic changes occur as the body begins to
conserve and attempt to generate heat. This
process occurs through activation of the sympathetic nervous system and includes shivering, hyperglycemia, tachycardia, vascular
constriction and hypertension. 3
When core body temperature drops below
89.6° F, moderate hypothermia sets in. 2 It
results in significant altered mental status
including hallucinations, agitation, somnolence and possible loss of pupillary reflex.
Other findings include bradycardia, decreased
cardiac output and hypoventilation. 3 ECG
abnormalities are also common, specifically
a J or Osborn wave, which is specifically a distortion of early membrane repolarization and
indicative of moderate hypothermia. 4
In severe hypothermia (when body temperature drops below 82. 4° F), a patient will
exhibit marked stupor and all shivering will
cease. 2 The patient will experience progressively worsening bradycardia, hypotension
and hypoapnea, progressing to shock and
multi-organ system failure. 3
This patient exhibited signs of mild hypothermia throughout the incident. During the
time when he had his lowest blood pressure
readings and became increasingly lethargic,
EMTs on scene were concerned about potential onset of moderate hypothermia.
Although it was not possible to quantify the
patient’s temperature by direct measurement
due to his confined position, his rapid recovery suggests his condition never advanced
beyond the mildest stage of hypothermia.
The rates at which a patient’s core temperature drops and stages of hypothermia are
experienced are highly dependent on ambient conditions. The timescale can vary from
minutes (i.e., when submersed in cold water)
to days (i.e., when exposed to freezing air temperatures with inadequate clothing).
During this cave rescue, onset of hypothermia was slow because the patient was dry and
winds were calm, particularly due to shielding by rock formations. The bedrock he was
in direct contact with initially lowered his
temperature by conductive heat loss more
rapidly than heat lost directly to the atmosphere. This is because the rock was colder
than the afternoon air temperature. However,
the rock walls eventually worked to insulate
him, because the cooling of the rock surface
lagged behind the plummeting temperature
of the air. (Note: Had the patient been trapped
inside the cave, as opposed to its entrance, the
ambient temperature would have been a constant 54° F, the mean annual temperature for
this location.) The patient’s large body mass of
around 220 lbs. also contributed to relatively
slow conductive heat loss.
This rescue illustrates the challenges when key
factors that are normally taken for granted on
calls are absent, namely patient access, a stable
environment and limited scene time. Unlike
most situations, it wasn’t possible to remove
this patient to a safe ambient setting.
Because of his confinement, it was difficult to even obtain vital signs. It wasn’t possible to establish an IV or intraosseous access,
given the limited access to his extremities and
because of the rigorous motions involved in
the rescue. EMTs couldn’t have placed defibrillator pads on the patient had they been
needed, and even oxygen by mask wasn’t
feasible because of the amount of hammering around the patient’s head and the motion
required of him during the effort. Keeping the
patient warm, which was the primary goal
of the EMTs during the rescue effort, also
required flexibility and creativity.
The orientation and confinement of the
patient prevented wrapping him in blankets
or additional clothing. The primary effort to
warm him consisted of applying 20-minute
duration chemical heat packs wherever accessible, including his hips, arms and neck. The
responding units quickly depleted all of their
heat packs and eventually drained the storerooms of several neighboring EMS agencies,
ultimately consuming about 175 packs.
Other means of warming included a
propane space heater, but this couldn’t be
brought close enough to be effective and
posed a risk of fumes and fire to the rescu-
ers inside the cave. An electric hair dryer
borrowed from a local farmer was moder-
ately successful at warming the air around the
patient’s upper body, while an electric blanket
draped over the patient’s head and shoulders
helped as well.
The lesson to take away is that some calls
require creative, even ingenious efforts to
keep patients alive and bring them to safety.
In this case, first responder thinking had to
evolve quickly and then continuously adjust
and seek out alternatives as the rescue effort
When hypothermia from exposure is a
risk, anything that warms without harming
should be considered. Prolonged wintertime
rescues like this also require special attention
to scene safety to avoid cold-related injury and
exhaustion of the first responders themselves.
This rescue illustrates that in addition to
standard qualities of first responders, particularly diligence, selflessness, calmness and professionalism, some complex rescue scenes
demand creativity and flexibility as well. JEMS
Collin Hu, EMT-E, is second lieutenant in the U. S. Army, and
a fourth-year medical student at the Edward Via College of
Osteopathic Medicine. He is a member of the Blacksburg
(Va.) Volunteer Rescue Squad.
James A. Spotila, PhD, EMT-B, is associate professor of
geology at Virginia Polytechnic Institute and State University
and a member of the Blacksburg Volunteer Rescue Squad.
in;PHTLSPrehospital;Trauma Life Support,6th Edition.
Crit;Care;Clin.;1999; 15( 2):235–249.
Resuscitation;2005; 64( 2):133–134.