RESUMEN
Background: It is well known that the addition of CO2 gas during cardiopulmonary bypass (CPB) can increase cerebral blood flow (CBF). In this study, we tried to find whether the increase of CBF by CO2 gas could be expressed on the measurement of body temperatures. Methods: This study included 22 adult patients who underwent CPB with moderate hypothermia and were assigned randomly to two groups by adding CO2 gas (CO2 group and Air group). We measured each tympanic (TM), nasopharyngeal (NP), oral, forehead, finger, rectal and CPB arterial line temperatures of CPB circuit for 20 times during cooling in every one minute for 20 minutes and during rewarming every two minutes for 40 minutes. Results: During cooling and rewarming, the TM, NP and oral temperatures changed more rapidly than the rectal and finger temperatures. In TM temperature, as time changed, the percent changes of temperature varied more prominently in the CO2 gas group than in the Air group. The statistical differences were significant especially during 13 minutes to 20 minutes in cooling and 8 minutes to 20 minutes during rewarming. Conclusion: From this data, we can postulate the effect of CO2 gas on CBF indirectly by measuring several sites of body temperatures.