基于增强CT影像组学鉴别胸腺瘤组织学分型

目的 观察基于增强CT影像组学鉴别胸腺瘤组织学分型的价值。方法 回顾性分析226例经病理证实的胸腺瘤患者,按7∶3比例将其分为训练集(n=159)及测试集(n=67);利用最大相关最小冗余(mRMR)及最小绝对收缩和选择算子(LASSO)算法筛选最佳影像组学特征,构建鉴别胸腺瘤组织学分型的影像组学模型;以单因素及多因素logistic回归分析筛选鉴别胸腺瘤组织学分型相关的临床及CT表现,构建临床模型和联合影像组学特征及临床、CT特征的影像组学列线图。绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),评价3种模型鉴别胸腺瘤组织学分型的效能并比较其差异,评价影像组学列线图的临床价值。结果 最终基于增强动脉期及静脉期CT筛选出19个最佳影像组学特征,以建立影像组学模型。临床模型由患者年龄、重症肌无力、病灶CT表现形态、侵犯邻近组织及动脉期CT值构成。训练集中,影像组学列线图及影像组学模型区分低危组胸腺瘤与高危组胸腺瘤的AUC (0.91、0.89)均高于临床模型(0.79,Z=3.62、2.49,P均＜0.05),而影像组学列线图与影像组学模型AUC差异无统计学意义(Z=1.54,P=0.12);3种模型在测试集中的AUC差异均无统计学意义(P均＞0.05)。阈值概率为0.1~1.0时,影像组学列线图的临床获益均大于临床模型及影像组学模型。结论 基于增强CT影像组学模型和基于临床、CT表现及影像组学特征的影像组学列线图均有利于鉴别胸腺瘤组织学分型,后者临床获益更高。     

血管内介入治疗缺血性脑卒中后脑内高密度影与出血转化的关系

目的 采用双源CT量化评价经血管内介入治疗缺血性脑卒中(CIS)后脑内高密度影,探讨其与出血转化的关系。方法 回顾性分析167例CIS患者经介入治疗后即刻颅脑双能量CT资料,根据术后24~72 h CT平扫或MR检查结果分为出血组(n=42)及无出血组(n=125),比较组间患者临床资料、脑内新发高密度影CT值及其体积的差异,分析影响出血转化的因素,评价CT参数与出血转化的相关性;绘制受试者工作特征曲线,评价各指标判断出血转化的效能。结果 出血组患者高血脂比例低于无出血组(P<0.05);出血组新发高密度影占比、高密度影的最大CT值、平均CT值及其体积均大于无出血组(P均<0.001)。高血脂病史为出血转化的保护因素(P<0.05);新发高密度影最大CT值、平均CT值及其体积为出血转化的危险因素(P均<0.001),且均与出血转化呈正相关(P均<0.001),以之判断血管内介入治疗CIS后患者发生出血转化的曲线下面积(AUC)分别为0.950、0.910及0.888,联合应用新发高密度影最大CT值+体积、平均CT值+体积及最大CT值+平均CT值+体积判断发生出血转化的AUC分别为0.944、0.923及0.941。结论 血管内介治疗CIS后即刻CT显示缺血区新发高密度影的最大CT值、平均CT值及其体积均与术后出血相关。     

CT影像组学联合CT特征预测肺亚实性结节侵袭性

目的 观察CT影像组学联合CT特征预测肺亚实性结节侵袭性的价值。方法 回顾性分析170例肺亚实性结节患者资料,包括6例非典型腺瘤样增生(AAH)、12例原位腺癌(AIS)、58例微浸润性腺癌(MIA)及94例浸润性腺癌(IAC),将AAH、AIS和MIA归为非侵袭组、IAC归为侵袭组。按7∶3比例将患者分为训练集(n=119,含5例AAH、9例AIS、36例MIA及69例IAC)和验证集(n=51,含1例AAH、3例AIS、22例MIA及25例IAC)。采用单因素及logistic回归分析训练集患者一般资料及病灶CT表现,筛选预测肺亚实性结节侵袭性的独立危险因素并建立CT模型;基于训练集提取及筛选病灶最佳影像组学特征,以之构建影像组学模型。基于CT模型及影像组学模型构建联合模型,并以列线图将其可视化。绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),基于验证集评估各模型诊断效能;以校准曲线评价联合模型的校准程度。结果 CT所示结节长径和最大CT值为预测肺亚实性结节为IAC的CT相关独立危险因素,以之构建CT模型。基于训练集筛选出6个最佳影像组学特征并构建影像组学模型。CT模型、影像组学模型及联合模型预测验证集肺亚实性结节侵袭性的AUC分别为0.772、0.785及0.869;联合模型的AUC高于CT模型(Z=2.336,P=0.019)而与影像组学模型差异无统计学意义(Z=1.925,P=0.054),其预测结果与实际结果的一致性较高。结论 CT影像组学联合CT特征可有效预测肺亚实性结节侵袭性。     

基于临床、超声及基因特征列线图预测甲状腺乳头状癌侵袭性

目的 观察基于临床、超声及基因特征的列线图预测甲状腺乳头状癌(PTC)侵袭性的价值。方法 回顾性分析207例PTC患者,根据术后病理所示病灶侵及甲状腺被膜和/或发生患侧颈部淋巴结转移与否分为侵袭组(n=130)及非侵袭组(n=77);对比2组临床、超声及基因特征,筛选PTC侵袭性的危险因素,并以之建立列线图模型,观察其预测PTC侵袭性风险的价值。结果 2组患者年龄,结节最大径、与被膜直线距离、微钙化、数目和分布,以及BRAF V600E基因检测差异均有统计学意义(P均＜0.05)。结节最大径＞1 cm[OR=2.540,95%CI(1.341,4.810),P=0.004]、微钙化[OR=2.276,95%CI(1.203,4.308),P=0.011]、双侧叶多灶[OR=3.414,95%CI(1.578,7.385),P=0.002]及突变型BRAF V600E[OR=2.663,95%CI(1.147,6.182),P=0.023]为PTC侵袭性的独立危险因素。列线图模型预测PTC侵袭性的曲线下面积为0.747[95%CI(0.679,0.815)]。结论 以基于结节最大径、微钙化、数目和分布及BRAF V600E基因检测的列线图预测PTC侵袭性具有一定价值。     

吞咽造影录像检查定量评价脑卒中患者吞咽功能改变

目的 观察吞咽造影录像检查(VFSS)定量评价脑卒中患者吞咽功能改变的价值。方法 回顾性分析107例脑卒中患者的VFSS资料,并将其分为吞咽功能正常组(n=19)、口期吞咽障碍组(n=14)和咽期吞咽障碍组(n=74);比较3组间舌骨喉复合体VFSS相关参数的差异,包括舌骨及喉部的前移幅度和上移幅度、舌骨喉复合体咽期启动延迟时间及运动时间、会厌折返功能及环咽肌功能。结果 3组间舌骨前移幅度及舌骨喉复合体咽期启动延迟时间总体差异均有统计学意义(F＝3.788、P＝0.026,H＝30.229、P＜0.001),咽期吞咽障碍组舌骨前移幅度小于吞咽正常组(P＝0.026),舌骨喉复合体咽期启动延迟时间大于吞咽功能正常组及口期吞咽障碍组(P均＜0.001);3组间其余参数差异均无统计学意义(P均＞0.05)。咽期吞咽障碍组中,56例会厌折返障碍,47例环咽肌功能障碍,占比均高于其余2组(P均＜0.05)。结论 VFSS有助于量化评估脑卒中患者吞咽功能改变;脑卒中后咽期吞咽障碍者舌骨前移幅度缩短,舌骨喉复合体启动时间延迟,易出现会厌折返障碍和环咽肌功能障碍。     

下肢能谱CT静脉成像最佳重建能级和自适应统计迭代重建权重

目的 探讨下肢能谱CT静脉成像(CTV)最佳重建能级和自适应统计迭代重建(ASIR-V)权重。方法 收集82例接受下肢CTV的疑诊下肢深静脉血栓(DVT)患者,根据扫描模式分为常规120 kVp组(A组,n=42)和能谱扫描组(B组,n=40);将A组CTV图像重建为40% ASIR-V图像,将B组图像分别重建为40、50、60及70 keV结合40%、60%及80% ASIR-V图像。针对所获13种图像,比较下腔静脉、股静脉及腘静脉CT值、噪声(SD)、信噪比(SNR)及对比度噪声比(CNR),并对静脉和血栓显示情况进行主观评估。结果 13种图像之间,各静脉CT值、SD、SNR及CNR差异均有统计学意义(P均<0.001)。B组12种图像中,ASIR-V权重一致时,随keV能级增加,各静脉CT值、SD、SNR及CNR均降低;keV能级水平一致时,随ASIR-V权重增加,SD减小、SNR和CNR增加。B组40、50、60 keV图像中的各静脉CT值均高于A组(P均<0.05);40、50、60、70 keV结合60%、80% ASIR-V图像中,除70 keV结合60% ASIR-V图像外,其余图像各静脉SNR和CNR均高于A组(P均<0.05)。13种图像中,50 keV结合40%、60%、80% ASIR-V图像显示静脉主观评分最高(P均<0.05);50 keV结合60% ASIR-V图像显示DVT清晰度≥4分者占比最高。结论 50 keV结合60% ASIR-V为能谱下肢CTV成像最佳重建方法。     

超声引导下经皮细针穿刺抽吸及穿刺活检诊断胰腺占位性病变

目的 观察超声引导下经皮细针穿刺抽吸(FNA)及穿刺活检(CNB)诊断胰腺占位性病变的价值。方法 回顾性分析112例接受超声引导下FNA和/或CNB的胰腺占位性病变患者、共114组穿刺病理,根据穿刺方式将其分为FNA组(n=53)及CNB组(n=61)。以手术病理或临床随访为金标准,对比组间患者一般资料、穿刺及诊断效能差异,分析影响穿刺并发症发生的因素,评价FNA及CNB的价值。 结果 114组病理中,113组(99.12%,113/114)取材满意;FNA组取材满意率为98.11%(52/53),CNB组为100%(61/61)。穿刺过程中38例出现轻、中度疼痛、1例一过性晕厥,未见严重并发症。FNA组并发症及疼痛发生率均低于CNB组(P均<0.05),FNA诊断胰腺占位性病变的准确率和敏感度亦低于CNB(P均<0.05)。logistic回归分析显示,年龄和穿刺方式是并发症的独立影响因素。结论 超声引导下经皮FNA及CNB均可安全有效地诊断胰腺占位性病变;CNB诊断准确率及敏感度较高,而FNA并发症率较低。     

Orsrio生物可降解聚合物支架与第2代耐用聚合物支架预防心肌梗死:Meta分析

目的 采用meta分析对比观察Orsiro生物可降解聚合物西罗莫司洗脱支架(Orsiro-SES)与第2代耐用聚合物支架(DPS)预防心肌梗死(MI)的效果。方法 检索PubMed、Embase、Cochrane Library、中国知网、万方医学网和维普数据库自建库至2022年9月关于Orsiro-SES和第2代DPS的随机对照研究;依据纳入及排除标准筛选文献,利用RevMan 5.3软件分析Orsiro-SES与第2代DPS预防MI效果。结果 纳入20篇文献,共13 247例接受Orsiro-SES(Orsiro-SES组,n=6 809)或第2代DPS(DPS组,n=6 438)植入术患者。支架植入后1、2、3、5年, 组间MI发生率差异均无统计学意义(OR=0.86、0.85、0.82、0.91,P=0.17、0.18、0.10、0.37)。支架植入后1、2、5年组间靶血管MI发生率差异均无统计学意义(OR=0.83、0.84、0.94,P=0.12、0.21、0.64);支架植入后3年,Orsiro-SES组靶血管MI发生率低于DPS组(OR=0.76,P=0.04)。结论 Orsiro-SES与第2代DPS预防MI效果相当,前者或对预防靶血管MI具有一定优势。     

经颈内静脉植入输液港:导管尖端处于不同位置时1年内并发症发生率与导管通畅率

目的 对比观察经颈内静脉（IJV）入路植入完全植入式静脉输液港（TIVAP）后,导管尖端处于不同位置时1年内并发症发生率及导管通畅率。方法 回顾性分析2 104例接受经IJV入路植入TIVAP的肿瘤患者,将接受经右IJV入路者（R组,n=1 903）分为导管尖端位于右心房上部［即上腔静脉（SVC）与右心房交界（CAJ）下方0.5～1.0 cm亚组（R1亚组,n=376）］与位于SVC下1/3至CAJ间亚组（R2亚组,n=1 527）,将接受经左IJV入路者（L组,n=201）相应分为L1亚组（n=64）及L2亚组（n=137）;记录2组内各亚组患者基本资料、植入TIVAP 1年内并发症发生率及导管通畅率,并进行亚组间比较。结果 2组内亚组间患者性别、年龄、临床诊断及肿瘤分期,以及气胸/血气胸、局部皮肤损伤、TIVAP感染、导管相关性血栓、药物外渗、导管移位及心律失常等并发症发生率差异均无统计学意义（P均＞0.05）。R1（94.15%）与R2亚组（93.78%）（χ²=0.069,P=0.793）、L1（98.44%）与L2亚组（89.78%）1年内导管通畅率差异均无统计学意义（Yates连续性校正χ²=3.563,P=0.059）。结论 经左或右IJV入路植入TIVAP后,导管尖端位于右心房上部与SVC下1/3与CAJ之间时,1年内并发症发生率及导管通畅率均无明显差异。     

CT鉴别诊断原发性与继发性肺淋巴瘤

目的 观察CT鉴别诊断原发性肺淋巴瘤(PPL)与继发性肺淋巴瘤(SPL)的价值。方法 回顾性分析接受胸部CT平扫的28例PPL(PPL组)及27例SPL(SPL组)患者,其中18例PPL及16例SPL接受增强扫描,观察病变CT表现;采用单因素分析及多因素logistic回归分析其CT平扫相关征象,筛选鉴别PPL与SPL的独立预测因素,并绘制受试者工作特征(ROC)曲线,评估各指标单独及联合鉴别诊断效能。结果 PPL及SPL均可表现为肺结节、肿块或实变。PPL多为分布于肺外周的单发病变,可见支气管充气征伴扩张;SPL常为多发病变,多伴纵隔/肺门淋巴结肿大及胸腔积液(P均＜0.05)。接受增强CT的18例PPL与16例SPL之间,病变强化方式差异有统计学意义(P=0.04),强化程度及是否存在血管造影征差异均无统计学意义(P均＞0.05)。病变数目、充气支气管征伴扩张及胸腔积液是鉴别PPL与SPL的独立预测因素,其鉴别PPL与SPL的曲线下面积(AUC)分别为0.74、0.68、0.69,三者联合诊断的AUC为0.91。结论 CT所见病变数目、充气支气管征伴扩张及胸腔积液有助于鉴别PPL及SPL。     

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.