瑞马唑仑联合地佐辛用于老年患者无痛胃镜检查的半数有效量和95%有效量

目的观察瑞马唑仑复合地佐辛用于老年患者无痛胃镜检查的半数有效量(median effective dose,ED_(50))和95%有效量(95%effective dose,ED_(95))。方法选取2020年12月在扬州大学附属医院日间手术中心行无痛胃镜检查的老年患者31例,年龄65~86岁,体重45~87 kg,ASA分级Ⅰ~Ⅲ级。监测患者生命体征,静脉给予20μg/kg地佐辛,10 min后给予瑞马唑仑,待患者意识消失后立即行胃镜检查,观察受试患者对胃镜检查的反应情况。设定瑞马唑仑0.20 mg/kg为初始剂量,采用改良序贯法确定瑞马唑仑的剂量。采用概率单位Probit回归分析法计算瑞马唑仑ED_(50)、ED_(95)及其95%CI。结果与用药前相比,患者使用瑞马唑仑后出现一过性MAP、心率和SpO2的降低。复合地佐辛时,瑞马唑仑用于老年患者无痛胃镜检查的ED_(50)为0.184(0.062~0.275)mg/kg、ED_(95)为0.354(0.268~1.677)mg/kg。结论瑞马唑仑复合地佐辛用于老年患者无痛胃镜检查的ED_(50)为0.184 mg/kg、ED_(95)为0.354 mg/kg。     

瑞马唑仑复合瑞芬太尼在无痛胃镜检查中的临床应用

目的探讨瑞马唑仑复合瑞芬太尼在无痛胃镜检查中的最佳使用剂量。方法本研究为随机、单盲对照研究。行无痛胃镜检查的患者699例,按随机数字表法分为7组:A组(0.2 mg/kg瑞马唑仑复合0.25μg/kg瑞芬太尼,100例)、B组(0.3 mg/kg瑞马唑仑复合0.25μg/kg瑞芬太尼,100例)、C组(0.4 mg/kg瑞马唑仑复合0.25μg/kg瑞芬太尼,100例)、D组(0.2 mg/kg瑞马唑仑复合0.50μg/kg瑞芬太尼,100例)、E组(0.3 mg/kg瑞马唑仑复合0.50μg/kg瑞芬太尼,100例)、F组(0.4 mg/kg瑞马唑仑复合0.50μg/kg瑞芬太尼,100例)、R组(2 mg/kg丙泊酚,99例)。记录7组患者入室后(T_(0))、给药结束后1 min(T_(1))、胃镜操作时第1分钟(T_(2))、胃镜操作时第3分钟(T_(3))、胃镜操作时第5分钟(T_(4))、离院时(T_(5))的心率、MAP,记录7组患者胃镜检查操作时间、苏醒时间、离院时间、并发症(呼吸抑制、低氧血症、低血压、呛咳、呃逆、体动等)发生情况、镇静成功率、患者满意度评分及操作者满意度评分。记录瑞芬太尼0.25μg/kg的3组、瑞芬太尼0.50μg/kg的3组、瑞马唑仑0.2 mg/kg的2组、瑞马唑仑0.3 mg/kg的2组、瑞马唑仑0.4 mg/kg的2组呃逆的发生率,分析两种药物剂量与呃逆的相关性。结果A、B、C、D、E、F组的镇静成功率高于R组(P<0.05)。当瑞芬太尼剂量恒定时、增加瑞马唑仑的剂量,或者当瑞马唑仑剂量恒定时、增加瑞芬太尼的剂量,镇静成功率都随之增加(P<0.05),胃镜检查过程中心率和MAP波动减小、呛咳及体动发生率降低、患者及操作者满意度评分增高(P<0.05);但同时,呼吸抑制及低血压的发生率也随之升高、心率和MAP下降幅度增大、患者苏醒时间与离院时间也逐渐延长(P<0.05)。瑞马唑仑剂量与呃逆的发生间呈弱正相关(0.25μg/kg,r=0.180,P<0.05;0.50μg/kg,r=0.272,P<0.05),瑞芬太尼剂量与呃逆的发生间呈负相关(0.2 mg/kg,r=−0.400,P<0.05;0.30 mg/kg,r=−0.386,P<0.05;0.40 mg/kg,r=−0.303,P<0.05)。结论瑞马唑仑复合瑞芬太尼可安全用于无痛检查,0.3 mg/kg瑞马唑仑复合0.25μg/kg瑞芬太尼剂量更为合适。     

复合阿芬太尼时瑞马唑仑抑制双腔支气管插管反应的半数有效剂量

目的 探讨复合阿芬太尼时瑞马唑仑抑制双腔支气管插管反应的半数有效剂量(ED₅₀)。方法 选择2022年5—7月行双腔支气管插管患者35例,男17例,女18例,年龄18～64岁,BMI 18～30 kg/m²,ASAⅠ—Ⅲ级。首例患者给予瑞马唑仑0.35 mg/kg,警觉/镇静评分(OAA/S评分)为0分时,给予阿芬太尼50μg/kg、罗库溴铵0.6 mg/kg后行气管插管。双腔支气管插管反应阳性定义为气管插管后2 min内HR或MAP升高幅度超过基础值的20%,否则为阴性反应。按照改良Dixon序贯法,设定相邻剂量梯度为0.05 mg/kg,若出现阳性反应,下一例患者升高1个剂量梯度;反之降低一个剂量梯度,观察到第7个阳性反应-阴性反应交叉点时终止试验。采用Probit回归分析计算瑞马唑仑ED₅₀、ED₉₅及其95%可信区间(CI)。结果 共纳入患者35例,其中阳性反应15例(43%)。瑞马唑仑抑制双腔支气管插管反应的ED₅₀为0.206 mg/kg(95%CI 0.135～0...     

复合舒芬太尼时瑞马唑仑抑制老年患者鼻咽通气道置入反应的半数有效剂量

目的 探讨复合舒芬太尼时瑞马唑仑抑制老年患者鼻咽通气道置入反应的半数有效剂量（ED₅₀）。
方法 选择择期在鼻咽通气道下完成白内障手术的老年患者38例，年龄≥65岁，BMI 18～25 kg/m²，ASAⅠ—Ⅲ级。患者依次静脉注射舒芬太尼0.1 μg/kg，3 min后静脉注射瑞马唑仑，2 min后置入鼻咽通气道。首例患者给予瑞马唑仑0.2 mg/kg，采用改良Dixon序贯法确定下一例患者瑞马唑仑的剂量，若前一例患者鼻咽通气道置入时出现以下任意一种阳性反应（摇头、呛咳、体动、HR增快幅度>基础值的20%、SBP或DBP升高幅度>基础值的20%），则下一例麻醉诱导时瑞马唑仑剂量增加0.01 mg/kg，反之则减少0.01 mg/kg，直到出现7次折返后停止。采用Probit回归分析计算复合舒芬太尼时瑞马唑仑抑制老年患者鼻咽通气道置入反应的ED₅₀、95%有效剂量(ED₉₅)及95％可信区间（CI）。
结果 复合舒芬太尼时瑞马唑仑抑制鼻咽通气道置入反应的ED₅₀为0.193 mg/kg（95%CI 0.191～0.195 mg/kg），ED₉₅为0.209 mg/kg（95%CI 0.205～0.213 mg/kg）。
结论复合舒芬太尼时瑞马唑仑抑制老年患者鼻咽通气道置入反应的ED₅₀为0.193 mg/kg（95%CI 0.191～0.195 mg/kg）。     

利多卡因对复合阿芬太尼时瑞马唑仑抑制老年患者胃镜置入反应量效关系的影响

目的评价利多卡因对复合阿芬太尼时瑞马唑仑抑制老年患者胃镜置入反应量效关系的影响。方法选择在全身麻醉下接受无痛胃镜检查术的老年患者, ASA分级Ⅰ或Ⅱ级, 性别不限, 年龄65～80岁, BMI 18～28 kg/m2, 采用随机数字表法分为2组:瑞马唑仑组(C组)和利多卡因复合瑞马唑仑组(L组)。麻醉诱导时所有患者均给予阿芬太尼6 μg/kg后L组患者静脉注射利多卡因2 mg/kg, 采用改良Dixon序贯法进行研究, 首例患者静脉注射瑞马唑仑剂量为0.18 mg/kg, 待患者睫毛反射消失且改良警觉/镇静评分≤3分时置入胃镜。胃镜置入反应阳性标准:进镜过程中患者出现吞咽、呛咳、体动等影响检查质量的反应。若胃镜置入反应阳性, 则下一例患者瑞马唑仑的用量增加1个阶梯剂量, 否则降低1个阶梯剂量。相邻剂量差值为0.02 mg/kg, 重复此过程直至出现9个转折点。采用probit法计算2组瑞马唑仑抑制胃镜置入反应的半数有效剂量(ED50)及其95%置信区间(CI)。结果 C组复合阿芬太尼时瑞马唑仑抑制老年患者胃镜置入反应的ED50(95%CI)为0.158(0.133～0.183) mg/...     

不同剂量瑞马唑仑复合舒芬太尼在无痛胃镜检查术中的比较

目的 探讨不同剂量瑞马唑仑复合舒芬太尼用于无痛胃镜检查术的有效性及适宜剂量。方法 选择2021年8—11月拟行无痛胃镜检查术患者160例,男84例,女76例,年龄18～64岁,BMI 18～30 kg/m²,ASAⅠ或Ⅱ级。采用随机数字表法将患者分为四组：丙泊酚2 mg/kg组(P组)、瑞马唑仑0.2 mg/kg组(R1组)、瑞马唑仑0.3 mg/kg组(R2组)和瑞马唑仑0.4 mg/kg组(R3组),每组40例。P组、R1组、R2组和R3组静脉注射舒芬太尼0.1μg/kg行镇痛预处理后,60 s内分别静脉注射丙泊酚2 mg/kg、瑞马唑仑0.2、0.3和0.4 mg/kg,改良警觉/镇静(MOAA/S)评分≤2分时即开始胃镜操作。记录首次镇静成功率、胃镜检查时间、苏醒时间、离院时间。记录术中低氧血症、低血压、体动、呛咳、呃逆、注射痛和术后恶心呕吐等不良反应发生情况。记录患者和内镜医师对麻醉的满意度。结果 与P组比较,R1组首次镇静成功率、低氧血症、低血压、注射痛发生率和内镜医师满意率明显降低,苏醒时间和离院时间明显缩短,体动和呛咳发生率明显升高(P<0....     

依托咪酯联合瑞芬太尼用于老年患者胃镜检查时依托咪酯的半数有效剂量

目的测定依托咪酯联合瑞芬太尼用于老年患者胃镜检查依托咪酯的ED50和ED95。方法选择行胃镜检查的老年患者23例,男13例,女10例,年龄65~78岁,体重45~76kg,ASAⅠ~Ⅲ级。预先缓慢静脉注射瑞芬太尼0.3μg/kg,然后注射依托咪酯0.20 mg/kg,待睫毛反射消失后行胃镜检查。依托咪酯的剂量采用改良序贯法确定,起始剂量为0.20 mg/kg,胃镜检查患者反应阳性标准:在整个检查过程中出现躁动、皱眉、吞咽、呛咳等。相邻间隔剂量为0.05 mg/kg,当出现七个交叉点终止研究。应用概率回归分析法计算依托咪酯复合瑞芬太尼老年患者胃镜检查的依托咪酯ED50和ED95及95%CI。结果依托咪酯ED50为0.17mg/kg,95%CI为0.14~0.21mg/kg,ED95为0.23mg/kg,95%CI为0.20~0.42mg/kg。结论依托咪酯联合瑞芬太尼用于老年患者无痛胃镜ED50、ED95分别为0.17mg/kg和0.23mg/kg。     

不同剂量瑞马唑仑复合丙泊酚应用于无痛胃镜检查的效果

目的 比较不同剂量瑞马唑仑复合丙泊酚在无痛胃镜检查中的应用效果.方法 选择2020年11—12月拟行无痛胃镜检查的患者160例,男76例,女84例,年龄18～64岁,BMI 18～30 kg/m2,ASAⅠ或Ⅱ级.采用随机数字表法将患者分为四组:丙泊酚2 mg/kg组(C组)、瑞马唑仑0.1 mg/kg复合丙泊酚1 m...     

瑞马唑仑诱发不同BMI患者呼吸抑制的半数有效剂量

目的 探讨瑞马唑仑引起不同BMI患者呼吸抑制的半数有效剂量（ED₅₀）。
方法 选择超声引导下腹横平面神经阻滞患者102例,男48例,女性54例,年龄18～60岁,BMI 19～40 kg/m²,ASA Ⅰ或Ⅱ级。根据患者BMI分为四组：正常体重组（C组,19 kg/m²≤BMI<25 kg/m²,n=25),偏胖组（D1组,25 kg/m²≤BMI<30 kg/m²,n=29）,肥胖组（D2组,30 kg/m²≤BMI<35 kg/m²,n=26）和重度肥胖组（D3组,35 kg/m²≤BMI<40 kg/m²,n=22）。常规消毒铺巾后静脉注射瑞马唑仑,每组患者的第1例均静脉注射0.04 mg/kg（校正体重）、注射时间1 min,下1例患者根据上1例患者的整合呼吸功能指数（IPI）调高或者降低瑞马唑仑剂量,当上一例患者的IPI≥5时,调高瑞马唑仑剂量,当IPI<5时,降低瑞马唑仑剂量,相邻剂量的比值为1.2。根据序贯法分别测定瑞马唑仑对不同BMI患者产生呼吸抑制的ED₅₀和95%可信区间（CI）。
结果 C组瑞马唑仑引起呼吸抑制的ED₅₀为0.162 mg/kg（95%CI 0.143～0.183 mg/kg）。D1组瑞马唑仑引起呼吸抑制的ED₅₀为0.113 mg/kg（95%CI 0.094～0.130 mg/kg）。D2组瑞马唑仑引起呼吸抑制的ED₅₀为0.105 mg/kg（95%CI 0.082～0.136 mg/kg）。D3组瑞马唑仑引起呼吸抑制的ED₅₀为0.065 mg/kg（95%CI 0.055～0.085 mg/kg）。
结论 瑞马唑仑诱发不同BMI患者呼吸抑制的ED₅₀不同,随着BMI的增加,ED₅₀降低。     

联合舒芬太尼时瑞马唑仑抑制气管插管心血管反应的半数有效剂量

目的 评价联合舒芬太尼时瑞马唑仑抑制气管插管心血管反应的半数有效剂量（ED₅₀）。
方法 选择全身麻醉置入单腔气管导管手术患者49例,男29例,女20例,年龄18～64岁,BMI 20～25 kg/m²,ASA Ⅰ或Ⅱ级。首例患者给予瑞马唑仑0.20 mg/kg,待患者意识消失,警觉/镇静评分（OAA/S评分）≤1分且BIS≤60后,给予舒芬太尼0.25 μg/kg,根据上一例患者气管插管心血管反应情况,采用抛偏倚硬币法决定下一例瑞马唑仑剂量。若上一例气管插管心血管反应为阳性,下一例患者瑞马唑仑升高1个剂量梯度;若上一例气管插管心血管反应为阴性,则下一例随机有11%的概率降低瑞马唑仑1个剂量梯度,有89%的概率维持上一例的剂量梯度。设定瑞马唑仑相邻剂量差值为0.01 mg/kg。计算瑞马唑仑抑制气管插管心血管反应的ED₅₀、95%有效剂量（ED₉₅）及其95%可信区间（CI）。
结果 瑞马唑仑抑制气管插管心血管反应的ED₅₀为0.190 mg/kg（95%CI 0.131～0.194 mg/kg）,ED₉₅为0.202 mg/kg（95%CI 0.198～0.220 mg/kg）。
结论 联合舒芬太尼0.25 μg/kg时,瑞马唑仑抑制气管插管心血管反应的ED₅₀为0.190 mg/kg（95%CI 0.131～0.194 mg/kg）。     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

The multiply injured child

Blunt trauma is the principal cause of childhood death in many developed countries. This review outlines the differences between adults and children with respect to resuscitation and treatment of orthopaedic injuries in a child with polytrauma. Recent advances in techniques of fracture stabilization are reported.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.     

Intravenous endotoxin does not increase tissue extravasation of albumin in rats

Background : It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.
Methods : Chloralose anaesthetised male Wistar rats received E. coli lipopolysacharide (LPS), 3 mg kg^-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.
Main Results : LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5-h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).
Conclusion : After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.