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。     

小儿深麻醉喉罩通气道拔除时安氟醚的最低肺泡有效浓度

本文观察喉罩通气道拔除时安氟醚的最低肺泡有效浓度（MACLMA）。 资料与方法 ASAⅠ级择期整形手术小儿21例,男20例,女1例,年龄4～11岁,平均（6.6±1.8）岁,体重（21.7±5.6）kg,身高（111.6±16.4）cm。喉罩留置时间（150.5±22.6）min。术前禁食禁水8h,不用术前药。面罩吸入5％七氟醚和60％N2O诱导,用翻转法置入喉罩通气道。置入前抽空喉罩,背面涂     

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%)。     

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...     

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。     

切剥儿童腭瓣时异氟醚最低肺泡有效浓度的测定

自Ｓａｉｄｍａｎ和Ｅｇｅｒ[1] 测定阻止 5 0 %病人对切皮刺激产生体动反应肺泡最低有效浓度 (ＭＡＣＳＩ)以来 ,临床麻醉中气管插管、剥切肋骨和清醒等的ＭＡＣ亦有较多报道[2 ] 。为探讨儿童腭裂术中适宜的麻醉深度 ,作者进行了切剥腭瓣所需ＭＡＣ(ＭＡＣＰＥ)的测定 ,现介绍如下。资料与方法一般资料　择期行Ⅱ°～Ⅲ°腭裂修复术患儿 30例 ,年龄 4～ 12岁 ,体重 14～ 32ｋｇ ,ＡＳＡⅠ～Ⅱ级 ,心肺及肝肾功能检查无异常 ,近 1周内未服用镇痛类药物。麻醉方法及监测　术前半小时肌注阿托品 0 0 1ｍｇ/ｋｇ ,入室后监测心电图、血压、血…     

可乐定降低异氟醚最低肺泡有效浓度的研究

研究了麻醉前应用可乐定影响异氟醚最低肺泡有效浓度（ＭＡＣ）的效应。设可乐定组和对照组各１５例，采用随机双盲法给药，根据Ｅｇｅｒ法确定ＭＡＣ值。发现麻醉前２小时口服可乐定５μｇ／ｋｇ，可使异氟醚１ＭＡＣ从对照组的１．１８５％降至０．７７５％，降低百分率为３４．６０％。推测此与可乐定的中枢性镇静、镇痛等效应有关。证实可乐定可做为麻醉前用药，降低异氟醚ＭＡＣ。研究中采用皮肤电刺激为切皮刺激确定ＭＡＣ预设     

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%。     

小儿深麻醉喉罩拔除时安氟醚的最低肺泡有效浓度

目的　本研究旨在确定小儿喉罩平稳拔除时的安氟醚最低肺泡有效浓度。方法　选择 2 1例ASAⅠ级 ,4 - 11岁在全麻下行脐以下整形手术的病人。面罩吸入 5 %七氟醚和 6 0 %笑气诱导后置入喉罩 ,术中吸入安氟醚和 6 0 %笑气维持麻醉 ,手术结束后停止吸入笑气并维持预定的安氟醚浓度 10分钟后拔除喉罩。根据Dixon序贯法确定喉罩拔除时的安氟醚浓度 ,每 0 1%安氟醚为一个增减单位。拔除喉罩时病人没有出现咳嗽、咬牙拔管困难、体动、喉痉挛及屏气为拔管满意。结果　 5 0 %病人获得满意喉罩拔除时的呼气末安氟醚浓度(ED5 0 )为 1 0 2 % (95 %的可信区间 0 95 % - 1 11% ) ,95 %满意拔管浓度 (ED95 )为 1 14 %(95 %的可信区间 1 0 7% - 1 6 6 % )。结论　 4 - 11岁小儿喉罩满意拔除的呼气末安氟醚ED5 0和ED95分别为 1 0 2 %和 1 14 %。     

静注卡托普利降低安氟醚麻醉用于剖腹手术期间过度应激反应

目的　探讨静注卡托普利降低安氟醚麻醉用于剖腹手术期间过度应激所致循环不良反应的效果及机制。方法　择期剖腹手术病人 4 0例 ,随机分为两组 ,每组 2 0例。常规插管 ,安氟醚麻醉。试验组麻醉诱导前 1 0min及切皮后 30min分别静注卡托普利 0 30～ 0 35mg/kg及 0 1 5～ 0 1 8mg/kg。于麻醉前 (基础值 )、插管、切皮、探查、缝皮后各 1min及术后 1h测定SBP、DBP、HR、心率 收缩压乘积 (RPP)及血浆去甲肾上腺素 (NE)、肾上腺素 (E)、一氧化氮 (NO)、内皮素 (ET)、血栓素B2(TXB2 )、6 酮 前列腺素F1α(6 keto PGF1α)的含量 ,计算NO/ET、TXB2 /PGF1α比值。结果　麻醉后 ,对照组BP、HR、RPP、NE、E及TXB2 /PGF1α较其基础值明显升高 ,NO/ET比值显著降低 (P <0 0 5或P <0 0 1 ) ;而试验组NO/ET于插管后 1min显著升高 (P <0 0 5 ) ,余指标无明显改变 (P >0 0 5 )。与对照组相比 ,试验组麻醉手术期间BP、HR、RPP、NE及E显著降低 ,NO/ET比值明显升高 ,插管和探查后 1min的TXB2 /PGF1α显著降低 (P <0 0 5或P <0 0 1 )。结论　静注卡托普利降低血浆NE、E的水平 ,改善NO/ET平衡 ,降低TXB2 /PGF1α比值 ,可有效地降低安氟醚麻醉剖腹手术期间过度应激的循环不良反应。     

异氟醚、安氟醚麻醉诱导期大鼠边缘系统部分核团一氧化氮合酶阳性神经元的改变

目的 观察异氟醚、安氟醚诱导麻醉对大鼠边缘系统部分核团一氧化氮合酶(NOS)阳性神经元的的改变,探讨异氟醚、安氟醚麻醉诱导期的作用机制。方法 18只SD雄性大鼠随机分为3组:对照组、安氟醚组、异氟醚组。对照组动物除不吸入麻醉气体外,其他条件均与两麻醉组相同。安氟醚组、异氟醚组大鼠分别吸入2％安氟醚或2％异氟醚至步态不稳、一侧肢体着地,即翻正反射即将消失时,移出麻醉箱,立即取标本。用NADPH-d组化法观察吸入2％异氟醚、2％安氟醚诱导麻醉对大鼠边缘系统部分核团NOS阳性神经元数量和灰度值的影响。结果 安氟醚组大鼠脑的外侧隔核、下丘脑室旁核、下丘脑室周核、视上核、杏仁基外侧核和伏隔核等6个核团NOS阳性神经元数量和染色深度均低于对照组,异氟醚组在上述6个核团中NOS阳性神经元的数量和平均灰度水平也低于对照组,下丘脑室周核和视上核NOS阳性神经元数目有减少趋势,但与对照组比较差异无统计学意义(P>0.05),其余核团与对照组比较差别均有显著性(P<0.01)。结论 异氟醚、安氟醚诱导期的作用机理可能与边缘系统部分核团NOS阳性神经元的改变有关。     

比较硬膜外阻滞复合安氟醚或异氟醚对肝血流及氧代谢的影响

目的 探讨硬膜外阻滞与安氟醚或异氟醚吸入复合麻醉对血流动力学,肝血流及代谢的影响。方法 选用健康杂种犬２０只行胸段硬膜外阻滞后分为两缚,分别吸入,０．５和１．０ＭＡＣ安氟醚或异氟醚,监测麻醉前后体循环,肝动脉,门静脉血流动力及肝脏氧供,氧耗。结果 硬膜外阻滞后血压,门静脉血流和氧供下降,加吸安氟醚０．５ＭＡＣ使心排血量也下降,１．０ＭＡＣ后肝动脉血流及氧供也减少,加吸异氟醚０．５ＭＡＣ心排血量稳定     

The relationship of brain catecholamine levels to enflurane requirements among three strains of mice with different anesthetic sensitivities

Purpose. It has been reported that brain catecholamines alter the minimum alveolar concentration (MAC) of anesthetics. The extent of the relation between the levels of brain catecholamine and anesthetic sensitivity should be evaluated by excluding several factors. Methods. Anesthetic sensitivity was measured by using loss of the righting reflex in three strains of mice with different sensitivities. The mice were decapitated without any anesthesia, adding on ddN and C57BL/6J mice in 2% enflurane, their brains were divided into three parts, and dopamine and norepinephrine levels were analyzed by high-performance liquid chromatography (HPLC). Results. The values of enflurane requirement (%) were 1.30 ± 0.05 in ddN, 1.10 ± 0.02 in C57BL/6J, and 1.05 ± 0.02 in MSM mice. The values of dopamine (μg · g⁻¹) in the mesencephalon were 0.23 ± 0.02 in ddN, 0.15 ± 0.02 in C57BL/6J, and 0.12 ± 0.02 in MSM (mean ± SE). No statistical significance in the values in 2% enflurane could be obtained between ddN and C57BL/6J. The stepwise regression line showed a significant correlation: enflurane requirement (%) = −0.89 + 1.60 × (dopamine levels of mesencephalon) (r ² = 0.571, P < 0.0001). Conclusion. Dopamine in the mesencephalon seems to play an important role in the production of different anesthetic sensitivities, and the anesthetic mechanism might be related to the regulation of dopamine levels that promote arousal. Received: September 4, 2000 / Accepted: December 20, 2000     

Plasma concentration of fentanyl with xenon to block somatic and hemodynamic responses to surgical incision

BACKGROUND: Although anesthesia with xenon has been supplemented with fentanyl, its requirement has not been established. This study was conducted to determine the plasma concentrations of fentanyl necessary to suppress somatic and hemodynamic responses to surgical incision in 50% patients in the presence of 0.7 minimum alveolar concentration (MAC) xenon. METHODS: Twenty-five patients were allocated randomly to predetermined fentanyl concentration between 0.5 and 4.0 ng/ml during 0.7 MAC xenon anesthesia. Fentanyl was administered using a pharmacokinetic model-driven computer-assisted continuous infusion device. At surgical incision each patient was monitored for somatic and hemodynamic responses. A somatic response was defined as any purposeful bodily movement. A positive hemodynamic response was defined as a more than 15% increase in heart rate or mean arterial pressure more than the preincision value. The concentrations of fentanyl to prevent somatic and hemodynamic responses in 50% of patients were calculated using logistic regression. RESULTS: The concentration of fentanyl to prevent a somatic response to skin incision in 50% of patients in the presence of 0.7 MAC xenon was 0.72 +/- 0.07 ng/ml and to prevent a hemodynamic response was 0.94 +/- 0.06 ng/ml. CONCLUSIONS: Comparing these results with previously published results in the presence of 70% nitrous oxide, the fentanyl requirement in xenon anesthesia is smaller than that in the equianesthetic nitrous oxide anesthesia.     

Minimum alveolar concentration of sevoflurane that blocks the adrenergic response to surgical incision in women: MACBAR

We have investigated the cardiovascular and plasma noradrenaline response to surgical incision under sevoflurane anaesthesia and determined the end-tidal concentration of sevoflurane that blocks the adrenergic response or responses to surgical incision (MACBAR) and changes in mean arterial pressure (MAP) in response to surgical incision (MACBCR) in 50% of women. We randomly assigned 64 female patients, aged 20-49 years, to eight groups according to end-tidal sevoflurane concentration: 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0% and 8.5%. All patients received only sevoflurane anaesthesia. An increase of 10% or more from prestress (incision) values of MAP or plasma noradrenaline concentration was considered a positive response. The probability of no response to stress was analysed using logistic regression to obtain the probability of no response vs. end-tidal sevoflurane concentration and the best-fit curve from the maximum likelihood estimators of the model parametes. MACBAR (mean +/- SE) was 8.0 +/- 0.2%, MACBCR was 7.9 +/- 0.2%. However, such high doses of sevoflurane cannot be used clinically because of their high toxicity. It may be preferable to combine sevoflurane with other anaesthetics to reduce haemodynamic responses to strong stimulation.     

Diabetes attenuates the minimum anaesthetic concentration (MAC) and MAC-blocking adrenergic response reducing actions of clonidine in rats

BACKGROUND: It is well known that clonidine, an alpha2 agonist, reduces anaesthetic requirement and attenuates haemodynamic responses against noxious stimuli. However, the diabetic state is known to affect several functions of alpha2 adrenoceptors. We investigated the effects of streptozotocin (STZ)-induced diabetes mellitus (DM) on these beneficial actions of clonidine in halothane-anaesthetized rats. METHODS: The rats were randomly assigned to one of three groups: diabetes (n=24, induced by 50 mg x kg(-1) IV STZ), diabetes treated with insulin (n=24), or control (n=24). We evaluated the effects of clonidine on minimum anaesthetic concentration (MAC) and minimum concentration of halothane needed to suppress cardiovascular responses evoked by a noxious stimulus (MAC-blocking adrenergic responses: MAC-BAR) in each group. MAC and MAC-BAR of halothane were determined by the tail clamp method. MAC-BAR was defined as the MAC which attenuated haemodynamic responses within 10% following the tail clamp. RESULTS: The diabetic state decreased MAC of halothane by approximately 10%, while MAC-BAR of halothane had been little affected. In the diabetes group, MAC reducing action of clonidine (30 and 100 microg x kg(-1), IV) was completely abolished and MAC-BAR reducing action of clonidine was partially reduced (30 but not 100 microg x kg(-1), IV). Insulin treatment preserved these actions of clonidine. CONCLUSION: It is suggested that the diabetic state attenuates the beneficial actions of clonidine and that insulin treatment of diabetes preserves these actions of clonidine.     

Anterior resection of rectal cancer through a one hand-size incision with or without laparoscopy: proposal of one hand-size incision surgery (OHaSIS)

BACKGROUND: One hand-size incision surgery (OHaSIS) is a surgery that is carried out through one hand-size incision with or without laparoscopy. Safety, feasibility and recovery advantage of the anterior resection of rectal cancer by the OHaSIS were studied. STUDY DESIGN: Nineteen consecutive patients with rectal cancer, consisting of seven rectosigmoid, six upper rectal, and six lower rectal cancers, were treated with anterior resection, including seven high, six low, three super-low, and three partial intersphincteric resections, through a suprapubic longitudinal one hand-size incision. The initial 11 patients were treated in combination with laparoscopy and the following eight patients were treated without laparoscopy. RESULTS: All anterior resections with mesorectal excision were completed in a safe manner with acceptable operative time (average 245 min), blood loss (average 280 g), and postoperative complications without any elongation of the initial incision. When compared with 12 previous high and low anterior resections by conventional open surgery (OS), the 13 high and low anterior resections by the OHaSIS showed equivalent operative time, blood loss, anastomotic procedures of single stapling, lymph node numbers dissected, surgical margin of the anal side of the tumor, and complications. Moreover, analysis of perioperative parameters for surgical invasiveness, including a body temperature >37 degrees C, days of bed rest, and days of use of parenteral narcotics, revealed a recovery advantage in the OHaSIS group compared with that in the OS group. CONCLUSIONS: These results suggest that anterior resection for patients with rectal cancer by the OHaSIS is safe, feasible, and less invasive than conventional OS, and has sufficient operative performance. Although the survival benefit and recurrence rate by this approach must be ensured in a future trial, we would like to propose the new concept of OHaSIS for treating rectal cancer.     

Concentrations of sevoflurane with and without nitrous oxide to block vasomotor reflexes to incision (MACBVR)

The minimum alveolar concentration of an anesthetic that blocks the skin vasomotor reflex to surgical incision (MACBVR) for sevoflurane was determined in 37 patients aged 30-60 years scheduled for laparotomies with or without nitrous oxide. Thirty seven patients were randomly allocated to one of the two groups: a sevoflurane group and a sevoflurane/N2O (50 vol%) group. The skin blood flow of the finger tip was measured using a laser Doppler flowmeter. Anesthesia was induced with sevoflurane and N2O and tracheal intubation was facilitated with vecuronium 0.1 mg.kg-1. Predetermined end tidal concentrations of sevoflurane and N2O were maintained for at least 15 min before incision. The MACBVR values of sevoflurane in O2 and in the presence of 50% N2O were 3.07% and 1.63%, respectively. The MACBVR level in the total anesthetic MAC multiple was 1.75 MAC for sevoflurane alone and the value decreased to 1.43 MAC when 50% N2O was used. There were no relations between the amplitude of the reduction in skin blood flow and the changes of hemodynamic variables in each group. However, the changes in SBP and HR at incision were significantly suppressed by addition of N2O (changes in SBP and HR: 41.6 +/- 20.4 mmHg and 35.4 +/- 12.5 bpm in the sevoflurane group vs. 24.6 +/- 10.2 mmHg and 18.1 +/- 9.5 bpm in the sevoflurane/N2O group, P < 0.01). The results suggest that N2O is useful to suppress adrenergic responses to a surgical stimulus during sevoflurane anesthesia.