30%脂肪乳剂对异氟醚血/气分配系数以及"洗入"的影响

目的 观察30%脂肪乳剂对异氟醚的血/气分配系数（B/G）的影响以及静脉注射不同剂量的30%脂肪乳剂对异氟醚“洗入”的影响.方法 （1）采集桡动脉血,配成不同浓度的30%脂肪乳剂与血的混合液.用二次平衡法测定异氟醚对上述混和液的B/G.（2）24例行冠状动脉旁路移植术的患者分为四组,每组6例.麻醉诱导后,静脉单次注射0、0.2、0.4及0.8 ml/kg的30%脂肪乳,随后开启异氟醚挥发罐,将挥发罐刻度设定在2%,并同时用微量泵注入相应剂量的30%脂肪乳0、0.2、0.4、0.8 ml·kg^-1·h^-1.持续吸入异氟醚1 h,监测异氟醚呼气末浓度（Fa）和吸入浓度（Fi）.其中0 m1/kg的30%脂肪乳组为对照组.结果 （1）异氟醚B/G随血中混合的30%脂肪乳剂浓度的增加而升高.（2）0.8 ml/kg剂量组的异氟醚Fa/Fi值与对照组比较明显降低（P＜0.05）.结论 注入较大剂量脂肪乳剂后,造成异氟醚“洗入”速度减慢,这可能是由于输注的脂肪乳剂造成异氟醚的B/G增大所致.     

异氟醚控制性降压对颅内动脉瘤夹闭术血中S100B含量的影响

目的　测定颅内动脉瘤夹闭前后血中S1 0 0B蛋白含量 ,研究异氟醚控制性降压对脑功能的影响。方法　择期颅内动脉瘤夹闭术病人 30例 ,ASAⅠ～Ⅱ级 ,随机分为两组 :异氟醚降压组 (n=1 5 )和异氟醚非降压组 (n =1 5 )。非降压组术中吸入 1MAC异氟醚维持麻醉。降压组行异氟醚控制性降压 ,平均动脉压下降幅度 30 %～ 4 0 % ,夹闭动脉瘤后降低异氟醚吸入浓度 ,终止降压。分别于切皮前、动脉瘤夹闭后即刻、2、4h、术后第 1、2天取血测定S1 0 0B蛋白含量 ,并于术后 1周随访病人 ,记录有无术后神经系统并发症。结果　 (1 )异氟醚降压后 30min平均动脉压由诱导前的 (95 2± 1 2 3)mmHg降至 (5 8 8± 5 4 )mmHg ,停止降压后 30min血压回升至 (75 1± 8 3)mmHg。降压后外周血管阻力及心肌收缩加速度下降 ,但心率及心输出量均无显著性变化 ;(2 )异氟醚降压组与非降压组间同一时间点血中S1 0 0B蛋白浓度无明显差异。降压组术后第 1天及第 2天血中S1 0 0B蛋白浓度均显著升高 (F =2 94 4 ,P =0 0 1 8)。结论　在颅内动脉瘤夹闭术中应用异氟醚控制性降压可能加重了术后脑损伤 ,不利于病人围麻醉期脑功能的保护     

丙泊酚和异氟醚对支气管粘液运输速度的影响

目的　观察丙泊酚静脉麻醉和异氟醚吸入麻醉对人支气管粘液运输速度的影响。方法　选择 4 0例ASAⅠ～Ⅱ级病人 ,随机分两组 ,每组 2 0例。异氟醚组吸入 2MAC异氟醚 ,丙泊酚组静脉丙泊酚麻醉 ,两组病人分别在机械通气 1 0和 6 0min后 ,测量支气管粘液运输速度。方法是在小儿支气管镜直视下 ,在左主支气管背部粘膜上方注射亚甲蓝 ,标记染料在 0、2、4、6min的移动距离 ,计算支气管粘液运输速度。结果　异氟醚组机械通气 1 0和 6 0min后的测量值分别为 (1 4 1 0±1 4 5 )mm/min和 (1 0 1 0± 2 0 0 )mm/min ,通气 6 0min较 1 0min粘液运输速度显著下降 (P <0 0 5 ) ;丙泊酚组 1 0和 6 0min的测量值分别为 (1 4 1 0± 1 6 3)mm/min和 (1 4 70± 1 4 6 )mm/min ,通气 6 0min较 1 0min粘液运输速度上升 ,但无统计学差异 (P >0 0 5 )。两组在机械通气 1 0min后 ,差异不显著 (P >0 0 5 ) ;在 6 0min后 ,分别为 (1 4 70± 1 4 6 )mm/min和 (1 0 1 0± 2 0 0 )mm/min ,丙泊酚组运输速度显著高于异氟醚 (P <0 0 5 )。结论　异氟醚抑制支气管粘液的运输速度 ;丙泊酚静脉麻醉加快粘液运输速度 ,有保护气道粘膜的作用     

异氟醚控制性降压对颅内动脉瘤夹闭术病人脑脊液游离脂肪酸浓度的影响

目的探讨异氟醚控制性降压对颅内动脉瘤夹闭术病人脑脊液游离脂肪酸(FFAs)浓度的影响。方法择期行颅内动脉瘤夹闭术病人30例,ASAⅠ级或Ⅱ级,随机分为2组(n=15):对照组(A组)和控制性降压组(B组)。2组均在术中持续吸入异氟醚维持麻醉,A组术中呼气末异氟醚浓度为1.2%;B组切开硬脑膜时开始行异氟醚控制性降压,平均动脉压(MAP)下降幅度为基础值的30%～40%,夹闭动脉瘤即刻开始降低异氟醚吸入浓度停止控制性降压,使血压回升至降压前水平。分别于麻醉诱导前(T_0)、硬脑膜切开即刻(T_1)、硬脑膜切开后10、20、30min(T_(2-4))、动脉瘤夹闭后即刻(T_5)、动脉瘤夹闭后10、20、30min(T_(6～8))记录血液动力学指标;于T_1、L_5动脉瘤夹闭后2、4h(T_(9.10))取脑脊液,测定FFAs浓度。结果(1)B组硬脑膜切开后MAP由(96±9)mm Hg降至(62±4)mm Hg(P<0.05或0.01),夹闭动脉瘤后MAP恢复至(78±11)mm Hg,心输出量和心率无明显变化(P>0.05)。(2)B组在T_5、T_9、T_(10)时脑脊液FFAs浓度增高(P<0.05),B组FFAs浓度增高的程度高于A组(P<0.05)。结论异氟醚控制性降压可以增加颅内动脉瘤夹闭术病人脑脊液中FFAs的浓度。     

紫绀型与非紫绀型先天性心脏病患儿吸人麻醉药血／气分配系数

目的测定并比较紫绀型与非紫绀型先天性心脏病患儿吸入麻醉药血／气分配系数(B／G),判断红细胞压积(Hct)对B／G的影响。方法紫绀型与非紫绀型先天性心脏病患儿各10例,平均年龄5岁,采桡动脉血10ml,用两次平衡法测定地氟醚、异氟醚和氟烷的B／G,并测定血浆总胆固醇、甘油三脂、白蛋白、球蛋白浓度和Hct,t检验比较两组间血液成分和吸入麻醉药B／G有无差别。结果紫绀型与非紫绀型先天性心脏病患儿Hct有显著差异(紫绀型为68．7％±11．1％,非紫绀型37．7％±2．9％,P<0．05);但两组间其他血浆成分和三种吸入麻醉药的B／G无差异(P>0．05)。结论Hct对B／G无影响,紫绀型与非紫绀型先天性心脏病患儿的B／G无显著性差异。     

丙泊酚靶控输注或异氟醚吸入对罗库溴铵药效学的影响

目的　探讨丙泊酚靶控输注和异氟醚吸入对罗库溴铵药效学的影响。方法　选择无神经肌肉疾患 ,在全麻下择期手术的病人 4 8例 ,随机分成丙泊酚靶控输注组 (B组 )和异氟醚吸入组(Y组 )维持麻醉。采用TOF刺激方式监测拇内收肌的收缩反应。当T1恢复至对照值的 2 0 %时追加罗库溴铵 0 15mg/kg。记录每次追加罗库溴铵的间隔时间以及肌松恢复情况。 结果　两组肌松维持时间无明显差异 (P >0 0 5 ) ,而B组罗库溴铵总用药量明显高于Y组 (P <0 0 5 )。B组各次追加罗库溴铵间隔时间平均为 (2 6 1± 9 3)s,Y组平均间隔时间为 (36 2± 13 2 )s,明显比B组长 (P<0 0 5 )。Y组第 1、2次给药后的间隔时间相似 (P >0 0 5 ) ,第 3、4、5次给药后间隔时间也相似 (P <0 0 5 ) ,但是比第 1、2次延长 (P <0 0 5 )。Y组T1恢复到对照值的 2 5 %、5 0 %和 75 %的时间及拔管时间比B组长 (P <0 0 5 ) ,但两组的恢复指数相似 (P >0 0 5 )。结论　丙泊酚靶控输注对罗库溴铵的药效学没有影响。而异氟醚对罗库溴铵则起增效作用 ,异氟醚维持麻醉时应酌情减少罗库溴铵的用量。     

地氟醚、异氟醚和七氟醚对脑血流速率的影响

目的　通过经颅多普勒超声 (TCD)监测大脑中动脉 (MCA)血流速率 ,观察地氟醚、异氟醚和七氟醚三种吸入麻醉药对平均血流速率 (Vm)的影响。方法　 42例 18～ 6 0岁、ASAⅠ～Ⅱ级、择期非颅脑手术病人 ,随机接受地氟醚、异氟醚或七氟醚吸入麻醉。机械通气维持PETCO2 在 40± 1mmHg。当呼气末吸入麻醉药浓度分别为 :1 0MAC平衡 15分钟后 ,快速 (2分钟内 )从 1 0MAC升高至 1 5MAC即时 ,1 5MAC平衡 15分钟后 ,以及稳定于 1 5MAC并且维持和 1 0MAC平衡下相似的MAP时 ,记录Vm、MAP和心率。结果　 (1)吸入浓度从 1 0MAC上升至 1 5MAC ,且MAP维持相同水平的情况下 ,地氟醚和异氟醚使Vm增加非常显著 (分别从 5 6cm/s上升至 6 1cm/s,从47cm/s上升至 5 2cm/s,P <0 0 1) ,而七氟醚无显著变化 (从 6 0cm/s至 6 0cm/s,P >0 0 5 )。 (2 )当吸入浓度快速从 1 0MAC上升至 1 5MAC时 ,地氟醚使血压升高、心率增快 ,同时 ,脑血流速率显著增加 (从 5 6cm/s上升至 6 1cm/s,P <0 0 1)。而异氟醚和七氟醚在MAP显著下降的同时使Vm无显著变化 (从 47cm/s升至 49cm/s,P >0 0 5 ) ,或显著下降 (从 6 0cm/s降至 5 6cm/s,P <0 0 1)。结论　 (1)吸入浓度从 1 0MAC增加到 1 5MCA时 ,地氟醚、异氟醚使脑血流速率显著增加 ,而七氟醚作     

七氟醚增强个培养鼠背根神经节细胞γ—氨基丁酸调控的氯电流

目的　观察七氟醚 ( 0 38至 3× 10 -3 mol/L)对单个培养SD鼠背根神经节细胞 3× 10 -6mol/Lγ 氨基丁酸 (GABA)调控的氯电流影响。方法　采用膜片钳全细胞记录和“Y型管”技术。结果　0 38× 10 -3 ,0 76× 10 -3 ,1 5 2× 10 -3 ,2 2 8× 10 -3 ,3 0 4× 10 -3 mol/L七氟醚分别增强氯电流峰值高度至对照值的 149%± 2 5 % ,2 0 3%± 2 7% ,32 7%± 79% ,331%± 10 9% ,2 43%± 71%。结论　相关临床麻醉浓度的七氟醚能增强培养鼠背根神经节细胞 3× 10 -6mol/LGABA调控的氯电流     

七氟醚对心脏病病人维库溴铵肌松效力的影响

目的 :观察吸入七氟醚对维库溴铵肌松效力的影响。方法 :4 0例择期体外循环心内直视术病人随机分成两组 ,分别为静脉麻醉组 (对照组 )和静脉麻醉复合吸入 1 3MAC七氟醚组 (七氟醚组 ) ,采用累积剂量反应的方法测定两组维库溴铵的量效关系曲线。结果 :诱导期吸入七氟醚 15分钟后使维库溴铵的量效关系曲线左移 ,七氟醚组的ED50 和ED95分别为 19 2± 5 6和 3 7 0± 10 3 μg/kg ,与对照组的 3 0 7± 8 6和 5 7 8± 11 6μg/kg相比 ,分别减少3 6 5 %和 3 5 8% (P <0 0 1)。结论 :七氟醚麻醉能明显增强维库溴铵的肌松效力。     

婴幼儿腹部手术两种麻醉方法比较

目的:观察婴幼儿常用的两种麻醉方法氯胺酮复合硬膜外麻醉和氯胺酮复合安(异)氟醚吸入麻醉的优缺点。方法:将78例病人随机分为氯胺酮复合硬膜外组、氯胺酮复合安(异)氟醚组,分别在围麻醉期对其生命体征、麻醉诱导时间及清醒时间、麻醉药物用量等方面观察。结果:氯胺酮复合硬膜外组麻醉诱导时间20±3min、氯胺酮平均用量16mg/kg、术中比术前血压下降10±5mmHg、术后清醒时间5±3/min、术中复用安定4例;氯胺酮复合安(异)氟醚吸入组麻醉诱导时间7±2min、氯胺酮平均用量13.6mmHg、术中比术前血压下降3±1mmHg、术后清醒时间1±1min、术中复用安定0例。结论:氯胺酮复合安(异)氯醚吸入组在麻醉诱导时间、氯胺酮用量、术后清醒时间、对循环系的干扰方面明显优于氯胺酮复合硬膜外组。     

Comparison of the haemodynamic actions of desflurane/N2O and isoflurane/N2O anaesthesia in vascular surgical patients

Background: The purpose of this study was to compare heart rate and arterial blood pressure response to desflurane/N₂O vs isoflurane/N₂O anaesthesia in a randomised clinical trial performed in patients before vascular surgery.
Methods: To evaluate associated changes in the autonomic nervous system with maintenance of anaesthesia, we used power spectral analysis (PSA) of heart rate and blood pressure and measured plasma catecholamine concentrations. Twenty-five patients whose trachea had been intubated after propofol induction were given either desflurane or isoflurane at 1 and 1.5 MAC in N₂O (60%) in a random manner.
Results: At an anaesthetic depth of up to 1.5 MAC, arterial blood pressure, indices of sympathetic activity derived from PSA, decreased with both anaesthetics, while heart rate and plasma catecholamine concentrations did not significantly change. Plasma renin activity significantly increased at 1.5 MAC anaesthesia in both groups.
Conclusions: We conclude that sympathetic hyperactivity previously reported during desflurane anaesthesia in healthy volunteers is not frequent in clinical practice in elderly vascular surgical patients under desflurane/N₂O anaesthesia, since it occurs at an anaesthetic depth which cannot be reached in these patients because of the lowering arterial blood pressure effects of desflurane, which are similar to those of isoflurane.     

Clinical relevance of the B12/N2O interaction A report of a seminar

The interaction of nitrous oxide and vitamin B₁₂ and its implications are not the exclusive territory of any one discipline. The initial discovery was by a chemist but it is of obvious relevance to anaesthetists and intensivists; some complications are neurological others haematological. The interaction provides an extremely important research tool as the first easily available B₁₂-deficient animal model. Finally there are implications for exposure to contaminated atmospheres in hospitals and in industry.     

Principles of CO2/Erbium Laser Safety

BACKGROUND: There are a variety of potential hazards with laser technology. METHODS: A review of the literature. OBJECTIVE: To summarize the potential hazards of CO2 and erbium laser technologies and the safety guidelines and equipment developed to minimize them. RESULTS: Laser hazards can be divided into the following categories: mechanical, environmental, macrobiologic, microbiologic, and iatrogenic. CONCLUSION: At the conclusion of this learning activity, the reader should be able to discuss the mechanical, environmental, macrobiologic, microbiologic, and iatrogenic hazards of resurfacing laser technology, the literature cited to support current safety guidelines, and the equipment developed to promote laser safety.     

Acute Xenograft Rejection Mediated by Antibodies Produced Independently of TH1/TH2 Cytokine Profiles

There is substantial support for the hypothesis that T(H)1 cytokine responses are critical for the normal elaboration of allograft rejection. Recent studies by Wang et al. (1) underscore the importance of T(H)2 responses in xenograft rejection and revealed that T(H)1 cytokines, IL-12 and interferon-gamma (IFN-gamma), can negatively regulate the development of humoral responses necessary for xenograft rejection. Their exceptional studies prompted us to test whether the ability of allografts to elicit cellular rejection and xenografts to induce humoral rejection also result from the differential ability to induce T(H)1 and T(H)2 responses. We compared the kinetics of antibody and cytokine (IFN-gamma and IL-4) production in C57BL/6 mice following allograft transplantation with BALB/c hearts and in C57BL/6 and BALB/c mice following transplantation with Lewis rat hearts. We also compared the ability of BALB/c mice, deficient in the ability to produce IL-4 or IFN-gamma, to reject xenografts and produce xenoantibodies. We observed that T(H)1/T(H)2 cytokine production minimally affected the kinetics of graft rejection but regulated the magnitude of IgG subclass production. Anti-graft IgM played a critical role in initiating acute antibody-mediated xenograft rejection, and the production antigraft IgM was unaffected by IL-4 or IFN-gamma deficiency. In contrast to the report by Wang et al. (1), we conclude that antibody-mediated xenograft rejection in the concordant Lewis rat heart-to-C57BL/6 mouse xenotransplantation model is dependent on anti-IgM production but independent of T(H) cytokine profiles.