新生及成年大鼠七氟醚MAC值的测定

目的测定并比较新生及成年大鼠七氟醚的最低肺泡有效浓度(MAC)。方法选择健康新生及成年SD大鼠各25只。两组大鼠分别放入自制大鼠麻醉装置,露出其尾部。七氟醚气体经麻醉机挥发罐输入麻醉装置。采用序贯法及夹尾刺激测定七氟醚MAC。七氟醚初始测定浓度为1.5%,调节梯度为±0.2%。每间隔20 min重复夹尾试验判断麻醉效果并抽取气体样本3~5 ml测定七氟醚浓度。如此反复,使每只大鼠均获得一个阳性与阴性反应的交叉点。组内每只大鼠MAC值的均值即为该组大鼠的MAC值。结果新生大鼠MAC值为(2.58±0.11)%,明显高于成年大鼠的MAC值(2.32±0.13)%(P0.01)。结论新生大鼠的七氟醚MAC值明显高于成年大鼠,达到同一麻醉深度时新生大鼠所需七氟醚浓度更高。     

新辅助化疗后胃癌手术七氟醚最低肺泡有效浓度的测定

目的确定接受新辅助化疗后1个月行胃癌根治术的患者全凭吸入麻醉时外科切皮无体动反应的七氟醚最低肺泡有效浓度(minimum alveolar concentration,MAC)。方法择期行胃癌根治术患者25例,男14例,女11例,年龄30~50岁,ASAⅠ或Ⅱ级,于手术1个月前结束2个周期的奥沙利铂复合替吉奥化疗(1个化疗周期为14 d)。吸入6%七氟醚全麻诱导,至患者意识消失行气管插管术后,将呼气末七氟醚浓度调整至预定值,维持15 min不变,然后外科切皮。根据Dixon上下法进行试验,初始呼气末七氟醚浓度为2.2%,切皮时发生体动反应,下一例升高一个浓度梯度,切皮时未发生体动反应,下一例降低一个浓度梯度,相邻浓度梯度为0.2%。采用Probit分析计算出七氟醚的MAC和95%CI。结果本研究中进行外科切皮操作时,患者的体动反应表现为肢体轻微活动,所有患者均未发生身体大幅扭动、睁眼或术中知晓等严重并发症。有11例(44%)患者发生体动。接受新辅助化疗的胃癌患者在外科切皮时无体动反应的七氟醚MAC值为1.52%,95%CI为1.37%~1.65%。结论接受新辅助化疗的胃癌患者切皮无体动反应的七氟醚的MAC值为1.52%。     

七氟醚抑制帕金森病患者切皮时肾上腺素能反应的最低肺泡有效浓度

目的探讨七氟醚抑制帕金森病(PD)患者切皮时肾上腺素能反应的最低肺泡有效浓度(MAC_(BAR))。方法选择2019年10月至2021年3月择期行脑深部刺激器植入术患者21例,男10例,女11例,年龄40～64岁,BMI 18～30 kg/m~2,ASAⅠ—Ⅲ级。采用吸入8%七氟醚进行麻醉诱导,喉罩置入后调整呼气末七氟醚浓度(C_(ET)Sev)至预设水平。采用序贯法测定七氟醚MAC_(BAR)。第1例患者C_(ET)Sev调整至3%,稳定后15 min切开锁骨下皮肤。将切皮前3、1 min HR和MAP的平均值记录为基础值,将切皮后1、3 min HR和MAP的平均值记录为变化值,若HR或MAP升高幅度超过基础值的20%则定义为肾上腺素能反应阳性。若切皮时肾上腺素能反应为阳性,下一例采用高一级浓度,否则采用低一级浓度,浓度梯度为0.2%。当出现7个"阳性反应-阴性反应"的转折点时停止试验。采用概率回归法计算七氟醚MAC_(BAR)及其95%可信区间(CI)。结果肾上腺素能反应阳性的患者MAP变化值明显高于肾上腺素能反应阴性的患者(P0.05)。通过概率回归法算得PD患者切皮时七氟醚MAC_(BAR)为2.11%(95%CI 1.94%～2.27%)。结论七氟醚抑制帕金森病患者切皮时肾上腺素能反应的最低肺泡有效浓度为2.11%(95%CI 1.94%～2.27%)。     

Anesthesia with 1.5 minimum alveolar concentration sevoflurane is not altered by physostigmine as measured by bispectral and clinical indices

STUDY OBJECTIVE: To evaluate the effect of physostigmine on 1.5% sevoflurane anesthesia and recovery. DESIGN: Prospective, randomized, double-blinded study. SETTING: Operating room of a university-affiliated, metropolitan hospital (Aretaieion Hospital and St Savas Hospital). PATIENTS: Forty female American Society of Anesthesiologists physical status I and II patients scheduled for breast biopsy. INTERVENTIONS: Patients were randomly assigned in physostigmine (PHYSO) and normal-saline (NS) group. Anesthesia was induced with sevoflurane 8% using a vital capacity breath technique, and rocuronium 0.6 mg/kg was given to facilitate Laryngeal Mask Airway (LMA) No. 4 insertion. Anesthesia was maintained with end-tidal sevoflurane 1.5 minimum alveolar concentration (MAC; 3% end-tidal concentration) throughout the procedure. MEASUREMENTS: After skin closure and under steady-state sevoflurane anesthesia 1.5 MAC, heart rate, blood pressure, and Bispectral Index (BIS) were recorded. Immediately after, the PHYSO group received intravenous 2 mg of physostigmine, whereas the NS group received equal volume of normal saline. Bispectral Index and hemodynamic measurements were recorded 5, 8, and 10 minutes after treatment. Anesthesia was then discontinued and the LMA was removed. Zero, 15, and 30 minutes after LMA removal, patients were evaluated for orientation, sedation, sitting ability, and the "picking up matches" test, as well as for nausea and vomiting. MAIN RESULTS: No difference was found in BIS (29 +/- 4, 32 +/- 6, 31 +/- 6, 30 +/- 7, 84 +/- 11 in the PHYSO group vs 29 +/- 6, 30 +/- 6, 30 +/- 5, 31 +/- 5, 86 +/- 7 in the NS group), hemodynamic parameters, or recovery parameters between the 2 groups at any time. No nausea or vomiting was observed in either group. CONCLUSIONS: Physostigmine did not influence BIS values or early recovery when administered to patients anesthetized with 1.5 MAC sevoflurane anesthesia.     

不同孕酮浓度对手术切皮时七氟醚最低肺泡有效浓度的影响

目的 探讨女性生理周期中不同孕酮浓度对手术切皮时七氟醚最低肺泡有效浓度(MAC)及用量的影响.方法 选择2019年6月至2020年12月拟行妇科腹腔镜手术的患者46例,年龄20～40岁,BMI 18～24 kg/m2,ASA I或Ⅱ级.按生理周期将患者分为两组:卵泡期(L组,n=22)和黄体期(H组,n=24).在Na...     

犬静脉注射乳化异氟醚最低肺泡有效浓度的研究

目的测定犬静脉注射乳化异氟醚的最低肺泡有效浓度(MAC静脉),并与吸入异氟醚麻醉时的最低肺泡有效浓度(MAC吸入)进行比较。方法将40只杂种犬平均分成静脉和吸入麻醉两组。应用序贯法和自身交叉法同时测定犬的MAC值。结果静脉组序贯法所测得的MAC静脉(0.94±0.10)%,与自身交叉法所测得的前6个交叉点的MAC静脉(0.89±0.14)%或全部交叉点的MAC静脉(0.93±0.13)%之间差异均无显著意义(P>0.05)。吸入组序贯法所测得的MAC吸入(1.29±0.10)%,与自身交叉法所测得的前6个交叉点的MAC吸入(1.24±0.06)%或全部交叉点的MAC吸入(1.33±0.09)%之间差异亦无显著意义(P>0.05)。但两组间比较MAC静脉均小于MAC吸入,差异有显著意义(P<0.05)。结论乳化异氟醚静脉麻醉时的MAC静脉明显小于吸入异氟醚麻醉时的MAC吸入,序贯法和自身交叉法对MAC的测定结果无明显影响。     

早产儿平稳气管插管时七氟醚的最低肺泡有效浓度

目的探讨早产儿气管插管无体动反应时的七氟醚最低肺泡有效浓度(MACEI)。方法选择择期吸入全麻下行眼科手术的早产儿27例,矫正胎龄37周,ASAⅠ或Ⅱ级。吸入6%七氟醚进行全麻诱导,至患儿意识消失后,将呼气末七氟醚浓度调整至预定值,维持15min,然后行气管插管。根据序贯法进行研究,初始呼气末七氟醚浓度为3.0%,如气管插管时发生体动反应,下一例升高一个浓度梯度,如气管插管时未发生体动反应,下一例降低一个浓度梯度,相邻浓度梯度为0.2%。将无体动反应时呼气末七氟醚浓度到体动反应时呼气末七氟醚浓度的中点设为一个平衡点,计算所有平衡点七氟醚浓度的平均值即为MACEI。结果患儿气管插管无体动反应的七氟醚MACEI为2.55%±0.20%,MAC95是2.81%(95%CI 2.67%~3.58%)。结论早产儿平稳气管插管的七氟醚MACEI为2.55%,低于足月产儿的参考值。     

65岁以上老年人地氟醚肺泡气最低有效浓度测定

目的　测定我国 6 5岁以上老年人地氟醚的肺泡气最低有效浓度 (MAC)。方法　选择ASAⅠ～Ⅱ级择期手术的 6 5岁以上患者 ,术前检查排除肝、肾、脑及心脏系统疾病 ,无酗酒史 ,无术前用药。入室后常规监测心电图、无创血压及血氧饱和度。氧和 3%地氟醚吸入诱导插管 ,全凭吸入地氟醚麻醉。采用Dixon’sup and down方法 ,交叉出现 6对切皮不动 动的患者即终止。 6对切皮不动 动患者切皮时地氟醚浓度的平均值即为MAC。结果　 17例患者中出现 6对不动 动的交叉对 ,MAC为 (5 0 8± 0 2 6 ) %。结论　老年人地氟醚MAC较文献报道的年轻人MAC小。     

脑内去甲肾上腺素、肾上腺素含量与异氟醚MAC的关系

目的 研究脑内神经递质去甲肾上腺素（ＮＥ）、肾上腺素（Ｅ）与异氯醚ＭＡＣ之间的关系。方法 １８只成所雄性大鼠吸入异氯醚,浓度分别为０．６％、０．８％、１．０％、１．２％及１．４％,脑皮层内插入０．０５ｍｍ内径的微透析探针,用人工脑 液灌注,收集透析液,监测定量脑电图,测定ＭＡＣ及角膜反射流失时ＮＥ及Ｅ的浓度后,将大鼠了随机分为三组：尾静脉慢注射（〉２ｍｉｎ）可乐定０．２ｍｇ／ｋｇ＋持续泵注０．１５     

吸烟患者细胞色素P450酶2E1的表达与七氟醚阻断肾上腺素能反应最低肺泡气浓度的相关性研究

目的 通过检测吸烟患者细胞色素P450酶2E1(cytochrome P450 family 2 subfamily E member 1,CYP2E1)含量变化,分析其与七氟醚阻断肾上腺素能反应的最低肺泡气浓度(minimum alveolar concentration to block the adrenergic response,MACBAR)值的相关性,探讨吸烟对七氟醚MACBAR值的影响及机制.方法 选择ASA分级Ⅰ、Ⅱ级,年龄30~50岁,择期拟在全身麻醉下行腹腔镜胆囊切除术的患者90例.通过询问患者本人及其家属评估两组患者吸烟情况,同时结合血清可替宁含量,将其分为吸烟组(A组,49例)和非吸烟组(B组,41例).采用快诱导气管内插管静吸复合麻醉,两组患者七氟醚目标呼气末浓度平衡时间>20 min,使用气腹刺激,观察MAP和HR变化,采用单次刺激法测定七氟醚MACBAR.手术前1 d抽取患者晨起静脉血5 ml,离心收集血清,检测可替宁和CYP2E1含量.结果 A组、B组诱导前HR和MAP组间比较,差异无统计学意义(P>0.05);组内HR和MAP基础值(气腹针穿刺前3 min、1 min的平均值)比诱导前明显下降(P<0.05);气腹后HR和MAP明显上升,其中MAP在A组升高幅度大于B组(P<0.05),HR组间比较差异无统计学意义(P>0.05).A组七氟醚MACBAR、CYP2E1和可替宁水平均高于B组(P<0.05).A组CYP2E1含量与MACBAR有相关性,且呈正相关(r=0.51,P<0.05).结论 吸烟患者CYP2E1含量与七氟醚MACBAR值有一定相关性,提示吸烟者血清中CYP2E1可能对七氟醚MACBAR值有影响.     

小剂量氯胺酮对妇科下腹部手术患者七氟醚肺泡气最低有效浓度的影响

目的 探讨小剂量氯胺酮对妇科下腹部手术患者七氟醚肺泡气最低有效浓度(MAC)的影响.方法 择期拟行妇科下腹部手术患者51例,年龄36～49岁,体重指数≤30 kg/m2,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将患者随机分为对照组(C组,n=29)和氯胺酮组(K组,n=22).K组静脉注射氯胺酮负荷量0.2 mg/kg,随后以14μg·kg-1·min-1维持,C组静脉输注等容量生理盐水,两组均吸入8%七氟醚进行麻醉诱导.麻醉维持:气管插管后,调节七氟醚蒸发罐,使呼气末七氟醚浓度达到预定值并至少稳定15 min后开始切皮.采用序贯法进行试验,初始浓度设为1.8%,发生体动反应,则下一例患者浓度增加0.2%,未发生体动反应,则下一例患者浓度降低0.2%.发生体动反应的标准:切皮时和切皮后60 s内患者躯干、四肢及头颈有可见的肌束收缩.计算七氟醚MAC及其95%可信区间.结果 K组七氟醚MAC为1.51%(95%可信区间为1.45%～1.58%),C组七氟醚MAC为2.49%(95%可信区间为2.40%～2.57%),两组比较差异有统计学意义(P<0.05).结论 静脉输注小剂量氯胺酮可增强七氟醚的麻醉效应.

Abstract：

Objective To investigate the effects of the low-dose ketamine on the minimum alveolar concentration (MAC) of sevoflurane in patients undergoing gynecological abdominal surgery.Methods Fifty-one ASA Ⅰ or Ⅱ patients aged 36-49 yr with body mass index ≤ 30 kg/m2 scheduled for gynecological abdominal surgery were randomly divided into control group (group C, n = 29) and ketamine group (group K, n = 22) . The paitents were unpremedicated. In group K, a loading dose of ketamine 0.2 mg/kg was injected intravenously followed by infusion at a rate of 14 μg·kg-1 ·min-1 , while equal volume of normal saline was given in group C. Anesthesia was induced with inhalation of sevoflurane (end-tidal concentration 4%-5%, maintaining for 5 min) in both groups. Endotracheal intubation was performed. The patients breathed sevoflurane until the predetermined target end-tidal sevoflurane concentration was reached for at least 15 min before skin incision. Occurrence of body movement was determined by any visible contraction of the muscle bundle of trunk, limbs, head and neck during skin incision and/or within 60 s after skin incision. The initial end-tidal concentration of sevoflurane was set at 1.8 % .If body movement occurred, the end-tidal concentration of sevoflurane was increased by 0.2% , while if not, decreased by 0.2% . MACs of sevoflurane were calculated. Results The MAC of sevoflurane was 1.51% (95% confidence interval 1.45%-1.58%) in group K, and 2.49% (95% confidence interval 2.40%-2.57%) in group C, and there was significant difference between the two groups ( P < 0.05) . Conclusion Intravenous infusion of the low-dose ketamine can enhance the anesthetic effect of sevoflurane in patients undergoing gynecological abdominal surgery.     

股神经阻滞对七氟醚抑制膝关节镜置入时肾上腺素能反应的最低肺泡有效浓度的影响

目的探讨超声引导下股神经阻滞对膝关节镜手术患者膝关节镜置入时七氟醚抑制肾上腺素能反应的最低肺泡有效浓度(MAC_(BAR))的影响。方法选择2019年5—8月拟行择期单侧膝关节镜手术患者36例,男19例,女17例,年龄18～64岁,ASAⅠ或Ⅱ级。采用随机数字表法将患者分为两组:阻滞组和对照组。阻滞组全麻诱导前于超声引导下行患侧股神经阻滞,采用针刺法评估VAS疼痛评分判断阻滞效果;对照组仅行全麻。两组全麻方法相同。采用序贯法测定七氟醚MAC_(BAR)。采用ELISA法测定膝关节镜置入前3 min、置入后3 min血浆肾上腺素及去甲肾上腺素浓度。记录拔管时间、拔管时VAS疼痛评分。结果阻滞组和对照组的MAC_(BAR)分别为2.73%(95%CI 2.65%～2.82%)和3.50%(95%CI 3.32%～3.68%)。与对照组比较,阻滞组七氟醚MAC_(BAR)明显降低(P0.05),拔管时间明显缩短(P0.05),VAS疼痛评分明显降低(P0.05)。阻滞组膝关节镜置入后血浆肾上腺素和去甲肾上腺素浓度分别为(784.82±348.52)pg/ml和(882.76±430.50)pg/ml,对照组膝关节镜置入后血浆肾上腺素和去甲肾上腺素浓度分别为(721.84±314.32)pg/ml和(806.69±467.88)pg/ml,两组差异无统计学意义。结论超声引导下股神经阻滞可明显降低膝关节镜手术患者膝关节镜置入时七氟醚MAC_(BAR),缩短拔管时间,有利于术后镇痛。当50%患者肾上腺素能反应被抑制时,血浆肾上腺素和去甲肾上腺素浓度变化不受股神经阻滞的影响。     

Minimum alveolar concentration of sevoflurane for tracheal extubation in children

Background: One advantage of tracheal extubation during deep anaesthesia is that respiratory complications are reduced. Sevoflurane is a suitable anaesthetic agent for children. This study was conducted to determine the minimum alveolar concentration of sevoflurane required to prevent cough or movement during and after tracheal extubation (MAC_extubation).
Methods: We studied 30 nonpremedicated children, aged 2–10 yr, undergoing plastic surgery. They were allocated randomly to five groups (end-tidal sevoflurane concentrations: 2.0, 2.5, 3.0, 3.5, 4.0%). After surgery, 60% nitrous oxide was discontinued and the target concentration of sevoflurane was maintained for at least 10 min in 100% oxygen, then the trachea was extubated to determine MAC_extubation. Logistic regression was used to estimate MAC_extubation. of sevoflurane.
Results: MAC_extubation. was 2.3 (0.2; standard error)% (95% confidence limits: 1.2% and 2.7%).
Conclusions: Tracheal extubation in 50% of anaesthetized children age 2–10 yr may be accomplished without coughing or moving at 2.3% end-tidal concentration of sevoflurane.     

The minimum alveolar concentration (MAC) of sevoflurane in humans

Forty surgical patients were divided into two groups and anesthetized with either sevoflurane and oxygen or sevoflurane, oxygen, and nitrous oxide. The minimum alveolar concentration (MAC) for sevoflurane required to prevent movement in response to surgical incision in healthy patients was 1.71 +/- 0.07% (SE). The AD95 (anesthetic ED95) that prevented 95% of patients from moving was 2.07%. The addition of 63.5% end-tidal nitrous oxide allowed a reduction in the alveolar sevoflurane concentration to 0.66 +/- 0.06% (SE). The reduction in sevoflurane MAC was 61.4%. The AD95 for sevoflurane with 63.5% end-tidal nitrous oxide was 0.94%.     

年龄对妇科手术七氟醚麻醉清醒肺泡浓度的影响

目的观察年龄对妇科手术七氟醚麻醉清醒肺泡浓度(MAC-awake)的影响。方法择期行妇科短小手术患者60例,ASAⅠ或Ⅱ级,依据年龄均分为三组:Ⅰ组,20~29岁;Ⅱ组,30~39岁;Ⅲ组,40~50岁。8%七氟醚诱导,眼睑反射消失后维持呼气末七氟醚浓度3%10 min后插入喉罩,术中七氟醚浓度维持在3%。手术结束后以0.1%浓度梯度按Dixon序贯法调整七氟醚浓度并拔出喉罩。计算意识恢复时呼气末七氟醚的MAC-awake即EC50及相应的95%可信区间(CI)。结果Ⅰ、Ⅱ、Ⅲ组意识恢复时呼气末七氟醚EC50及相应的95%CI分别为0.64%(0.57%~0.70%)、0.55%(0.50%~0.60%)及0.44%(0.37%~0.50%)。结论妇科手术七氟醚麻醉随着年龄增长其七氟醚的MAC-awake逐渐下降。     

在无痛分娩中局麻药最低有效感觉及运动阻滞浓度的研究和应用

背景 随着1992年可行走式分娩镇痛服务首次公布,学者们关于局麻药浓度如何确定面临新的挑战.目的 寻找出局麻药引起感觉和运动阻滞的最低有效浓度,才能在镇痛完善的同时保留产妇运动功能,为可行走式分娩镇痛提供循证医学依据.内容 介绍局麻药最低有效感觉阻滞浓度(minimum local-anaesthetic concen...     

Association of ethnicity with the minimum alveolar concentration of sevoflurane

BACKGROUND: Selective breeding produces animal strains with varying anesthetic sensitivity. It thus seems unlikely that various human ethnicities have identical anesthetic requirements. Therefore, the authors tested the hypothesis that the minimum alveolar concentration of sevoflurane differs significantly as a function of ethnicity. METHODS: The authors recruited 90 American Society of Anesthesiologists physical status I and II adult patients belonging to three Jewish ethnic groups: European, Oriental, and Caucasian (from the Caucasus Mountain region). All were scheduled to undergo surgery requiring a skin incision exceeding 3 cm. Without premedication, anesthesia was induced with 6-8% sevoflurane in 100% oxygen, and tracheal intubation was facilitated with succinylcholine. The skin incision was made after a predetermined end-tidal concentration of sevoflurane of 2.0% was maintained for at least 10 min in the first patient in each group. Blinded investigators observed the patient for movement during the subsequent minute. The concentration in the next patient was increased by 0.2% when patients moved, or decreased by the same amount when they did not. Results are presented as means [95% confidence intervals]. RESULTS: Morphometric and demographic characteristics were similar among the groups; however, mean arterial pressure was slightly greater in European Jews. Minimum alveolar concentration for sevoflurane was greatest in Caucasian Jews (2.32% [2.27-2.41%]), less in Oriental Jews (2.14% [2.06-2.22%]), and still less in European Jews (1.9% [1.82-1.99%]) (P < 0.001). CONCLUSIONS: The results suggest that minimum alveolar concentration varies as a function of ethnicity. However, the extent to which confounding characteristics contribute, including lifestyle choices and environmental factors, remains unknown.     

Decrease in minimum alveolar concentration of sevoflurane during anaesthesia and arthroscopy

BACKGROUND AND OBJECTIVE: Although the MACtetanus (minimum alveolar concentration that prevents movement in response to electrical tetanus stimulation in 50% of patients) of isoflurane decreases during anaesthesia and surgery, it is not known whether this occurs to the same extent with other inhalational anaesthetics. We determined the MACtetanus of sevoflurane before and after surgery. METHODS: Eleven patients who underwent arthroscopy of the shoulder underwent inhalational induction of anaesthesia with sevoflurane and tracheal intubation by succinylcholine. MACtetanus was determined in each patient by testing the response to a 10 s, 50 Hz, 80 mA transcutaneous tetanic electrical stimulus to the ulnar nerve at varying concentrations of sevoflurane. The end-tidal concentration of sevoflurane was kept constant for 15 min before each stimulus and the concentration of sevoflurane varied in increments of 0.1% until a sequence of three alternate responses (move, not move, move) or (not move, move, not move) was obtained. After arthroscopy of the shoulder, individual MACtetanus were measured as described above. RESULTS: The mean MACtetanus decreased from 2.22 +/- 0.29% before arthroscopy to 1.82 +/- 0.26% after arthroscopy (P < 0.01). CONCLUSIONS: It is concluded that the MACtetanus of sevoflurane decreases during anaesthesia and surgery.     

Influence of sepsis on sevoflurane minimum alveolar concentration in a porcine model

Sevoflurane is widely used in anaesthetic protocols for patientsundergoing surgical procedures. However, there are no reportson the influence of sepsis on minimum alveolar concentrationof sevoflurane (MAC_SEV) in animals or in humans. The aim ofthis study was to test the hypothesis that sepsis could alterthe MAC_SEV in a normotensive septic pig model. Twenty young,healthy pigs were used. After they had received 10 mg kg^–1of ketamine i.m. for premedication, anaesthesia was establishedwith propofol 3 mg kg^–1 and the trachea wasintubated. Sevoflurane was used as the sole anaesthetic agent.Baseline haemodynamic recording included electrocardiography,carotid artery blood pressure and a pulmonary thermodilutioncatheter. Baseline MAC_SEV in each pig was evaluated by pinchingwith a haemostat applied for 1 min to a rear dewclaw. MAC_SEVwas determined using incremental changes in sevoflurane concentrationuntil purposeful movement appeared. Pigs were assigned randomlyto two groups: the saline group (n=10) received a 1-h i.v. infusionof sterile saline solution while the sepsis group (n=10) receiveda 1-h i.v. infusion of live Pseudomonas aeruginosa. Epinephrineand hydroxyethylstarch were used to maintain normotensive andnormovolemic haemodynamic status. In both groups, MAC_SEV wasevaluated 5 h after infusion. Significant increases inmean artery pulmonary pressure, filling, epinephrine and vascularpulmonary resistances occurred in the sepsis group. MAC_SEV forthe saline group was 2.4% [95% confidence interval (CI) 2.1–2.55%]and the MAC_SEV for the sepsis group was 1.35% (95% CI 1.2–1.45%,P<0.05). These data indicate that MAC_SEV is significantlydecreased in this normotensive septic pig model. Br J Anaesth 2001; 86: 832–6     

创伤对七氟醚MAC的影响及血浆β-内啡肽浓度变化的实验研究

目的 探讨创伤对麻醉耐受性的影响及与血浆β－内啡肽改变的关系。方法 新西兰兔２０只随机分为对照组和创伤组。连续监测ＭＡＰ、ＣＶＰ、ＰＥＴＣＯ２和ＥＣＧ,测定对照级七氟醚ＭＡＣ;创伤组兔一侧下肢股骨粉碎骨折合并软组织损伤,测量七氟醚ＭＡＣ,两组动物分别于下列时间点测定－内啡肽浓度：实验准备前、实验准备后、实验准备后３０ｍｉｎ和６０ｍｉｎ或创伤后５ｍｉｎ和３０ｍｉｎ、ＭＡＣ测定点（即夹尾呈阳性反应点和