25例PICC继发奇静脉异位患者的护理

总结25例PICC继发奇静脉异位的护理经验。当左侧PICC置管出现导管功能障碍,在排除其他原因后,怀疑异位至奇静脉时,通过胸部侧位片或胸部CT来确诊。及时处理继发奇静脉异位,复位成功后关注后续有无再次异位,使用腐蚀性药物前使用腔内心电图定位技术确认导管尖端位置。导管退出奇静脉后继续输液,严格控制输注药物的性质和浓度,关注堵管及再次异位等并发症。本组患者经处理均未发生感染、血栓、外渗等严重并发症。     

Wide QRS-complex tachycardia with variable VA-conduction: what is the mechanism?

We describe the case of a 16-year-old woman with a surgically corrected tetralogy of Fallot presenting with recurrent wide-QRS-complex tachycardia. The tachycardia could be induced and terminated with ventricular stimulation only. QRS morphology during sinus rhythm and tachycardia was identical and variable VA-conduction was observed. Mapping of the tachycardia showed that variations of HH intervals preceded VV intervals. Therefore, a mechanism involving re-entry within the bundle branches was suggested. However, detailed mapping showed cranial to caudal depolarization of the His bundle, leading to the diagnosis of atrioventricular node re-entrant tachycardia. The tachycardia was abolished by radiofrequency catheter ablation of the slow AV nodal pathway. We conclude that variable VA conduction can occur in patients with atrioventricular node re-entrant tachycardia. The atrial tissue is not always an integral part of the re-entrant circuit.     

肿瘤患者中不同中心静脉导管的临床应用及比较

目的对比两种不同中心静脉导管在肿瘤患者中的临床应用效果。方法145例肿瘤患者分为两组,使用中心静脉导管62例为A组,使用一次性无菌中心静脉导管穿刺包83例为B组,观察记录两组导管留置时间、导管相关性感染的感染率和不良反应的发生率及置管部位、操作技术、导管维护等情况。结果导管平均留置时间A组35d,B组39d,差异无显著性（P〉0．05）。导管相关性感染率A组14．52％,B组2．41％,差异有显著性（P〈0．05）。不良反应发生率A组11．29％,B组1．21％,差异显著（P〈0．05）,置管部位、操作技术、导管维护组间相比无显著区别。结论肿瘤科深静脉置管患者使用一次性无菌中心静脉导管穿刺包发生置管后导管相关性感染的感染率和不良反应的发生率低,在临床上值得推广使用。     

氨氯地平对射频消融术后血小板聚集率的影响

目的探讨射频消融术(RFCA)对血小板聚集率(PAG)的影响及氨氯地平的防治效果。方法采用Bom比浊法,观察96例患者射频消融术前、后PAG的变化及氨氯地平的干预效果。结果对照组PAG由术前的(57.17±11.08)%升高到术后的(70.25±11.89)%,差异有统计学意义(P<0.05)。结论射频消融术使血小板聚集率增加,氨氯地平有预防作用。     

射频消融术延迟血栓形成及低分子肝素的防治

目的探讨射频导管消融术(RFCA)延迟血栓形成的发生机制及防治对策。方法选取48例行RFCA患者为治疗组和21例行心内电生理检查(EPS)患者为对照组。治疗组随机分为两亚组,A组23例术后不予肝素,B组25例术后运用低分子肝素,A组以肝细胞生长因子(HGF)0.4ng/ml为界分为高HGF组和正常HGF组。在不同时间测定凝血酶-抗凝血酶Ⅲ复合物(TAT)及HGF。结果①A组TAT呈现两次高峰:术后即刻第一次高峰(42.9±15.8ng/ml),术后3天第二次高峰(20.3±19.2ng/ml),第二次高峰与EPS组术后3天(2.7±1.7ng/ml)及B组术后3天(4.3±5.3ng/ml)比较差异有显著性(P<0.05);②A组术后6hHGF值与TAT两次高峰相关(r=0.542,P<0.01);术后6h高HGF组TAT术后3天高峰更显著。结论RFCA致血栓形成可分两阶段:术后即刻的急性阶段和术后3天的延迟阶段。术后肝素化可影响凝血系统,有阻止血栓形成的效果。     

A European perspective on intravascular catheter-related infections: report on the microbiology workload, aetiology and antimicrobial susceptibility (ESGNI-005 Study)

The laboratory workload, microbiological techniques and aetiology of catheter-related infections in European hospitals are mostly unknown. The present study (ESGNI-005) comprised a 1-day (22 October 2001), laboratory-based, point-prevalence survey based on a questionnaire completed by microbiology laboratories in European (European Union (EU) and non-EU) hospitals. Also included were questions requesting retrospective information for the year 2000. In total, 151 hospitals from 26 European countries participated, of which 78.1% were teaching institutions. Overall, the estimated population served by these institutions was 121,363,800, and the estimated number of admissions during 2000 was 6,712,050. The total number of catheter tips processed during 2000 was 142,727, or 21/1,000 admissions, of which 23.7% were considered to be positive in the institutions using semiquantitative or quantitative techniques. Overall, EU centres received significantly more catheter tip samples/1,000 admissions and had a significantly higher rate of 'positivity' (p < 0.0001) than non-EU centres. Of the institutions surveyed, 11.4% (7.2% in EU countries and 23.7% in non-EU countries; p 0.04) used only qualitative techniques for catheter tip sample processing. On the day of the study, 167 microorganisms were recovered from significant catheter tip cultures (122 patients), of which Gram-positive bacteria represented 70.7%, Gram-negative bacteria 22.2%, and yeasts 7.2%. The five most common microorganisms were coagulase-negative staphylococci, Staphylococcus aureus, Candida spp., Enterococcus spp. and Pseudomonas spp. Overall, 19% of catheter tip cultures were polymicrobial. In the case of S. aureus, 40% of isolates were resistant to oxacillin, as were 63.4% of coagulase-negative staphylococcus isolates. Of 37 Gram-negative isolates, 35% were resistant to cefotaxime, 31% to ceftazidime, and 27% to ciprofloxacin. Imipenem and cefepime had the lowest reported rates of resistance (11%).     

三线减张鼻中隔矫正联合射频消融治疗持续性变应性鼻炎

目的　探讨三线减张鼻中隔矫正联合低温等离子射频消融治疗伴有鼻中隔偏曲的中-重度持续性变应性鼻炎（persistent allergic rhinit is,PAR）的疗效。方法 分别采用三线减张鼻中隔矫正术（对照组32例）和三线减张鼻中隔矫正联合低温等离子射频消融（观察组36例）治疗伴有鼻中隔偏曲的PAR,术后随访1年,根据症状和体征记分评定其疗效：≥66%为显效,65%～26%为有效,≤25%为无效。结果　对照组总有效率59.4%,观察组总有效率91.7%。观察组总有效率显著高于对照组（P＜0.05）。结论  对伴有鼻中隔偏曲的PAR,三线减张鼻中隔矫正联合低温等离子射频消融治疗PAR的疗效明显优于单纯三线减张鼻中隔矫正术。     

心脏螺旋波演化与驱动的计算机实验

我们利用FitzHugh-Nagumo(FHN)类型方程,对二维心肌可激媒质系统螺旋波(Spiral wave,SW)的形成、演化和控制进行了数值模拟,主要有以下研究结果:(1)改变系统的可激性,不会影响SW的激发区宽度,却改变SW的自转周期和旋波核的大小;当可激性达到某一极限值时,SW的自转周期与旋波核的半径趋于无穷大,系统不再出现SW。(2)对SW的均匀近共振小电流驱动,可以引导旋波头(Spiral wave tip,SWT)的漂移运动;当驱动频率接近SW的自转频率时,SWT会沿着圆周漂移,当驱动频率达到共振频率时,SWT会沿着直线漂移。     

Generalized training subset selection for statistical estimation of epicardial activation maps from intravenous catheter measurements

Catheter-based electrophysiological studies of the epicardium are limited to regions near the coronary vessels or require transthoracic access. We have developed a statistical approach by which to estimate high-resolution maps of epicardial activation from very low-resolution multi-electrode venous catheter measurements. This technique uses a linear estimation model that derives a relationship between venous catheter measurements and unmeasured epicardial sites from a set of previously recorded, high-resolution epicardial activation-time maps used as a training data set based on the spatial covariance of the measurement sites. We performed 14 dog experiments with various interventions to create an epicardial activation-time map database. This database included a total of 592 epicardial activation maps which were recorded using a sock array placed on the ventricles of dog hearts. We present five approaches, which examined sequential addition and removal of maps to select a generalized training set for the estimation technique. The selection consisted of choosing a subset of epicardial ectopic activation-time maps from the database of beats which resulted in estimation accuracy levels better than or at least similar to using all the maps in database. Our aim was to minimize the redundancy in the database and to be able to guide the eventual procedures required to obtain training data from open-chest surgery patients. The results from this study illustrated this redundancy and suggested that by including an optimal subset (around 100 maps) of the full database the estimation technique was able to perform as well as and even in some cases better than including all the maps in the database. The results also suggest that such an approach is feasible for providing accurate reconstruction of complete epicardial activation-time maps in a clinical setting and with fewer maps we can obtain similar reconstruction accuracy levels.