颈髓损伤后气管切开影响因素的Meta分析

目的 :系统评价颈髓损伤后气管切开的影响因素,为制定颈髓损伤患者的呼吸道管理措施提供循证依据。方法:计算机检索Pubmed数据库、Embase生物医学数据库、Medline数据库、Cochrane图书馆、中国生物医学文献服务系统(CBM)、中国期刊全文数据库(CNKI)及万方数据资源系统,收集由建库至2018年2月公开发表的关于颈髓损伤后气管切开影响因素的研究文献。采用Rev Man 5.3软件进行Meta分析,用固定效应模型或随机效应模型进行数据合并,计算比值比(odds ratio,OR)/均数差(mean difference,MD)值和95%可信区间(confidence interval,CI)。用漏斗图来判定发表偏倚。结果 :经过文献筛选共纳入16篇文献,累计颈髓损伤患者9697例,气管切开率为18.3%(1773/9697)。Meta分析结果显示,在颈髓损伤患者中,男性[OR=1.29,95%CI(1.12,1.49),P=0.0004]、ASIA A级[OR=7.79,95%CI(5.28,11.50),P0.00001]、ASIA B级[OR=1.15,95%CI(1.13,2.02),P=0.005]、ASIA C级[OR=0.28,95%CI(0.20,0.41),P0.00001]、ASIA D级[OR=0.04,95%CI(0.02,0.09),P0.00001]、神经损伤水平(高位颈髓损伤)[OR=2.36,95%CI(1.51,3.68),P=0.0002]、损伤严重程度评分(ISS)[MD=8.97,95%CI(8.11,9.82),P0.00001]、格拉斯哥昏迷评分(GCS)≤8[OR=6.03,95%CI(2.19,16.61),P=0.0005]、合并胸部损伤[OR=1.78,95%CI(1.55,2.04),P0.00001]、呼吸系统并发症[OR=5.97,95%CI(4.03,8.86),P0.00001]因素与气管切开指标差异均有统计学意义。而患者年龄、高龄、合并脑损伤、吸烟史、车祸伤机制和跌落伤机制与气管切开无显著相关性(P0.05)。结论:当前证据表明,男性、ASIA分级A级或B级、神经损伤水平(高位颈髓损伤)、ISS、GCS≤8、合并胸部损伤、呼吸系统并发症是颈髓损伤后气管切开的危险因素,ASIA分级C级或D级是其保护性因素,应根据这些因素指导颈髓损伤患者行气管切开术。     

2012～2019年度956例创伤性脊髓损伤住院患者流行病学分析

目的 :分析我院创伤性脊髓损伤(traumatic spinal cord injury,TSCI)患者的流行病学特点及变化趋势。方法:回顾性分析2012年1月～2019年12月在我院住院治疗的956例TSCI患者的临床资料,收集患者性别、年龄、受伤原因、损伤部位及损伤程度等相关信息,按每两年时间段进行不同时间段的流行病学特点分析,探讨其变化规律。结果:956例患者中,男性670例(70.1%),女性286例(29.9%);年龄11～84岁(49.87±20.74岁)。常见受伤原因依次为坠落伤(54.3%)、交通事故(37.2%)、重物砸伤(3.4%),其他原因所致损伤(3.5%)。C1-C4颈髓损伤25.5%,C5-C8颈髓损伤27.4%,胸髓损伤31.5%,腰骶髓损伤15.6%。按ASIA分级:A级415例(43.5%),B级120例(12.5%),C级220例(23.0%),D级201例(21.0%)。完全四肢瘫154例,不完全四肢瘫352例,完全截瘫261例,不完全截瘫189例。2012～2013年267例(27.9%),2014～2015年235例(24.6%),2016～2017年229例(23.9%),2018～2019年225例(23.5%)。从2012～2013年到2016～2017年,坠落伤所致TSCI逐渐增多(由47.1%增至64.9%),且平均年龄逐渐增加(由45.70岁增至55.64岁);交通事故所致TSCI逐渐减少(由45.3%减少至22.6%)。结论:TSCI住院患者以颈脊髓损伤为主,男性多于女性;坠落伤所占比例呈上升趋势,而交通事故伤比例则逐渐减少。     

危重症患者高氯血症对急性肾损伤影响的Meta分析

目的 评价在重症监护室危重症患者中高氯血症对急性肾损伤的影响。方法 检索PubMed、Embase、Cochrane Library、Web of Science、中国知网、万方、维普数据库从建库至2022年9月29日公开发表的关于高氯血症与危重症患者结局相关的文献。利用文献提供的调整或未调整的优势比（OR）及95%置信区间（95%CI）统计量,应用R语言软件进行Meta分析。结果 共纳入文献15篇,包括29 005例患者。Meta分析结果显示危重症患者入住重症监护室后高氯血症发生率为43%(OR=0.43,95%CI:0.30～0.56),发生高氯血症的危重症患者急性肾损伤发生风险明显增加（OR=1.35,95%CI:1.10～1.64,P<0.01）,敏感性分析显示结果稳健。结论 危重症患者高氯血症与急性肾损伤发生有显著相关性。     

p16基因和p21基因表达异常与膀胱癌预后的Meta分析

目的探讨p16基因和p21基因表达异常对膀胱癌预后的影响.方法以“bladder carcinoma”或“bladder neoplasm”、“prognosis”、“p16”/“p21”和“膀胱癌”、“预后”等为检索词,检索Medline、PubMed、中国生物医学文献及中国学术期刊数据库有关p16基因和p21基因表达异常与膀胱癌预后的文献,应用Meta分析Dersimonian-Laird模型对这些文献进行综合定量评价.结果纳入Meta分析的19篇文献累计病例1584例,阳性率40.4%;其中p16基因表达异常12篇,累计病例975例,阳性率37.4%;p21基因异常表达7篇,累计病例609例,阳性率45.4%.p16基因表达异常、p21基因表达异常、p16基因和p21基因表达异常与膀胱癌预后的合并RH值分别为3.70（95%CI 3.42～3.99）、3.01（95%CI 2.81～3.21）和3.18（95%CI 3.01～3.35）.结论p16基因和p21基因表达异常是膀胱癌患者预后不良的生物标记物,有助于膀胱癌的治疗决策.     

腹腔镜胃袖状切除联合食管裂孔疝修补术治疗肥胖合并胃食管反流病疗效Meta分析

目的 评价腹腔镜胃袖状切除联合食管裂孔疝修补术（LSG+HHR）治疗肥胖合并胃食管反流病（GERD）的疗效。方法 计算机检索PubMed、EMbase、The Cochrane Library、万方数据、中国知网等数据库,按照纳入标准和排除标准筛选文献,提取纳入文献的相关数据,并对其进行方法学质量评价和Meta分析。结果 共纳入9篇文献、499例病人。Meta分析结果显示,LSG+HHR手术前后BMI（MD=11.92,95%CI 12.68～13.15,P<0.001）、GERD症状（OR=3.35,95%CI 1.15～9.75,P=0.03）以及术后GERD症状缓解率（OR=0.53,95%CI 0.19～0.87,P=0.002）比较差异有统计学意义。结论 LSG+HHR可改善GERD病症,也可预防无症状病人中新GERD症状的出现,术后GERD症状缓解提高明显。     

经皮肝穿刺胆囊引流联合腹腔镜胆囊切除术与急诊腹腔镜胆囊切除术对中度急性胆囊炎疗效的Meta分析

目的 系统评价经皮肝穿刺胆囊引流联合腹腔镜胆囊切除术与急诊腹腔镜胆囊切除术的治疗方案选择对中度急性胆囊炎的治疗效果及不良反应。方法 检索PubMed、EMBASE、Web of Science、Cochrane Library、中国期刊全文数据库（CNKI）、维普中文科技期刊数据库（VIP）、中国生物医学文献数据库（CBM）、万方数据库中有关经皮肝穿刺胆囊引流术联合腹腔镜胆囊切除术与急诊腹腔镜胆囊切除术对中度急性胆囊炎治疗的随机对照试验研究，检索时限为建库之日起至2018 年5 月。所有检索出并纳入研究的文献均由2 名研究者进行独立的文献质量评价和数据提取。文献数据统一采用RevMan 5.3 软件进行分析，对无法进行Meta分析的文献指标进行描述性分析。结果 总共纳入11 篇文献，包括1 283 例中度急性胆囊炎患者。Meta分析结果显示：在发生中度急性胆囊炎时经皮肝穿刺胆囊引流术联合腹腔镜胆囊切除术与急诊腹腔镜胆囊切除术相比可降低中转开腹率（RR 0.45，95%CI 0.23～0.85，P=0.01），减少术中出血量（SMD -41.50，95%CI -51.18～-31.82，P＜0.001）和术后并发症发生率（RR 0.50，95%CI0.31～0.81，P＜0.001），但两种治疗方式在手术时间上的差异并无统计学意义（SMD 1.10，95%CI -4.27～6.47，P=0.69）。此外，经皮肝穿刺胆囊引流术联合腹腔镜胆囊切除术比急诊腹腔镜胆囊切除术能够更好地缩短患者术后住院时间（SMD -1.21，95%CI -2.17～-0.25，P=0.01）。结论 在治疗中度急性胆囊炎时，经皮肝穿刺胆囊引流术联合腹腔镜胆囊切除术比急诊腹腔镜胆囊切除术具有更好的效果。     

IPC和低分子肝素对亚洲胃肠恶性肿瘤患者术后静脉血栓栓塞症预防效果的Meta分析

目的：评价间歇性充气加压装置（IPC）和低分子肝素（LMWH）在亚洲胃肠道恶性肿瘤患者术后预防静脉血栓栓塞症（VTE）的安全性和有效性。方法：计算机检索中国知网（CNKI）、万方数据库、维普数据库、Sinomed数据库、Cochrane Library、Embase及Pub Med数据库关于比较亚洲胃肠道恶性肿瘤患者术后给予IPC、IPC联合LMWH预防VTE效果的随机对照试验（RCT）。检索日期为数据库建库至2020年12月。纳入符合标准的相关文献,并提取数据,采用Rev Man 5.3.0软件进行Meta分析。结果：共有5项RCT结果 1821例患者数据纳入研究,其中IPC组为936例,IPC+LMWH组885例。Meta分析结果显示：与单纯IPC比较,IPC联合LMWH明显降低VTE发病风险（RR=0.48,95%CI:0.28～0.82,P=0.007）,DVT和PE发病率明显减少（RR=0.55,95%CI:0.31～0.97,P=0.04;RR=0.23,95%CI:0.07～0.81,P=0.02）;出血事件发生率（RR=0.23,95%CI:0.07～0.81,P<...     

左卡尼汀对维持性血液透析患者慢性心力衰竭疗效的系统评价

目的：评价左卡尼汀对维持性血液透析患者慢性心力衰竭的疗效。方法：检索2005年1月～2011年国内公开发表的左卡尼汀对维持性血液透析患者慢性心力衰竭的相关文献,采用RevMan5.0对符合条件的文献进行Meta分析。结果：共有5篇文献,268例患者满足纳入标准。治疗后,LVEDD和LVEF标准化均数差（SMD）及其95%CI分别是-0.63（-0.87,-0.38）和0.91（0.65,1.16）;有效率方面,合并后的OR为3.56,95%CI为（2.03,6.24）。结论：左卡尼汀对维持性血液透析患者慢性心力衰竭的疗效优于对照组。     

ICU患者压力性损伤风险评估工具准确性的网状Meta分析

目的 评价不同压力性损伤风险评估工具对ICU患者压力性损伤风险预测的准确性,为准确筛查ICU压力性损伤风险患者提供依据。 方法 计算机检索PubMed、Cochrane Library、CINAHL、EMbase、Web of Science、中国知网、维普网、万方数据和中国生物医学文献服务系统中ICU患者压力性损伤风险评估工具相关研究,经文献筛选、质量评价、资料提取后,采用ANOVA模型实现基于贝叶斯方法的诊断实验准确性网状Meta分析。 结果 共纳入28篇文献,共计11 221例患者,涵盖12个压力性损伤风险评估工具。Meta分析结果显示,改良版Cubbin & Jackson量表优势指数最高,灵敏度［0.72,95%CI（0.59,0.82）］,特异度［0.75,95%CI（0.63,0.84）］,其次为EVARUCI量表,灵敏度［0.75,95%CI（0.54,0.90）］,特异度［0.65,95%CI（0.42,0.83）］;Braden量表优势指数最低,灵敏度［0.66,95%CI（0.62,0.71）］,特异度［0.58,95%CI（0.54,0.61）］。 结论 改良版Cubbin & Jackson量表、EVARUCI量表具有较好的诊断试验准确性,临床医护人员评估ICU患者压力性损伤风险时可优先选用。     

国人脊柱原发肿瘤流行病学特征的Meta分析

目的 :系统评价中国人脊柱原发肿瘤的流行病学特征。方法 :计算机检索Pubmed、Medline、Ovid、Science Direct、Embase、Web of Science、万方、中国知网(China national knowledge infrastructure,CNKI)、维普(vip citation databases,VIP)、中国生物医学文献(China biology medicine disc,CBM)数据库,检索时间为1980年1月~2017年6月,收集有关中国地区脊柱原发肿瘤流行病学特征及临床病例分析的研究,对文献所报道的各肿瘤占比、男女比例、年龄分布、解剖学部位分布等数据进行提取,按照澳大利亚循证护理中心推荐的标准(JBIcriteria)对文献质量进行评价,采用Rev Man 5.3软件对数据进行Meta分析。结果 :纳入符合标准的中英文文献23篇,文献质量评分均在7分以上。对文献中报道的3462例脊柱原发肿瘤进行Meta合并分析,结果显示:(1)在脊柱原发肿瘤中,良性肿瘤所占比例为61%(95%CI:56%~66%),恶性肿瘤所占比例为39%(95%CI:34%~44%)。(2)良、恶性肿瘤分类中,男性所占比例均高于女性,但骨巨细胞瘤中女性所占比例为52%(95%CI:47%~58%),男性为48%(95%CI:42%~53%)。(3)良性肿瘤21~40岁患者占40%(95%CI:35%~45%),恶性肿瘤41~60岁患者占44%(95%CI:40%~48%),超过70%的脊柱原发肿瘤患者年龄在21~60岁。(4)颈、胸、腰、骶椎肿瘤分别占25%、26%、22%、27%,良性肿瘤好发于颈椎,恶性肿瘤以骶椎多见。敏感性分析结果显示,Meta分析结果可靠,除解剖学分布外漏斗图基本对称,不存在较大发表偏倚。结论:中国人脊柱原发肿瘤中,良性肿瘤比例高于恶性,男性比例高于女性;良性肿瘤好发于21~40岁,恶性肿瘤好发于41~60岁;脊柱原发肿瘤在颈、胸、腰、骶节段的分布大致相当,良性肿瘤颈椎居多,恶性肿瘤骶椎居多。     

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.     

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.