早期胃癌淋巴结转移规律的探讨

目的 研究早期胃癌淋巴结转移的规律.方法 对青岛大学医学院附属医院2001年7月至2007年7月期间手术治疗的177例早期胃癌的临床病例资料进行Logistic回归分析.结果 本组177例早期胃癌的淋巴结转移率为13%,第一站(N1)和第二站(N2)的转移率分别为13%和3%.单因素分析发现,黏膜内癌和黏膜下癌的淋巴结转移率分别为3%(3/88)和22%(20/89)(X2=14.222,P<0.01);肿瘤长径小于2cm和2cm以上的胃癌的淋巴结转移率分别为3%(4/117)和32%(19/60)(X2=27.992,P<0.01);分化型胃癌与未分化型胃癌的淋巴结转移率分别为4%(3/81)和21%(20/96)(X2=11.402,P=0.001);大体分型I型、Ⅱ型和Ⅲ型淋巴结转移率分别为33%(2/6)、8%(7/99)和19%(14/92)(X2=8.172,P=0.014).Logistic回归分析提示,肿瘤长径大于2cm(OR=8.408,P<0.01)、侵及黏膜下层(OR=5.926,P=0.009)和未分化型胃癌(OR=4.880,P=0.020)为早期胃癌淋巴结转移的独立危险因素.结论 早期胃癌淋巴结转移与肿瘤浸润深度、肿瘤长径和肿瘤分化程度有关.     

早期胃癌淋巴结转移的相关危险因素分析

目的探讨早期胃癌淋巴结转移的相关危险因素,为合理制定治疗方案提供参考依据。方法对安徽省肿瘤医院胃肠肿瘤外科于2013年2月至2017年11月期间行胃癌根治术的148例早期胃癌患者的临床病理资料进行回顾性研究,对早期胃癌患者的年龄、性别、肿瘤大小、肿瘤部位、大体类型、组织学类型、浸润深度及是否有脉管神经侵犯与淋巴结转移的关系进行单因素及多因素分析。结果本组148例早期胃癌患者中有15例发生淋巴结转移,淋巴结转移发生率为10.14%,其中黏膜内癌的淋巴结转移率为1.43%(1/70),黏膜下层癌的淋巴结转移率为17.95%(14/78)。单因素分析结果显示,早期胃癌患者的年龄、肿瘤大体类型、肿瘤大小、浸润深度及有脉管神经侵犯情况与其淋巴结转移有关(P0.050);多因素logistic回归分析结果显示,肿瘤浸润深度和有脉管神经侵犯是早期胃癌发生淋巴结转移的独立危险因素(P0.050)。结论肿瘤浸润深度及有脉管神经侵犯与早期胃癌淋巴结转移密切相关,术前正确评估淋巴结转移情况对早期胃癌患者的治疗方式选择及判断患者的预后至关重要。     

早期胃癌淋巴结转移的影响因素分析

目的探索早期胃癌淋巴结转移的影响因素。方法回顾性分析2009年1月至2016年1月期间在笔者所在医院接受手术治疗的187例早期胃癌患者的临床资料,探索年龄、性别、肿瘤位置、肿瘤直径、肿瘤数目、浸润深度、组织学类型、大体形态、脉管浸润及局部溃疡与淋巴结转移的关系。结果本组187例早期胃癌患者中,检测出淋巴结转移32例(17.1%)。多因素logistic回归分析结果显示,早期胃癌患者的淋巴结转移与肿瘤直径(OR=2.080,P=0.022)、浸润深度(OR=21.048,P=0.001)、组织学类型(OR=3.507,P=0.018)、脉管浸润(OR=2.406,P=0.009)及局部溃疡(OR=2.738,P=0.001)均有关,肿瘤直径2 cm、浸润深度达黏膜下层、组织学类型为未分化型、存在脉管浸润及存在局部溃疡者的淋巴结转移率较高。结论肿瘤直径、浸润深度、组织学类型、脉管浸润和局部溃疡均是淋巴结转移的影响因素。     

单中心186例早期胃癌区域淋巴结转移特征与预后分析

目的:探讨早期胃癌(EGC)的临床病理特征和淋巴结转移的关系以及淋巴结转移对EGC患者预后的影响。方法:对安徽医科大学附属安庆医院2010年10月—2018年12月手术治疗的186例EGC患者临床资料进行回顾性分析。结果:186例EGC患者中,17例(9.1%)出现区域淋巴结转移。单因素分析显示,黏膜下癌(T1b)患者淋巴结转移率高于黏膜内癌患者(T1a)(15.1%vs. 4.2%,χ~2=5.177,P=0.023);病灶最大径2cm患者淋巴结转移率高于病灶最大径≤2cm患者(14.3%vs. 5.5%,χ~2=4.190,P=0.041);伴有脉管浸润患者淋巴结转移率高于无脉管浸润患者(50.0%vs. 6.8%,χ~2=21.247,P=0.000);总淋巴结清扫≥15枚患者淋巴结转移率高于淋巴结清扫15枚患者(12.5%vs. 0,χ~2=6.879,P=0.009);患者性别、年龄、肿瘤部位、大体类型、分化程度、手术方式与淋巴结转移均无明显关系(均P0.05)。多因素分析结果显示,伴有脉管浸润是EGC淋巴结转移的独立危险因素(RR=6.886,95%CI=1.399～33.898,P=0.018)。173例(93.0%)患者具有完整随访资料,随访时间2～95个月。全组EGC患者3、5年累计生存率分别为96.1%、92.4%,其中无淋巴结转移患者分别为97.1%、95.5%,有淋巴结转移患者分别87.5%、65.6%,尽管前生存率优于后者,但差异无统计学意义(χ~2=2.478,P=0.115)。结论:黏膜下层浸润、病灶最大径2cm、伴有脉管浸润的EGC患者有更高的区域淋巴结转移风险,因此对EGC要进行规范的淋巴结清扫以准确的判断术后病理分期及决定后续治疗。淋巴结转移对EGC患者预后的影响还需进一步的长期随访研究确定。     

Siewert Ⅱ型和Ⅲ型食管胃结合部腺癌淋巴结转移规律及预后分析

目的 探讨Siewert Ⅱ型和Ⅲ型食管胃结合部腺癌淋巴结转移规律及预后分析.方法 选取2013年7月-2017年3月在首都医科大学附属北京友谊医院普外科接受根治性手术并具有完整临床资料的Siewert Ⅱ型和Ⅲ型食管胃结合部腺癌患者65例,主要研究指标为性别、年龄、肿瘤部位、肿瘤大小、大体类型、组织学类型、浸润深度、手术方式、脉管内癌栓、癌结节;采用Logistic回归模型分析淋巴结转移危险因素,Kaplan-Meier法进行生存分析.出院后通过门诊、电话等方式随访,随访截至2017年4月.结果 所有患者淋巴结转移率为63.1％(41/65),各组淋巴结转移中,以第1、2、3、7、11和110组淋巴结转移频次最高,转移率分别为45.3％、32.5％、28.8％、22.5％、19.4％和8.2％;肿瘤最大径＜2 cm淋巴结转移率为0,肿瘤最大径≥2 cm淋巴结转移率为71.9％(P=0.000);早期癌(T1)和进展期癌(T2 ～T4)淋巴结转移率分别为0、12.5％、69.0％和95.2％(P=0.000);分化型淋巴结转移率为45.2％,低于未分化型淋巴结转移率79.4％ (P =0.009);33例患者合并脉管内瘤栓,其中28例(84.8％)伴有淋巴结转移(P=0.001);多因素分析显示,组织学类型及脉管瘤栓是影响Siewert Ⅱ型和Ⅲ型食管胃结合部腺癌淋巴结转移的独立危险因素.65例患者均获得随访,术后随访1 ～45个月,平均18.81个月.生存分析显示,无淋巴结转移者3年总体生存率较合并淋巴结转移者差异无统计学意义(P=0.167),但较合并淋巴结转移者存在生存优势;肿瘤分期对于3年总体生存率差异无统计学意义(P =0.429),但早期肿瘤较进展期肿瘤具有生存优势.结论 Siewert Ⅱ型和Ⅲ型食管胃结合部腺癌淋巴结转移主要与组织学类型及脉管内瘤栓相关;其中第1、2、3、7、11和110组淋巴结转移率高,因而建议行根治性全胃切除术、D2淋巴结清扫术及常规清扫第110组淋巴结或清扫纵隔及食管裂孔周围淋巴结,对于合并淋巴结转移及肿瘤分期晚者,远期预后仍有待进一步研究证实.     

早期胃癌淋巴结转移潜在危险因素分析

目的:探讨影响早期胃癌淋巴结转移的潜在危险因素,指导胃癌淋巴结清扫术(D1或D2)的合理应用。方法:回顾性分析1995年3月—2010年6月经手术治疗的336例早期胃癌患者的临床病理资料,对影响早期胃癌淋巴结转移的潜在危险因素进行单因素及多因素分析。结果:早期胃癌淋巴结转移与性别(P=0.010)、年龄(P=0.013)、肿瘤部位(P=0.042)、有无合并溃疡(P=0.001)、浸润深度(P<0.0001)、有无脉管癌栓(P<0.0001)有关,合并有溃疡(P=0.012)、浸润至黏膜下层(P=0.008)及有脉管癌栓(P=0.001)是淋巴结转移的独立性危险因素;黏膜内癌淋巴结转移与肿瘤部位(P=0.007)及大小(P=0.010)有关,肿瘤直径>20mm(P=0.041)是黏膜内癌淋巴结转移的独立性危险因素。结论:合并有溃疡、浸润至黏膜下层及有脉管癌栓的早期胃癌患者进行手术时,建议行淋巴结清扫(D2)术;肿瘤直径>20mm黏膜内癌也要考虑行淋巴结清扫(D2)术。     

早期胃癌淋巴结转移和临床病理特征的关系(附467例报道)

目的:探讨早期胃癌病人各临床病理因素与淋巴结转移的关系,为制定合理的治疗方案提供帮助.方法:对467例早期胃癌病人进行回顾性分析,对其年龄、性别、肿瘤大小、大体类型、分化程度、浸润深度、淋巴管癌栓与淋巴结转移的关系进行单因素和多因素分析.结果:影响早期胃癌淋巴结转移的因素主要有:肿瘤大小(最大径,≤2 cm比>2 cm,P<0.01)、分化程度(分化良好比分化不佳,P<0.01)、浸润深度(黏膜层比黏膜下层,P<0.01)、淋巴管癌栓(无比有,P<0.01).Logistic回归多因素分析结果显示,肿瘤大小、分化程度、浸润深度、淋巴管癌浸润均是提示胃癌是否有淋巴结转移的独立因素.结论:早期胃癌淋巴结转移与肿瘤大小、肿瘤分化程度、浸润深度、淋巴管癌栓等因素有关.确定早期胃癌手术方案时,可参考上述因素判断淋巴结转移风险,决定是否行淋巴结清扫术.     

早期胃癌临床病理学特征与预后的关系

目的:探讨和总结早期胃癌的临床病理学特征及其与病人预后间的关系,分析早期胃癌的淋巴结转移规律,为微创治疗、缩小手术提供依据。方法:采用单因素及多因素的分析法,回顾分析2003年1月至2008年9月仁济医院普外科接受手术治疗的231例早期胃癌病人的临床及病理学资料。结果:单因素分析显示,肿瘤大小、浸润深度及淋巴结转移程度与早期胃癌的预后相关;多因素分析提示,淋巴结转移是早期胃癌预后的独立性危险因素。单发早期胃癌的淋巴结转移率为15.6%(36/231),黏膜内癌淋巴结转移率为5.7%(4/70),黏膜下癌淋巴结转移率为19.9%(32/161)。Logistic回归分析提示,肿瘤直径>2 cm(P=0.038,OR=1.351)和肿瘤浸润至黏膜下层(P=0.027,OR=3.635)是淋巴结转移的独立危险因子。本研究中,无淋巴结转移的早期胃癌病人,其术后3年生存率为98.6%,显著优于有淋巴结转移者(P2 cm、肿瘤浸润至黏膜下层是早期胃癌淋巴结转移的独立危险因子;术前应用影像学技术评估早期胃癌淋巴结转移情况有助于选择合理的治疗方案。     

早期远端胃印戒细胞癌淋巴结转移的危险因素分析及外科手术指征探讨

目的研究早期远端胃印戒细胞癌淋巴结转移的危险因素,进一步分析其外科手术指征。方法回顾性分析2013年3月至2018年11月期间在苏州大学附属第一医院普外科接受外科根治手术且术后病理学检查证实为远端胃印戒细胞癌的91例早期胃癌患者的临床资料,收集患者的性别、年龄、肿瘤最大径、病灶数量、浸润深度、肿瘤大体外观、脉管癌栓、合并溃疡等数据,探索发生淋巴结转移的危险因素,进一步分析外科手术指征。结果91例早期远端胃印戒细胞癌均接受了外科根治性手术,其中淋巴结转移10例。单因素分析结果显示,肿瘤最大径(χ^2=5.631,P=0.025)、浸润深度(χ^2=4.389,P=0.016)、病灶数量(χ^2=5.615,P=0.023)及脉管癌栓(χ^2=22.500,P=0.001)均与早期远端胃印戒细胞癌的淋巴结转移有关。多因素分析结果显示,肿瘤最大径(OR=3.675,P=0.012)、浸润深度(OR=3.886,P=0.015)及脉管癌栓(OR=8.711,P<0.001)是早期远端胃印戒细胞癌发生淋巴结转移的影响因素,肿瘤最大径≥2 cm、浸润至黏膜下层及有脉管癌栓的患者有更高的淋巴结转移率。结论肿瘤最大径≥2 cm、浸润至黏膜下层及存在脉管癌栓的早期远端胃印戒细胞癌患者有更高的淋巴结转移风险;满足肿瘤最大径≥2 cm和存在脉管癌栓中任何1项条件者均可能需接受外科根治性手术。     

胃黏膜下层癌淋巴结转移临床病理因素分析

【摘要】 目的 研究胃黏膜下层癌淋巴结转移率及其影响因素。 方法 回顾性分析南京医科大学第一附属医院1998年1月至2007年12月手术证实的181例胃黏膜下层癌的临床病理资料,对病人年龄、性别、肿瘤组织学类型、形态学类型、大小、部位、浸润深度、脉管内癌栓等与淋巴结转移的关系进行单因素与多因素分析。 结果 胃黏膜下层癌淋巴结转移率为20.44%。影响胃黏膜下层癌淋巴结转移的因素主要有肿瘤组织学类型（分化型 vs 分化不良型,P =0.0352）、直径大小（＜2cm vs ≥2cm,P =0.0143）、部位（近端胃vs胃体vs远端胃,P =0.0254）及脉管内癌栓（无vs有,P =0.0323）。Logistic回归分析显示肿瘤组织学类型与大小为胃黏膜下层癌淋巴结转移的独立性危险因素。结论 胃黏膜下层癌淋巴结转移与肿瘤组织学类型、大小、部位及脉管内癌栓等因素有关。临床上应参考上述临床病理因素判断淋巴结转移风险,制定合适的治疗方案。     

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 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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.