Very hot intravenous fluid in the treatment of hypothermia

The efficacy and safety of very hot (65 degrees C/149 degrees F) intravenous fluid (IVF) were compared with those of conventional warm (38 degrees C/100.4 degrees F) IVF in the treatment of hypothermia. Eight anesthetized beagles (11-20 kg) were studied. Blood pressure (BP), pulse (P), and core temperature (cT degrees) were recorded at baseline, during hypothermia, and during rewarming. The plasma free hemoglobin (PFHg) was measured to assess hemolysis. Each subject was cooled to 32 degrees C/89.6 degrees F and assigned to receive either 65 degrees C or 38 degrees C IVF via a specially designed multiport balloon-tipped catheter in the superior vena cava (SVC). The IV fluid rate was 80% of the blood volume per hour. Conventional rewarming methods were used in all subjects. After 2 hours the subjects were killed and the SVC was examined for injury. The rate of rewarming was 2.9 degrees C/hour in the 65 degrees C IVF group and 1.25 degrees C/hour in the 38 degrees C IVF group. The cT degrees was significantly different in all subjects after 1 (35.2 degrees +/- 1.03 degrees C vs. 33.2 degrees +/- 0.5 degrees C; p < 0.006) and 2 (37.6 degrees +/- 1.17 degrees C vs. 34.3 degrees +/- 0.9 degrees C; p < 0.004) hours of rewarming. The BP, P, and PFHg were not different. Visual examination of the SVC revealed two lesions in the 65 degrees C IVF group and one in the 38 degrees C group. Mechanical or thermal injury could not be differentiated.(ABSTRACT TRUNCATED AT 250 WORDS)