高渗氯化钠对单肺通气时呼吸力学的影响

目的 探讨高渗氯化钠对单肺通气患者呼吸力学参数的影响.方法 选择拟单肺通气剖胸手术患者60例,随机均分为高渗氯化钠治疗组(H组)和对照组(C组).在单肺通气30 min后经中心静脉导管输注7.5％氯化钠溶液(H组)或生理盐水(C组)2 ml/kg.观察单肺通气前(T1)、单肺通气后30 min(T2)、输注后30 min(T3)、60 min(T4)、单肺通气结束时(T5)的动态肺顺应性(Cdyn)、气道峰压(Ppeak)、气道平均压(Pmean)、动脉血氧分压(PaO2)、血清Na+浓度.结果 与T1时比较,两组患者T2时的Cdyn、PaO2明显降低,Ppeak、Pmean明显升高(P＜0.05).与T2时比较,T3～Ts时H组Cdyn、PaO2逐渐升高,Ppeak、Pmean逐渐下降(P＜0.05),且Cdyn、PaO2明显高于C组,Ppeak明显低于C组(P＜0.05).T4、T5时H组Pmean明显低于C组(P＜0.05).结论 7.5％氯化钠溶液对单肺通气患者的各呼吸力学参数有改善作用,对肺通气功能具有保护作用.     

高渗氯化钠羟乙基淀粉40对颅脑内肿瘤切除术颅内压的影响

目的 比较高渗氯化钠羟乙基淀粉40(HSH40)和20%甘露醇对颅内肿瘤切除术颅内压(ICP)的影响.方法 择期颅内肿瘤切除术患者60例,随机均分为HSH40组(H组)和甘露醇组(M组).麻醉前行L3～4蛛网膜下腔穿刺置管术.接压力传感器监测ICP,麻醉后按4 ml/kg量输入HSH40(H组)或20%甘露醇(M组),30 min输完.记录开始输入即刻(T0)、输完即刻(T1)、输完后15 min(T2)、30 min(T3)、60 min(T4)和120 min(T5)时的MAP、CVP、ICP、尿量和动脉血气分析结果.结果 两组T2～T5时ICP显著低于T0时(P<0.05).H组CVP在T2～T4时显著高于T0时和M组(P<0.05).H组Na+在T2、T3时显著高于T0时和M组.H组K+在T2和T3时显著低于T0时,且T2时H组低于M组.H组T3和T4时PaO2显著高于T0时.且T3时PaO2显著高于M组(P<0.05).M组T2～T5时尿量显著多于H组(P<0.05).结论 HSH40和甘露醇均能有效降低ICP,但HSH40更能维持围术期血流动力学稳定.     

高渗氯化钠羟乙基淀粉40注射液用于硬膜外麻醉的扩容效果

目的观察高渗氯化钠羟乙基淀粉40注射液(HSH40,霍姆)用于硬膜外麻醉的扩容效果及对电解质的影响。方法硬膜外麻醉下行腰椎内固定手术男性患者80例,随机均分为HSH40组(H组)和生理盐水对照组(C组)。记录麻醉前(T0)、输注HSH40或生理盐水后5 min(T1)、1 h(T2)、手术结束时(T3)CVP、血浆胶体渗透压(COP)、血电解质等。结果 T1、T2时两组Hb均明显降低,且H组明显低于C组(P<0.05)。T1~T3时H组CVP明显升高,而C组明显降低(P<0.05或P<0.01)。T1、T2时H组Na+升高(P<0.05),C组无明显变化;K+明显降低,且T3明显低于T0(P<0.05)。T1时H组COP明显降低,且低于C组(P<0.05);T2、T3时两组COP均明显降低(P<0.05或P<0.01);T3时H组高于C组(P<0.05)。结论 HSH40快速输注可有效扩充血容量,不会导致持续的电解质紊乱。     

等渗透剂量20%甘露醇与3%高渗盐水对大脑半球胶质瘤切除术患者血浆渗透浓度和电解质影响的比较

目的 比较择期大脑半球胶质瘤切除术中应用等渗透剂量的3%高渗盐水(hypertonie saline,HTS)和20%甘露醇(mannitol,M)降颅内压(intracranial pressure,ICP)的同时,患者血浆渗透浓度和电解质的变化及其临床意义. 方法 择期行大脑半球胶质瘤切除术患者40例,根据计算机随机分组表分为高渗盐水组(HTS组)和甘露醇组(M组)(n=20).两组均行静吸复合麻醉,异氟醚呼气末浓度达1 MAC后,在15 min内输注等渗透剂量3%HTS(5.33 ml/kg)或20%M(1 g/kg).记录输注前即刻(T0)、输注后即刻、输注后5、15、30、60、90、120 min(T1～T7)平均动脉压(MAP)、心率(HR),同时采取5 ml动脉血测定血球压积、血浆Na+、K+、Cl浓度、血pH、血浆渗透浓度,同时监测颅内压.结果 两组血浆渗透浓度在输注高渗溶液后均明显升高,在T1达高峰[HTS组:(305.1+4.3)mOsm/L;M组:(304.6±3.5)mOsm/kg](P<0.05),HTS组血浆Na+和cl浓度明显升高,于T1达高峰(152.3+5.2)mEq/kg(P<0.05),M组血浆Na+度降低,在T1达低谷(131.2±3.3)mEq/kg(P<0.05);血浆Cl-浓度在HTS组升高(P<0.05),M组降低(P<0.05).HTS组ICP在T2～T5降低(P<0.05),尤以T1～T2时段降低幅度更为明显,M组ICP在T3～T5降低(P<0.05).结论 在实施择期神经外科手术的患者,单剂静脉输注5.49 mOsm/kg的3%HTS和20%M引起同等程度的血浆渗透浓度上升,并在输注末达到高峰.     

5%转化糖电解质液不同输注速度对患者围术期血糖及电解质的影响

目的观察5%转化糖电解质液不同输注速度对患者围术期血糖及电解质的影响。方法2013年4~9月择期手术患者96例,ASAⅠ或Ⅱ级,按5%转化糖电解质液输注速度随机分为4ml/min输注组(A组)、8ml/min输注组(B组)和12ml/min输注组(C组)。观察并记录三组患者5%转化糖电解质液输入前(T0)、输入后即刻(T1)、输入后1h(T2)、2h(T3)的患者静脉血血糖及动脉血气电解质分析结果。结果与T0时比较,T1时B组和T1、T2时C组血糖明显升高(P0.05);T1时C组Na+、K+明显升高(P0.05)。与A组比较,T1时B组和T1、T2时C组血糖明显升高(P0.05);T1时C组Na+、K+明显升高(P0.05)。与B组比较,C组T1、T2时血糖、T1时Na+、K+明显升高(P0.05)。结论 5%转化糖电解质液输注速度不超过8ml/min,不仅为患者扩充容量,且维持电解质的稳定,适用于手术患者围术期的补液。     

高渗氯化钠羟乙基淀粉40注射液对中重度创伤性脑损伤手术患者的脑保护作用

目的探讨高渗氯化钠羟乙基淀粉40注射液(HSH40)对中重度创伤性脑损伤(TBI)手术患者的脑保护作用。方法选择脑外伤手术患者60例,格拉斯哥昏迷评分(glasgow coma scale,GCS)8~10分,随机均分为:HSH40组和甘露醇组,打开硬脑膜前30 min分别输注HSH405ml/kg和甘露醇5ml/kg。记录液体输注前(T0)、输注结束后30 min(T1)、60 min(T2)、120 min(T3)的PaO2、SaO2、动脉血红蛋白含量(Hba)、颈内静脉球氧分压(PjvO2)、颈内静脉球氧饱和度(SjvO2)、颈内静脉球血红蛋白含量(Hbv)。根据Fick公式计算动脉血氧含量(CaO2)、颈内静脉血氧含量(CjvO2)、脑动脉-颈内静脉球氧含量差(Ca-jvDO2),并计算脑氧摄取率(CERO2);于手术前(a1)、液体输注结束后即刻(a2)、术后2h(a3)、1d(a4)抽取外周静脉血,检测神经损伤标志物S100β蛋白含量。采用GOS量表和Barthel指数评定患者神经功能预后。结果与T0时比较,T2、T3时两组SjvO2明显升高、T1~T3时两组Ca-jvDO2和HSH40组CERO2明显降低(P0.05)。与甘露醇组比较,T2、T3时HSH40组SjvO2明显升高(P0.05);T1~T3时Ca-jvDO2和CERO2明显降低(P0.05)。a3时甘露醇组和a4时两组S100β蛋白含量明显高于a1时(P0.01),且a3时HSH40组S100β蛋白含量明显低于甘露醇组(P0.05),HSH40组Barthel指数评定完全自理和轻度缺陷患者18例(60%),明显高于甘露醇组12例(40%)(P0.05)。中、重度缺陷患者12例(40%),明显低于甘露醇组18例(60%)(P0.05)。结论 HSH40注射液和甘露醇均可减少创伤性脑损伤手术患者的脑组织耗氧和S100β蛋白含量,改善GOS评分及Barthel指数,两者均有脑保护作用,且前者保护作用更为显著。     

7.2%高渗羟乙基淀粉(200/0.5)氯化钠注射液对神经外科手术患者术中血流动力学的影响

目的探讨7.2%高渗羟乙基淀粉(200/0.5)氯化钠注射液(HS-HES)对神经外科手术患者血流动力学的影响。方法选择神经外科择期胶质瘤手术患者24例,ASAⅠ或Ⅱ,随机分为HS-HES组(n=14)和羟乙基淀粉(HES)组(n=10)。HS-HES组以500ml/h的速度给予HS-HES 250ml,HES组以1 000ml/h的速度输入HES 1 000ml扩容。记录输注前即刻(T0)、输注后30min(T1)、60min(T2)、70min(T3)、120min(T4)和180min(T5)HR、MAP、CVP、CO、每搏输出量(SV)和每搏变异度(SVV)。结果与T0时比较,T2～T5时两组HR明显增快(P0.05),T3～T5时两组MAP明显降低(P0.05),T1～T4时两组CVP明显升高、CO、SV明显增加,T1～T5时SVV明显降低(P0.05)。不同时点两组HR、MAP、CVP、CO、SV和SVV差异均无统计学意义。结论 HS-HES具有良好的血流动力学调节效应,为神经外科手术患者术中液体管理提供了一个新的选择。     

地佐辛术后镇痛对妇科恶性肿瘤患者血浆儿茶酚胺及免疫功能的影响

目的观察地佐辛用于妇科恶性肿瘤手术患者术后镇痛的效果及对血浆儿茶酚胺和免疫功能的影响。方法择期行妇科恶性肿瘤手术患者60例,随机均分为地佐辛组(D组)和芬太尼组(F组),采用静脉复合全麻,术毕使用患者静脉自控镇痛(PCIA),D组PCIA配方为地佐辛0.8mg/kg加托烷司琼6mg加生理盐水配至100ml,F组PCIA配方为芬太尼0.01mg/kg加托烷司琼6mg加生理盐水配至100ml。记录患者术前(T0)、术毕(T1)、术后2h(T2)、6h(T3)、24h(T4)和48h(T5)的SBP、DBP、HR、SpO2及T1~T5时静息时和活动时VAS疼痛评分、Ramsay镇静评分及恶心、呕吐、低血压、呼吸抑制等不良反应。于T0、T1、T4、T5时抽取静脉血4 ml,其中2 ml采用ELISA法测定血浆肾上腺素(E)、去甲肾上腺素(NE)、多巴胺(DOP)水平,剩余2ml采用流式细胞仪测定CD3+、CD4+、CD8+、CD4+/CD8+及NK细胞活性。结果两组患者SBP、DBP、HR、SpO2、Ramsay镇静评分差异均无统计学意义。T2~T4时D组安静时和活动时VAS评分明显低于F组(P0.05)。与T0时比较,T1时两组E、NE、DOP水平明显降低(P0.05或P0.01)。与T1时比较,T4、T5时两组E、NE、DOP水平明显升高(P0.01)。与F组比较,T4、T5时D组NE水平明显降低(P0.05)。与T0时比较,T1、T4时D组CD3+、CD4+、CD4+/CD8+、NK细胞活性明显降低(P0.01),T1时CD8+活性明显升高(P0.01),T1时F组CD3+、CD4+、CD4+/CD8+、NK细胞活性和T4时CD3+、NK细胞活性,T5时NK细胞活性明显降低(P0.05或P0.01)。与F组比较,T5时D组CD3+、CD4+、NK细胞活性明显升高(P0.05或P0.01)。两组患者术后48h不良反应发生情况差异无统计学意义。结论地佐辛用于妇科恶性肿瘤术后镇痛安全有效,与芬太尼比较镇痛效果好,术后应激反应较轻、细胞免疫功能恢复更快。     

喉罩全麻控制呼吸在患儿纤维支气管镜手术中的应用

目的比较喉罩全麻下控制呼吸与自主呼吸在患儿纤维支气管镜手术中的应用效果及安全性。方法选择择期行纤维支气管镜检查及介入治疗的住院患儿60例,随机均分为控制呼吸组(C组)和自主呼吸组(S组)。C组患儿喉罩置入成功后给予顺苯磺酸阿曲库铵0.2 mg/kg,行控制呼吸;S组患儿喉罩置入成功后保留自主呼吸,必要时手控辅助通气。观察并记录诱导前5 min(T0)、置入喉罩即刻(T1)、手术开始即刻(T2)、手术开始5 min(T3)及拔除喉罩即刻(T4)的HR、MAP、SpO2、P ET CO2,记录T1~T4时的V T,并采集桡动脉血行血气分析。记录手术时间、苏醒时间、手术中断次数、瑞芬太尼的用量、术中及术后呛咳、憋气等不良反应的发生情况,调查内镜医师满意度。结果与S组比较,C组手术时间明显缩短(P0.05),手术中断次数明显减少(P0.01),瑞芬太尼的用量明显增多(P0.01)。C组内镜医师的满意度明显高于S组(P0.01)。与S组比较,T2、T3时C组HR明显减慢(P0.01),MAP、P ET CO2、PaCO2、HCO-3明显降低(P0.05或P0.01),pH值、PaO2、BE、SaO2、SpO2、V T明显升高(P0.05或P0.01)。与T0时比较,T2、T3时C组P ET CO2明显降低(P0.05),T3时S组P ET CO2明显升高(P0.05)。与T1时比较,T2、T3时C组V T明显升高(P0.01),S组V T明显降低(P0.01),两组PaO2明显升高(P0.05或P0.01),S组PaCO2明显升高(P0.05)。与S组比较,C组术中呛咳、憋气和肢体运动发生率明显降低(P0.05或P0.01)。结论喉罩全麻控制呼吸在患儿纤维支气管镜手术中的应用效果可靠、安全有效,不良反应少,医师满意度高,值得在临床上推广应用。     

颅内高压患者术中应用3％高渗盐水与20％甘露醇后血流动力学的变化

目的 观察颅内高压患者术中应用3％高渗盐水(HS)与20％甘露醇(M)的血流动力学及内环境的变化.方法 60例颅内高压患者随机分为HS组(n=30)和M组(n=30),观察开始用药时(T0)、用药后(T1)、5 min( T2)、15 min(T3)、30 min( T4)、45 min(T5)、60 min( T6)、90 min (T7)、120 min( T8)的心率(HR)、平均动脉压(MAP)、每搏量指数(SVI)、每搏量变异度(SVV)、中心静脉压(CVP)、体循环血管阻力指数(SVRI)和尿量,T0、T8时点桡动脉血pH值、Na+、K+、Ca2、血乳酸(BLA).结果 (1)HS组:与T0比较,输注后T1～T8时点SVV降低,SVI、CVP、MAP值升高(P＜0.05)；HR值T1时点升高,T6～T8时点降低(P＜0.05)；SVRI值T1～T5时点降低(P＜0.05).(2)与T0比较,HS组T8时点Na+值升高,BLA值降低(P＜0.05)；两级比较,T8时点组间Na+值比较差异有统计学意义(P＜0.05).(3)与M组比较,T5～T8时点SVV、SVI、CVP、MAP、HR、SVRI差异有统计学意义(P＜0.05).(4)各时点M组尿量多于HS组(P＜0.05).结论 颅内高压患者术中输注3％ HS在维持血流动力学稳定和改善内环境方面优于20％M.     

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.     

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.     

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.