X-Message-Number: 17730
From: "Igor Artyuhov" <>
Subject: Hypothermia for revived cardiac arrest patients appears safe
Date: Tue, 9 Oct 2001 15:55:55 +0400

Source: EurekAlert
http://www.eurekalert.org/pub_releases/2001-10/aha-hfr100301.php >>>

Public release date: 8-Oct-2001

Contact: Carole Bullock

214-706-1279
American Heart Association

Hypothermia for revived cardiac arrest patients appears safe

DALLAS, Oct. 9   Reducing the body temperature of someone revived from
cardiac arrest is feasible and safe, but cooling time must be faster to make
it a practical treatment, according to a report in today s Circulation:
Journal of the American Heart Association.
Those who are revived after cardiac arrest often suffer brain damage because
the flow of oxygen to the brain was shut off for too long. "Many surviving
patients are left with significant neurological disabilities," says senior
author J. C. Grotta, a neurologist at the University of Texas Houston
Medical School. In animal studies, lowering body temperature (hypothermia)
has consistently reduced brain injury. The sooner hypothermia begins and the
longer it lasts, the less chance for severe neurological damage. Exactly how
hypothermia protects the brain is unclear. However, reducing body
temperature decreases the brain s demand for oxygen, reduces the release of
nerve-killing chemicals, suppresses inflammation, and stabilizes cell
membranes.

Grotta and his colleagues studied nine patients whose cardiac arrests did
not occur in the hospital. After acute life support, each patient was
sedated and wrapped in two cooling blankets, one around the torso and the
other around the pelvis and legs. The goal was to lower body temperature to
33  C (91.4  F) within 120 minutes after initiating cooling and maintaining
that temperature for 24 hours.

Four of the patients survived, three of them without neurological
disabilities. The fourth survivor went home but required 24-hour supervision
due to memory problems. Achieving a body temperature of 33  C proved a slow
process taking an average of 301 minutes (1 and ? hours) in some
individuals. Initiating hypothermia in the nine patients took between 40 and
109 minutes, and averaged 78 minutes.

"Much of this time was spent obtaining informed consent," Grotta says. "An
average of 46 minutes was required obtaining the patient s or family s
consent to perform hypothermia treatment." It took an average of 391 minutes
(6 ? hours) from cardiac arrest until the patient s temperature dropped to
33  C. The time from hypothermia initiation to 33  C took 90 to 690 minutes
and averaged 301 minutes (5 hours). "Mild to moderate hypothermia appears
feasible and safe, especially when the poor prognosis after cardiac arrest
is taken into account," Grotta says. "It warrants further study, but
shortening the time to hypothermia will be important in further
evaluations." The team did not assess the efficacy of the technique.

The National Institutes of Health supported this research.

Co-authors are R. A. Felberg; M.D.; D.W. Krieger; M.D.; R. Chuang, D.E.
Persse M.D.; W. S. Burgin; S.L. Hickenbottom, M.D.; L.B. Morgenstern; M.D.
and O. Rosales, M.D.


###
CONTACT: For journal copies only,
please call: 214-706-1396
For other information, call:
Carole Bullock: 214-706-1279
Bridgette McNeill: 214-706-1135

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