Use of pulsed field gel electrophoresis to determine the source of microbial contamination of central venous catheters

Microorganisms detected in situ on the distal tip of central venous catheters (CVC) within 90 min of insertion were investigated using pulsed-field gel electrophoresis to analyse genomic fragments obtained with theSmaI restriction enzyme. Thirty patients received a triple lumen CVC, which was inserted directly through the skin using the Seldinger technique. In a further 30 patients a triple lumen CVC was inserted through a Swan sheath, thereby avoiding direct contact of the CVC with the skin. Staphylococci were isolated from the distal tips of the catheters in 6 patients (5 who had the CVC inserted directly through the skin and 1 who had the CVC inserted via a Swan sheath.) Twenty-three staphylococcal isolates were also isolated from the insertion equipment and the skin swabs surrounding the insertion site of these six patients. All the isolates were genotyped. In one of the patients the organisms isolated from the skin were identical to those on the CVC tip. In two further patients similar organisms were isolated from the insertion equipment and the patients' skin. These results, in addition to the reduced colonisation rates observed when catheters were introduced through a Swan sheath, support the hypothesis that microorganisms from the skin are impacted onto the CVC tip and the CVC insertion equipment at catheter insertion.     

Interpretation of venous occlusion plethysmography using a nonlinear model

Venous occlusion plethysmography (VOP) is a noninvasive technique widely employed for the detection of deep-vein thrombosis. Previous reports that VOP outflow curves are closely fit by a first-order exponential suggest that venous compliance and resistance are nearly constant. Typically, however, the venous compliance function has a sigmoid shape; in addition, the resistance in a collapsing tube must increase. This paradox was resolved by the surprising finding that for realistic nonlinear compliance and resistance these nonlinearities cancel, producing a quasilinear venous outflow that approximates a simple exponential.     

Role of Relative Changes in Caval Flows for Evaluation of Right Atrial Pressure Shifts Induced by Nitroglycerin

Experiments on cats treated with nitroglycerin showed dynamic relationship between changes in caval venous flows: blood flow increased in the superior vena cava and decreased in the inferior vena cava. Blood pressure in the right atrium either decreased, or increased. No significant changes in total venous return were observed during maximum shifts in right atrial pressure, while contractility of the right ventricular myocardium usually decreased. Our findings suggest that the direction of the right atrial pressure shifts induced by nitroglycerin does not depend on venous return, but is determined by the prevalence of flow changes in the superior vena cava or inferior vena cava.     

Three novel PROC gene lesions causing protein C deficiency

Hallam PJ, Mannucci P, Tripodi A, Bevan D, Laursen B, Tengborn L, Wacey A, Cooper DN. Three novel PROC gene lesions causing protein C deficiency. Clin Genet 1998: 54: 231–233. 0 Munksgaard, 1998
Missense mutations. three of them novel (Am210→Val, Asn248→ Ile, Ah355→Val), were found in the protein c ( PROC ) genes of 7 patients with inherited protein C deficiency associated with venous thrombosis. Comparison with the phenotypic effects of mutations in the analogous residues of factor IX causing hdernophilia B and the use of molecular modelling has provided explanations as to how these lesions might alter either the structure, function or secretion of the protein C molecules encoded.     

Effects of dynamic leg exercise on subcutaneous blood flow rate in the lower limb of man

Subcutaneous blood flow (SBF) was studied simultaneously in the upper arm at heart level and in the lower limb during positional changes and during leg exercise in seven healthy males. SBF was estimated by local clearance of ‘“Xenon registered by portable cadmium telluride detectors. Venous pressure was recorded directly on dorsum on the foot. Changinr the position from supine to head-up tilt, SBF decreased by 43 % (P < 0.01) at the arm level, 40% at the thigh (P < 0.01), 47% at the calf (P < 0.01) and decreased by 51 % at the ankle level (P < 0.01). Performing 20 heel-raisings per min in nearly erect posture, SBF increased by 96% at the thigh (P < 0.01), 25% at the calf (P > 0.1) and increased by 18% at the ankle level (P > 0.1). At 40 heel-raisings per min SBF increased by 99% at the thigh (P < 0.0 1), 121 % at the calf (P < 0.0 1), but only 44% at the ankle level (P > 0.1). During leg exercise subcutaneous vascular resistance was significantly increased at arm and ankle levels. In contrast, a vasodilatory response was noticed at the thigh and calf levels and seemed associated with a decrease in local venous pressure to below the trigger level of the sympathetic veno-arteriolar reflex mechanism. In conclusion, SBF in the lower limb of man was increased during exercise. The increase in SBF could only partly be ascribed to the concomitant increase in perfusion pressure. The local blood flow response seemed modified by changes in sympathetic nervous activity and metabolic rate.     

Estimation of central venous pressure by measurement of proximal axillary venous pressure using a "half-way" catheter

The pressure in the proximal axillary vein (AVP) was compared with central venous pressure (CVP) in eight patients during and after elective abdominal surgery. Both pressures were recorded from soft, elastic, polyurethane catheters inserted in the basilic or cephalic veins ("half-way" catheters), punctured at the fossa cubiti (AVP), and via the right jugular vein (CVP). The AVP and CVP were recorded simultaneously using hydrostatic, conventional disposable venous pressure measurement sets. The measurements were performed during intermittent positive pressure ventilation with positive end-expiratory pressure from 0 to 7.5 cmH2O (0-0.74 kPa), as well as during spontaneous breathing. During both controlled and spontaneous respiration, small mean differences (0.2-1.0 cmH2O) (0.02-0.1 kPa), and a highly significant (P less than 0.001) positive correlation between CVP- and AVP-values were found. An increase of 1 cmH2O (0.10 kPa) in the CVP was associated with an increment of practically identical order (0.99-1.04 cmH2O) (0.10-0.11 kPa) in the AVP. The results suggest that monitoring of the AVP by a basilic "half-way" catheter produces diagnostic information similar to that from the measurement of the CVP from subclavian, external or internal jugular, as well as "long-way" brachial catheter, with no risk of the major mechanical complications which accompany the use of the latter catheters.     

不同疗法对活动性肝硬化门静脉高压症大出血的疗效比较

目的　观察断流术、分流术和保守治疗对活动性肝硬化门静脉高压症大出血的疗效。方法　 112例随机分组 ,分别进行断流术 (5 7例 )、分流术 (19例 )和保守治疗 (36例 )。于治疗前后测定门静脉血流量 (PVF)和自由门静脉压 (FPP) ,随访了解患者的肝炎稳定率、再出血率和病死率等。结果　术后分流组的PVF较断流组显著减少 (P <0 .0 5 )。治疗后 1年内 ,断流、分流和保守治疗各组的肝炎稳定率分别是 35 .1%、10 .5 %和 13.9% (断流组显著高于其它两组 ,均P <0 .0 5 )。 3组患者的再出血率分别是 3.5 %、5 .3%和 2 7.8% (两手术组显著低于保守治疗组分别为P <0 .0 0 1和P <0 .0 5 )。结论　此类患者的治疗以采用断流术为宜     

股浅静脉戴戒术治疗原发性下肢深静脉瓣膜功能不全

目的 用股浅静脉戴戒术治疗原发性下肢深静脉瓣膜功能不全。方法 本文应用股浅静脉戴戒术治疗原发性下肢深静脉瓣膜功能不全34例,并应用无创性光电容积描记（PPG）结合临床症状改善状况对手术疗效进行评估。结果 手术前后静脉返流时间（VRT）有显著差异（P＜0．01）,临床症状改善。结论 股浅静脉戴戒术是治疗下肢深静静脉瓣膜功能轻度不全的有效方法,PPG检查结合临床改善程度是判断手术疗效更有效的方法。     

湖北省胃肠道肿瘤病人围手术期静脉血栓栓塞症多中心调查及分析

目的 调查分析湖北省胃肠道肿瘤病人围手术期静脉血栓栓塞症（VTE）防治现状。方法 回顾性分析2019-01-01至2019-12-31湖北省胃肠外科联盟成员医院收治的行手术治疗的胃肠道肿瘤病人VTE防治相关临床资料。 结果 收集62家医院调查问卷7751份,其中有效问卷共计7474份,有效率96.4%。所有病人中,术前736例（9.8%）接受恰当预防措施,7012例（93.8%）术前行D-二聚体检查,2301例（30.7%）术前行下肢静脉超声检查。术后451例（6.0%）病人接受恰当预防措施。术后6434例（86.1%）病人行D-二聚体检查;1675例（22.2%）行下肢静脉超声检查,其中164例发生下肢深静脉血栓（DVT）,20例病人发生肺动脉栓塞（PE）,有5例PE病人住院期间死亡。结论 当前湖北省胃肠道肿瘤病人围手术期下肢静脉超声检查及恰当预防比例偏低,围手术期VTE规范化防治水平有待提高。