不同肺动脉高压病人心瓣膜手术期间氧代谢及血液动力学的变化

目的 研究不同肺动脉高压病人心瓣膜手术期间氧代谢及血液动力学的变化。方法 ３６例择期行心瓣膜手术病人根据术前肺动脉平均压（ＰＡＭＰ）分为两组,组ⅠＰＡＭＰ〈４．０ｋＰａ,组ⅡＰＡＭＰ〉４．０ｋＰＡ,采用Ｓｗａｎ－Ｇａｎｚ导管及反向Ｆｉｃｋ方法,麻醉手术期间对氧代谢及血液动力学进行测定。结果 麻醉前组Ⅱ的ＤＯ２、ＰｖＯ２和Ｏ２ＥＲ与组Ⅰ组比存在显著性差异（Ｐ〈０．０５）。ＣＰＢ前组Ⅰ的ＤＯ２。组Ⅱ的     

一氧化氮对肺动脉高压的作用观察

１７例先天性心脏病合并中到重度肺动脉高压小儿，吸入１６～６０ｐｐｍＮＯ２０ｍｉｎ，观察短时间吸入低浓度ＮＯ对肺动脉高压的作用，结果表明，吸入ＮＯ１ｍｉｎＰＡＰ开始下降，吸入１０ｍｉｎ后ＰＡＰ明显下降（Ｐ〈０．０５）停止吸入ＮＯ后５ｍｉｎＰＡＰ明显升高。实验中ＮＯ２浓度平均小于２ｐｐｍ，ＭｅｔＨｂ无明显增加，ＳＢＰ，ＤＢＰ，ＨＲ，ＳｐＯ２均无明显改变，提示ＮＯ是一种选择性的肺血管扩张药，临床低浓度短     

山莨菪碱对ARDS的氧输送及血流动力学改变的作用

早期、大剂量山莨菪碱治疗外科术后成人呼吸窘迫综合征（ＡＲＤＳ），观察病程第１￣４天氧输送与血流动力学等指标。治疗组用山莨菪碱＋常规治疗，对照组用常规治疗。结果：第２￣４天治疗组Ｃｌ、ＤＯ２、ＶＯ２、Ｏ２Ｅｘｔ、ＰａＯ２／ＦｉＯ２分别显著高于对照组（Ｐ〈０．０５）；Ａ－ａＤＯ２、ＰＶＲＩ显著低于对照组（Ｐ〈０．０５）。ＶＯ２与ＤＯ２呈直线相关（ｒ＝０．５８，Ｐ〈０．０５）。治疗组８例死亡１例，对照组     

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。     

氧化亚氮,安氟醚,异氟醚单独及复合使用时肺摄取和排出的临床…

观察分析了１２名麻醉患者在１％普鲁卡因静脉麻醉下，单独及复合吸入Ｎ２Ｏ，安氟醚，异氟醚时肺摄取及排出这些吸入麻醉药的情况。结果表明，ＦＡ／Ｆｉ和ＦＡ／ＦＡＯ的经时过程可用ｙ＝Ａ±ＢＩｎ（ｔ＋ｆ）描述（ｒ＝０．９８，Ｐ〈０．００１，ｔ≤１６分）；通过对ｔ１／２ＦＡ／Ｆｉ，ｔ１／２ＦＡ／ＦＡＯ和Ｂ值的比较分析，未见临床麻醉中有明显的第二气体效应。上述麻醉药的肺排出过程基本上是肺摄入的逆过程；但复合吸…     

氟烷七氟醚对酶诱导缺氧大鼠脂过氧化反应的影响（氟烷性肝炎的研究Ⅰ）

雄性ＳＤ大鼠饮用含苯巴比妥（１ｍｇ／ｍｌ）的饮水一周后，随机分为６组，每组６例：ＮＣ，２１％Ｏ２／７９％Ｎ２；ＨＣ，１４％０；１８６％Ｎｅ；ＮＨ，２１％Ｏ２／７９％Ｎ２／１．２ＭＡＣ氟烷；ＨＨ，１４％Ｏ２／８６％Ｎ２／１．２ＭＡＣ氟烷；ＮＳ，２１％Ｏ２／７９％Ｎ２／１．２ＭＡＣ七氟醚；ＨＳ，１４％Ｏ２／８６％Ｎ２／１．２ＭＡＣ七氟醚。吸入时间１ｈ，２４ｈ后测定血浆及肝匀浆中ＭＤＡ、ＳＯＤ、游离琉基的含量。结果ＨＨ、ＮＨ组肝匀浆及血浆中ＭＤＡ、ＳＯＤ的含量均高于其它各组（Ｐ＜０．０１，Ｐ＜０．０５），余各组间均无显著差异（Ｐ＞０．０５）。ＮＨ、ＨＨ组血浆及肝匀浆中游离琉基的含量显著低于其它各组（Ｐ＜０．０１）。提示氟烷所致的肝脂过氧化反应增强的作用可能与其肝毒性有关，而七氟醚无促进肝脏脂过氧化反应增强的作用。     

七氟醚及其它挥发性麻醉药对肝药酶的影响

目的：观察七氟醚及其它挥发性麻醉药对肝药酶的影响。方法：将４０只月龄２～３月的ＳＤ大鼠随机分：对照组（Ｃ组，ｎ＝１０，０ＭＡＣ）、氟烷组（Ｆ组，ｎ＝１０，０．５ＭＡＣ）、异氟醚组（Ｉ组，ｎ＝１０，０．５ＭＡＣ）和七氟醚组（Ｓ组，ｎ＝１０，０．５ＭＡＣ）。各组动物分别吸入相应浓度的麻醉药，３小时／天，共７天。结果：表现为Ｆ组及Ｓ组肝脏代谢戊巴比妥钠的能力明显高于对照组（Ｐ＜０．０１）；Ｉ组有高于对照组的倾向（Ｐ＞０．０５）。结论：七氟醚、氟烷和异氟醚有酶诱导作用或倾向。     

异氟醚和异氟醚/N2O麻醉时的脑血流CO2反应性

目的 比较颅脑手术中相同ＭＡＣ（１．３ＭＡＣ）的异氟醚和异氟醚／Ｎ２Ｏ麻醉时的脑血流ＣＯ２反应性。方法 选择ＡＳＡⅠ￣Ⅱ级颅内肿瘤病人行择期开颅手术２０例,随机分为两组：异氟醚组（Ⅰ）：吸入１．５％异氟醚、空气、氧气;异氟醚／Ｎ２Ｏ组（Ｎ）：吸入０．８％异氟醚、（６０￣６５）％Ｎ２Ｏ、氧气,每组１０例。在ＰａＣＯ２为５．３ｋＰａ、３．７ｋＰａ时分别抽取动脉、颈内静脉球部血行血气分析。根据Ｆｉｃｋ公     

尼群地平对缺血再灌注肺脂质过氧化反应的影响

目的探讨肺缺血再灌注损伤的发病机理，观察尼群地平的防治效果。方法７２只大鼠随机分成假手术组、缺血再灌注组和治疗组，采用肺在体温缺血再灌注损伤模型，于缺血４５分钟、再灌注后１小时、２小时、４小时取损伤肺组织测丙二醛（ＭＤＡ）、超氧化物歧化酶（ＳＯＤ）和总钙含量。结果缺血再灌注组各时相肺组织ＭＤＡ含量上升（Ｐ＜０．０５），ＳＯＤ含量显著下降（Ｐ＜０．０５），总钙含量显著升高（Ｐ＜０．０５），尼群地平可减轻肺组织ＭＤＡ和组织总钙含量的升高（Ｐ＜０．０５）。结论钙超载和自由基反应共同参与了肺缺血再灌注损伤，二者可能相互影响，相互促进；尼群地平通过阻滞钙通道，影响自由基系统而对缺血再灌注肺起保护作用     

急性心肌缺血再灌注时中性粒细胞胞浆游离钙和氧自由基的变化

本研究旨在观测急性心肌缺血，再灌注时外周血中性粒细胞（ＰＭＮ）胞浆游离钙［Ｃａ２＋］ｉ、氧自由基的变化规律及与心肌钙、氧自由基的关系，以评定外周血指标对心肌缺血再灌注损伤（ＭＩＲＩ）的诊断价值。用家兔３０只，随机分为缺血前、缺血３０分钟、再灌注３０、９０、３６０分钟５组，取外周血ＰＭＮ和心肌测定丙二醛（ＭＤＡ），超氧化物歧化酶（ＳＯＤ）及ＰＭＮ［Ｃａ２＋］ｉ和心肌组织钙。结果示缺血３０分钟外周血ＰＭＮ［Ｃａ２＋］ｉ、ＭＤＡ较缺血前明显升高，而ＳＯＤ活性则明显下降，至再灌注期上述变化更显著（Ｐ均＜０．０１）。且其变化规律与心肌钙、ＭＤＡ和ＳＯＤ的改变是一致的；二者间呈显著正相关（Ｐ＜０．０５～０．０１）。结论为自由基与钙超负荷共同参与了ＭＩＲＩ，外周血ＰＭＮ的检测可作为判断ＭＩＲＩ的可靠方法。     

Analysis of oxygen transport and oxygen utilization combined

We propose a model which combines oxygen transport system from blood to tissue with oxygen utilization system at the tissue.The model consists of 3 equations; the relationship between tissue P_{O 2} (Pts_{O 2}) and O₂ utilization (Vrc_{O 2}), diffusion from vessel to tissue, and Fick equation. This model has two advantages. First, it is self-consistent. Varying Vrc_{O 2} varies the oxygen transport. Second, it enables to analyze the effects of various factors of oxygen transport/utilization on other factors.We applied this model to the brain tissue. Following values were assumed. Critical tissue P_{O 2} (Pcrit_{O 2}) 2mmHg; oxygen utilization above this level 3ml·min^–1·100g^–1; diffusion coefficient from blood vessel to tissue (D) 0.2ml·min^–1·mmHg^–1·100g^–1; cerebral blood flow (CBF) 50ml·min^–1·100g^–1; hemoglobin 15g·100ml^–1. Hill equation was used for oxygen dissociation curve with n of 2.7 and P50 of 27.0mmHg.From these, the following values were obtained; Pv_{O 2}, Pts_{O 2} and Vrc_{O 2}. The changes were analyzed for the 5 input values, Pa_{O 2}, CBF, D, P50 and Hb, changing from zero to their respective normal values. A reduction of a single parameter down to 50% of normal barely affected oxygen utilization. A further reduction resulted in significant oxygen utilization. Under conditions studied, a decrease in P50 reduced oxygen utilization faster than that in any other parameters.(Suwa K: Analysis of oxygen transport and oxygen utilization combined. J Anesth 6: 51–56, 1992)     

Independent measurement of oxygen consumption and oxygen delivery

This experiment investigated the relationship between oxygen consumption and oxygen delivery (cardiac output X arterial oxygen content) in an acute canine model. Previous studies investigating this relationship have largely utilized methods in which oxygen consumption and oxygen delivery were each calculated using the same measured variables resulting in mathematical coupling of variables. In this study, oxygen consumption was measured directly by closed-circuit spirometry. Oxygen delivery was independently controlled using right atrial bypass. These techniques assured that the values for oxygen consumption and oxygen delivery were derived entirely independently. In our study using 11 dogs, we found that oxygen consumption was constant and independent of oxygen delivery at oxygen delivery levels greater than 8.0 cc/kg/min (normal canine oxygen delivery 20-25 cc/kg/min). Oxygen consumption was linearly related to oxygen delivery at oxygen delivery levels less than or equal to 8.0 cc/kg/min. Below this critical level of oxygen delivery, animals were more acidotic and hypotensive than at higher delivery levels.     

Concentrations of oxygen delivered by air entrainment oxygen masks

The air entrainment devices from oxygen masks of four manufacturers (Henleys Medical Supplies Ltd, Vickers Medical, Intersurgical Ltd, C R Bard International Ltd) were studied. All were found to deliver concentrations of oxygen close to those specified. The literature is reviewed and it is suggested that provision of a total flow in excess of 60 litres/minute is most likely to provide a constant inspired oxygen concentration, whichever nominal concentration or design of mask is selected and provided distal obstruction is avoided.     

Cerebral oxygen vasoreactivity and cerebral tissue oxygen reactivity

There has long been an appreciation that cerebral blood flowis modulated to ensure adequate cerebral oxygen delivery inthe face of systemic hypoxaemia. There is increasing appreciationof the modulatory role of hyperoxia in the cerebral circulationand a consideration of the effects of such modulation on themaintenance of cerebral tissue oxygen concentration. These newerfindings are particularly important in view of the fact thatcerebrovascular and tissue oxygen responses to hyperoxia maychange in disease. Such alterations provide important insightsinto pathophysiological mechanisms and may provide novel targetsfor therapy. However, before the modulatory effects of hyperoxiacan be used for diagnosis, to predict prognosis or to directtherapy, a more detailed analysis and understanding of the physiologicalconcepts behind this modulation are required, as are the limitationsof the measurement tools used to define the modulation. Thisoverview summarizes the available information in this area andsuggests some avenues for further research. Br J Anaesth 2003; 90: 774–86