地氟醚对红外分光测定法呼气末二氧化碳浓度测定的影响

目的 观测吸入不同浓度的地氟醚对普通红外分光测定法呼气末二氧化碳浓度（ＰＥＴＣＯ２）测定的影响。方法 １５例全麻气管内插管的病人,用一台可同时测定ＰＥＴＣＯ２和地氟醚的红外分光测定仪Ｃａｐｎｏｍａｃ－ｕｌｔｉｍａ和一台单纯测定ＰＥＴＣＯ２的普通红外分光测定仪Ｃａｐｎｏｍａｃ－Ⅱ同时监测ＰＥＴＣＯ２。结果 在使用地氟醚后,Ｃａｐｎｏｍａｃ－ｕｌｔｉｍａ测定得的ＰＥＴＣＯ２明显低于Ｃａｐｎｏｍａｃ－Ⅱ测定得的ＰＥＴＣＯ２,其差异随着呼气末地氟醚浓度的升高而加大（直线相关ｙ＝０．６２＋０．７３,ｒ＝０．８３,Ｐ〈０．０１）,而关闭Ｃａｐｎｏｍａｃ－ｕｌｔｉｍａ地氟醚浓度测定（忽略其存在）后测定得的ＰＥＴＣＯ２则和Ｃａｒｄｉｏｃａｐ－Ⅱ测定得的ＰＥＴＣＯ２完全相关（ｙ＝１．６１χ－４．１,ｒ＝０．９７,Ｐ〈０．０１）。     

静脉注射不同剂量异丙酚对血流动力学及通气功能的影响

应用阻抗法和分气流监测法观察静脉注射不同剂量异丙酚（Ｐｒｏｐｏｆｏｌ，ＰＲＯ）后患者血流动力学（ＭＡＰ、ＮＲ、ＳＬＣＩ、ＩＦＩ、ＶＥＴ、ＥＶＩ、ＳＶＲＩ、ＩＣ、ＰＦＩ、ＬＳＷＩ）与通气功能（ＶＴ、ＲＲ、ＶＥ、ＦＥＶ１％、ＥＴＣＯ２、ＳＰＯ２、 Ｉ－ＥｔＯ２）的变化。 ４０例（ＡＳＡⅠ～ Ⅱ）随机分成四组，ＰＲＯ剂量分别为 １．０ｍｇ／ｋｇ、１．５ｍｇ／ｋｇ、２．０ｍｇ／ｋｇ、２．５ｍｇ／ｋｇ。结果：（１）１～４组呼吸暂停发生率为０％、２０％、３０％、８０％，苏醒时间分别为３ ０±１．５、７．４±２．３、９．１±３．６、９．６±４．２分钟：（２）静脉注射不同剂量ＰＲＯ启ＳＡＰ、ＤＡＰ、ＭＡＰ、ＳＩ下降，ＨＲ、ＣＩ、ＳＶＲＩ无明显变化，心肌收缩性（ＩＣ、ＰＦＩ、ＥＶＩ）明显减弱，ＳＶＲＩ减少；（３）ＰＲＯ对呼吸有抑制作用，以ＶＴ和ＶＥ影响最大，与剂量呈正相关；对面罩吸氧患者ＳｐＯ２、ＲＲ、ＥＴＣＯ２无明显改变，Ｉ－ＥｔＯ２减少；舌后坠者托起下颌对ＶＴ、ＶＥ的恢复颇为有效。     

相同MAC浓度的安氟醚和异氟醚对脑电图功率谱的影响

２４例 ２０～５０岁、ＡＳＡⅠ级、行择期外科手术的患者，随机分成两组：安氟醚组和异氟醚组。不用术前药，麻醉诱导以静脉硫喷妥钠５ｍｇ／ｋｇ、阿曲库胺０．６～０．７ｍｇ／ｋｇ。单纯吸入安氟醚或异氟醚维持全麻。气管插管后控制呼吸，维持呼气末二氧化碳分压（ＰＥＴＣＯ２）４．２７。４．９３ｈｐａ。以ＴＯＦ监测肌松，间断给予阿曲库胺 １０～１５ｍｇ，维持Ｔ４／Ｔ１＜２５％。采用 ＦＰ１－Ａ１、ＦＰ２－Ａ２双导联监护脑电，验证呼气末麻醉药浓度在 ０． ５、０．８、１． ０、１． ３和 １．５ ＭＡＣ时的脑电功率谱、９５％边缘频率（ＳＥＦ）和中心频率（ＭＰＦ）改变。结果发现，随ＭＡＣ增加脑电功率谱表现出波增加，α和β波减少，而ＳＥＦ、ＭＰＦ值随ＭＡＣ增加而减少的改变呈负性线性关系，ｒ＝－０．９５。提示脑电功率谱、ＳＥＦ和ＭＰＦ在评价全麻深度上有一定意义。     

腹腔镜胆囊切除术中肺功能变化的临床研究

本文观察了１２例ＡＳＡ１级胆囊结石病人腹腔镜胆囊切除术中的肺功能变化。年龄为４０．７±９．４岁，体重６１．４±９．４ｋｇ。Ｍｉｄａｚｏｌａｍ－Ｆｅｎｔａｎｙｌ－Ｉｓｏｆｌｕｒａｎｅ－Ｔｒａｃｒｉｕｍ维持麻醉，控制呼吸，间歇正压通气。连续监测吸气气道峰压（ＰＩＰ），动态肺应性（ＬＣ），ＰＥＣＯ２，ＥＫＧ，ＮＩＢＰ和ＳｐＯ２。结果：体位改变对ＰＩＰ和ＰＥＣＯ２无明显影响（Ｐ＞０．０５），却使ＬＣ下降９．７％（Ｐ＞０．０５）。腹腔充气后３０分钟ＰＩＰ上升１７％（Ｐ＜０．０５），ＬＣ与麻醉后和充气前相比分别下降２５．８％和２０．８％（Ｐ＜０．０１），ＰＥＣＯ２增加１９．１％（Ｐ＜０．０１）；腹腔充气后６０分钟，ＰＩＰ和ＰＥＣＯ２未继续增加，但ＬＣ继续下降，比麻醉后和充气前下降３４．２％和２７．１％（Ｐ＜０．０１）。本文显示腹腔镜胆囊切除术中肺顺应性显著下降，气道压明显升高，ＰＥＣＯ２明显增加。     

腹腔镜下胆囊切除术对动脉血气及循环的影响

接受该手术患者３０例，全部采用控制呼吸，通气参数：Ｖｒ男６．６－７ｍｌ／ｋｇ，女６－７ｍｌ／ｋｇ，Ｆ１８次／分，Ｉ／Ｅ１：２，ＦｉＯ２９４％－９７％。分别于机械通气后１５分，ＣＯ２气腹后１５分，３５分及术毕拔管后改鼻管吸Ｏ２４０分四阶段进行动脉血气，ＰｅｔＣＯ２，ＭＡＰ及ＨＲ的监测，结果表明：ＣＯ２气腹可使ＰａＣＯ２，ＰｅｔＣＯ２及ＨＲ变化显著（Ｐ〈０．０５），但属正常范围。提示按该通气参数通气…     

咪唑安定硬膜外注射时患者血流动力学及通气功能变化

咪唑安定（ＭＩＤ）硬膜外注射的节段性镇痛效应及其对患者血流动力学（ＭＡＰ、ＨＲ、ＳＩ、ＣＩ、ＴＦＩ、ＶＥＴ、ＥＶＩ、ＳＶＲＩ、ＩＣ、ＰＥＩ、ＬＶＷＩ、ＲＰＰ）与通气功能（ＶＴ、ＲＲ、ＶＥ、ＦＥＶ１、Ｉ－ＥｔＯ２、ＰＥＴＣＯ２、ＳｐＯ２）的影响。４４例患者随机分成四组：Ｅ１组硬外注ＭＩＤ０．０５ｍｇ／ｋｇ，Ｅ２组硬外注ＭＩＤ０．１ｍｇ／ｋｇ，Ｖ１、Ｖ２组为静脉组，剂量与Ｅ１、Ｅ２组相同。结果：（１）     

单肺通气时PETCO2与PaCO2的关系

对２６例ＡＳＡＩ～Ⅱ级开胸肺手术的患者，分为Ａ、Ｂ两组，分别以双肺通气（ＴＬＶ）为对照行单肺通气（ＯＴＶ）或ＯＴＶ ＋术侧肺用Ｂａｉｎ回路行ＣＰＡＰ，测量ＴＬＶ３０分，ＯＬＶ３０分、６０分和Ｒ－ＴＬＶ３０分的ＰＥＴＣＯ２和ＰａＣＯ２值，观察两者的关系。结果表明，两组中ＯＬＶ时的ＰＥＴＣＯ２和ＰａＣＯ２均正常，但较ＴＬＶ时有升高的趋势（Ｐ＜０．０５），Ｒ－ＴＬＶ后又复原（Ｐ＞０．０５）；两组间ＯＬＶ时的测量值无差异（Ｐ＞０．０５），而ＰＥＴＣＯ２与Ｐ。ＣＯ２有密切的相关性（Ｐ＜０．０５）；Ｐ（ａ－ＥＴ）ＣＯ２和ＰＥＴＣＯ２的计算值在不同通气时无显著性差异，说明ＰＥＴＣＯ２可作为一种无创监测手段指导ＯＬＶ时的通气效果。     

脑氧饱和度监测的临床意义及评价

通过体外循环心内直视术（ｎ＝２０）及颅脑手术（ｎ＝２０）脑氧饱和度的监测发现，麻醉诱导时脑氧饱和度增加（Ｐ＜０．０５），体外循环心内直视手术患者复温过程中，脑氧饱和度明显下降（由７０．０％±４．５％降至６０．３％±９．２％，Ｐ＜０．０１），转流停止后上升。脑外患者拔管后脑氧饱和度下降（Ｐ＜０．０５）。无论在降温还是复温过程中，脑氧饱和度与转流量之间呈线性相关（ｒ＝０．８６５～０．９４５，Ｐ＜０．０５），ＰＥＴ－ＣＯ２明显影响脑氧饱和度。ＨＲ（５０～１４０次／分）及转流中ＭＡＰ（３·４６～１４·６ｋＰａ），脑氧饱和度无明显变化。结论：（１）监测脑氧饱和度可反映脑氧供需平衡；（２）凡能影响脑氧供（如动脉血氧合、转流量及Ｐ。ＴＣＯ２等）及脑氧需（如体温等）的因素均可引起脑氧饱和度变化；（３）脑氧饱和度严重进行性下降而且不能恢复提示预后不良。     

术后镇痛对老年人上腹部手术后肺功能的影响

３２例 ＡＳＡ Ⅱ～Ⅲ级择期行上腹部手术（ＵＡＳ）的老年患者随机分成两组：对照组（ｎ＝１６）和术后每６小时用 ０． １２５％丁听卡因十芬太尼０．０２５ｍｇ １０ｍｌ行硬膜外镇痛（ＰＥＡ）组（ｎ＝１６），分析两组患者术前，拔管时，术后４、８和２４小时的呼吸频率（ＲＲ）、潮气量（ＶＴ）、分钟通气量（ＭＶ）和动脉血ｐＨＰａＯ２、ＰａＣＯ２、ＮＣＯ０－３、ＢＥ－Ｂ、Ｏ２Ｓａｔ。结果表明：虽术后持续鼻导管吸氧，对照组仍出现严重的呼吸抑制和酸碱平衡紊乱，尤以术后８小时内，特别是４小时内最严重；而镇痛组则程度轻微且无明显缺氧、二氧化碳蓄积和酸碱平衡失调。可见用０．１２５％丁哌卡因十芬太尼０．０２５ｍｇ １０ｍｌ行ＰＥＡ能改善老年患者的术后肺功能。但在ＰＥＡ期间仍应继续进行呼吸监测，并常规给予吸氧至少８小时。//     

脑电功率谱分析用于监测手术切皮时的麻醉深度

目的：评价脑电功率谱分析技术反映麻醉深度的准确性。方法：６５例ＡＳＡⅠ级腹部手术病人，快速静脉诱导气管插管后，机械通气，维持ＰＥＴＣＯ２在正常范围内。麻醉：Ｏ２－Ｎ２Ｏ（１∶２）－七氟醚吸入，切皮前不追加长效肌松药。随机分为三组：Ⅰ组ｎ＝２５、Ⅱ组ｎ＝２０、Ⅲ组ｎ＝２０。七氟醚呼气末浓度分别为１．０％、１．５％、２．０％，至少维持１５分钟。应用数量化脑电图监测仪监测手术切皮前、后３分钟脑电图的改变，同时监测ＭＡＰ、ＨＲ的改变，切皮后四肢肌肉活动、面部表情变化、呛咳或切皮前不能耐受气管插管刺激者定为切皮反应阳性。结果：切皮前三组病人的ＥＥＧ随七氟醚呼气末浓度增加，波谱边缘频率（ＳＥＦ）、中频率（ＭＦ）、双谱指数（ＢＩＳ）明显降低（Ｐ＜０．０１），δ波比率（δＲ）明显升高（Ｐ＜０．０１），ＭＡＰ仅Ⅰ组和Ⅲ组之间有差异（Ｐ＜０．０５），ＨＲ三组之间无统计学差异。切皮反应者的ＳＥＦ、ＭＦ、ＢＩＳ明显高于无反应者，δＲ明显低于无反应者（Ｐ＜０．０１）。反应者切皮前、后的ＭＡＰ和ＨＲ变化差明显大于无反应者（Ｐ＜０．０１）。结论：ＥＥＧ数量化指标ＳＥＦ和ＢＩＳ能较准确地反映切皮前七氟醚麻醉深度。     

End-tidal CO2 for prediction of cardiac output following weaning from cardiopulmonary bypass

This prospective study included 32 patients undergoing cardiopulmonary bypass (CPB) for elective coronary artery bypass grafting correlates the respiratory end-tidal CO2 (ETCO2) during partial separation from CPB with cardiac output (CO) following weaning from CPB. After induction of general anesthesia, a pulmonary artery catheter was inserted for measurement of cardiac output by thermodilution. Patients were monitored using a 5-lead ECG, pulse oximeter, invasive blood pressure monitoring, rectal temperature probe, and end-tidal capnography. At the end of surgery, patients were weaned from CPB in a stepwise fashion. Respiratory ETCO2 and in-line venous oximetry were continuously monitored during weaning. The ETCO2 was recorded at quarter pump flow and after complete weaning from CPB. Following weaning from CPB, CO was measured by thermodilution. The CO values were correlated with the ETCO2 during partial bypass and following weaning from bypass. Regression analysis of ETCO2 at quarter-flow and post-bypass CO showed significant correlation (r = 0.57, p < .001). Also, regression analysis of ETCO2 after complete weaning from bypass and post-bypass CO showed significant correlation (r = 0.6, p = .002). The correlation between ETCO2 and CO showed that an ETCO2 >30 mm Hg during partial CPB will always predict an adequate CO following weaning from CPB. An ETCO2 <30 mm Hg may denote either a low or a normal cardiac output and hence other predictive parameters such as SvO2 must be added.     

A comparison of transcutaneous,end-tidal and arterial measurements of carbon dioxide during general anaesthesia

A randomized, prospective study was performed to evaluate the accuracy of a new transcutaneous carbon dioxide (CO2) monitor (Fastrac) during general anaesthesia. Twenty-two adult patients undergoing elective surgery were subjected to three different levels of minute ventilation by varying their respiratory rates in a randomized cross-over design. Simultaneous measurements of transcutaneous CO2 (PTCCO2) and arterial CO2 (PaCO2) were obtained at three levels of minute ventilation (low, medium and high). End-tidal CO2 (PETCO2) values were also recorded from a mass spectrometer (SARA) at each time period. A total of 66 data sets with PaCO2 ranging from 28-62 mmHg were analyzed. The PTCCO2 values demonstrated a high degree of correlation with PaCO2 over the range of minute ventilation (y = 0.904x + 6.36, r = 0.92, P less than 0.001). The PETCO2 measurement also demonstrated a generally good correlation with PaCO2 (y = 0.62x + 9.21, r = 0.89, and P less than 0.01). However, the PETCO2-PaCO2 gradients (mean 7.0 +/- 3.1 mmHg) were greater than the PTCCO2-PaCO2 gradients (mean 2.3 +/- 2.4 mmHg) at all three levels of minute ventilation (P less than 0.05). These differences were greatest when PaCO2 was in the high range (48-60 mmHg). We conclude that the new Fastrac CO2 monitor is accurate for monitoring carbon dioxide levels during general anaesthesia. The new transcutaneous devices provide an effective method for non-invasive monitoring of CO2 in situations where continuous, precise control of CO2 levels is desired.     

Endocrine Stress Response during General and Epidural Anaesthesia for Elective Caesarean Sections

In 17 patients scheduled for elective caesarean sections, the influence of general (GA, n = 9) and epidural anaesthesia (EA, n = 8) on maternal and umbilical vein blood plasma concentrations of ACTH, Cortisol, 17-α-hydroxyprogesterone (OHP) and blood glucose (BG) was studied. Mean blood pressure (MBP mmHg) and heart rate (HR beats min^-1) were also followed during the operation and Apgar scores were evaluated in all neonates. With epidural anaesthesia, an MBP of 102±6.5 mmHg and an HR of 87 ±4.9 beats min^-1 was found at hysterotomy (HT). With general anaesthesia, the corresponding values were 143 ±6.9 mmHg (P<0.01) and 108 ±6.3 beats min^-1 (P<0.05). The plasma concentration of ACTH at HT was higher during GA than during EA (P<0.01), while the plasma concentration of Cortisol during GA was higher 30 min alter HT (P<0.05). Maternal ACTH and Cortisol levels at HT were higher than umbilical vein levels, while OHP was 2–3 times higher in the umbilical vein than in maternal blood at HT. Umbilical vein Cortisol concentration was higher in the EA than in the GA group (P<0.01). With epidural anaesthesia, neonates had higher Apgar scores than with general anaesthesia (P<0.01). The increased umbilical vein Cortisol concentration with epidural anaesthesia challenged the assumption of a higher fetal stress response. The results might have a bearing on the choice of the most suitable anaesthetic method in complicated pregnancies.     

Effect of small bowel perforation during laparoscopy on end-tidal carbon dioxide: observation in a small animal model

INTRODUCTION: There are currently no reports in the literature regarding changes in end-tidal carbon dioxide (ETCO(2)) when the small bowel is deliberately or inadvertently perforated during laparoscopic surgery. The aim of this study was to assess the influence of small bowel perforation during laparoscopy on ETCO(2) in a rat model. MATERIALS AND METHODS: Two groups of Wistar rats (n = 8/group) were anesthetized, tracheostomized, and mechanically ventilated at a fixed tidal volume and respiratory rate. After a stabilization phase of 30 min, CO(2) pneumoperitoneum was established to 5 mmHg in one group and 12 mmHg in the other group, and maintained for 30 min. A small bowel perforation was then created and pneumoperitoneum was reestablished for another 30 min. Blood pressure, heart rate, peak ventilatory pressure, and ETCO(2) were recorded throughout the experiment. RESULTS: No significant changes in blood pressure throughout the experiment were noted in either group. The ventilatory pressure increased in both groups after the induction of pneumoperitoneum. In the 5 mmHg group, there was a modest increase in ETCO(2) following the induction of pneumoperitoneum (from 39.4 +/- 1.9 to 41.1 +/- 1.4, P = 0.014), and a further increase following the small bowel perforation (from 41.1 +/- 1.4 to 42 +/- 0.8, P = 0.007). In the 12 mmHg group, there was no change in ETCO(2) after the induction of pneumoperitoneum; however, there was a substantial increase in ETCO(2) following bowel perforation (35.0 +/- 2.0 to 49.8 +/- 7.1, P = 0.002). CONCLUSIONS: ETCO(2) increases when the small bowel is perforated during CO(2) pneumoperitoneum. This increase seems more substantial under higher pneumoperitoneal pressures. Small bowel injury may enable the diffusion of CO(2) through the bowel mucosa, causing ETCO(2) elevation. Therefore, an abrupt increase in ETCO(2) observed during laparoscopy may indicate small bowel injury.     

General anaesthesia for Nd: YAG laser resection of obstructing endobronchial tumours using the rigid bronchoscope

Provision of general anaesthesia for patients undergoing Nd:YAG laser resection of obstructing endobronchial tumours using the rigid bronchoscope presents unique problems for the anaesthesiologist. We studied 15 patients who underwent 20 of these procedures under general anaesthesia. Patients were anaesthetized and ventilated with either potent inhalation agents via the side arm of the ventilating bronchoscope (Croup I: N = 8), or with intravenous agents and the Sanders jet injector attached to the rigid bronchoscope (Group II: N = 12). Patients were paralyzed and ventilation was controlled. The inspired gas mixture was nitrogen and oxygen, and the FlO₂ was decreased to 0.3-0.4 during periods of resection. Group I patients had significantly higher peak p^{CO 2}’s than Group II (8.3 kPa (62 mmHg) vs. 5.6 kPa (44 mmHg): lowest recorded p^{O 2}’s were comparable and similar to pre-induction values. Both groups exhibited wide blood pressure fluctuations. Heart rales remained within 15 per cent of pre-induction levels. There were no intraoperative deaths, and no airway fires, massive haemorrhages or pneumothoraces. We conclude that these procedures can be undertaken with the use of general anaesthesia and the rigid bronchoscope, but that patients may encounter potentially serious respiratory or haemodynamic instability during the procedure.     

General anaesthesia for Nd:YAG laser resection of obstructing endobronchial tumours using the rigid bronchoscope

Provision of general anaesthesia for patients undergoing Nd:YAG laser resection of obstructing endobronchial tumours using the rigid bronchoscope presents unique problems for the anaesthesiologist. We studied 15 patients who underwent 20 of these procedures under general anaesthesia. Patients were anaesthetized and ventilated with either potent inhalation agents via the side arm of the ventilating bronchoscope (Group I: N = 8), or with intravenous agents and the Sanders jet injector attached to the rigid bronchoscope (Group II: N = 12). Patients were paralyzed and ventilation was controlled. The inspired gas mixture was nitrogen and oxygen, and the FIO2 was decreased to 0.3-0.4 during periods of resection. Group I patients had significantly higher peak pCO2's than Group II (8.3 kPa (62 mmHg) vs. 5.6 kPa (44 mmHg); lowest recorded pO2's were comparable and similar to pre-induction values. Both groups exhibited wide blood pressure fluctuations. Heart rates remained within 15 per cent of pre-induction levels. There were no intraoperative deaths, and no airway fires, massive haemorrhages or pneumothoraces. We conclude that these procedures can be undertaken with the use of general anaesthesia and the rigid bronchoscope, but that patients may encounter potentially serious respiratory or haemodynamic instability during the procedure.     

Respiratory management during endotracheal placement of the Dumon stent for tracheobronchial stenosis

BACKGROUND: Endotracheal stenting at the stenotic area of the trachea or bronchus is less invasive and beneficial for patients, compared with conventional surgical treatment. METHODS: We investigated intraoperative respiratory managements for 26 patients (65+/-14 years-old) with Dumon type stent in a retrospective manner. SpO2 over 90% was an index for the intraoperative respiratory managements. RESULTS: Nine of the 26 subjects were emergency cases. Four of the 26 patients had been preoperatively under controlled respiration (CR) with an endotracheal tube, while the remaining 22 had been left under spontaneous respiration (SR). The lung cancer (10 patients) was the most frequent causative disease, followed by tracheo-broncheal invasion of the esophageal cancer (6 patients). Preoperative PaO2 in 8 of the SR group was under 70 mmHg. When SR was preserved during subsequent operation, intravenous anesthesia using propofol and fentanyl was given in combination with surface local anesthesia. I-type stent was used for 17 patients with tracheal or bronchial stenosis and Y-type stent for 9 with carina stenosis. As to the respiratory management during stenting, SR was preserved in 14 patients, CR including jet ventilation under the use of a muscle relaxant was performed in 8 patients and percutaneous cardiopulmonary support (PCPS) was used in 4 patients. In one SR patients, SR was switched to emergency PCPS on the way because of airway obstruction. In another SR patient with successful bronchial stenting, the collapsed lung was rapidly re-expanded by using jet ventilation, causing multi-embolism to the vital organs including the heart and the brain. Traumatic complications on bucking were not seen even under the condition of SR. Postoperatively, 21 of the 26 patients were transferred to ICU without endotracheal intubation. CONCLUSIONS: In a case in which severe respiratory insufficiency or airway bleeding is anticipated, PCPS on standby is necessary for safety assurance.     

Haemodynamic stability during moderate hypotensive anaesthesia for spinal surgery. A comparison between desflurane and isoflurane

BACKGROUND: The aim of this study was to compare desflurane and isoflurane for spinal procedures requiring moderate levels of controlled arterial hypotension, when these agents were administered via a semi-closed circuit at 1 l x min(-1) fresh gas flow. METHODS: After ethics committee approval and written informed consent, 20 ASA I or II patients were randomly allocated to receive either desflurane (n=10) or isoflurane (n=10), in O2/ N2O (1:1) for maintenance of anaesthesia. Induction of anaesthesia, fentanyl dosing and volume loading were standardized. Blood pressure was invasively monitored and maintained within a target systolic blood pressure (SBP) range of 80 to 100 mmHg during the study period. Results were presented as medians and interquartiles, and non-parametric statistical methods were used. RESULTS: Patient demographic data, SBP and heart rate prior to surgery, and duration of the procedure were similar between the two groups. During the study period, tighter arterial blood pressure control was maintained with desflurane as compared with isoflurane. SBP was 21.2% (9.5-41.7) of time outside the range 80-100 mmHg with isoflurane and 5.1% (0.6-10.3) with desflurane (P<0.01). CONCLUSIONS: Desflurane, administered via a semi-closed circuit at 1 l x min(-1) fresh gas flow, maintained better haemodynamic stability in spinal surgery requiring moderate arterial hypotension than isoflurane.     

Continuous end-tidal CO2 sampling within the proximal endotracheal tube estimates arterial CO2 tension in infants

End-tidal CO2 (ETCO2) sampled using a 22-gauge needle inserted through the wall of the proximal endotracheal tube was compared with ETCO2 obtained from the standard proximal connector to determine which was the more accurate sampling site for estimation of arterial CO2 tension (PaCO2). Fourteen infants were anaesthetized and their lungs ventilated using a Drager ventilator and a paediatric circle system. Blood gas determination of PaCO2 was obtained from an arterial catheter and compared with continuous sampling of ETCO2 analyzed by raman spectroscopy. The PaCO2 (35.3 +/- 4.9 mmHg, x +/- SD) was not different from the ETCO2 sampled within the proximal endotracheal tube (34.7 +/- 3.8 mmHg), but was greater (P less than 0.05) than the ETCO2 at the proximal connector (31.6 +/- 4.0 mmHg). We conclude that in infants during ventilation with a circle system, the PaCO2 can be accurately assessed by continuous sampling of ETCO2 from the proximal endotracheal tube.     

七氟醚吸入诱导在心脏手术病人的应用及其对呼吸循环功能的影响

目的研究七氟醚或七氟醚-N