Inada T, Shingu K, Uchida M, Kawachi S, Tsushima K, Niitsu T
Department of Anesthesiology, Kansai Medical University Hospital, Osaka, Japan.
Can J Anaesth. 1996 Oct;43(10):1019-24. doi: 10.1007/BF03011903.
To investigate changes of cerebral arteriovenous oxygen content difference (AVDO2) induced by surgical incision and to determine carbon dioxide (CO2) reactivity of the cerebral circulation during sevoflurane and isoflurane anaesthesia.
Twenty-one ASA 1-2 patients undergoing elective surgery for supratentorial tumours were randomly allocated to receive either 1.3 MAC sevoflurane/N2O anaesthesia (n = 10) or equi-MAC isoflurane/N2O anaesthesia (n = 11). Before and after incision, haemodynamic measurements and AVDO2 determinations were performed. After opening the dura, AVDO2 was determined before and after the respiration rate was increased by 50%.
Incision produced an increase in mean arterial pressure from 69 +/- 11 to 97 +/- 22 mmHg (mean +/- SD) (P < 0.0005) and from 71 +/- 6 to 89 +/- 12 mmHg (P < 0.0001) in the sevoflurane and isoflurane groups, respectively, whereas the heart rate increased from 60 +/- 9 to 72 +/- 8 bpm (P < 0.001) and from 65 +/- 6 to 70 +/- 7 bpm (P < 0.001), respectively. Arterial carbon dioxide tension (PaCO2) was increased from 33.6 +/- 2.3 to 34.6 +/- 1.8 mmHg (P < 0.05) with incision in the sevoflurane group. The AVDO2 was decreased from 6.5 +/- 1.6 to 5.3 +/- 1.6 vol% (P < 0.0005) in the sevoflurane group and from 6.7 +/- 1.1 to 6.0 +/- 1.1 vol% (P < 0.01) in the isoflurane group. The % change of AVDO2 was larger in the sevoflurane group than in the isoflurane group (-18.3 +/- 8.4% vs -9.1 +/- 9.0%; P < 0.05) but no difference remained after the post-incisional AVDO2 value of the sevoflurane group was corrected for pre-incisional PaCO2. Carbon dioxide reactivity, calculated as the percent change in AVDO2 per mmHg change in PaCO2, was 6.1 +/- 3.0%.mmHg-1 in the sevoflurane group and 5.9 +/- 2.4%.mmHg-1 in the isoflurane group (P = NS).
Sevoflurane and isoflurane are associated with similar impairment of cerebral flow-metabolism coupling at incision, while CO2 reactivity is maintained during both anaesthetics.
研究手术切口引起的脑动静脉氧含量差（AVDO2）变化，并确定七氟醚和异氟醚麻醉期间脑循环的二氧化碳（CO2）反应性。
21例美国麻醉医师协会（ASA）1-2级择期行幕上肿瘤手术的患者被随机分为两组，分别接受1.3最低肺泡有效浓度（MAC）的七氟醚/N2O麻醉（n = 10）或等效MAC的异氟醚/N2O麻醉（n = 11）。在切口前后进行血流动力学测量和AVDO2测定。打开硬脑膜后，在呼吸频率增加50%前后测定AVDO2。
在七氟醚组和异氟醚组中，切口分别使平均动脉压从69±11 mmHg升高至97±22 mmHg（平均值±标准差）（P < 0.0005）和从71±6 mmHg升高至89±12 mmHg（P < 0.0001），而心率分别从60±9次/分钟增加至72±8次/分钟（P < 0.001）和从65±6次/分钟增加至70±7次/分钟（P < 0.001）。七氟醚组切口后动脉血二氧化碳分压（PaCO2）从33.6±2.3 mmHg升高至34.6±1.8 mmHg（P < 0.05）。七氟醚组的AVDO2从6.5±1.6 vol%降至5.3±1.6 vol%（P < 0.0005），异氟醚组从6.7±1.1 vol%降至6.0±1.1 vol%（P < 0.01）。七氟醚组AVDO2的变化百分比大于异氟醚组（-18.3±8.4%对-9.1±9.0%；P < 0.05），但在七氟醚组切口后的AVDO2值校正切口前的PaCO2后，差异不再存在。以每mmHg PaCO2变化时AVDO2的变化百分比计算的二氧化碳反应性，七氟醚组为6.1±3.0%·mmHg-1，异氟醚组为5.9±2.4%·mmHg-1（P = 无统计学意义）。
七氟醚醚和异氟醚在切口时对脑血流-代谢耦合的损害相似，而在两种麻醉期间二氧化碳反应性均得以维持。
