尼莫地平对体外循环过程中脑氧耗与脑糖利用的影响

目的：观察体外循环心肺转流（ＣＰＢ）期间脑氧耗与脑糖利用相关性及尼莫地平对其影响。方法：３５例心脏直视手术病人随机分为对照组（ｎ＝１５）和观察组（ｎ＝２０）．监测ＣＰＢ期间不同时期的桡动脉和颈内静脉上球部ＰａＯ２、ＰｊＯ２、ＳａＯ２、ＳｊＯ２及血糖（Ｇ）的变化,并分析Ｃａ－ｊＯ２与Ｇａ－ｊ的关系。结果：两组Ｃａ－ｊＯ２与Ｇａ－ｊ于ＣＰＢ期间均进行性下降,与术前有显著性差异（Ｐ〈０．０１）;观察组Ｇ     

七氟醚控制性降压对脑氧供需平衡的影响

目的：观察七氟醚降压对脑氧供需平衡状态的影响,并与硝普钠（ＳＮＰ）进行对比。方法：择期手术病人３６例,随机分为Ⅰ组七氟醚降压组,Ⅱ组七氟醚常压组和Ⅲ组ＳＮＰ降压组,Ⅰ组增加七氟醚吸入浓度,Ⅲ组静滴ＳＮＰ溶液,降低血压持续４０分钟,连续监测ＭＡＰ、ＨＲ、及ＥＣＧ,并同步采集桡动脉和颈内静脉血行血气分析,计算脑氧摄取率（ＥＲＯ２）,动－静脉氧含量差（Ｄａ－ｊｖＯ２）。结果：Ⅰ组降压后ＥＲＯ２、Ｄａ－ｊ     

异丙酚对体外循环中脑氧代谢的影响

目的：探讨异丙酚对体外循环（ＣＰＢ）各阶段脑氧及乳酸代谢的影响。方法：选择心内直视手术病人３１例，随机分为异现酚组（Ａ组）１６例，对照组（Ｂ组）１５例。分别于ＣＰＢ前、降温及３３℃和３０℃，低温期，复温至３０℃和３３℃以及ＣＰＢ后１５分钟七个时点动脉，颈内静脉血气及乳酸值（ＬＡ）并计算脑摄氧率（Ｏ２Ｅｘｔ）及动脉－颈内静脉乳酸差值。     

异丙酚防止体外循环复温期脑氧供需失衡

目的：观察ＣＰＢ复温期使用异丙酚对颈静脉血氧饱和度（ＳｊＯ２）的影响。方法：２２例瓣膜置换术病人随机分为两组。异丙酚组１２例（１组），复温开始时至ＣＰＢ结束１５分钟以异丙酚４～６ｍｇ．ｋｇ＾－１．ｈ＾－１持续静脉泵入：对照组１０例（Ⅱ组），不同异丙酚。观察两组病人ＣＰＢ前、ＣＰＢ后５分钟、低温稳定期、复温国对鼻咽温（ＮＰＴ）３４℃及ＣＰＢ后５分钟及１５分钟时ＳｊＯ２变化。结果：异丙酚组复温至ＮＰＴ     

低温体外循环心内直视手术麻醉期间脑氧供需平衡状况

心内直视手术３０例，通过监测脑氧饱和度、颈内静脉球部血氧饱和度以及动脉－颈内静脉血乳酸差值，综合分析心内直视手术期间脑氧供需平衡。结果：（１）在体外循环复温过程中，ｒＳＯ２及ＳｊＯ２均明显下降；（２）体外循环开始后，动脉血乳酸和颈内静脉血乳酸进行性增加，但在整个手术麻醉过程中ＡＶＤＬ均未见明显增加，提示：在低温体外循环手术麻醉过程中，复温期间有脑氧供需失衡的趋势，应加强监测，术中若维持ＰａＣＯ２４     

体外循环期间颈静脉血氧饱和度变化的观察

对１０例体外循环（ＣＰＢ）心内直视手术患者的颈静脉血氧饱和度（ＳｊＯ２）变化进行了观察。结果显示，低温时ＳｊＯ２升高，复温时ＳｊＯ２降低。复温期间ＳｊＯ２与鼻咽温呈负相关（ｒ＝一０．５４，Ｐ＜０．０５），复温至３３．５７℃时，ＳｊＯ２由低温时的８６．３４％降至７２．２３％，复温速度与ＳｊＯ２降低率密切相关（ｒ＝０．９１，Ｐ＜０．０１），复温速度越快，ＳｊＯ２下降越大。ＳｊＯ２为ＣＢＦ（脑血流量）和ＣＭＲＯ２（脑氧代谢率）的函数，ＣＰＢ期间监测ＳｊＯ２能获得脑氧供需平衡的实际信息，比监测ＣＢＦ更有价值。     

异丙酚在心脏瓣膜置换术中对氧供、氧耗、氧摄取率及氧合状态的影响

目的：观察异丙酚在心脏瓣膜置换术中对氧供（ＤＯ２）,氧耗（ＶＯ２）,氧摄取率（ＥＲＯ２）及氧合状态的影响。方法：２０例心脏瓣膜置换术病人随机分为两组。组麻醉诱导与维持用异丙酚,对照组用咪唑安定。观察体外循环（ＣＰＢ）期间ＤＯ２,ＶＯ２,ＥＲＯ２,混合静脉血氧饱和度（ＳＶＯ２）及动脉血乳酸（ＡＢＬ０的变化。结果：（１）组内各时点ＤＯ２无明显变化,复温后观察组ＥＲＯ２增加非常显著;降温开始及复温后观察     

七氟醚控制性降压对脑代谢的影响

目的 观察七氟醚控制性降压的效果及对脑氧供需平衡、脑能量代谢的影响,并与硝普钠（ＳＮＰ）降压进行对比。方法 择期手术病人４０例随机分为三组：Ｉ组七氟醚降压组,Ⅱ组七氟醚常压组和Ⅲ组ＳＮＰ降压组。Ｉ组增加七氟醚吸入浓度,Ⅲ组静滴ＳＮＰ溶液,降至基础值的５０％～６０％持续４０ｍｉｎ,连续监测ＭＡＰ、ＨＲ、及ＥＣＧ,并同步采集桡动脉和颈内静脉血行血气分析,计算动－颈内静脉氧含量差（Ｄａ－ｊｖＯ２）;测定     

低温心肺转流期间干扰脑氧平衡主要因素的探讨

为了探讨低温心肺转流（ＣＰＢ）期间干扰脑氧平衡的主要因素，本研究对１６例心脏瓣膜置换术患者，在６个时点同步测定脑氧饱和度（ｒＳＯ２）颈静脉球血氧饱和度（ＳｊＯ２），鼻咽温（ＮＰＴ），血红蛋白（Ｈｂ）浓度及其他脑氧合参数，血流动力学和血气指标，并比较了ｒＳＯ２和ＳｊＯ２的相关性，结果表明，ｒＳＯ２与ＳｊＯ２变化显著相关性（ｒ＝０．８１，Ｐ〈０．００１），提示两种方法的观察效果是一致的。ＮＰＴ变化与ｒ     

颅脑外伤病人的麻醉管理

颅脑外作后急性期可发生脑血流（ＣＢＦ）和脑代谢的改变。脑血管的调节功能系乱，ＣＢＦ成为压力依赖性；脑血管对ＣＯ２反应性减弱或消失；脑氧摄取率增加，Ｓｊｏ２下降及ａ－ｊＤＯ２增大，进一步可造成ＣＭＲＯ２下降及脑细胞内乳酸性酸中毒，其结果是脑水肿和ＩＣＰ增高；ＩＣＰ增高又可加重继发性脑损害，形成恶性循环。因此，脑外伤病人的抢救措施和麻醉管理的首要步骤是保持气道畅通，保证氧供，以减少因缺氧和高碳酸血症的     

Jugular bulb oxygen saturation during propofol and isoflurane/nitrous oxide anesthesia in patients undergoing brain tumor surgery.

We investigated, in brain tumor patients, the jugular bulb venous oxygen partial pressure (PjO2) and hemoglobin saturation (SjO2), the arterial to jugular bulb venous oxygen content difference (AJDO2), and middle cerebral artery blood flow velocity (Vmca) during anesthesia, and the effect of hyperventilation on these variables. Twenty patients were randomized to receive either isoflurane/ nitrous oxide/fentanyl (Group 1) or propofol/fentanyl (Group 2). At normoventilation (PacO2 35 +/- 2 mm Hg in Group 1 and 33 +/- 3 mm Hg in Group 2), SjO2 and PjO2 were significantly higher in Group 1 than in Group 2 (SjO2 60% +/- 6% and 49% +/- 13%, respectively; P = 0.019) (PjO2 32 +/- 3 and 27 +/- 5 mm Hg, respectively; P = 0.027). In Group 2, 5 of 10 patients had SjO2 < 50%, and 3 of these patients had SjO2 < 40% and AJDO2 > 9 mL/dL. All patients in Group 1 had SjO2 > 50%. During hyperventilation, there were no differences in SjO2, PjO2, or AJDO2 between the two groups. On hyperventilation, there was no correlation between the relative decreases of Vmca and 1/AJDO2 (r = 0.21, P = 0.41). The results indicate during propofol anesthesia, half of the brain tumor patients showed signs of cerebral hypoperfusion, but not during isoflurane/nitrous oxide anesthesia. Furthermore, during PacO2 manipulations, shifts in Vmca are inadequate to evaluate brian oxygen delivery in these patients. Implications: During propofol anesthesia at normoventilation, 50% of brain tumor patients showed signs suggesting cerebral hypoperfusion, but this could not be demonstrated during isoflurane/nitrous oxide anesthesia. During PacO2 manipulations, consecutive measurements of the cerebral blood flow velocity may be inadequate to assess cerebral oxygenation.     

Jugular bulb oxygen saturation under propofol or sevoflurane/nitrous oxide anesthesia during deliberate mild hypothermia in neurosurgical patients

Sevoflurane and propofol have been widely used as anesthetic agents for neurosurgery. Recent evidence has suggested that the influence of these anesthetics on cerebral oxygenation may differ. In the present study, the authors investigated jugular bulb oxygen saturation (SjO2) during propofol and sevoflurane/nitrous oxide anesthesia under mildly hypothermic conditions. After institutional approval and informed consent, 20 patients undergoing elective craniotomy were studied. Patients were randomly divided to the group S/N2O (sevoflurane/nitrous oxide/fentanyl anesthesia) or the group P (propofol/fentanyl anesthesia). After induction of anesthesia, the catheter was inserted retrograde into the jugular bulb and SjO2 was analyzed. During the operation, patients were cooled and tympanic membrane temperature was maintained at 34.5 degrees C. SjO2 was measured at normocapnia during mild hypothermia and at hypocapnia during mild hypothermia. There were no statistically significant differences in demographic variables between the groups. During mild hypothermia, SjO2 values were significantly lower in group P than in group S/N2O. The incidence of SjO2 less than 50% under mild hypothermic-hypocapnic conditions was significantly higher in group P than in group S/N2O. These results suggest that hyperventilation should be more cautiously applied during mild hypothermia in patients anesthetized with propofol and fentanyl versus sevoflurane/nitrous oxide/fentanyl.     

Heart rate response to intravenous atropine during propofol anesthesia

During propofol/fentanyl anesthesia, a large percentage of patients have jugular bulb oxygen saturation (SjO(2)) <50%. The incidence is less with isoflurane/N(2)O. We evaluated the effect of N(2)O on SjO(2) during remifentanil-based anesthesia with concurrent propofol or sevoflurane in 20 adults undergoing brain tumor surgery. Anesthesia was randomized: Group 1 (n = 10), target-controlled infusion propofol; and Group 2 (n = 10), thiopental 2-3 mg/kg followed by sevoflurane 0.9% end-tidal. Jugular bulb and arterial blood samples for gas analysis were withdrawn during the administration of oxygen 33% with nitrogen 67% and then with N(2)O 67%. All samples were drawn before surgery and 20 min after the addition of the study gas and with an ETCO(2) 26-28 mm Hg and mean arterial pressure >90 mm Hg. Both groups had similar demographic and physiologic data. In the Propofol group, SjO(2) was 50% +/- 10% with nitrogen and 52% +/- 9% with N(2)O (not significant); in the Sevoflurane group, however, N(2)O 67% increased SjO(2) from 56% +/- 13% to 66% +/- 12% (P < 0.01). This indicates that N(2)O does not reduce the incidence of low SjO(2) values during propofol anesthesia. IMPLICATIONS: This study demonstrates that nitrous oxide can increase jugular bulb venous oxygen saturation when added to sevoflurane/remifentanil anesthesia, but not to propofol/remifentanil anesthesia, in patients with brain tumors.     

Comparative effects of propofol versus fentanyl on cerebral oxygenation state during normothermic cardiopulmonary bypass and postoperative cognitive dysfunction

BACKGROUND: The purpose of this study was to examine the comparative effects of propofol and fentanyl on cerebral oxygenation during normothermic cardiopulmonary bypass and postoperative cognitive dysfunction. METHODS: One hundred eighty patients scheduled for elective coronary artery bypass grafting were randomly divided into two groups: propofol group (n = 90) and fentanyl group (n = 90). After induction of anesthesia, a fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to monitor jugular venous oxygen hemoglobin saturation continuously. Hemodynamic measurements and arterial and jugular venous blood gases were measured at seven time points. All patients underwent a battery of neurologic and neuropsychological tests on the day before the operation and at 6 months after the operation. RESULTS: Cerebral desaturation (defined as a jugular venous oxygen hemoglobin saturation value less than 50%) during cardiopulmonary bypass was more frequent in the fentanyl group than in the propofol group. Cerebral desaturation time (duration when jugular venous oxygen hemoglobin saturation was less than 50%) and the ratio of cerebral desaturation time to total cardiopulmonary bypass time in the fentanyl group differed significantly from those in the propofol group (fentanyl group: 27 +/- 14 minutes, 20% +/- 9%; propofol group: 18 +/- 11 minutes, 14% +/- 7%, respectively, p < 0.05). There was no significant difference in postoperative cognitive dysfunction at 6 months after operation between the two groups (propofol group: 5 of 77, 6%; fentanyl group: 5 of 75, 7%). CONCLUSIONS: Propofol preserved cerebral oxygenation state estimated by jugular venous oxygenation during cardiopulmonary bypass compared with the fentanyl group. However, propofol did not affect postoperative cognitive dysfunction.     

异丙酚中对中低温体外循环脑氧合的影响

目的 观察异丙酚对中低温体外循环心肺转流术（CPB）期间脑氧合的影响。8方法 心内直视手术患者17例随机分为芬太尼组和异丙酚组,通过监测动脉、颈内静脉血和混合静脉血氧含量以及乳酸浓度,计算全身和脑动静脉氧含量差、氧摄取率和动静脉乳酸浓度差,分析异丙酚对CPB期间脑氧合的影响。结果 两组复温过程中动静脉氧含量差和氧摄取率均较低温时升高;异丙酚组在CPB过程中动脉－颈内静脉血氧含量差和脑的氧摄取率要高于芬太尼组（P＜0．05）,动脉－混合静脉血氧含量差和全身的氧摄取率两组差异无显著意义（P＞0．05）。CPB全过程中两组血乳酸浓度均进行性升高。结论 CPB期间应用异丙酚麻醉并不能明显改善脑氧合。CPB期间脑保护机理有其复杂性一面,不能仅停留于氧代谢平衡方面。     

Effects of thoracic epidural meperidine on arterial oxygenation during one-lung ventilation in thoracic surgery

OBJECTIVE: To compare the effects that the use of general intravenous anesthesia (propofol-fentanyl) (GA) or general anesthesia combined with thoracic epidural anesthesia with meperidine (TEA-M) may have on arterial oxygenation during one-lung ventilation (OLV). DESIGN: Prospective. SETTING: Tertiary care hospital. PARTICIPANTS: Seventy-two patients undergoing OLV for thoracic surgery. INTERVENTIONS: Patients were prospectively randomized into two groups: GA (n = 37) fentanyl, propofol, rocuronium anesthesia was used; and group TEA-M (n = 35) were anesthetized with propofol, rocuronium and thoracic epidural meperidine (2 mg/kg in 10-12 mL) administered before anesthetic induction. A double-lumen endotracheal tube was inserted, and mechanical ventilation with 100% oxygen was used during study. Mean arterial pressure, heart rate and arterial and venous blood gases were recorded with the patients in the lateral decubitus position in three phases: during two-lung ventilation (TLV), 15 and 30 minutes after beginning OLV (OLV + 15 and OLV + 30 respectively). The authors measured arterial and venous central oxygen tension, arterial and venous central oxygen saturation, arterial and venous central oxygen content and venous admixture percentage (Qs/Qt%). MEASUREMENTS AND MAIN RESULTS: There were no statistical differences between the two groups for PaO(2) during OLV + 15 (GA = 165 mmHg, TEA-M = 153 mmHg) and OLV + 30 (GA = 176 mmHg, TEA-M = 158 mmHg); and with values for Qs/Qt%. CONCLUSIONS: It is concluded that GA combined with TEA-M (2 mg/kg) do not affect arterial oxygenation during OLV in thoracic surgery.     

Spatially resolved spectroscopy (NIRO-300) does not agree with jugular bulb oxygen saturation in patients undergoing warm bypass surgery

PURPOSE: Near infrared spectroscopy (NIRS) is a promising non-invasive method for continuous monitoring of cerebral oxygenation during cardiac surgery with cardiopulmonary bypass (CPB). This study was designed to study the agreement between tissue oxygen index (TOI) measured by spatially resolved spectroscopy (NIRO-300) and jugular bulb oxygen saturation (SjO2) in patients undergoing warm coronary bypass surgery. METHODS: Seventeen patients undergoing warm coronary artery bypass surgery were studied. NIRS was continuously monitored and was averaged before CPB, five, 20, 40, 60 min on CPB, five minutes before end of CPB and ten minutes after CPB to coincide with SjO2 measurements. Bypass temperature was maintained at 34-37 degrees C. RESULTS: Bland and Altman analysis showed a bias (TOI-SjO2) of -6.7%, and wide limits of agreement (from 16% to -28%) between the two methods. In addition, mean TOI was lower than mean SjO2 during and after CPB. We observed a statistically significant correlation between arterial carbon dioxide and SjO2 measurements (r2=0.33; P=0.0003), but the former did not correlate with TOI values (r2=0.001; P=0.7). CONCLUSION: Our results demonstrate a lack of agreement between SjO2 and TOI for monitoring cerebral oxygenation during cardiac surgery. We conclude that the two methods are not interchangeable.     

异丙酚对中低温体外循环脑氧合的影响

目的观察异丙酚对中低温体外循环心肺转流术(CPB)期间脑氧合的影响。方法心内直视手术患者17例随机分为芬太尼组和异丙酚组,通过监测动脉、颈内静脉血和混合静脉血氧含量以及乳酸浓度,计算全身和脑动静脉氧含量差、氧摄取率和动静脉乳酸浓度差,分析异丙酚对CPB期间脑氧合的影响。结果两组复温过程中动静脉氧含量差和氧摄取率均较低温时升高;异丙酚组在CPB过程中动脉-颈内静脉血氧含量差和脑的氧摄取率要高于芬太尼组(P<0.05),动脉-混合静脉血氧含量差和全身的氧摄取率两组差异无显著意义(P>0.05)。CPB全过程中两组血乳酸浓度均进行性升高。结论CPB期间应用异丙酚麻醉并不能明显改善脑氧合。CPB期间脑保护机理有其复杂性一面,不能仅停留于氧代谢平衡方面。     

Clinical evaluation of cerebral oxygen balance during cardiopulmonary bypass: on-line continuous monitoring of jugular venous oxyhemoglobin saturation.

To prevent brain damage during cardiopulmonary bypass (CPB), adequate cerebral perfusion for cerebral oxygen demand should be maintained. We monitored jugular venous oxyhemoglobin saturation (SjO2), which reflects the overall balance of cerebral oxygen supply and demand, continuously in 12 patients undergoing cardiac surgery. We examined whether this balance is disrupted during CPB, and if so, analyzed critical factors that affect this phenomenon. At the initiation of CPB, in spite of a significant decrease in mean arterial pressure, SjO2 did not change, and it was stable during the hypothermic period of CPB. On the other hand, a significant reduction in SjO2 was observed during the rewarming period, and SjO2 had an inverse linear correlation with nasopharyngeal temperature. Furthermore, the percent decrease of SjO2 was significantly related to "rewarming speed" (an average increase in temperature per minute). Our results indicate that temperature change during the rewarming period is a critical factor affecting the balance of cerebral oxygen supply and demand during CPB.