改良衰弱指数对胸腔镜肺叶切除术老年患者术后肺部并发症的预测价值

目的 评估改良衰弱指数（mFI）对胸腔镜肺叶切除术老年患者术后肺部并发症（PPCs）的预测价值。
方法 回顾性收集胸腔镜肺叶切除术老年患者资料674例,男357例,女317例,年龄65～80岁,BMI<30 kg/m²,ASA Ⅰ—Ⅲ级。评估术后住院期间的PPCs发生情况,根据是否发生PPCs将患者分为两组：PPCs组和非PPCs组。将单因素回归分析中P＜0.1的因素纳入多因素Logistics回归分析,筛选PPCs的独立危险因素。通过受试者工作特征曲线下面积（AUC）评价mFI对PPCs的预测价值。
结果 有108例（16%）患者发生PPCs。单因素分析显示,与非PPCs组比较,PPCs组ASA分级、ARISCAT评分和mFI明显升高（P<0.05）,Hb<100 g/L及术前SpO₂ <95%比例明显升高（P<0.05）,单肺通气时间明显延长（P<0.05）。多因素Logistic回归分析显示,术前mFI升高（OR=2.28,95% CI 1.75～4.52,P=0.007）是PPCs发生的独立危险因素。ROC曲线显示,mFI的预测效能（AUC=0.90,95%CI 0.87～0.93,P=0.001）优于ARISCAT评分（AUC=0.81,95%CI 0.70～0.93,P=0.036）。
结论 术前mFI升高是老年肺叶切除手术患者发生PPCs的独立危险因素,应积极制定以改善衰弱为导向的围术期干预措施,以期降低PPCs的发生率。     

腰椎术后手术部位感染的危险因素分析及列线图模型建立

目的 探讨开放性腰椎后入路手术患者术后手术部位感染（SSI）的相关危险因素,并建立与验证术后SSI的列线图风险预测模型。
方法 选择2017年1月至2021年12月行开放性腰椎后入路手术的患者920例,男422例,女498例,年龄≥18岁,BMI≥18.5 kg/m²,ASA Ⅰ—Ⅳ级。将患者按照7∶3随机分为训练数据集和验证数据集,并基于训练数据集建立预测模型。采用Lasso回归结合二元Logistic回归最终筛选的预测因素构建列线图模型。使用C指数、校准曲线及决策曲线（DCA）等对列线图模型的区分度、校准度及临床适用度进行分析评估。
结果 本研究中发生SSI的有17例（1.85%）,训练集中有10例（1.55%）,验证集中有7例（2.54%）。列线图模型中的预测因素包括术前低白蛋白血症（OR=36.928,95%CI 6.585～235.997,P<0.001）、肥胖（BMI≥28.0 kg/m²）（OR=4.994,95%CI 1.202～24.781,P=0.032）和术后3天内切口渗出（OR=6.133,95%CI 1.473～28.775,P=0.014）。该模型的C指数为0.879（95%CI 0.760～0.998）。校准曲线显示良好的一致性。DCA曲线分析显示当SSI发生风险阈值＞1%时,该列线图更具临床价值。
结论 术前低白蛋白血症、肥胖及术后3 d内切口渗出是行开放性腰椎后入路患者术后发生SSI的危险因素,基于以上危险因素构建的风险预测模型可以较好地预测术后SSI的发生。     

复发性鼻咽癌患者鼻内镜手术围术期输血的危险因素及预测模型的建立

目的：筛选复发性鼻咽癌患者鼻内镜手术围术期输血的危险因素,建立列线图预测模型。
方法：回顾性分析2021年1月至2023年5月行鼻内镜手术的262例复发性鼻咽癌患者的临床资料,根据围术期是否输血分为两组：未输血组和输血组。通过单因素和多因素Logistic回归分析筛选围术期输血的危险因素,构建列线图预测模型,绘制受试者工作特征（ROC）曲线并计算曲线下面积（AUC）。
结果：有46例（17.6%）患者在鼻内镜手术围术期输血。多因素Logistic回归分析显示,术前Hb浓度70～<100 g/L（OR=6.178,95%CI 2.271～16.805,P<0.001）、术前白蛋白浓度25～<35 g/L（OR=2.126,95%CI 1.021～4.424,P=0.044）、手术分型Ⅲ或Ⅳ型（OR=4.725,95%CI 1.634～13.584,P=0.004）是复发性鼻咽癌患者鼻内镜手术围术期输血的独立危险因素。列线图模型的AUC为0.769（95%CI 0.701～0.838）,敏感性为67.6%,特异性为76.1%。
结论：复发性鼻咽癌患者鼻内镜手术围术期输血的独立危险因素是术前Hb浓度70～<100 g/L、术前白蛋白浓度25～<35 g/L、手术分型Ⅲ或Ⅳ型,基于以上危险因素建立的列线图模型对围术期输血有良好的预测能力。     

高龄患者术后严重并发症的危险因素分析

目的 探讨高龄患者择期手术后严重并发症的危险因素。
方法 选择行骨科、妇科、胃肠外科手术的患者332例，男123例，女209例，年龄≥80岁。根据患者是否发生术后严重并发症分为两组：严重并发症组和对照组。记录一般情况、术前合并症、实验室检查、手术和麻醉情况。采用多因素Logistic回归分析术后发生严重并发症的危险因素。
结果 有43例（13.0%）患者发生术后严重并发症。与对照组比较，严重并发症组BMI和术中最低MAP值明显降低，ASA分级、改良Goldman分级、合并控制不良糖尿病比例明显升高，手术开始时间明显延迟（P<0.05）。Logistic回归分析显示，术后严重并发症的危险因素为BMI降低（OR=1.145，95%CI 1.042～1.261，P=0.016）、ASA分级升高（OR=3.587，95%CI 1.210～10.632，P=0.021）、改良Goldman分级升高（OR=7.175，95%CI 2.355～21.861，P=0.001）、控制不良的糖尿病（OR=2.202，95%CI 1.041～4.657，P=0.039）、手术开始时间延迟（OR=2.611，95%CI 1.242～5.491，P=0.011）和术中最低MAP值降低（OR=1.068，95%CI 1.116～1.119，P=0.009）。
结论 高龄患者择期手术后严重并发症发生的独立危险因素为BMI降低、ASA分级和改良Goldman分级升高、控制不良的糖尿病、手术开始时间延迟、术中最低MAP值降低。     

全麻患者术后麻醉重症监护室中新发下肢深静脉血栓的危险因素

目的 筛选全麻术后转入麻醉重症监护室（AICU）的患者新发下肢深静脉血栓（DVT）的危险因素。
方法 回顾性收集2022年5—8月择期行全麻下手术后带气管插管转入AICU的患者192例，男105例，女87例，年龄18～85岁，BMI 18～31 kg/m²，ASA Ⅱ或Ⅲ级。收集患者基线资料、麻醉手术资料及实验室检查资料。根据入AICU 6 h内的超声结果是否有新发DVT将患者分为两组：DVT组和非DVT组。采用多因素Logistic回归分析筛选AICU中患者术后6 h内新发DVT的危险因素及其95%可信区间（CI）。
结果 全麻术后在AICU新发DVT的患者有64例（33.3%），均为小腿肌间静脉血栓（CMVT）。多因素Logistic回归分析结果显示，术前心律失常（OR=2.236，95%CI 1.011～4.943，P=0.047）、术前血小板计数高（OR=1.006，95%CI 1.002～1.010，P=0.007）、术前D-二聚体浓度高（OR=1.203，95%CI 1.046～1.383，P=0.010）、术中低血压（OR=1.010，95%CI 1.002～1.019，P=0.020）和术中应用去甲肾上腺素（OR=3.796，95%CI 1.697～8.492，P=0.001）是全麻术后AICU中患者新发DVT的危险因素；阿司匹林规律服用史（OR=0.176，95%CI 0.060～0.518，P=0.002）是其保护因素。
结论 术前心律失常、术前血小板计数高、术前D-二聚体浓度高、术中低血压及术中应用去甲肾上腺素是全麻手术后AICU患者6 h内新发DVT的危险因素。     

心脏外科术后肺部并发症的危险因素

目的 分析心脏外科术后肺部并发症（PPCs）的危险因素。
方法 回顾性分析2017年1月至2020年12月行心脏外科手术患者的病历资料,根据患者是否发生PPCs分为两组：并发症组（n=271）和无并发症组（n=331）。提取性别、年龄、ASA分级、高血压病史、糖尿病病史、慢性阻塞性肺疾病（COPD）病史、脑血管病史、手术史、术前房颤、肺动脉高压、心功能指标、凝血功能指标、肝肾功能指标、乳酸脱氢酶、血糖、手术时间、心肺转流（CPB）时间、术中药物使用情况、术中输血量、术中液体输注量、术中尿量、术后肝肾功能指标、心电图等临床指标,采用单因素分析评估上述指标与PPCs的相关性。将组间差异有统计学意义的单因素纳入Logistic回归模型,分析心脏外科PPCs的独立危险因素。
结果 与无并发症组比较,并发症组年龄、左心房直径明显增大,ASA分级、糖尿病和术前房颤比例、肺动脉高压分级、淋巴细胞含量、尿素氮、球蛋白、总蛋白、乳酸脱氢酶、AST浓度明显升高（P＜0.05）;手术时间和CPB时间明显延长,术中输注血小板比例明显升高,晶体液输注量明显增多（P＜0.05）;术后尿素氮、肌酐浓度明显升高,引流量明显增多（P<0.05）。多因素Logistic回归分析结果显示,ASA Ⅳ级（OR=1.886,95%CI 1.030～3.456,P=0.040）、术前房颤（OR=1.526,95%CI 1.031～2.257,P=0.034）、CPB时间≥2 h（OR=2.418,95%CI 1.692～3.456,P＜0.001）是心脏外科PPCs的独立危险因素。
结论 术前房颤、ASA Ⅳ级、CPB时间≥2 h是心脏外科PPCs发生的独立危险因素。     

术前衰弱对老年患者心脏手术后肺部并发症的预测价值

目的 探讨术前衰弱对于老年患者心脏手术后肺部并发症（PPCs）的预测价值。
方法 选择2022年7月至2023年1月行择期开胸心脏手术老年患者162例,男109例,女53例,年龄65～83岁,BMI 18～36 kg/m²,ASA Ⅱ—Ⅳ级。根据是否发生PPCs将患者分为两组：PPCs组（n=57）和非PPCs组（n=105）。收集一般资料、吸烟史、饮酒史、EuroSCORE Ⅱ、衰弱情况、慢性合并症（高血压、糖尿病、心肌梗死、肺动脉高压、慢性阻塞性肺疾病、睡眠呼吸暂停综合征等）、Hb、肌酐、白蛋白、肺功能指标、左心室射血分数、手术类型、手术时间、主动脉钳夹时间和心肺转流时间。将单因素回归分析中P<0.2及具有临床意义的因素纳入多因素Logistic回归分析,通过受试者工作特征（ROC）曲线下面积（AUC）比较Fried衰弱量表和EuroSCOREⅡ对PPCs的预测效能。
结果 有57例（35.2%）患者发生PPCs。多因素Logistic回归分析显示,衰弱（OR=3.14,95%CI 1.05～9.37,P<0.05）和EuroSCORE Ⅱ（OR=2.16,95%CI 1.01～4.60,P<0.05）是发生PPCs的危险因素。Fried衰弱量表的预测效能（AUC=0.76,95%CI 0.68～0.82）明显高于EuroSCORE Ⅱ （AUC=0.65,95%CI 0.57～0.72）（P<0.05）。
结论 术前衰弱是老年患者心脏手术后肺部并发症的独立危险因素,与传统的风险预测指标EuroSCORE Ⅱ比较,Fried衰弱量表的预测效能更佳。     

胸腔镜肺切除术患儿术后肺部并发症的危险因素

目的 分析患儿胸腔镜下肺切除术后肺部并发症（PPCs）的危险因素。
方法 回顾性分析行胸腔镜肺切除术566例患儿的临床资料，男334例，女232例，年龄≤6岁，ASA Ⅰ或Ⅱ级。根据患者术后7 d内是否发生PPCs分为两组：PPCs组和非PPCs组。将单因素分析中P≤0.2以及临床认为可能有意义的协变量纳入多因素Logistic回归分析。绘制受试者工作特征（ROC）曲线并计算曲线下面积（AUC）。
结果有123例（21.7%）发生PPCs。多因素Logistic回归分析显示，单肺通气时间长、单肺通气时呼吸频率快、手术医师经验不足是PPCs的独立危险因素，术中最大PEEP升高（最大为7 cmH₂O）是保护因素。预测模型为Logit（P）=-4.410+0.006×单肺通气时间+0.063×单肺通气呼吸频率+0.569×手术医师经验不足（赋值为1）-0.160×最大PEEP值，该模型预测患儿胸腔镜肺切除术PPCs发生率的AUC为0.682（95%CI 0.631～0.734），敏感性76.4%，特异性69.6%。
结论单肺通气时间长、单肺通气时呼吸频率快、手术医师经验不足是患儿胸腔镜肺切除术PPCs的危险因素，术中最大PEEP升高是PPCs的保护因素。     

胰十二指肠切除术后手术部位感染的危险因素分析

目的 分析引起胰十二指肠切除术（PD）后手术部位感染（SSI）的危险因素。
方法 回顾性分析2015年1月至2018年12月择期行PD 1 688例患者的临床资料,男1 047例,女641例,年龄18~87岁,BMI 14~40 kg/m²,ASA Ⅰ—Ⅲ级。记录性别、年龄、BMI、ASA分级、术前合并症、术前检验结果、影像学资料、麻醉时间、手术时间、手术方式、麻醉用药、患者术后去向等。根据术后是否发生SSI将患者分为两组：感染组（n=301）和非感染组（n=1 387）。采用单因素与多因素Logistic回归分析PD术后发生SSI的危险因素。
结果 单因素分析结果显示,感染组BMI、丙氨酸氨基转移酶＞100 U/L的比例、血清白蛋白、白细胞计数及术后进入ICU的比例均明显高于非感染组（P＜0.05）,手术时间以及麻醉时间明显长于非感染组（P＜0.05）。多因素Logistic回归分析结果显示,BMI (每增加1 kg/m²,OR=1.075, 95%CI 1.034~1.118,P＜0.001)、术前丙氨酸氨基转移酶水平＞100 U/L (OR=1.317, 95%CI 1.013~1.707, P=0.039)、术前白细胞计数＞10×10⁹/L (OR=1.920, 95%CI 1.160~3.089, P=0.009)及术后进入ICU (OR=2.317, 95%CI 1.796~2.994, P＜0.001)是PD术后SSI发生的独立危险因素。
结论 BMI每增加1 kg/m²、术前白细胞>10×10⁹/L、丙氨酸氨基转移酶水平>100 U/L以及术后进入ICU是胰十二指肠切除术后发生手术部位感染的危险因素。     

高原患者髋关节置换术后谵妄的危险因素分析

目的 探讨全麻下行髋关节置换术的高原患者发生术后谵妄（POD）的危险因素。
方法 选择择期行全麻髋关节置换术的高原患者1 010例,男373例,女637例,年龄24～76岁,BMI 19.0～34.7 kg/m²,ASA Ⅰ—Ⅲ级。根据术后7 d内是否发生谵妄分为两组：POD组和非POD组,采用多因素Logistic回归分析确定行髋关节置换术的高原患者发生POD的相关危险因素。
结果 术后7 d内有120例（11.9%）患者发生POD。多因素Logistic回归分析显示,年龄（每增加10岁,OR=2.106,95%CI 1.616～2.745,P<0.001）、脑梗死病史（OR=9.712,95%CI 3.620～26.055,P<0.001）、术后中重度疼痛（OR=6.826,95%CI 2.991～15.578,P<0.001）以及常居海拔高度3 500～4 500 m（OR=2.844,95%CI 1.448～5.587,P=0.002）和高原红细胞增多症（OR=5.374,95%CI 3.900～7.404,P<0.001）是发生POD的危险因素。
结论 年龄、脑梗死病史、术后中重度疼痛以及常居海拔高度3 500～4 500 m和高原红细胞增多症是高原患者全麻下髋关节置换发生POD的危险因素。     

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.     

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.     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.