应用组织多普勒应变率技术评价米力农、多巴胺对心脏瓣膜手术患者左心室功能的作用

目的利用组织多普勒应变率技术评估心瓣膜置换术患者使用小剂量多巴胺、米力农对其左心室收缩及舒张功能的影响。方法选择2011年3～5月四川大学华西医院择期行心瓣膜置换术患者共40例,将其随机分为米力农组(20例)和多巴胺组(20例),于麻醉诱导后、体外循环前测量两组患者左心室射血分数(LVEF),应用组织多普勒应变率技术测定四腔心切面左心室侧壁、间壁的组织,并对多普勒参数进行比较。结果两组患者LVEF、左心室舒张早期和舒张晚期血流比值(E/A)、左心室舒张早期血流和舒张早期心肌运动峰值的比值(E/Et)给药前后差异有统计学意义(P<0.05);米力农组有4个节段收缩期峰值速度(Vs),1个节段舒张早期峰值速度(Ve),4个节段舒张晚期峰值速度(Va),3个节段Ve/Va比值,2个节段收缩期峰值应变率(SRs),2个节段舒张晚期峰值应变率(SRa),3个节段舒张早期峰值应变率(SRe)/SRa比值高于给药前(P<0.05);多巴胺组有4个节段Vs,1个节段Ve,4个节段Va,1个节段Ve/Va比值,2个节段SRs,1个节段SRe,1个节段SRa,1个节段SRe/SRa比值高于给药前(P<0.05)。两组间比较,给药后米力农组有2个节段Vs,4个节段Va,1个节段SRe,1个节段SRa,2个节段Ve/Va比值,2个节段SRe/SRa比值高于多巴胺组(P<0.05);其中1个节段Vs,2个节段SRs低于多巴胺组,E/A比值给药10 min时,E/Et比值给药20 min时低于多巴胺组。结论运用组织多普勒应变率技术评估米力农、多巴胺均能改善心瓣膜置换术患者围术期左心室收缩功能,其中米力农对左心室长轴舒张功能的改善较多巴胺明显。     

冠状动脉旁路移植术患者左心室舒张功能的初步评估

目的 评价冠状动脉旁路移植术（CABG）患者左心室舒张功能（LVDF）.方法 采用经食管超声心动图（TEE）技术观察46例不停跳CABG（OPCABG）患者手术前后LVDF的变化.结果 与术前比较，术后经二尖瓣尖脉冲多普勒血流频谱（TMF）的舒张早期充盈波（E波）和舒张晚期充盈波（A波）流速显著加快（P＜0.01）；E波血流时间积分（VTIE）和A波血流时间积分（VTIA）显著增加（P＜0.05或P＜0.01）；E波减速时间（DT）和加速时间（AT）显著缩短（P＜0.05或P＜0.01）；而E/A、A波间期和舒张早期充盈分数（RFF）值差异无统计学意义.术后经左上肺静脉血流频谱（PVF）的S、D和AR波的流速显著加快（P＜0.01）；而S/D、AR波间期和AR-A（AR波间期与A波间期之差）差异无统计学意义.面积减少分数（FAC）和心排血量（CO）显著增加（P＜0.01）.PCWP与AR波直线回归方程：PCWP=2.6＋0.4 AR.结论 CABG患者普遍存在以左心室松弛功能减低为主的舒张功能不全，术后早期收缩功能迅速改善，但舒张功能不全依然存在.TEE可区分心脏的收缩和舒张功能.     

七氟烷对体外循环冠状动脉旁路移植术患者左心室功能的影响

目的 评价七氟烷对体外循环(CPB)冠状动脉旁路移植术(CABG)患者左心室功能的影响.方法 择期CPB下行CABG的冠心病患者35例,男性30例,女性5例,年龄53～75岁,身高150～183 cm,体重46～100 kg,AsAⅡ或Ⅲ级,七氟烷分为冠脉搭桥前后2个阶段给药,分别为气管插管后至锯胸骨前和关闭胸腔至手术结束前,CPB期间停止吸入七氟烷.七氟烷呼气末浓度相当于1 MAC.围术期行食管超声心动图(TEE)检查,于锯胸骨前未吸入七氟烷(T_1)、吸入5 min(T_2)、15 min(T_3)、关闭胸腔后未吸入七氟烷(T_4)、吸入5 min(T_5)、15 min(T_6)时记录平均动脉压(MAP)和TEE监测指标:E波、A波、S波.D波和AR波的峰值、心指数(CI)、左室短轴缩短率(FS)、左室射血分数(LVEF),左心室舒张早期血流播散速度(Vp),计算E波与A波峰值比(E/A)、S波与D波峰值比(S/D) 和E波与Vp的比值(E/Vp).结果 与T_1时比较,T_(2,3)时MAP降低,T_3时LVEF、FS和CI降低,T_4时HR、LVEF、FS、CI升高,.E波:A波、S波、D波和AR波的峰值升高(P<0.05或0.01);与T_4时比较,T_(5,6)时MAP降低,T_6时LVEF、FS和CI降低(P<0.05或0.01).结论 呼气末浓度相当于1 MAc的七氟烷可明显抑制CPB下CABG患者左心室收缩功能,但对舒张功能无明显影响.     

MSCT检测冠心病患者心外膜脂肪组织容积与左心室舒张功能的相关性

目的观察冠心病(CAD)患者心外膜脂肪组织(EAT)容积与左心室舒张功能的相关性。方法纳入55例接受冠状动脉CTA的CAD患者,将冠状动脉CTA薄层图像导入GE AW 4.4工作站,手动勾画心包线,测量EAT容积;采用彩色多普勒超声测量舒张早期、舒张晚期经二尖瓣血流峰值流速(E、A)以及舒张早期二尖瓣隔部组织运动峰值速度(Ea),计算E/A和E/Ea值。分析EAT容积与E/A和E/Ea的相关性。结果 CAD患者EAT容积与E/A呈负相关(r=-0.376,P=0.005),与E/Ea呈正相关(r=0.368,P=0.006)相关;校正CAD危险因子后,EAT容积是E/Ea的独立影响因子(b=0.011,t=2.12,P=0.04)。结论 CAD患者EAT容积与左心室舒张功能相关性较好;MDCT定量测量EAT容积对评价左心室舒张功能异常具有重要意义。     

经食管超声心动图在心血管手术麻醉与监测中的应用

目的　评价经食管超声心动图 (TEE)在心血管手术麻醉中的价值。方法　本组共完成 1 2 2例TEE监测。主要观察指标 :(1 )对 4 1例瓣膜置换患者的瓣膜作返流和狭窄分级及评价机械或生物瓣的功能 ;(2 ) 4 8例不停跳冠状动脉搭桥 (CABG)患者手术前后心功能变化〔①面积减少分数(FAC) ;②E波与A波峰值流速比率 (E/A)和各自的流速时间积分比率 (VTIE/VTIA) ;③E波减速时间 (DT) ;④心脏指数 (CI)〕 ;(3)手术前后对 2 0例不停跳CABG患者左室室壁 (前壁、后壁、侧壁和室间隔 )运动分级 ;(4 )监测先心病矫正前后心脏结构变化。结果　TEE检测瓣膜病变与经胸超声结果一致 ,手术后瓣膜活动正常。术后FAC、CI和VTIE/VTIA分别为 (0 5 2± 0 0 8)、(2 6 4± 0 6 9)L·min 1 ·m 2 和 1 2 9± 0 1 8,与术前比较 (0 4 2± 0 0 9)、(2 0 5± 0 4 8)L·min 1 ·m 2 和 1 1 4± 0 1 6有显著性差异 (P <0 0 5 ) ;术后E/A 0 86± 0 2 1与术前 0 77± 0 1 8比较P <0 0 1。DT无显著性变化。术前节段性室壁运动异常大于 2级的占 1 0 % ,术后为 5 %。结论　在心血管手术中 ,TEE是一种新的有用的监测技术     

小左心室患者瓣膜置换术的麻醉策略及围术期处理

目的研究小左心室患者心脏瓣膜术后早期形态学及左心室收缩功能变化,探讨小左心室患者瓣膜置换术的麻醉策略及围术期处理。方法 2003年1月至2008年8月接受心脏瓣膜置换术的合并小左心室的患者51例,均采用全凭静脉麻醉,持续泵注丙泊酚维持麻醉,并根据血流动力学及BIS监测,间断静注舒芬太尼及哌库溴铵,围术期维持BIS<50。监测并记录麻醉诱导前(T1)、诱导后(T2)、CPB前(T3)、CPB后(T4)、手术结束关胸后(T5)的SBP、HR、CVP、平均肺动脉压(PAP)和肺动脉楔压(PCWP)。结果与T1时比较,T2、T3时SBP明显下降,T2～T5时HR明显减慢(P<0.05),T4、T5时CVP、PAP及PCWP均明显著降低(P<0.05)。14例(27.5%)患者术后早期发生重度低心排,围术期死亡2例(3.9%)。术前及术后早期(7～14d)超声心动图显示左心室大小无明显变化,左心室收缩功能较术前有提高,但差异无统计学意义。结论小左心室瓣膜术后早期易发生低心排,应积极防治;缩小的左室舒张末径在术后早期不会立即恢复,要对心肌功能予以较长时间的维护以保证左室功能的恢复。     

肺动脉漂浮导管在冠状动脉旁路术中的应用

目的　评价肺动脉漂浮导管连续监测心排血量 (CO)、混合静脉血氧饱和度 (S VO2 )在冠状动脉旁路移植术 (CABG)中的应用。方法　CABG术者 32例 ,年龄 (6 1 31± 6 92 )岁 ,平均搭桥(3 19± 1 12 )支。麻醉诱导用芬太尼 2 0～ 30 μg/kg、维库溴铵 0 3mg/kg、咪唑安定 (3 5 8± 2 0 0 )mg ;术中以芬太尼、异氟醚维持。经右颈内静脉置CCO S VO2 肺动脉漂浮导管 ,连续监测CO、S VO2 、平均动脉压 (MAP)、肺动脉压 (PAP)、肺毛细血管楔压 (PCWP)和中心静脉压 (CVP)等 ,记录诱导前、插管后、心肺转流 (CPB)前、停CPB及关胸时的数据。结果　心排指数 (CI)、MAP和S VO2 在插管后各时段较诱导前明显下降 (P <0 0 5 ) ,CVP、PCWP及PAP停CPB后较插管后升高 (P <0 0 5 )。HR在插管后下降 (P <0 0 5 ) ,停CPB后升高 (P <0 0 5 )。结论　在CABG术中 ,利用肺动脉漂浮导管连续监测CO、S VO2 及各项相关指标 ,及时了解心脏功能、全身及心肌的氧供需平衡状况 ,并调整用药 ,以利于围手术期意外的处理 ,防止心肌缺血的发生     

再次冠状动脉旁路移植术一例

患者　男 ,6 2岁。发生心绞痛 10年。3.5年前在外院行冠状动脉造影示左右冠状动脉均有病变 ,多处狭窄 ,行冠状动脉旁路移植术 (CABG)治疗。术后 2个月出现胸痛 ,心电图示陈旧性下壁和广泛前壁心肌梗死 ,左心室下壁和间壁严重缺血 ,心尖区心肌活动力极度下降。经药物治疗胸痛有所好转 ,但仍然反复发作。 5天前胸痛加剧收入我院。入院后作心电图示急性下壁心肌梗死 ,陈旧性前壁、后壁心肌梗死。冠状动脉造影示左冠状动脉主干及 3支血管病变 ;左前降支移植的静脉血管通畅无狭窄 ;后降支移植的静脉血管完全闭塞。在心内科治疗病情较平稳后 ,接…     

Swan—Ganz气囊飘浮导管测压法

中心静脉压(CVP)在危重病人用于判断心脏前负荷是一大进展,但它只能反映右心室充盈情况,不能及早反映肺动脉压的变化和直接反映左心情况。当心源性休克时,左心室泵功能衰竭,首先升高的是左室舒张末期压(LVEDP)、左房压(LAP),其次是肺动脉压(PAP)和肺毛细血管楔压(PCWP),最后是右房压(RAP)和CVP。此时CVP升高可能已发展到充血性     

全麻联合硬膜外阻滞下经典式原位肝移植术期间血流动力学的改变

目的 观察全麻联合硬膜外阻滞行经典式原位肝移植期间血流动力学的变化.方法 24例肝癌全麻联合硬膜外阻滞下行经典式原住肝移植术,麻醉前放置Swam-Gaze导管,右桡动脉导管及右股静脉导管,监测麻醉前期,切皮时,无肝前期末,无肝期5 min,无肝期30 min,新肝期15 min及术毕各个时期血流动力学参数,用t检验组间变化的差异性.再分别以麻醉前作时照处理数据.结果 24例肝癌患者均行经典式原位肝移植术,手术时间(435±48)min,术中出血量(2 258±325)ml.术中输库存浓缩RBC(6.6±1.5)U、血浆(785±68)ml、平衡液(1 856±86)ml、血浆代用品(1 625±115)ml.①切皮时,中心静脉压(CVP),股静脉压(FVP),平均肺动脉压(MPAP),肺毛细血管楔压(PCWP)下降(P≤0.05或P≤0.01),心输出量(CO),心指数(CI)也随着降低(P≤0.05),MPAP降低(P≤0.05).②无肝前期末,CVP,FVP,MPAP,PCWP进一步下降(P≤0.01),CO和CI也随着进一步下降(P≤0.01),MPAP也进一步降低(P≤0.01).③无肝期5 min,CVP,MPAP,PCWP,CO,CI以及MPAP进一步剧烈下降(P≤0.01),即使周围血管阻力和肺血管阻力升高(P≤0.05),MPAP依然进一步剧烈下降(P≤0.01),但FVP骤然升高(P≤0.01).④无肝期30 min,股静脉压有所回落(P≤0.01),MPAP,PCWP,CO以及CI较无肝期5 min有回升趋势(P≤0.01).⑤新肝期,CVP,MPAP,PCWP,CO,CI以及MPAP明显回升(P≤0.01);周围阻力下降(P≤0.05),FVP骤然下降(P≤0.01).⑥手术结束时,CVP,FVP及MPAP较新肝期进一步回升(P≤0.01),其他指标如MAP,MPAP,PC聊,CO以及CI也基本上恢复至麻醉前水平(P≤0.05).FVP基本上和CVP相差不大(P≤0.05).结论 全麻联合硬膜外阻滞下原位肝移植术期间,协同麻醉作用,减少全身麻醉药对患者重要脏器的影响,扩张硬膜外阻滞区域血管,在门静脉和下腔静脉阻断时,可增加回心循环的血流量,部分代替体外静脉-静脉技术的作用,减少血流动力剧烈波动.     

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.     

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.     

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.