前锯肌平面阻滞与胸椎旁神经阻滞用于胸腔镜手术患者术后镇痛效果的比较

目的比较前锯肌平面阻滞与胸椎旁神经阻滞用于胸腔镜手术患者术后的镇痛效果。方法选择择期行胸腔镜手术患者60例,男38例,女22例,年龄18～65岁,BMI 18～25kg/m2,ASAⅠ或Ⅱ级,采用随机数字表法分为前锯肌平面阻滞组(S组)和胸椎旁阻滞组(T组),每组30例。两组患者均采用支气管插管静脉全身麻醉,术后采用PCIA。S组于麻醉诱导前行超声引导下前锯肌平面阻滞,T组则行超声引导下胸椎旁阻滞,两组均使用0.4%罗哌卡因30ml,阻滞完成后30min使用针刺法测定并记录感觉阻滞平面;记录阻滞操作时间、起效时间、持续时间;记录术后2、4、8、12、24、48h的静息和咳嗽VAS评分;记录首次按压镇痛泵时间、术后48h内镇痛泵有效按压次数、舒芬太尼使用总量和哌替啶补救性镇痛例数;记录阻滞相关并发症、镇痛不良反应发生情况。结果与T组比较,S组阻滞操作时间明显缩短,阻滞持续时间明显延长(P0.01);S组术后12h静息时和咳嗽时VAS评分明显降低(P0.01),S组PCIA首次按压时间明显延长,S组PCIA 48h内按压次数、舒芬太尼使用量明显减少(P0.01),两组气胸、恶心呕吐发生率差异无统计学意义。结论超声引导下前锯肌平面阻滞或胸椎旁阻滞均可为胸腔镜手术患者提供良好术后镇痛,但前锯肌平面阻滞较胸椎旁阻滞作用更持久、操作时间更短、并发症更少,且能有效减少患者术后对阿片类药物的需求量。     

超声引导下腹横肌平面阻滞对剖宫产产妇催乳素及术后镇痛的影响

目的评价超声引导下腹横肌平面阻滞对剖宫产产妇催乳素(PRL)及术后镇痛的影响。方法选择择期行剖宫产产妇40例,单胎,足月(孕38~41周),年龄20~39岁,体重50~80kg,ASAⅠ或Ⅱ级,采用随机数字表法分为两组,每组20例。C组不实施腹横肌平面阻滞,T组于手术结束即刻在超声引导下行双侧腹横肌平面阻滞。术后所有患者均采用1μg/ml舒芬太尼行PCIA,负荷量2ml,背景输注速率2ml/h,单次剂量2ml,锁定时间15min。若VAS评分3分,静脉注射曲马多50mg行镇痛补救。记录初乳时间及术前30min、术后24、48h产妇血清PRL浓度;记录术后静息状态下2、4、12、24和48hVAS评分,术后24h内舒芬太尼累积消耗量,镇痛补救率,镇痛泵按压次数;术后24h内不良反应发生情况。结果 T组初乳时间明显早于C组(P0.05);T组术后24、48h血清PRL浓度明显高于C组(P0.05);T组母乳喂养成功率明显高于C组(P0.05);T组术后静息状态下2、4、12和24hVAS评分明显低于C组(P0.05);T组术后24h内舒芬太尼累积消耗量明显少于C组、镇痛补救率明显低于C组、镇痛泵按压次数明显少于C组(P0.05);T组术后24h内恶心呕吐发生率明显低于C组(P0.05)。结论超声引导下腹横肌平面阻滞用于剖宫产术后镇痛可促进产妇早泌乳,提高母乳喂养成功率,镇痛效果显著,且不良反应较少,值得在临床推广应用。     

超声引导下菱形肌-肋间肌-低位前锯肌平面阻滞对腹腔镜肾切除术患者术后镇痛的影响

目的观察超声引导下菱形肌-肋间肌-低位前锯肌(RISS)平面阻滞对腹腔镜肾切除术患者术后镇痛的影响。方法择期行腹腔镜肾切除术患者40例,男19例,女21例,年龄25~65岁,ASAⅠ或Ⅱ级,随机分为单纯全麻组(C组)和全麻联合RISS平面阻滞组(T组),每组20例。T组在麻醉诱导前行超声引导下患侧RISS平面阻滞,注射0.25%罗哌卡因30 ml,C组不行RISS平面阻滞。两组患者手术后均行PCIA。观察术后1、6、12、24、48 h静息及活动时VAS疼痛评分以及舒芬太尼用量、镇痛泵有效按压次数,记录术后48 h内不良反应或并发症情况。结果 T组术后1、6、12、24 h的静息和活动时VAS疼痛评分明显低于C组(P<0.05),舒芬太尼用量和镇痛泵有效按压次数明显少于C组(P<0.05)。两组均未观察到气胸、局麻药中毒、血肿、严重低血压等并发症。结论诱导前RISS平面阻滞可有效提高腹腔镜肾切除术后静脉自控镇痛的效果。     

前锯肌平面阻滞对非小细胞肺癌胸腔镜根治术患者术后镇痛效果的影响

目的探讨前锯肌平面阻滞对胸腔镜手术患者术后镇痛效果的影响。方法选取2017年7—12月住院治疗的早期非小细胞肺癌患者40例,性别不限,年龄48～67岁,BMI 21.3～26.7 kg/m~2,ASAⅠ或Ⅱ级,按照随机分组的原则,将患者分为前锯肌平面阻滞组(SP组,n=20)和对照组(C组,n=20)。记录术后在PACU内舒芬太尼追加剂量及总用量、48 h内疼痛VAS评分、48 h内镇痛泵有效按压次数及总按压次数;记录功能锻炼依从性及慢性疼痛的发生率;记录患者局麻药中毒、皮下血肿、感染、皮肤瘙痒、头晕、恶心呕吐、尿潴留、便秘等不良反应的发生情况。结果与C组比较,SP组术后舒芬太尼追加剂量及总舒芬太尼用量明显减少(P0.05);术后2、4、8、24、48 h疼痛VAS评分明显降低(P0.05);48 h内PCIA有效按压次数及总按压次数明显减少(P0.05);功能锻炼依从性明显较好(P0.05)。两组慢性疼痛发生率差异无统计学意义。两组镇痛不良反应差异无统计学意义。结论对于非小细胞肺癌胸腔镜手术患者,前锯肌平面阻滞联合静脉自控镇痛的多模式镇痛可有效控制术后疼痛,减少镇痛药的用量、镇痛泵按压次数和慢性疼痛的发生率,提高患者呼吸功能锻炼的依从性。     

超声引导下竖脊肌平面阻滞在慢性脓胸患者术中及术后镇痛中的效果

目的观察超声引导下竖脊肌平面(erector spinae plane, ESP)阻滞对慢性脓胸患者术中及术后镇痛效果的影响。方法择期行胸腔镜下胸膜纤维板剥脱术的慢性脓胸患者60例,男35例,女25例,年龄30～70岁,ASAⅠ或Ⅱ级,随机分为两组:ESP阻滞复合全身麻醉组(E组)和单纯全身麻醉组(G组)。两组均行全身麻醉,E组全身麻醉前实施超声引导下ESP阻滞,术毕均采用患者自控静脉镇痛(patient controlled intravenous analgesia, PCIA)。记录E组超声下胸椎旁间隙显示情况,ESP阻滞20 min后在锁中线处感觉阻滞范围;记录两组术中瑞芬太尼用量、PACU停留时间、术后PCIA泵有效按压次数、术后1、4、12、24、48 h静息和活动时VAS评分。结果 E组有24例胸椎旁间隙显示不清,ESP阻滞20 min后感觉阻滞节段为4.9±1.0。E组术中瑞芬太尼用量和术后PCIA泵有效按压次数明显少于G组(P0.05),PACU停留时间明显短于G组(P0.05),术后1、4、12、24 h静息和活动时VAS评分明显低于G组(P0.05)。结论超声引导下ESP阻滞对慢性脓胸患者是一种安全的镇痛方法,能够提供有效的术中及术后镇痛。     

腹横肌平面阻滞联合盐酸羟考酮在全麻剖宫产术后镇痛中的应用

目的观察超声引导下腹横肌平面阻滞(TAPB)联合盐酸羟考酮静脉自控镇痛(PCIA)在全麻剖宫产术后镇痛效果。方法选取90例全麻下行择期剖宫产术的产妇,ASA 1~2级。根据不同术后镇痛方法分为3组,每组30例。A组TAPB联合盐酸羟考酮PCIA,B组TAPB联合舒芬太尼PCIA,C组单纯舒芬太尼PCIA。记录3组术后2 h、4 h、8 h、12 h、24 h静息和运动时的VAS评分,术后24 h内PCIA有效按压次数、镇痛效果满意度及术后恶心呕吐、呼吸抑制、头晕头痛等不良反应。结果与C组比较,A和B组术后2 h、4 h、8 h和12 h静息和运动时的VAS评分明显降低(P0.05),术后镇痛满意度明显较高(P0.05),术后24h内PCIA有效按压次数明显减少(P0.05),与B、C 2组比较,A组发生恶心呕吐、头晕头痛等不良反应明显减少。结论超声引导下TAPB联合盐酸羟考酮PCIA可为全麻剖宫产术产妇提供安全有效的术后镇痛。     

超声引导下前锯肌平面阻滞对乳腺癌患者术后镇痛的影响

目的探讨超声引导下前锯肌平面(serratus plane, SP)阻滞对乳腺癌患者术后急性疼痛和细胞免疫功能的影响。方法选择2016年1月至2018年6月在本院行择期乳腺癌改良根治术女性患者60例,年龄40～65岁,BMI 20.1～24.5 kg/m~2,ASAⅠ或Ⅱ级。采用随机数字表法随机分为两组:SP阻滞联合全身麻醉组(S组)和全身麻醉组(N组),每组30例。两组均采用气管插管静脉全身麻醉,S组在麻醉诱导后在超声引导下行患侧SP阻滞,注射0.3%罗哌卡因25 ml。N组不行SP阻滞。术后两组均行舒芬太尼PCIA。记录术后舒芬太尼用量、术后首次按压镇痛泵时间和48 h内镇痛泵有效按压次数。记录麻醉诱导前、术毕、术后24和48 h NK细胞、NKT细胞、调节性T细胞百分比。记录术后48 h内不良反应的发生情况。结果与N组比较,S组术后舒芬太尼用量明显减少(P0.05),术后首次按压时间明显延长(P0.05),术后48 h内镇痛泵有效按压次数明显减少(P0.05)。与麻醉诱导前比较,术毕、术后24、48 h N组NK细胞、NKT细胞百分比明显降低,调节性T细胞百分比明显升高(P0.05)。与N组比较,术毕、术后24、48 h S组NK细胞、NKT细胞百分比明显升高,调节性T细胞百分比明显降低(P0.05)。两组术后48 h内均无一例不良反应。结论乳腺癌手术患者实施超声引导下前锯肌平面阻滞能明显缓解术后急性疼痛,减少围术期镇静镇痛药使用并减轻免疫抑制程度。     

超声引导下椎板阻滞对胸腔镜下肺叶切除术术后镇痛的影响

目的观察超声引导下椎板阻滞对胸腔镜下肺叶切除术患者术后镇痛效果的影响。方法择期行胸腔镜下肺叶切除术的患者40例,采用随机数字表法将患者分为两组(每组20例):椎板阻滞复合全身麻醉组(R组)和单纯全身麻醉组(G组)。R组患者全身麻醉前实施超声引导下椎板阻滞,阻滞20 min后测量患者感觉阻滞平面。两组患者全身麻醉方法相同,术毕两组患者均使用患者自控静脉镇痛(patient controlled intravenous analgesia,PCIA)。记录术后2、6、18、24、48 h静息和活动时VAS评分,记录患者PACU停留时间、术后PCIA按压次数、术后舒芬太尼用量、补救镇痛情况、副作用发生情况、住院时间及患者满意度。结果R组椎板阻滞20 min后测量锁骨中线处感觉阻滞节段为(5.7±0.9)个,R组患者术后2、6、18、24、48 h静息和活动时VAS明显低于G组(P<0.05);R组患者PACU停留时间、术后PCIA按压次数和术后舒芬太尼用量明显少于G组(P<0.05),其中R组2例(10%)患者、G组13例(65%)患者追加了曲马多补救镇痛,两组补救镇痛差异有统计学意义(P<0.05);R组患者术后满意度明显高于G组(P<0.05),两组患者术后恶心、呕吐发生率和住院时间差异无统计学意义(P>0.05)。结论超声引导下椎板阻滞可安全应用于胸腔镜下肺叶切除术,并能够提供良好的术后镇痛,患者满意度高。     

超声引导下外侧弓状韧带上腰方肌前路阻滞与腹横肌平面阻滞在子宫切除术中的比较北大核心CSCD

目的评价超声引导下外侧弓状韧带上腰方肌前路阻滞(QLB-LSAL)和腹横肌平面阻滞(TAPB)对开腹子宫切除术患者镇痛效果及术后康复情况的影响。方法选择择期开腹子宫切除术患者60例,年龄35~64岁,BMI 21~29 kg/m^(2),ASAⅠ或Ⅱ级。随机分为两组:QLB-LSAL组(Q组)和TAPB组(T组),每组30例。麻醉诱导前,Q组在超声引导下行双侧QLB-LSAL,T组在超声引导下行双侧TAPB,两组每侧均给予0.375%罗哌卡因20 ml。术毕两组均行患者自控静脉镇痛(PCIA)。记录阻滞后5 min、6、24、48 h的阻滞平面节段,阻滞后6、24、48 h静息和活动时VAS疼痛评分和阻滞后48 h静息时VAS疼痛评分大于4分的发生情况,术后48 h舒芬太尼用量、镇痛泵按压次数和补救镇痛情况,下床活动时间、首次肛门排气时间、术后进食时间、术后住院时间,术后皮肤瘙痒、恶心呕吐等不良反应发生情况。结果阻滞后5 min、6、24、48 h Q组阻滞平面节段明显多于T组(P<0.05)。阻滞后6、24、48 h两组静息和活动时VAS疼痛评分差异无统计学意义,阻滞后48 h时,两组静息时VAS疼痛评分>4分发生率差异无统计学意义。术后48 h内Q组舒芬太尼用量、镇痛泵按压次数明显少于T组(P<0.05),补救镇痛率明显低于T组(P<0.05)。Q组首次下床活动时间、首次肛门排气时间和术后住院时间明显短于T组(P<0.05)。两组术后皮肤瘙痒、恶心呕吐发生率差异无统计学意义。结论与腹横肌平面阻滞比较,超声引导下外侧弓状韧带上腰方肌前路阻滞能有效缓解开腹子宫切除术患者术后疼痛,减少术后镇痛药物用量,术后恢复更快。     

椎板后阻滞和竖脊肌平面阻滞在多发肋骨骨折手术患者术中及术后镇痛效果的比较

目的探讨超声引导下椎板后阻滞(RLB)和竖脊肌平面阻滞(ESPB)对多发肋骨骨折患者术中和术后镇痛效果的影响。方法选择行肋骨骨折内固定手术患者80例,男57例,女23例,年龄25～65岁,ASAⅠ或Ⅱ级。随机分为两组:RLB组和ESPB组,每组40例。两组在全身麻醉后实施超声引导下RLB和ESPB,均给予0.5%罗哌卡因0.4 ml/kg。术后两组均行静脉自控镇痛(PCIA)。记录术中瑞芬太尼用量。记录术前静息以及术后2、4、12、24、48 h静息和咳嗽时VAS疼痛评分。记录PACU滞留时间、PCIA有效按压次数、补救镇痛例数、穿刺相关并发症及不良反应的发生情况。结果与EAPB组比较,RLB组术中瑞芬太尼用量明显减少(P0.05),术后2、4、12、24 h静息和咳嗽时VAS疼痛评分明显降低(P0.05),PACU滞留时间明显缩短(P0.05),PCIA有效按压次数明显减少(P0.05),补救镇痛率、恶心呕吐发生率明显降低(P0.05)。结论与ESPB比较,全身麻醉联合超声引导下RLB可以有效减少多发肋骨骨折患者术中阿片类药物的用量,减轻术后疼痛。     

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.     

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.     

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.     

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.