Fluid Replacement during Hypothermia,
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA
Pagination or Media Count:
Hypothermia produces acidoses, depressed cardiac function, hypovolemia and hypotension. This study was designed to examine the cardiovascular dynamics involved with restoration of the hypovolemia before rewarming. Mixed breed splenectomized adult dogs n16 were anesthetized with pentobarbital and cooled to a right atrial temperature of 25 deg C at a rate of 3 deg CHr. The animals were maintained at 25 deg C for 6 hours and rewarmed at 3 deg CHr. One group 1 was given no fluid, one group 2 was given saline 20 of plasma volume infused in 10 min. two hours after reaching 25 deg C and one group 3 received saline just prior to rewarming. The hematocrit was elevated in all groups Por 0.05 upon cooling, but did not differ between groups even after saline was given. Cardiac output CO at 25 deg C was 35 of precooled values. The second group increased their CO by 15 with fluid and this CO was maintained higher than groups 1 or 3 for the next four hours. Plasma volume, heart rate, and cardiac contractility returned to control levels upon rewarming, but CO remained low or 10. The level of CO at the start of rewarming did not affect the final level of CO.
- Anatomy and Physiology