DROWNING - Medicine for Mountaineering and Other Wilderness Activities - page 435

fromthewind,removingwetclothing,andcoveringthemwithinsulatingmaterialssuchas
blankets or clothing.
Defibrillation is ineffective if the heart is colder than about 90°F (32°C).
Distinction Between Drowning and Hypothermia
For individuals immersed in very cold water with a personal flotation device (PFD) for
long enough to be rendered unconscious by hypothermia, determining whether they have
drownedorareonlyseverelyhypothermiccanbedifficult.Iftheyhavedrowned,theyneed
CPR. However, if they are hypothermic, CPR would probably initiate ventricular fibrilla-
tion, and the hearts of individuals cold enough to be unconscious do not respond to electric
shocks.
Iftheindividuals aresupportedbytheirPFDswiththeirheadsoutofthewaterandtheir
hair is not wet, they are probably hypothermic and only need rewarming. Their heart rate
commonly is so slow and weak that it is difficult to detect. Before such individuals are as-
sumed to have drowned, the carotid artery should be palpated for a pulse. Palpation should
be continued for at least a minute, preferably three minutes. In a suitable situation such
palpation could be performed while the individuals are still in the water and their circu-
lation is supported by the pressure of the water. If the situation does not permit palpation
while the individuals are in the water, they should be gently lifted from the water in a hori-
zontal position and carotid palpation performed in the rescue vessel.
If an ambulance or similar source of medical support is nearby, taking an electrocardio-
gram to determine whether the heart is beating is probably worth the time it would require.
The delay probably would not have an adverse effect on an individual who had drowned
and could avoid initiating ventricular fibrillation for a person who was only hypothermic.
Treatment en Route to a Medical Facility
If the individual has not responded to CPR, efforts usually should be continued while
en route to a medical facility. The person should be kept warm, but overzealous warming
shouldbeavoided.Shivering,althoughagoodprognosticsign,doesincreasetissueoxygen
demands.
If the person is conscious and able to swallow, warm drinks containing sugar may
provide some benefit. Supplemental oxygen can be administered if available.
A medical facility that has the ability to provide cardiac bypass rewarming and circulat-
ory support is ideal if the individual is still not breathing and is pulseless.
PREVENTING DROWNING
Passive strategies appear to be the most successful for preventing drowning in young
people.Unfortunately,passivestrategiestendtohavelittlebenefitforadolescents.Primary