离体模式下地氟醚、异氟醚和氟烷通过氧合器应用的药代动力学研究

目的研究在离体模式下地氟醚、异氟醚和氟烷通过氧合器应用的药代动力学。方法选择成人型膜式氧合器，预充生理盐水2000ml，连接动静脉端形成环路。将预先配制在钢瓶内的2．4％地氟醚、0．46％异氟醚及0．308％氟烷混合气体输送至氧合器，气体流量3Umin，泵流量4Umin，温度30℃。在摄入及排出的0、1、2、4、8、16、32min采集氧合器入气口、排气口及动脉端样本，测定吸入麻醉药分压。结果在摄入阶段及排出阶段，动脉端溶液中三种吸入麻醉药分压迅速上升或下降，用药后8min时，三种药物的动脉端样本分压与吸入气分压之比(Pa／Pi)均达50％以上，停药后8min动脉端样本分压与动脉端样本分压峰值之比(Pa／Pa0)均降至10％以下。三种药物之间在同一时间点Pa／Pi及Pa／17aO均有显著性差异(P＜0．05)。各吸入麻醉药动脉端样本与氧合器排气口中分压之间呈线性相关关系(r=0．99)。结论(1)Bentley膜式氧合器具有快速转运吸入麻醉药的性能；(2)地氟醚、异氟醚及氟烷通过氧合器应用后摄取和排出速率随着药物的水／气分配系数的增高而减慢；(3)通过监测氧合器排气口中吸入麻醉药分压可以快速、准确地估计液相中吸入麻醉药分压。     

Should nitrous oxide be discontinued before desflurane after anaesthesia with desflurane/N2O?

Background : The appearance of hypoxaemia immediately after anaesthesia with nitrous oxide may be partially explained by diffusion hypoxia. This study was undertaken to evaluate circulatory and respiratory variables during emergence after desflurane/nitrous oxide anaesthesia, and whether there are any differences depending on which gas is discontinued first. Methods : 20 patients were studied after gynaecological laparoscopic surgery. The depth of anaesthesia was reduced 10 min prior to the emergence by stopping the administration of one of the two inhalational agents. Desflurane was discontinued first in Group 1, nitrous oxide in Group 2. Ventilation was controlled with E'C0₂ maintained at 5% until the administration of the second anaesthetic gas was discontinued. Thereafter, the patients breathed spontaneously. Results : The PaC0₂ at which the respiratory drive reappeared after controlled normoventilation was similar in both groups, 6.1–6.5 kPa, and extubation was performed after 10–11 min. At extubarion, the end–tidal C0₂ and total MAC were similar in the groups, about 6.2 vol% and 0.16, respectively. Mean arterial blood pressure was significantly higher in Group 1. The cardiac output increased in both groups from about 6 1/min at the conclusion of anaesthesia to 9.0 and 7.6 1/min at 15 min in the recovery period. End–tidal O₂ decreased and CO₂ increased in both groups during the first 10 min in the recovery period. pH was reduced at 15 and 30 min in both groups. Conclusion : Irrespective of which agent was discontinued first, there was an increase in cardiac output, decrease in oxygenation and a modest acidosis in the first 30–min recovery period. The only significant difference between the groups was in mean arterial blood pressure in the early emergence phase with a greater MAP when N₂O had been used until the conclusion of anaesthesia.     

地氟醚与NO预处理对大鼠肺缺血再灌注损伤的保护作用

目的建立在体大鼠肺缺血再灌注(I-R)损伤模型，观察吸人20ppmNO和／或1．3MAC地氟醚预处理对大鼠肺I-R损伤的作用。方法60只SD大鼠随机分为五组，假手术组、I-R组、地氟醚 I-R组、iNO I-R组及地氟醚 iNO I-R组。各组在缺血后与再灌注3h分别处死6只大鼠，检测肺组织IL-10、IL-1β、TNF-α以及ICAM-1表达，MDA、MPO含量和肺组织湿干重比。结果与假手术组相比，肺I-R后IL-10、IL-1β及TNF-α等细胞因子生成明显增加，ICAM-1呈显著上调，MDA与MPO显著升高，肺水含量增加。吸入NO和地氟醚均可在一定程度上抑制肺I-R后IL-1β和TNF-α的生成，降低ICAM-1的上调，减少MDA和MPO生成，同时抑制IL-10生成。结论吸人地氟醚和／或NO抑制促炎细胞因子以及黏附分子的表达，同时对抗炎因子也有明显抑制作用，对肺I-R损伤起到保护作用；但两者联合应用并未呈现显著的协同作用。     

A comparison of postoperative respiratory complications associated with the use of desflurane and sevoflurane: a single-centre cohort study

Sevoflurane and desflurane are the most commonly used volatile anaesthetics for maintenance of anaesthesia. In this study, we aimed to evaluate the relationship between choice of volatile anaesthetic and early postoperative respiratory complications, and to address a critical knowledge gap in safety outcomes between these two commonly used agents. We performed a retrospective analysis of adult (non-cardiac surgery) patients who received sevoflurane or desflurane for the maintenance of general anaesthesia at our institution between 2005 and 2018. We evaluated the association between desflurane exposure (when compared with sevoflurane) and the primary outcome of postoperative respiratory complications, defined by early post-extubation desaturation (S_pO₂ < 90%) or re-intubation within 7 days postoperatively. Multivariable regression analyses were performed and adjusted for confounding factors, including patient, anaesthetic and surgical factors. Propensity matched, interaction and sub-group analyses were performed to assess outcomes in high-risk groups: morbidly obese (BMI > 35 kg.m⁻²); elderly (age > 65 years); and high risk of respiratory complications as well as the primary outcome at 24 h. Desflurane was used for 23,830 patients and sevoflurane for 84,608 patients. Patients exposed to desflurane did not demonstrate a reduced risk of postoperative respiratory complications when compared with sevoflurane (adjusted odds ratio 0.99, 95%CI 0.94–1.04, p = 0.598). These findings were consistent across all sub-groups of high-risk patients and in the propensity score matched cohort. In summary, desflurane use was not associated with reduced postoperative respiratory complications when compared with sevoflurane. In the context of environmental and cost concerns with volatile anaesthetic agents, our study provides important data to support organisational decisions regarding the use of desflurane.     

地氟醚在循环紧闭麻醉中的药代动力学

目的　了解地氟醚在最低流量循环紧闭麻醉中药代动力学的临床表现。　方法　５０例麻醉分级（ＡＳＡ） Ⅰ～Ⅱ级全麻下的择期手术病人。麻醉诱导采用咪唑安定、芬太尼、琥珀胆碱。气管插管后开始１０ ｍ ｉｎ 氧流量为４ Ｌ／ｍ ｉｎ,行间歇正压控制呼吸,地氟醚挥发罐浓度（ＦＤ）８％ 。此后关闭回路,氧流量０．２０～０．３５Ｌ／ｍ ｉｎ,地氟醚ＦＤ １０％ ～１２％ 。维持地氟醚的肺泡浓度（ＦＡ）在６％ ±０．１％ 。间断给予维库溴胺维持肌肉松弛。　结果　地氟醚ＦＡ 达６％ 和ＦＡ／ＦＩ（吸入浓度）达０．９,分别为４．９±０．８ ｍ ｉｎ 和１２．４±０．２ ｍ ｉｎ,并能维持在０．９０～０．９５。麻醉停止后,５．７±２．４ ｍ ｉｎ 恢复自主呼吸,拔管时间９．７±０．８ ｍ ｉｎ。麻醉中脉搏血氧饱和度均１００％ ,吸入氧浓度≥８０％ 。　结论　地氟醚的低组织溶解特性使其麻醉诱导和麻醉恢复快,麻醉调控性强。地氟醚的药代动力学特性使其能安全、有效地在最低流量循环紧闭麻醉中使用。     

Metabolism of desflurane and isoflurane to fluoride ion in surgical patients

The metabolism of isoflurane and the investigational volatile anaesthetic desflurane to fluoride ion was examined in 25 surgical patients. The patients were randomly assigned to four groups, to receive isoflurane or desflurane at either 0.65 MAC or 1.25 MAC. Anaesthesia was induced in all patients with thiopentone and midazolam and included nitrous oxide 60% in addition to the volatile agent. Blood was drawn before induction and at the end of the operation for determination of serum fluoride ion concentration. Plasma fluoride ion concentrations increased (+ 1.36 +/- 0.93 microM, P less than 0.01) in patients receiving isoflurane but were unchanged (-0.13 +/- 0.50 microM) in patients receiving desflurane. Metabolic release of fluoride ion is less with desflurane than with isoflurane during administration of the anaesthetics to surgical patients, and is unlikely to be of clinical significance.     

低浓度地氟醚对胸部肿瘤病人手术麻醉时血液动力学和血浆血管内皮细胞生长因子水平的影响

目的：观察低浓度地氟醚吸入麻醉对胸部肿瘤病人手术麻醉时血液动力学和血浆血管内皮细胞生长因子（VEGF）水平的影响。方法：选择胸部肿瘤手术病人28例，ASA I－II级，麻醉诱导后气管插管，观察0．5，1．0肺泡气最低有效浓度（MAC）地氟醚对胸部肿瘤手术病人血液动力学和血浆VEGF水平的影响。结果：麻醉诱导后气管插管时，病人SBP，DBP和MAP均呈显著下降，HR显著增快（均P＜0．01），分别吸入0．5，1．0MAC地氟醚时，虽然SBP，DBP，MAP较麻醉前明显下降（P＜0．05），但与麻醉诱导后相比，血压和HR无明显变化，肿瘤患者血浆VEGF水平明显高于正常水平；麻醉诱导后，血浆VEGF水平明显降低，吸入地氟醚后，血浆VEGF水平进一步降低，随地氟醚吸入浓度的增加，血浆VEGF水平降低更明显。结论：低浓度地氟醚吸入对胸部手术病人血液动力学无明显影响，能降低胸部肿瘤病人血浆VEGF水平，这对降低术后肿瘤复发或转移风险可能有一定价值。     

右美托咪啶对地氟醚麻醉期间血浆中去甲肾上腺素和

目的 观察右美托咪啶对地氟醚麻醉期间血浆中去甲肾上腺素和肾上腺素水平的影响。 方法 回顾性分析ASA Ⅰ～Ⅱ级择期行腹腔镜下子宫次全切除手术60例病人,分为对照组（地氟醚组）和联合组（右美托咪啶与地氟醚联合麻醉组）,每组30例。两组术前和诱导用药相同,联合组麻醉诱导后开始每小时静脉输注右美托咪啶0.5 μg/kg并维持至麻醉结束。对照组在麻醉诱导后静脉注射给予相同体积的生理盐水。于麻醉诱导前（T₀）、吸入地氟醚30 min后（T₁）、手术开始后60 min（T₂）及关腹膜后即刻（T₃）分别抽取中心静脉血,测定血浆肾上腺素（EP）和去甲肾上腺素（NE）浓度;观察心率（HR）、平均动脉压（MAP）和呼吸恢复、拔管时间、术中知晓发生率以及苏醒期躁动评分。 结果 与T₀比,两组T₁、T₂和T₃ EP和NE水平明显升高（P<0.05）;与对照组比较,联合组T1、T2和T3 EP和NE水平明显降低（P<0.05）,HR减慢、MAP降低、呼吸恢复时间、拔管时间缩短（P<0.05）,苏醒期躁动的评分减低（P<0.05）。 结论 右美托咪啶可以降低地氟醚麻醉期间血浆中去甲肾上腺素和肾上腺素水平。