氟比洛芬酯或小剂量氯胺酮有效预防雷米芬太尼麻醉术后痛觉过敏

目的评价氟比洛芬酯或小剂量氯胺酮对于雷米芬太尼麻醉术后痛觉过敏的预防作用。方法60例ASAⅠ或Ⅱ级全身麻醉患者,年龄18～70岁,随机均分为三组:Ⅰ组应用雷米芬太尼的同时静脉注射氯胺酮0.5 mg/kg,继而5μg·kg-1·min-1静脉维持至手术结束;Ⅱ组术前氟比洛芬酯100 mg静脉注射;Ⅲ组不用氯胺酮或氟比洛芬酯作为对照。三组均用丙泊酚、雷米芬太尼维持麻醉。术后用曲马多持续静脉自控镇痛(PCIA)。结果Ⅲ组术后1、2、4、8 h视觉模拟评分(VAS)显著高于Ⅰ、Ⅱ组(P<0.05或P<0.01);术后24 h VAS三组间差异无统计学意义。术后24 h患者PCIA自控按压次数及加用芬太尼镇痛的病例数Ⅲ组显著多于Ⅰ、Ⅱ组(P<0.01)。结论超前应用氟比洛芬酯或术中持续应用小剂量氯胺酮均可有效预防雷米芬太尼麻醉术后痛觉过敏的发生,不影响患者苏醒,亦不增加不良反应的发生。     

持续泵注曲马多对靶控输注异丙酚血药浓度的影响

目的 观察麻醉中持续泵注曲马多对靶控输注(TCI)异丙酚麻醉血药浓度的影响。方法 随机将ASAⅠ～Ⅱ级病人50例分为两组(各25例),Ⅰ组单纯TCI异丙酚麻醉,Ⅱ组TCI异丙酚麻醉复合曲马多3mg/kg后以0.5 mg·kg-1·h-1持续泵注。以BIS值50±10来调节TCI血药浓度。麻醉中连续观察BIS、MAP、HR、异丙酚血药浓度(CP)、心率变异性(HRV)、LF/HF等指标,以及术中异丙酚用量和麻醉苏醒时间。结果 两组间BIS差异无显著性。Ⅰ组CP仅在切皮和拔管时显著高于Ⅱ组(P<0.05),而异丙酚总用量,苏醒及手术时间两组间差异无统计学意义。Ⅰ组仅在术毕时HRV高于Ⅱ组;切皮时和术中Ⅰ组HR明显高于Ⅱ组;Ⅰ组LF/HF在切皮前及术中较Ⅱ组显著升高。结论 持续泵注曲马多对TCI异丙酚麻醉血药浓度无明显影响,但曲马多的镇痛作用使其较单纯TCI异丙酚麻醉术中自主神经反应性下降,术后恢复期更加平稳。     

氯胺酮与吗啡超前镇痛对内脏牵拉痛及术后镇痛的影响

目的探讨氯胺酮与吗啡复合液硬膜外超前镇痛对抑制手术内脏牵拉痛的影响及术后镇痛情况的影响。方法60例ASAⅠ~Ⅱ级择期全子宫切除术患者,均于硬膜外麻醉下行全子宫切除术。随机分为两组,每组30例,即Ⅰ组(对照组):术前不施行超前镇痛;Ⅱ组(实验组):切皮前10 min将氯胺酮30 mg与吗啡2 mg用生理盐水稀释成5 ml注入硬膜外腔。所有患者术后均行自控硬膜外镇痛(PCEA)。镇痛药物为0.15%罗哌卡因+5 mg吗啡,共100 ml。观察两组患者术中牵拉反应、术后镇痛情况及并发症。结果Ⅱ组用药对抑制术中牵拉痛的效果明显优于Ⅰ组(P<0.01);Ⅱ组PCEA泵首次触发时间较Ⅰ组显著延长(P<0.01),48 h内有效触发次数显著减少(P<0.01),24 h PCEA泵总用量明显减少(P<0.05),术后并发症无明显差异。结论氯胺酮与吗啡硬膜外超前镇痛能明显抑制术中牵拉痛,提供良好的术后镇痛效果,减少阿片类药物的用量。     

超前镇痛在小儿扁桃体和腺样体切除术中的应用

目的 观察氟比洛芬酯、曲马多、氯胺酮用于全麻下小儿扁桃体和腺样体切除术后患者的镇痛效果及安全性,以及找到适合小儿短小手术的超前镇痛药物,从而减少小儿全麻苏醒期的躁动及减轻术后疼痛.方法 选择择期在全麻行扁桃体、腺样体切除术的患儿80例,年龄4岁～14岁,美国麻醉医师协会(ASA)分级I～Ⅱ级.采用完全随机双盲法将患儿分为4组:F组为氟比洛芬酯超前镇痛组,K组为氯胺酮超前镇痛组,T组为曲马多超前镇痛组,C组为空白对照组,每组20例.F组于手术开始前10 min缓慢静脉注射氟比洛芬酯1 mg/kg.K组于手术开始前10 min缓慢静脉注射氯胺酮0.5 mg/kg.T组于手术开始前10 min缓慢静脉注射曲马多2 mg/kg.C组于手术开始前10 min缓慢静脉注射生理盐水3ml.观察术后镇痛评分,苏醒期躁动评分,循环、呼吸、血氧饱和度变化及副作用.结果 术后苏醒期躁动评分F组、K组和T组明显低于C组.术后0hF组、K组、T组视觉模拟(VAS)评分和改良目的评分法(MOPS评分)分别为(0.6±1.0)和(0.8±1.0)、(1.9±1.9)和(1.8±1.7)、(0.8±1.4)和(0.8±1.3),均明显低于C组的(3.7±1.7)和(3.5±1.5)(P＜0.01);F组VAS评分在术后8h为(0.9±1.0)显著低于K组(1.8±1.7)、T组(1.8±0.7)和C组(1.7±0.7)(P＜0.01);F组MOPS评分为(0.3±0.7)在术后8h低于C组(0.7±0.6)(P＜0.05);F组和T组VAS评分在术后0h低于K组(P＜0.05).4组术后各个时点的循环、呼吸、血氧饱和度变化均在正常范围,F组血压在术后0h显著低于K组、T组和C组,组间比较差异有统计学意义(P＜0.01).4组均无心律失常、呼吸抑制、凝血功能异常发生,恶心、呕吐、头晕、烦躁、做噩梦、腹痛等副作用发生率4组之间差异无统计学意义(P＞0.05).术后睡眠不佳发生率C组高于F组(P＜0.05).结论 氟比洛芬酯、氯胺酮、曲马多均能有效减少苏醒期躁动,但氯胺酮、曲马多均未显示超前镇痛效果,氟比洛芬酯超前镇痛效果良好,作用时间长,能有效缓解小儿短小手术的术后疼痛,无明显副作用,可安全用于小儿短小手术的术后镇痛.     

不同剂量舒芬太尼复合曲马多用于烧伤患儿术后镇痛的比较

目的比较不同剂量舒芬太尼复合曲马多用于烧伤患儿术后静脉镇痛(PCIA)的效果,并探讨舒芬太尼适宜剂量。方法拟于全身麻醉下择期行躯干或四肢烧伤瘢痕整形术患儿60例,年龄3~10岁,ASAⅠ或Ⅱ级,随机均分为A、B、C组。术毕前30min给予负荷量舒芬太尼0.15μg/kg,术后接镇痛泵,其中A组舒芬太尼0.03μg·kg-1·h-1,B组舒芬太尼0.04μg·kg-1·h-1,C组舒芬太尼0.05μg·kg-1·h-1;三组均复合曲马多0.3mg·kg-1·h-1。分别在术后即刻(T1)、6h(T2)、12h(T3)、24h(T4)和48h(T5)采用改良面部表情评分法观察镇痛效果,记录FLACC评分和Ramsay镇静评分。观察并记录PCA按压次数及呼吸抑制、恶心、呕吐、头晕等不良反应。结果与A组比较,T2~T5时B组和C组面部表情评分、FLACC评分明显降低、Ramsay镇静评分明显升高(P0.05)。B组和C组面部表情评分、FLACC评分和Ramsay镇静评分差异均无统计学意义。与A组比较,B组和C组PCA有效按压次数明显减少,C组恶心呕吐、头晕发生率明显升高(P0.05)。与B组比较,C组PCA有效按压次数明显减少、恶心呕吐、头晕发生率明显升高(P0.05)。结论舒芬太尼0.04μg·kg-1·h-1复合曲马多0.3mg·kg-1·h-1用于小儿术后镇痛效果较好,不良反应少。     

等效剂量曲马多、吗啡或芬太尼用于老年病人术后静脉镇痛的临床研究

目的　研究等效剂量曲马多、吗啡或芬太尼用于老年病人术后静脉镇痛的临床疗效。方法　 12 0例老年病人 ,随机分为三组 ,每组 4 0例。术后病人第 1次感到疼痛时 ,给予等效初始量曲马多 1 5mg/kg(T组 )、吗啡 0 15mg/kg(M组 )、芬太尼 1 5 μg/kg(F组 )静注 ,然后分别持续静注曲马多 10mg·2ml-1·h-1、吗啡 1mg·2ml-1·h-1或芬太尼 10 μg·2ml-1·h-148小时。记录镇痛期间 1、2、3、4、6、12、2 4、4 8小时静息及活动时疼痛VAS值 ;监测用药前及用药后 10、2 0、30分钟、用药后 1、2小时的RR、SaO2 变化及各种不良反应。结果　三组病人静息时镇痛效果无明显差异 (P >0 0 5 )。前 4小时活动时M组、F组镇痛效果较T组优 (P <0 0 5 ) ;用药后 10、2 0分钟M组、F组RR明显减慢 ,与用药前相比差异显著 (P <0 0 5 ) ,所有病例用药前与用药后SaO2 均保持正常 ;恶心、呕吐的发生率T组明显高于M组、F组 (P <0 0 5 )。结论　连续静注等效剂量曲马多、吗啡或芬太尼用于老年病人术后镇痛均能取得满意的镇痛效果 ,但活动时吗啡和芬太尼的镇痛效果优于曲马多 ;吗啡和芬太尼于首次用药后能引起短暂的呼吸抑制 ,但在持续给氧时SaO2 仍保持正常     

静脉输注腺苷对胆道手术中异丙酚用量及术后芬太尼镇痛效果的影响

目的 观察胆道手术中持续静脉输注腺苷对术中异丙酚用量及术后芬太尼镇痛效果的影响.方法 45例择期全麻下行胆道手术的病人,ASA Ⅰ或Ⅱ级,年龄22岁～65岁,随机分为腺苷1组(A1组)、腺苷2组(A2组)和生理盐水组(NS组).于全麻诱导后10 min开始分别持续静脉输注腺苷35、70 μg·kg-1·min-1和生理盐水至术毕.术中持续输注芬太尼2μg·kg-1·h-1、阿曲库铵0.6 mg·kg-1·h-1,并根据脑电双频指数(bispectral index,BIS)、平均动脉压(MAP)和心率(HR)调整异丙酚的用量,维持BIS值40～50.术毕采用患者自控静注芬太尼镇痛.记录:①麻醉前(T0)、切皮即刻(T1)、切皮后15min(T2)、切皮后30min(T3)及术毕(T4)时的MAP和HR;②术中异丙酚平均用量;③术后30 min、2、4、24、48 h的视觉模拟评分(VAS),记录术后芬太尼用量和是否额外追加其他止痛药及用量.结果 在T0、T1时点,三组间MAP和HR无统计学差异(P＞0.05),在T2、T3、T4时点,A2组MAP和HR低于A1组和NS组(P＜0.05);A2组异丙酚平均用量少于A1组和NS组(P＜0.05);术后VAS评分及芬太尼用量3组间无统计学差异(P＞0.05).结论 胆道术中持续静脉输注腺苷70μg·kg-1·min-1能减少术中异丙酚用量,但不影响术后VAS评分及芬术尼用量.     

盐酸丁丙诺啡用于子宫下段剖宫产术的超前镇痛观察

目的:观察硬膜外腔注入盐酸丁丙诺啡用于子宫下段剖宫产术进行超前镇痛的效果.方法:80例ASAI～Ⅱ级择期子宫下段剖宫产术患者于硬-腰联合麻醉后随机分为两组:超前镇痛组(A组,n=40)于手术切皮前10min经硬膜外导管注入含盐酸丁丙诺啡0.15mg的生理盐水4ml,对照组(B组,n=40)于手术切皮前10min经硬膜外导管注入生理盐水4ml,观察术后4、8、12、24、48h两组患者的视觉模拟评分(VAS),各时段PCEA有效按压次数和不良反应.结果:术后4、8、12h VAS评分A组明显低于B组(P＜0.05),两组不良反应的发生率无统计学意义(P＞0.05).结论:盐酸丁丙诺啡硬膜外超前镇痛能有效减轻子宫下段剖宫产术的术后疼痛.     

超声引导单次髂筋膜间隙阻滞联合艾司氯胺酮对髋部骨折手术老年患者术后谵妄的影响

目的评价超声引导单次髂筋膜间隙阻滞联合艾司氯胺酮对髋部骨折手术老年患者术后谵妄(POD)的影响。方法择期蛛网膜下腔麻醉下行髋部骨折手术患者62例, 年龄60～85岁, BMI 18～30 kg/m2, ASA分级Ⅱ或Ⅲ级, 性别不限。采用随机数字表法将患者分为2组(n=31):单次髂筋膜间隙阻滞组(FICB组)和单次髂筋膜间隙阻滞联合艾司氯胺酮组(FICB+E组)。于蛛网膜下腔麻醉前30 min行超声引导髂筋膜间隙阻滞;FICB+E组于切皮前5 min静脉注射艾司氯胺酮0.3 mg/kg, 随后以0.25 mg·kg-1·h-1的速率静脉泵注至手术结束前30 min。术后采用PCIA, 并采用曲马多进行补救镇痛。记录术后48 h内镇痛泵按压次数、补救镇痛次数和曲马多用量;于切皮时、手术开始后30 min、手术结束前30 min、手术结束时、离开PACU时采用Ramsay镇静评分评估镇静程度;采用意识模糊评估法(CAM)评估术后7 d内POD的发生情况;于入室、术后3 d、术后7 d时采用ELISA法检测血清TNF-α、IL-6、S100β和胶质纤维酸性蛋白(GFAP)浓度;记录药物相关...     

腰椎手术麻醉方法的改良：艾司氯胺酮复合麻醉

目的评价艾司氯胺酮复合麻醉用于腰椎手术的改良效果。方法选择2022年6月至12月拟在全身麻醉下行腰椎后路减压植骨融合内固定术患者94例, 性别不限, 年龄18～64岁, BMI 18.5～29.9 kg/m2, ASA分级Ⅰ或Ⅱ级, 采用随机数字表法分为2组(n=47):对照组(C组)和艾司氯胺酮组(K组)。2组静脉注射咪达唑仑、舒芬太尼、依托咪酯及顺式阿曲库铵进行麻醉诱导, K组在此基础上静脉注射艾司氯胺酮0.5 mg/kg。2组均静脉输注丙泊酚和瑞芬太尼维持麻醉, 间断静脉注射顺苯磺酸阿曲库铵维持肌松, K组在此基础上静脉输注艾司氯胺酮0.25 mg·kg-1·h-1。术毕前10 min连接镇痛泵行PCIA, NRS评分>4分时静脉注射氟比洛芬酯50 mg进行补救镇痛。记录首次按压镇痛泵时间、术后48 h内镇痛泵按压次数和补救镇痛情况;记录术中瑞芬太尼初始剂量、瑞芬太尼累计用量、气管拔管时间及术后48 h内不良反应发生情况。结果与C组比较, K组术中瑞芬太尼累计用量减少, 首次按压镇痛泵时间延长, 镇痛泵按压次数减少(P<0.05), 术中瑞芬太尼初始剂量、术后补救镇痛...     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.