术中静脉输注乌司他丁对非体外循环冠状动脉旁路移植术患者围术期肺功能的影响

目的 评价术中静脉输注乌司他丁对非体外循环冠状动脉旁路移植术(OPCABG)患者围术期肺功能的影响.方法 择期OPCABG患者24例,NYHA心功能分级Ⅰ或Ⅱ级,年龄65～75岁,随机分为对照组(C组,n=12)和乌司他丁组(U组,n=12).U组于气管插管后经30 min静脉输注乌司他丁6 000 U/kg,随后以1 000 U·kg-1·h-1的速率静脉输注至术毕,C组采用同样方法静脉输注等容量生理盐水.分别于术前(T1)、术毕即刻(T2)、术后4 h(T3)、8 h(T4)和20 h(T5)时测定血浆白细胞介素6(IL-6)浓度、中性粒细胞CD11b/CD18表达水平、血清一氧化氮(NO)浓度,并行血气分析,计算肺泡-动脉血氧分压差[P(A-a)O2]和呼吸指数(RI);记录重症监护室期间机械通气时间.结果 与T1时比较,C组T3.4时血浆IL-6浓度、T2～5时中性粒细胞CD11b/CD18表达水平、P(A-a)O2和RI升高,血清NO浓度降低,U组T2～5时P(A-a)O2和RI升高(P<0.05或0.01),其余指标差异无统计学意义(P<0.05);与C组比较,U组T3.4时血浆IL-6浓度、T2～5时中性粒细胞CD11b/CD18表达水平、T2.3时RI和P(A-a)O2降低,T2.3时血清NO浓度升高(P<0.05或0.01);C组重症监护室期间机械通气时间长于U组(P<0.05).结论 术中静脉输注乌司他丁可改善OPCABG患者围术期肺功能,其机制可能与降低全身炎性反应有关.     

不同氧合器对体外循环心脏手术患儿中性粒细胞凋亡的影响

目的 研究小儿体外循环(cardiopulmonary bypass,CPB)中不同氧合器对中性粒细胞(PMN)凋亡的影响,为减轻体外循环伞身炎症反应提供新的思路.方法 将60例室间隔缺损患儿随机分为两组(n=30):西京-90鼓泡式氧合器组(B组)和希健-Ⅱ膜式氧合器组(M组).分别于CPB前、CPB结束时、CPB结束后4、8、24 h 5个时点采取静脉血,以伞血细胞计数仪测定PMN数量,流式细胞仪测定PMN凋亡率和PMN表面黏附分子CD11b表达变化,ELISA法测定血浆弹性蛋白酶浓度.结果 两组患者CPB结束后PMN凋亡率明显降低(P<0.05),PMN数量、CD11b表达、血浆弹性蛋白酶浓度明显升高(P<0.05),在CPB结束时及CPB结束后4、8 h PMN凋亡率M组均高于B组(P<0.05);而PMN数量、CD11b表达、血浆弹性蛋白酶水平B组均高于M组(P<0.05).CPB结束后24 h PMN数量B组高于M组(P<0.05).结论 与西京-90鼓泡氧合器相比,应用希健-Ⅱ膜式氧合器可以减轻CPB对PMN凋亡的抑制,进而减轻全身炎症反应.     

小剂量氯胺酮对心肺转流后肺损伤的保护作用

目的观察应用小剂量氯胺酮对心肺转流(CPB)后肺损伤的影响。方法30例二尖瓣置换手术病人随机均分为氯胺酮组(K组)和对照组(C组),两组麻醉方法相同。K组于麻醉诱导后和CPB开始前分别缓慢静注氯胺酮1mg/kg;C组静注同等容量的生理盐水。于手术开始前(T0)、CPB停止即刻(T1)、2h(T2)、12h(T3)记录气道峰压(Ppeak)、气道平台压(Pplautue),通过Flow-Directed漂浮导管测定平均肺动脉压(MPAP)、肺毛细血管楔压(PCWP)、心输出量(CO),计算肺血管阻力(PVR),同时抽取动脉血、混合静脉血测动脉血气、血常规、肿瘤坏死因子α(TNF-α)、白细胞介素1(IL-1)、血清可溶性细胞间黏附分子-1(sICAM-1)及中性粒细胞表面CD11b、CD18的表达。结果CPB后两组病人的所测各项指标均明显升高(P<0.05),但K组显著低于C组(P<0.05),CPB后C组中性粒细胞在肺组织中的浸润明显高于K组,CD11b、CD18表达较高的中性粒细胞容易浸润于肺组织中。结论CPB中应用小剂量氯胺酮可以减轻全身性炎症反应和缺血-再灌注损伤导致的肺组织损伤,对肺功能有显著的保护作用。     

心脏瓣膜置换术病人体外循环后肺损伤的机制

目的 探讨心脏瓣膜置换术病人心肺转流术(CPB)后肺损伤的机制。方法 选择8例行心脏瓣膜置换术的病人,其中男4例,女4例,全身麻醉后经颈内静脉置入Swan-Ganz导管。分别在CPB前即刻(T0)、腔静脉开放后5 min(T1)、停机时(T2)和术毕(T3)时采集桡动脉(肺静脉)血和混合静脉(肺动脉)血,测定中性粒细胞(PMN)计数、血浆肿瘤坏死因子-α(TNF-α)、超氧化物歧化酶(SOD)和脂质过氧化物(LPO)浓度,并计算肺动、静脉血各项指标的差值,反映肺内PMN滞留、TNF-α净生成、SOD消耗和LPO净生成;分别测定T0、T2和T3时肺动脉血液动力学指标和肺顺应性,行肺动、静脉血气分析计算肺泡-动脉血氧分压差(PA-aDO2)、肺分流量(QS/QT)和肺氧合指数(paO2/FiO2)。结果 所有病人上、下腔静脉阻断时间及转机时间分别为97±21、(124±27)min。与T0比较,在T3时MPAP升高、肺顺应性显著性降低,T2、T3时PVRI、PA-aDO2和QS/QT显著性升高(P<0.05或0.01),在T1、T2和T3时PMNv、PMNa、TNF-αa、LPOa显著性升高(P<0.05或0.01),在T1、T2时TNF-α和LPOa显著性升高(P<0.01),在T1、T2和T3时SODv、SODa显著性降低(P<0.01)。结论 CPB后肺功能损害与肺外组织生成的氧自由基及炎性反应激活的PMN和TNF-α有关。     

不同干预措施对大鼠体外循环后急性肺损伤的影响

目的观察异丙酚、咪达唑仑及吡咯烷二硫代氨基甲酸酯(PDTC)对大鼠体外循环(CPB)后急性肺损伤(ALI)的影响。方法成年SD大鼠26只,随机分4组:咪达唑仑组(CPBMZ组)、咪达唑仑 PDTC组(CPBPDTC组)、异丙酚组(CPBPROP组)和假手术组(Sham组),Sham组不实施CPB。CPBPROP组腹腔注射异丙酚、芬太尼行麻醉诱导,其它三组腹腔注射咪达唑仑、芬太尼行麻醉诱导, CPBPDTC组转流前30 min腹腔注射PDTC 100 mg·kg-1。CPB转流量为100 ml·kg-1·min-1,转流时间60 min。分别于转流前(T1)、转流结束时(T2)及停转流后60 min(T3)进行动脉血气分析,计算T1、T3时呼吸指数(RI),测定中性粒细胞(PMN)CD11b表达。CPB后60 min测定支气管肺泡灌洗液(BALF)中PMN计数、IL-8及总蛋白浓度,取肺组织,进行病理学检查并测定丙二醛(MDA)含量。结果CPBMZ组T3时RI高于T1(P<0.01)。与CPBMZ组相比,其它三组BALF中PMN计数、IL-8浓度及肺组织MDA含量降低(P<0.05)。CPBMZ组肺组织炎症反应程度最重。各组间及组内PMN上CD11b表达比较差异无统计学意义(P>0.05)。结论异丙酚和PDTC能减轻CPB后ALI,其机制与抗氧化作用和抑制PMN肺内积聚有关。     

异氟醚预处理对心脏瓣膜置换术病人血清一氧化氮与肌钙蛋白Ⅰ的影响

目的探讨异氟醚预处理对心肌缺血-再灌注损伤的保护效应及机制。方法择期行心脏瓣膜置换术的风湿性心脏瓣膜病病人32例,随机分为异氟醚组和对照组,每组16例。异氟醚组以1.5%~2%异氟醚吸入复合芬太尼维持麻醉,心肺转流(CPB)开始前洗脱10min,CPB后以芬太尼维持麻醉;对照组以芬太尼维持麻醉。分别于麻醉前(T0)、CPB前(T1)、CPB30min(T2)、术后8h(T3)、24h(T4)抽取中心静脉血测定一氧化氮(NO)、NO合酶(NOS)与心肌肌钙蛋白I(cTnI)浓度。结果两组病人T0时NO、NOS与cTnI浓度差异无显著意义;异氟醚组T1、T2时NO、NOS浓度明显高于对照组(P<0·05),T3、T4时cTnI浓度明显低于对照组(P<0·05)。结论异氟醚具有心肌预适应作用,其机制可能与增加NO释放有关。     

利多卡因对冠状动脉搭桥术患者体外循环致全身炎性反应的影响

目的探讨利多卡因对冠状动脉搭桥术患者体外循环(CPB)致全身炎性反应的影响。方法择期CPB下行冠状动脉搭桥术患者20例,男13例,女7例,年龄47-67岁,体重62-82 kg, ASAⅡ或Ⅲ级,随机分为对照组(C组)和利多卡因组(L组),每组10例。L组在切开心包时开始持续静脉泵注利多卡因4 mg/min至术毕,CPB预充液中另加入利多卡因4 mg/kg,C组以同样速率输入等量生理盐水。L组随机选取5例患者,分别于CPB开始后10、60 min和术毕取桡动脉血,用气相色谱法测定血浆利多卡因浓度。分别于CPB前切开心包时(T0)、主动脉开放心脏复跳后1 min(T1)、10 min (T2)、60min(T3)抽取桡动脉血,测定血浆肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和白细胞介素- 10(IL-10)浓度,并进行中性粒细胞(PMN)计数。结果 L组CPB开始后10、60 min、术毕时血浆利多卡因浓度分别是4．1±0．5、4．6±0．7、(5．9±0．9)μg/ml。CPB可引起血浆TNF-α、IL-6、IL-10浓度及PMN 计数升高,利多卡因可减轻CPB所致全身炎性反应。结论利多卡因可减轻冠状动脉搭桥术患者 CPB致全身炎症反应。     

抑肽酶对自体血回输脊柱矫形术病人炎性反应的影响

目的观察抑肽酶对自体血回输脊柱矫形术病人术中炎性反应的影响。方法全麻下行脊柱矫形手术病人24例,随机分为抑肽酶组和对照组(n=12)。以血液回收、洗涤技术处理创面出血,当洗涤血达300 ml时开始回输。麻醉诱导后至切皮前输注负荷剂量抑肽酶100万单位,术中静脉输注100万单位,总量达200万单位;对照组不使用抑肽酶。分别于开放静脉后(T1,基础值)、洗涤血回输后30min(T2)、术毕(T3)抽取中心静脉血,用流式细胞仪测定中性粒细胞表面CD11b和CD18的表达并进行白细胞和中性粒细胞计数。对洗涤后回输前血也取标本测定中性粒细胞表面CD11b和CD18的表达。结果与基础值比较,洗涤血的中性粒细胞表面CD11b和CD18表达均增加(P<0.01);对照组静脉血中性粒细胞表面CD11b和CD18表达于T2.3时增加(P<0.01),抑肽酶组CD11b表达于T2时增加(P <0.05);与对照组比较,抑肽酶组T2,3上述两指标降低(P<0.05)。与基础值比较,两组白细胞计数及对照组中性粒细胞计数在T2,3增加,抑肽酶组中性粒细胞计数在T2时增加(P<0.01);与对照组比较,抑肽酶组中性粒细胞计数在T3时降低(P<0.05)。结论抑肽酶对自体血回输脊柱矫形术病人术中炎性反应有一定的抑制作用。     

乌司他丁预处理对CPB下心脏瓣膜置换术患者鱼精蛋白诱发肺损伤的影响

目的 评价乌司他丁预处理对CPB下心脏瓣膜置换术患者鱼精蛋白诱发肺损伤的影响.方法 择期CPB下行心脏瓣膜置换术患者60例,性别不限,年龄21～59岁,心功能分级Ⅱ或Ⅲ级,ASA分级Ⅱ或Ⅲ级.采用随机数字表法,将患者分为3组(n=20):鱼精蛋白中心静脉给药对照组(C1组)、鱼精蛋白升主动脉给药对照组(C2组)和乌司他丁预处理组(U组).U组于气管插管后至上腔静脉和下腔静脉阻断前10 min经中心静脉输注乌司他丁20 000 U/kg.3组脱离CPB后10 min时均经8 min给予鱼精蛋白4 mg/kg;C1组及U组经右颈内静脉给药,C2组经主动脉根部给药.分别于给予鱼精蛋白前5 min和给予鱼精蛋白后15 min时采集左心房和右心房血样,进行血小板计数(Plt)和中性粒细胞计数(PMN),测定血浆血栓烷B2(TXB2)、6-酮-前列腺素F1α(6-keto-PGF1α)的浓度;采集左心房血样,测定TNF-α、IL-1、IL-8、CD1 1b/CD18、C3a、C5a、SOD和MDA的水平,进行血气分析,测定肺泡-动脉氧分压差(A-aDO2),计算呼吸指数(RI)和氧合指数(OI),并记录肺动脉压(PAP).结果 与右心房血比较,C1组给予鱼精蛋白后15 min时左心房血Plt和PMN降低,血浆TXB2浓度升高,C2组和U组血浆6-keto-PGF1α、SOD水平升高(P＜0.05);与C1组比较,C2组和U组给予鱼精蛋白后15 min时Ph、PMN、血浆6-keto-PGF1α浓度升高,血浆TXB2、TXB2/6-keto-PGF1α、TNF-α、IL-1、IL-8、C3a、C5a、MDA水平、PAP、A-aDO2和RI降低,CD1 1b/CD18表达下调,OI升高(P＜0.05);U组和C2组间上述指标差异无统计学意义(P＞0.05).结论 乌司他丁预处理可抑制CPB下心脏瓣膜置换术患者鱼精蛋白诱发肺损伤,其作用与经主动脉途径给予鱼精蛋白相似.     

乌司他丁对心肺转流心内直视术中细胞因子平衡和心肌细胞凋亡的影响

目的探讨乌司他丁对心肺转流(CPB)心内直视术患者细胞因子平衡和心肌细胞凋亡的影响。方法20例择期行二尖瓣置换术患者,随机均分为乌司他丁组(U组)和对照组(C组)。U组给予乌司他丁100万U,其中1万U于转机前静注作过敏试验,99万U加入预充液中;C组用生理盐水代替。于转机前(T0)、转机30min(T1)、CPB停止即刻(T2)、CPB停止后2h(T3)、6h(T4)和24h(T5)采集动脉血,测定血浆肿瘤坏死因子α(TNF-α)、白细胞介素-6(IL-6)、白细胞介素-8(IL-8)和白细胞介素-10(IL-10)浓度。采用TUNEL法测定两组CPB前和CPB停止后30min右心房的心肌凋亡细胞。结果U组T2~T5时的IL-6、IL-8和TNF-α浓度明显低于C组(P<0·01),而IL-10浓度明显高于C组(P<0·01)。CPB停止后30min,U组心肌细胞的凋亡指数明显低于C组(P<0·05)。结论乌司他丁抑制CPB期间TNF-α、IL-6和IL-8的释放,促进IL-10的释放,有利于细胞因子反应平衡的调节;乌司他丁通过抑制细胞凋亡,减少心肌细胞的死亡,可有效的保护心肌。     

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.