A technique that is unheard of in
this country is being used every day now to save heart attack patients in
Australia. Researchers there have found that cooling the body following a heart
attack lowers the risk of death and reduces damage to both the brain and heart.
You may recall incidence where
people have fallen through ice and their heart stopped for 20 minutes or longer,
yet they survived the ordeal with little or no brain damage. Normally, when the
heart stops for only a few minutes the brain becomes permanently damaged from a
lack of oxygen. And even if an individual is revived, further brain damage
results when oxygenated blood floods back into the area.
Hypothermia, or cooling of the
body. somehow provides a protective effect, and may actually let the brain
survive longer without oxygen. Cooling the body in heart attack victims was
attempted in the early 1950s but it never became an accepted form of treatment.
the Dandenong Hospital in Dandenong, Australia, doctors recently tested mild
hypothermia on heart attack patients. On odd-numbered days, doctors instructed
ambulances and other emergency teams to apply ice packs to comatose heart attack
patients upon resuscitation. The body core temperature of these patients was
then kept at between 32o C (89.6o
F) and 34o (93.2o
F) for the next 12 hours. (Normal body temperature is 37o
C.) On even-numbered days, they kept such patients warm after resuscitation.
When the results from 77 patients
were tallied, a dramatic difference was evident. Of the 43 patients that were
cooled, 21 (49%) were discharged to either their homes or a rehabilitation
center, compared with only 9 of the 34 patients (26%) who were kept warm. [N
Engl J Med 02;346(8):557-63]
Based on these findings,
Dandenong Hospital and other hospitals in the Melbourne area are now
immediately cooling all comatose-revived heart attack patients in the ambulance,
before they even reach the hospital.
A similar study recently
took place in Germany at Bonn University. Dr. Mattias Fischer and his colleagues
began to cool half their comatose heart attack patients to a body core
temperature of 33o (91.4o
F) for 24 hours immediately after resuscitation.
The odds of someone surviving a
heart attack after becoming comatose are not very good. Statistics show that
about 75% are never revived or die shortly thereafter. However, this study
showed that using mild hypothermia could significantly improve the odds of
The study involved a total of 273
patients with an average age of 59. Within six months, 41% of those who
received the hypothermia treatment died, compared to 55% of those who were kept
at normal body temperature. That represents a 14% increase in survival rate for
the cooled patients. Among the patients that were cooled, 55% recovered
well enough to live independently and work again, compared to only 39% of
those who had not been cooled. [N Engl J Med 02;346(8):549-56]
Using mild hypothermia, or the
technique of cooling the body to somewhere in the range of 32o
to 34o, can save lives and help
minimize brain damage in comatose heart attack patients. It does, however,
require a degree of expertise and the right equipment to maintain the proper
temperature for 12 to 24 hours following resuscitation of the individual.
Special cooling blankets are used in the hospital to drop down to and maintain
the proper temperature, and the re-warming of the patient must be done carefully
Although very few hospitals in
the U.S. have adopted the practice, it might be worth checking those in your
area, particularly if you have a heart condition. If the hospital you utilize
does use the technique, then, in addition to being trained in CPR, family
members should be aware of using ice packs and mild hypothermia until medical
help arrives. The best way to do this is to pack three or four bags of ice (such
as you get at the grocery store) around the head and on the chest for 15 to 30
minutes. This is particularly important if help will be some time in coming.
Hopefully this technique will
become commonplace in this country sooner rather than later.