BACKGROUND: To demonstrate the safety and efficacy of 65 degrees C (14
9 degrees F) centrally administered intravenous fluid (CIVF) compared
to conventional 40 degrees C (104 degrees F) CIVF in the treatment of
hypothermia. METHOD: Ten beagles (9-13 kg) were prospectively randomiz
ed to receive 65 degrees C or 40 degrees C CIVF. They were anesthetize
d and data were collected at baseline, during hypothermia, and after 1
and 2 hours of rewarming. The plasma free/total hemoglobin (PFHb/THb)
was measured to detect hemolysis. Each subject was cooled to 30 degre
es C (86 degrees F) and then received either 65 degrees C or 40 degree
s C CIVF through a specialized catheter in the superior vena cava for
2 hours in addition to conventional rewarming techniques. All subjects
survived 7 days, after which they were sacrificed and a complete auto
psy was performed. RESULTS: The rewarming rate was 3.7 degrees C/hr in
the 65 degrees C CIVF group and 1.75 degrees C/hr in the 40 degrees C
CIVF group. Core temperatures were significantly different after 1 ho
ur (33.4 degrees +/- 0.77 degrees versus 31.7 degrees +/- 0.57 degrees
, P < 0.01) and 2 hours (37 degrees +/- 1.03 degrees versus 33.4 degre
es +/- 0.89 degrees, P < 0.001). PFHb/THb was not different. Two intim
al injuries occurred in each group but these were remote from the infu
sion site. Blinded examination by two pathologists could not different
iate the etiology of these injuries from mechanical trauma. CONCLUSION
: CIVF at 65 degrees C is a safe and effective means of treating hypot
hermia.