不同剂量纳布啡复合曲马多对妇科手术全麻苏醒期镇痛效果的影响

目的观察不同剂量纳布啡复合曲马多用于腹腔镜下全子宫切除术患者全麻苏醒期镇痛的效果和安全性。方法择期行全身麻醉腹腔镜全子宫切除术患者400例,年龄45～65岁,体重50～90 kg,ASAⅠ或Ⅱ级,按完全随机法分为四组:手术结束前30 min,A组静注纳布啡0.1 mg/kg+曲马多2 mg/kg;B组静注纳布啡0.2 mg/kg+曲马多2 mg/kg;C组静注纳布啡0.3 mg/kg+曲马多2 mg/kg;D组静注曲马多2 mg/kg。记录四组手术时间、苏醒时间;记录拔管时间;记录拔管后5、15、30 min警觉/镇静评分和VAS评分;记录手术后24 h内不良反应的发生情况。结果四组手术时间、苏醒时间和拔管时间差异无统计学意义。四组拔管后5、15、30 min警觉/镇静评分差异无统计学意义。拔管后15、30 min D组VAS评分明显高于B、C组(P0.05)。拔管后30 min A组VAS评分明显高于C组(P0.05)。四组拔管后呼吸抑制、头晕嗜睡发生率差异无统计学意义。D组恶心呕吐发生率明显高于A、B和C组(P0.05)。结论全麻手术结束前30 min采用纳布啡0.2～0.3 mg/kg复合曲马多2 mg/kg较纳布啡0.1 mg/kg复合曲马多2 mg/kg全麻苏醒期镇痛效果好,不增加不良反应。     

纳布啡复合丙泊酚用于无痛人工流产术麻醉及术后镇痛效果观察

目的探讨纳布啡联合丙泊酚用于无痛人工流产术的麻醉及术后镇痛效果。方法选择2017-04—06间在郑州大学第二附属医院接受无痛人工流产术的68例早孕者,随机分为2组,各34例。F组应用芬太尼0.001 mg/kg+丙泊酚2 mg/kg,N组应用纳布啡0.15 mg/kg+丙泊酚2 mg/kg。观察麻醉前(T_1)、意识消失时(T_2)及清醒时(T_3)三个时点早孕者的MAP、HR及SpO_2的变化。记录其苏醒时间及T_3、苏醒后30 min(T_4)、苏醒后90 min(T_5)的疼痛VAS评分。比较2组早孕者的满意度(NRS)评分和不良事件发生例数。结果 N组T_3时的MAP及SpO_2明显优于F组(P0.05),丙泊酚用量及苏醒时间少于F组(P0.05),T_4及T_5时VAS评分明显低于F组(P0.05),对麻醉满意度明显高于F组(P0.05),呼吸抑制发生率明显低于F组(P0.05)。差异均有统计学意义。结论纳布啡联合丙泊酚用于无痛人工流产术的麻醉及术后镇痛,安全有效且不良反应少。     

纳布啡复合丙泊酚用于无痛人流术

正纳布啡是激动拮抗型吗啡类药物,是κ受体激动药,有镇痛镇静作用,仅有较轻的呼吸抑制作用~([1]),静注纳布啡2～3 min起效,维持镇痛3～6h~([2])。丙泊酚以其作用时间短、苏醒快常用于门诊无痛人流术,但其镇痛欠佳,尤其无法抑制宫缩痛~([3])。本研究将三种剂量纳布啡辅助丙泊酚行无痛人流术,现报道如下。资料与方法一般资料自愿终止妊娠并接受无痛人流术的患者90     

丙泊酚用于无痛胃镜检查术中纳布啡最佳剂量的选择

目的探讨在无痛胃镜检查术中使用纳布啡复合丙泊酚静脉麻醉时,纳布啡的最佳剂量。方法无痛胃镜检查病人250例,随机分成3组,N1组78例,纳布啡0.10 mg/kg;N2组89例,纳布啡0.15 mg/kg;N3组83例,纳布啡0.20 mg/kg)。记录各组患者麻醉前(T0)、置入胃镜时(T1)、退出胃镜时(T2)时收缩压(systolic pressure,SBP)、心率(heart rate,HR)、脉搏血氧饱和度(pulse oxygen saturation,SpO_2),并记录术中丙泊酚用量、胃镜检查时间,停药后苏醒时间、术中麻醉效果、术中辅助呼吸例数、术后恶心呕吐、离院时间、离院时眩晕例数等。结果 N2组、N3组麻醉效果优良率分别为93.3%和94.0%,N1组为82.1%,N2组、N3组优于N1组。N3组病人离院时眩晕人数多于N1、N2组,差异有统计学意义(P0.05);3组病人术中辅助呼吸、术后恶心呕吐例数比较差异均无统计学意义(P0.05)。N2、N3组病人丙泊酚用量较N1组减少,苏醒时间也较N1组缩短,同时N3组病人离院时间较N1组、N2组延长,差异有统计学意义(P0.05)。结论以0.15 mg/kg纳布啡复合适当剂量的丙泊酚,能有效地保证麻醉效果,同时尽量减少麻醉的不良反应。     

纳布啡抑制宫腔镜手术患者喉罩置入反应的半数有效剂量

目的在以血浆靶控输注丙泊酚的背景下,分析纳布啡抑制宫腔镜手术患者喉罩置入反应的半数有效剂量(ED_(50))。方法选择择期行全麻宫腔镜手术患者21例,年龄18～60岁,BMI 19～27 kg/m~2,ASAⅠ或Ⅱ级。麻醉诱导采用丙泊酚血浆靶控输注,靶控浓度3.0μg/ml。当效应室浓度与血浆浓度平衡一致时,缓慢静推纳布啡,初始剂量为0.2 mg/kg。注射结束5 min且BIS 50～60时,置入喉罩。采用序贯法确定纳布啡剂量,若置入喉罩时出现阳性反应,下一例患者选用高1个梯度的剂量;反之,则选用低1个梯度的剂量。相邻剂量的比值为1.1。计算靶控输注丙泊酚的背景下,纳布啡抑制喉罩置入反应的ED_(50)和ED_(95)以及各自的95%可信区间(CI)。结果纳布啡抑制宫腔镜手术喉罩置入反应的ED_(50)为0.145 mg/kg(95%CI 0.125～0.165 mg/kg),ED_(95)为0.163 mg/kg(95%CI 0.153～0.417 mg/kg)。结论靶控丙泊酚背景下,纳布啡抑制成年宫腔镜手术患者喉罩置入反应的ED_(50)为0.145 mg/kg(95%CI 0.125～0.165 mg/kg)。     

舒芬太尼复合纳布啡用于剖宫产术后自控静脉镇痛的效果

目的研究舒芬太尼复合纳布啡用于剖宫产术后患者自控静脉镇痛(PCIA)的效果。方法选择2016年1月至2017年3月于本院行剖宫产手术的初产妇150例,年龄20～35岁,体重54～89kg,ASAⅠ或Ⅱ级,随机将产妇分为三组,每组50例。舒芬太尼组(S组):舒芬太尼2μg/kg+托烷司琼10mg;纳布啡组(N组):纳布啡2mg/kg+托烷司琼10mg;舒芬太尼复合纳布啡组(SN组):舒芬太尼1μg/kg+纳布啡1mg/kg+托烷司琼10mg。记录术后1、3、6、9、12、24和36h静息和咳嗽时的疼痛VAS评分及镇静Ramsay评分;PCIA实际按压次数;恶心呕吐、呼吸抑制等不良反应的发生情况。结果三组静息时VAS评分、镇静Ramsay评分和呼吸抑制发生率差异无统计学意义;SN组咳嗽时VAS评分明显低于S组和N组(P0.05)。SN组PCIA实际按压次数明显少于S组、N组(P0.05)。N组和SN组恶心呕吐发生率明显低于S组(P0.05)。结论舒芬太尼复合纳布啡用于剖宫产术后PCIA可获得满意的镇痛效果。     

纳布啡与舒芬太尼在后腹膜镜术后镇痛效果的比较

目的观察和比较纳布啡和舒芬太尼在后腹膜镜下肾囊肿去顶术后镇痛中的临床效果。方法选择全身麻醉下后腹膜镜手术患者60例,男38例,女22例,年龄55～78岁,BMI 18～25 kg/m~2,ASAⅠ或Ⅱ级,采用随机数字表法将患者分为两组,每组30例。术后所有患者均行PCIA,其中,纳布啡组镇痛药配方为纳布啡100 mg+托烷司琼10 mg;舒芬太尼组为舒芬太尼100μg+托烷司琼10 mg;均用生理盐水稀释至100 ml,背景输注速度2 ml/h,单次剂量1 ml,锁定时间15 min。记录给药后2、4、8、16、32 h和48 h的VAS疼痛评分和Ramsay镇静评分,镇痛泵按压次数,镇痛满意率以及术后不良反应发生情况。结果两组VAS疼痛评分、镇痛泵按压次数差异无统计学意义。与舒芬太尼组比较,给药后8～48 h纳布啡组Ramsay镇静评分明显升高(P0.05),镇痛效果满意率明显提高(P0.05)。纳布啡组恶心呕吐发生率明显低于舒芬太尼组(P0.01)。两组低血压和心动过缓的发生率差异无统计学意义。结论纳布啡用于后腹膜镜术后静脉镇痛效果与舒芬太尼相当,但不良反应更少,患者满意度更高。     

纳布啡预防胃肠镜检查术患儿丙泊酚中长链脂肪乳注射痛的量效关系

目的:确定纳布啡预防胃肠镜检查术患儿丙泊酚中长链脂肪乳注射痛的量效关系。方法:选择胃肠镜检查术患儿,年龄3～8岁,ASA分级Ⅰ或Ⅱ。采用改良序贯法进行试验,第1例患儿静脉注射纳布啡0.2 mg/kg,5 min后静脉注射丙泊酚中长链脂肪乳2.5 mg/kg。采用Ambesh 4分法评价丙泊酚注射痛,注射痛预防无效,则下...     

环泊酚复合纳布啡在门诊无痛人工流产术中的应用

<正>随着舒适化医疗的推广,无痛人工流产术应用越来越广泛^[1]。丙泊酚具有起效迅速、代谢快、苏醒完全等特点,是无痛人工流产术、无痛胃肠镜检查、无痛取卵、无痛宫腔镜检查等门诊短小手术麻醉的主要静脉麻醉药^[2]。但丙泊酚所致的注射痛、呼吸抑制、低血压、低血氧等不良事件也引起了广泛关注^[3]。由于丙泊酚无镇痛作用^[4],在无痛人工流产术的麻醉中复合纳布啡虽然可以减少丙泊酚用量以及缓解术后子宫收缩痛^[5],但仍有部分患者会发生注射痛与呼吸抑制、     

复合羟考酮时环泊酚用于无痛人工流产术的半数有效剂量

目的 探讨复合羟考酮时环泊酚用于无痛人工流产术的半数有效剂量（ED₅₀）。
方法 选择择期行无痛人工流产术患者23例，年龄22～40岁，BMI 20～30 kg/m²，ASA Ⅰ或Ⅱ级。麻醉诱导前静脉推注羟考酮0.08 mg/kg，环泊酚剂量采用序贯法。第1例患者环泊酚剂量为0.6 mg/kg，阳性反应定义为术中发生体动反应，若出现阳性反应则升高一个剂量等级，相邻剂量相差为0.05 mg/kg，若出现阴性反应则降低一个剂量等级，直至出现第7个拐点终止研究。计算复合羟考酮时环泊酚用于无痛人工流产术的ED₅₀和95%有效剂量（ED₉₅）及其95%可信区间（CI）。根据术中是否发生体动将患者分为两组：阳性组和阴性组。记录睫毛反射消失时间、手术时间、苏醒时间。记录术中恶心、呕吐、注射痛、呼吸抑制、过敏的发生情况。
结果 复合羟考酮时环泊酚用于无痛人工流产术的ED₅₀为0.469 mg/kg（95%CI 0.453～0.486 mg/kg），ED₉₅为0.542 mg/kg（95%CI 0.519～0.583 mg/kg）。与阴性组比较，阳性组苏醒时间明显延长（P<0.05）。两组无一例出现恶心、呕吐、注射痛、呼吸抑制、过敏等不良反应。
结论 复合羟考酮时环泊酚用于无痛人工流产术的ED₅₀为0.469 mg/kg（95%CI 0.453～0.486 mg/kg），ED₉₅为0.542 mg/kg（95%CI 0.519～0.583 mg/kg）。     

Duration and recovery profile of cisatracurium after succinylcholine during propofol or isoflurane anesthesia

Study Objective: To determine the duration and recovery profile of maintenance doses of cisatracurium besylate following succinylcholine, and during propofol or isoflurane anesthesia.

Design: Randomized, open-label study.

Setting: Operating suite of a university-affiliated medical center.

Patients: Forty ASA physical status I and II adult patients having elective surgery with general anesthesia lasting longer than 90 minutes.

Interventions: Following a standardized induction sequence, a baseline electromyogram (EMG) was obtained. An intubating dose of intravenous (IV) succinylcholine 1.0 mg/kg was administered. Ventilation was maintained with a face mask until the first twitch (T₁) of the evoked train-of-four (TOF) reached 10% of control when tracheal intubation was performed. Spontaneous recovery from neuromuscular blockade was allowed to occur until the first twitch returned to 25% of control. Patients then were randomized to receive cisatracurium as follows. Group 1: 0.025 mg/kg [0.5 × 95% effective dose (ED₉₅)]; Group 2: 0.05 mg/kg (ED₉₅); Group 3: 0.05 mg/kg (ED₉₅); and Group 4: 0.1 mg/kg (2×ED₉₅). Anesthesia for Groups 1 and 2 were maintained with isoflurane 1% to 2%, 66% nitrous oxide (N₂O) in oxygen (O₂), and in Groups 3 and 4, anesthesia was maintained with propofol 80 to 160 μg/kg/min, 66% N₂O in O₂. The TOF-evoked EMG was recorded at 10-second intervals. The time for the evoked EMG to spontaneously return to 25%, 50%, and 75% of the original baseline was recorded.

Measurements and Main Results: There were 10 patients in each of the four groups. The duration of action of cisatracurium 0.05 mg/kg (ED₉₅) after an intubating dose of succinylcholine is 24.5 ± 10 minutes and 21.3 ± 9 minutes during anesthesia maintained with isoflurane and propofol, respectively. Doubling the dose of cisatracurium resulted in approximately twice the duration of action (40.2 ± 7 min) during propofol anesthesia. Following a dose of cisatracurium 0.025 mg/kg (0.5×ED₉₅), the T₁ of the EMG-evoked response did not decrease below 25% in 7 of 10 patients.

Conclusion: Following succinylcholine, the duration of action of a single dose of cisatracurium 0.05 mg/kg is 20 to 25 minutes during anesthesia maintained with propofol or isoflurane. The duration and recovery profile of cisatracurium is dose dependent during propofol and isoflurane anesthetics. Cisatracurium 0.025 mg/kg is an inadequate maintenance dose following recovery from succinylcholine and it fails to provide adequate surgical relaxation.     

An effective dose of ketamine for eliminating pain during injection of propofol: A dose response study

Background and purpose

Ketamine can completely eliminate pain associated with propofol injection. However, the effective dose of ketamine to eliminate propofol injection pain has not been determined. The purpose of this study was to determine the effective dose of ketamine needed to eliminate pain in 50% and 95% of patients (ED50 and ED95, respectively) during propofol injections.

Methods

This study was conducted in a double-blinded fashion and included 50 patients scheduled for elective gynecological laparoscopy under general anesthesia. The initial dose of ketamine used in the first patient was 0.25 mg/kg. The dosing modifications were in increments or decrements of 0.025 mg/kg. Ketamine was administered 15 seconds before injecting propofol (2.5 mg/kg), which was injected at a rate of 1 mL/s. Patients were asked to rate their pain during propofol injection every 5 seconds using a 0–3 pain scale. The highest pain score was recorded. The ED50, ED95 and 95% confidence intervals (CI) were determined by probit analyses.

Results

The dose of ketamine ranged from 0.175 to 0.275 mg/kg. The ED50 and ED95 of ketamine for eliminating pain during propofol injection were 0.227 mg/kg and 0.283 mg/kg, respectively (95%CI: 0.211–0.243 mg/kg and 0.26–0.364 mg/kg, respectively).

Conclusion

Ketamine at an approximate dose of 0.3 mg/kg was effective in eliminating pain during propofol injection.     

复合不同剂量丙泊酚时羟考酮抑制新辅助化疗乳腺癌患者喉罩置入反应的有效剂量

目的评价新辅助化疗乳腺癌患者复合不同浓度丙泊酚时羟考酮的半数有效剂量(median effective dose,ED50)和95%有效剂量(95%effective dose,ED95)。方法纳入新辅助化疗乳腺癌女性患者62例,年龄18~55岁,BMI 20~25kg/m2,ASAⅠ或Ⅱ级,采用随机数字表法分为两组,分别给予丙泊酚TCI血浆浓度3.0μg/ml(A组)和5.0μg/ml(B组),首例患者羟考酮剂量分别为0.13mg/kg和0.10mg/kg。根据上一例置入喉罩时情况,决定下一例羟考酮剂量。根据最终观察结果,分析计算羟考酮的ED50和ED95及其95%可信区间(CI)。结果A组和B组羟考酮抑制新辅助化疗乳腺癌患者喉罩置入反应的ED50分别为0.131(0.127~0.137)mg/kg和0.085(0.078~0.093)mg/kg。A组和B组羟考酮抑制新辅助化疗乳腺癌患者喉罩置入反应的ED95分别为0.136(0.127~0.186)mg/kg和0.115(0.101~0.241)mg/kg。结论新辅助化疗乳腺癌患者给予丙泊酚TCI血浆浓度3.0μg/ml和5.0μg/ml后,羟考酮抑制喉罩置入反应的ED50分别为0.131(0.127~0.137)mg/kg和0.085(0.078~0.093)mg/kg,ED95分别为0.136(0.127~0.186)mg/kg和0.115(0.101~0.241)mg/kg。     

氟比洛芬酯抑制瑞芬太尼致患者术后痛觉过敏的药效学研究

目的探讨氟比洛芬酯（凯芬）抑制瑞芬太尼致患者术后痛觉过敏反应的量效关系。方法选择我院2010年1至6月期间,择期全麻下腹部大手术患者50例,静脉注射咪达唑仑、芬太尼、丙泊酚和顺阿曲库铵麻醉诱导后,气管插管后行静脉麻醉。术中静脉输注0．25μg·kg^-1·min^-1瑞芬太尼和3～4mg·kg^-1．h^-1丙泊酚,间断静脉注射顺阿曲库铵维持麻醉。麻醉诱导后,采用序贯法静脉注射氟比洛芬酯,初始剂量为1mg／kg,相邻梯度为0．2mg／kg。采用概率单位分析法计算氟比洛芬酯抑制瑞芬太尼术后痛觉过敏的量效关系：半数有效剂量（ED50）、95％有效剂量（ED95）及其95％可信区间。结果氟比洛芬酯抑制瑞芬太尼致患者术后痛觉过敏的ED50为1．40（95％CI=I．13～1．61）mg／kg,ED95为2．21（95％CI=I．89～3．33）mg／kg。结论氟比洛芬酯抑制瑞芬太尼致术后痛觉过敏的ED50和ED95分别为1．40mg／kg和2．21mg／kg。     

地佐辛复合丙泊酚在无痛人工流产术的应用

目的探讨地佐辛复合丙泊酚在无痛人工流产术中的麻醉效果和安全性。方法将门诊行人工流产术的200例患者随机分成地佐辛复合丙泊酚组(A组)和单用丙泊酚组(B组)两组,观察两组丙泊酚用量、手术结束至睁眼时间、定向力恢复时间、呼吸抑制(Sp O292%或呼吸暂停15s)及恶心、呕吐等不良反应的发生率,记录患者麻醉前5 min(T0)、睫毛反射消失时(T1),扩宫颈时(T2)、吸刮子宫内膜时(T3)、呼之能睁眼时(T4)平均动脉压(MAP)、心率(HR)、呼吸(RR)的变化;记录患者术后宫缩痛的发生情况。结果 A组丙泊酚用量明显低于B组。A组手术结束至睁眼时间、定向力恢复时间明显短于B组。A组呼吸抑制及恶心呕吐等不良反应的发生率显著低于B组;2组比较,差异有统计学意义(P0.05),A组患者术中血流动力学稳定。结论地佐辛复合丙泊酚静脉麻醉较单用丙泊酚麻醉血流动力学更平稳。可明显缩短患者苏醒时间及定向力恢复时间,减少术后不良反应发生率及宫缩痛,提高患者的安全性和舒适度。     

氯胺酮抑制瑞芬太尼致患者术后痛觉过敏的量效关系

目的 确定氯胺酮抑制瑞芬太尼致患者腹腔镜胆囊切除术后痛觉过敏的量效关系.方法 择期全麻下腹腔镜胆囊切除术患者15例,年龄40～60岁,体重45～80 kg,ASA Ⅰ或Ⅱ级,静脉注射咪达唑仑、芬太尼、阿曲库铵和异丙酚麻醉诱导后,气管插管行机械通气.术中静脉输注瑞芬太尼和异丙酚,间断静脉注射阿曲库铵维持麻醉.麻醉诱导后,采用序贯法静脉注射氯胺酮,初始剂量为0.8 mg/kg,相邻剂量比为2,采用概率单位法计算患者术后痛觉过敏抑制时(气管拔管后10 min时VAS评分<4分)氯胺酮的半数有效剂量(ED_(50))、95%有效剂量(ED_(95))及其95%可信区间.结果 氯胺酮抑制瑞芬太尼术后痛觉过敏的ED_(50)(95%可信区间)为0.23(0.12～0.35)mg/kg,ED_(95)(95%可信区间)为0.62(0.51～0.68)mg/kg.结论 氯胺酮抑制瑞芬太尼致患者腹腔镜胆囊切除术后痛觉过敏的ED_(50)和ED_(95)分别为0.23、0.62 mg/kg.     

氟比洛酚在丙泊酚静脉麻醉行无痛人流中靶向超前镇痛作用

目的：评价氟比洛酚配伍丙泊酚静脉麻醉在无痛人工流产术中的超前镇痛疗效和安全性。 方法：门诊预诊妊娠1～2月自愿施行人工流产术者40例，随机分成单纯丙泊酚静脉麻醉（P）组和氟比洛酚（F）组．每组各20例，F组于术前静脉缓慢注射氟比洛酚50mg，15分钟后行丙泊酚静脉麻醉。两组丙泊酚均采用2次推注法郎首次给药至深镇静，在扩宫颈之前再追加首次量的20％．吸宫时根据有无体动适当追加丙泊酚。观察记录诱导过程及术中血压．心率、脉搏氧饱和度、呼吸频率、苏醒时间、丙泊酚用量．术后恶心呕吐（PONV）、头晕、术后宫缩痛（采用VAS评分）。 结果：两组术中血压、心率、脉搏氧饱和度比较差异无显著性；丙泊酚用景F组少于P组（p〈0．05），F组呼吸抑制发生率低于P组（p〈0．05），术后宫缩痛F组明显少于P组（p〈0．05）。 结论：氟比洛酚合用丙泊酚静脉麻醉行无痛人工流产术可以减少丙泊酚用量和呼吸抑制的发生，增强镇痛效果而不增加不良反应。     

Propofol: effective dose and induction characteristics in unpremedicated children

The induction dose, induction characteristics, and cardiovascular and respiratory effects of propofol were studied in 90 unpremedicated children 3-12 yr old. Propofol in a dose of 1-3 mg.kg-1 was injected in an antecubital vein over 10-30 s. Successful induction was defined by loss of eyelash reflex occurring within 50 s of the conclusion of propofol injection and followed by subsequent acceptance of face mask without excessive movement. The effective dose of propofol resulting in loss of eyelash reflex in 50% (ED50) and 95% (ED95) of children were 1.3 (1.1-1.4) and 2.0 (1.7-2.6) mg.kg-1 (95% confidence interval). The corresponding ED50 and ED95 for a successful induction that included acceptance of face mask were 1.5 (1.3-1.7) and 2.3 (2.1-3.0), respectively. There was a 6.6% incidence of mild to moderate pain on injection and a 12.7% incidence of involuntary movement. Apnea (cessation of breathing greater than 20 s) was seen in 21% of patients. Blood pressure decreased by more than 20% of baseline value in 48% of patients who received halothane (1-3%) after the bolus injection of propofol. It is concluded that propofol is an effective induction agent in children. A dose of 2.5-3.0 mg.kg-1 is recommended to ensure a smooth transition to an inhalational maintenance technique. The use of antecubital veins is associated with a low incidence of pain on injection.     

Oral clonidine premedication reduces propofol requirement for laryngeal mask airway insertion

PURPOSE: To determine the effect of oral clonidine premedication on propofol requirement (ED(50)) for the insertion of the laryngeal mask airway (LMA) in healthy patients undergoing abdominal hysterectomy. METHODS: After ethics committee approval and informed consent, 41 patients were randomly assigned to receive 5 microg x kg(-1) clonidine po premedication 90 min before entering the operating room (n = 22), or no clonidine (n = 19). To alleviate pain associated with iv propofol, 3 ml lidocaine 2%iv were administered. General anesthesia was induced, 30 sec later, with propofol at a rate of 100 mg x min(-1) (600 ml x hr(-1)) iv. The dose of propofol at which insertion of the LMA was attempted was predetermined by modification of Dixon's up-and-down method with an initial dose of 2.5 mg x kg(-1) and 0.25 mg x kg(-1) as the step size. An LMA was inserted, without muscle relaxants or other adjuvants 90 sec after completion of the propofol injection, by an anesthesiologist blinded to the treatment of the patient. RESULTS: The ED(50) of propofol for LMA insertion in clonidine-treated patients (2.0 +/- 0.2 mg x kg(-1), 1.8-2.3 mg x kg(-1) [95% confidence interval]), was less than that in patients without clonidine (2.5 +/- 0.1 mg x kg(-1), 2.4-2.6 mg x kg(-1), P < 0.01). CONCLUSION: Oral clonidine premedication reduces propofol requirement for LMA insertion.     

An alternate method for estimating the dose-response relationships of neuromuscular blocking drugs

Slopes of the dose-response relationships for all available neuromuscular blocking drugs appear to be essentially parallel and to approximate a log-dose/logit value of 4.75. We tested the possibility of estimating both 50% effective dose (ED(50)) and 95% effective dose (ED(95)) values from a single dose-response data point when that slope is postulated. We compared the ED(50) and ED(95) values of rocuronium and succinylcholine calculated by using traditional log-dose/logit regression analysis with the same values obtained by averaging individual estimates of potency as determined by using the Hill equation. After the induction of anesthesia (propofol/alfentanil), tracheal intubation was accomplished without the administration of neuromuscular blocking drugs. Anesthesia was maintained with nitrous oxide and propofol. The evoked electromyographic response to 0.10-Hz single stimuli was continuously recorded. After baseline stabilization, a single IV bolus of succinylcholine (0.08-0.26 mg/kg, n = 50) or rocuronium (0. 13-0.30 mg/kg, n = 40) was administered and the peak effect noted. By using log-dose/logit regression analysis, we calculated ED(50) and ED(95) values for rocuronium of 0.17 and 0.33 mg/kg and 0.14 and 0.27 mg/kg for succinylcholine. When potency was calculated from the Hill equation, the resultant ED(50) and ED(95) values did not differ by more than +/-4% from those obtained by using regression analysis. Averaging of single-dose estimates of neuromuscular potency provides a useful adjunct and reasonable alternative to conventional regression analysis.