E. Kornberger et al., HEMODYNAMICS AND OXYGEN-METABOLISM IN THE PIG DURING LONG-TERM HYPOTHERMIA - COMPARISON OF 2 PH STRATEGIES, Resuscitation, 30(1), 1995, pp. 43-50
The aim of this study was to investigate the influence of acid-base ma
nagement (pH stat or alpha stat) on hemodynamics and oxygen metabolism
during long-term hypothermia in the pig. Seventeen female pigs were a
nesthetized, slowly cooled to 28 degrees C with cooling mats and kept
at this temperature for 36 h. Thereafter, slow rewarming was performed
with inhalation of a 40 degrees C warm air/oxygen mixture and insulat
ion. Eight of the 17 pigs were ventilated according to the pH stat str
ategy and 9 according to the alpha stat strategy. Both groups were com
pared 4 times each for hemodynamics and metabolism during cooling, hyp
othermia and rewarming. The 2 strategies showed no significant differe
nce in cardiac output, heart rate or mean arterial pressure. The only
difference in hemodynamics was observed in mean pulmonary artery press
ure and pulmonary artery resistance during hypothermia, showing higher
values in pH stat animals. As for oxygen metabolism oxygen consumptio
n during hypothermia was significantly higher in alpha stat animals. L
ong-term hypothermia with spontaneous circulation revealed significant
differences in oxygen metabolism and pulmonary artery pressure as wel
l as resistance between alpha and pH stat acid-base management. These
differences may be of importance when using moderate hypothermia in a
clinical or experimental setting.