Prolonged rewarming after hypothermic cardiopulmonary bypass does not attenuate reduction of jugular bulb oxygen saturation.
OBJECTIVE
This study investigates the effects of rapid versus graded rewarming on decreases in jugular bulb oxygen saturation (SjO2) during cardiopulmonary bypass (CPB) in a prospective nonrandomized and nonblinded design.


METHODS
At the Department of Anesthesiology (University Hospital Eppendorf, Germany), 28 patients (ASA III) undergoing coronary artery bypass graft were investigated.


METHODS
CPB was managed according to alpha-stat conditions during moderate hypothermia (27 degrees C). In group 1 (n = 17), rewarming was performed by increasing the perfusate temperature to 36 degrees C within 7 minutes, in group 2 (n = 11) within 15 minutes.


RESULTS
SjO2 was measured by a fiberoptic catheter placed in the right jugular bulb. Data were recorded before and 40 minutes after the start of rewarming every 5 minutes. During rewarming of CPB, SjO2 was decreased to 43 +/- 7% in group 1 and to 44 +/- 4% in group 2. In groups 1 and 2, the maximum reduction of SjO2 occurred 17 minutes and 30 minutes after start of rewarming, respectively. The delayed reduction of SjO2 in group 2 correlated strongly with the prolonged increase in jugular bulb temperature.


CONCLUSIONS
The current data show that slow rewarming does not attenuate reductions of SjO2. This suggests that the reduction of SjO2 during rewarming of CPB is not a function of the rewarming speed but is strongly correlated with the increase in jugular bulb temperature, with a maximum effect just before reaching normothermia of the brain.
von Knobelsdorff
G
G
Department of Anesthesiology, University Hospital Eppendorf, Hamburg, Germany.
Tonner
P H
PH
Hänel
F
F
Bischoff
P
P
Scholz
J
J
Schulte am Esch
J
J
D000328:Adult; D000368:Aged; D001831:Body Temperature; D002315:Cardiopulmonary Bypass; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007036:Hypothermia, Induced; D007601:Jugular Veins; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D011446:Prospective Studies
D010100:Oxygen