超声心动图和下肢静脉超声联合血浆D-二聚体对孕产妇肺栓塞的临床诊断价值

目的分析和评价超声心动图和下肢静脉超声联合血浆D-二聚体对孕产妇肺栓塞（pulmonary thromboembolism, PE）的临床诊断和预测价值。方法回顾性收集2019年5月—2021年5月同济大学附属第一妇婴保健院收治120例临床疑诊PE的孕产妇临床资料,按照肺动脉断层血管造影（computed tomographic pulmonary angiographic, CTPA）的结果分为阴性组和阳性组,比较和评价超声心动图、下肢静脉超声、血浆D-二聚体单独及联合诊断孕产妇PE的临床诊断和预测效能。结果临床特征比较： 两组间年龄、孕次、产次、受孕方式、受孕胎数、终止妊娠方式、是否早产、既往妇产科手术史、既往外科手术史、是否合并高血压、糖尿病、肥胖及BNP等指标比较差异均无统计学意义（均P>0.05）。两组间仅血浆D-二聚体比较差异有统计学意义（t=-3.598,P＜0.001）。超声心动图、下肢静脉超声和血浆D-二聚体升高单独及联合诊断孕产妇PE的灵敏度分别为45.00%、53.33%、95.00%和85.00%,特异度分别为83.33%、91.67%、21.67%和81.67%,阳性预测值分别为72.97%、86.49%、54.81%和82.26%,阴性预测值分别为60.24%、66.27%、81.25%和84.48%。与单独诊断相比较,联合诊断显著提高灵敏度（χ2=49.669,P＜0.001）、特异度（χ2=88.413,P＜0.001）、阳性预测值（χ2=20.629,P＜0.001）和阴性预测值（χ2=11.169,P=0.01）。多因素Logistic回归分析提示超声心动图阳性（OR=18.266,P＜0.001）、下肢静脉血栓（OR=45.482,P＜0.001）及D-二聚体升高（OR=6.595,P=0.019）与孕产妇PE发生显著相关,ROC曲线分析显示单独及联合诊断的曲线下面积（AUC）分别为0.642、0.725、0.583和0.833。结论超声心动图和下肢静脉超声联合血浆D-二聚体对孕产妇PE具有良好的诊断和预测价值,为临床早期预防、诊断和治疗提供可靠依据。     

Monitoring of central venous oxygen saturation versus mixed venous oxygen saturation in critically ill patients

Continous monitoring of mixed venous (SvO₂) and central venous (ScO₂) oxygen saturation was compared in 7 critically-ill patients (Apache II score: 19±2.1) to determine whether or not information derived from ScO₂ were reliable in clinical practice. Patients were catheterized with both a pulmonary artery (PA) and a central venous (CV) catheter, each of them mounted with fiberoptic sensors (Opticath PA Catheter P7110 and Opticath CV Catheter U440, Abbott). A total of 580 comparative measurements were obtained during periods without and with therapeutic interventions (drug-titration, bronchial suction, use of PEEP, changes in FiO₂...). The systematic error between the 2 measurement techniques was 0.6% and 0.3% in periods with and without therapeutic interventions, respectively. The variability between the 2 techniques was 10% for both periods. Differences between the values were 5% in 49% of values during periods of stability and in 50% of values during periods with therapeutic interventions. There were poor correlations between the values during periods without (r=0.48) and with therapeutic interventions (r=0.62). Better, but still less than ideal, correlations were obtained with changes in SvO₂ and ScO₂ during periods without (r=0.70) and with therapeutic interventions (r=0.77). Although there is a need to develop a simple technique to monitor mixed venous oxygen saturation, the present study indicates that ScO₂ monitoring was not reliable in the study patients.     

兔耳纯静脉皮瓣血流量和血管网面密度观测

目的:观测纯静脉皮瓣术后血流量和血管网面密度变化。方法:利用家兔耳背设计纯静脉皮瓣和动脉皮瓣模型①观测术后血流量;②墨汁灌注后软蜡厚蜡切片,图像分析血管网面密度。结果:①纯静脉皮瓣术后48h血流量最低,第14d恢复至术前65%。②纯静脉皮瓣术后第1～7d的血管网面密度高于动脉皮瓣(P<0.05)。结论:纯静脉皮瓣术后血流量及血管网密度变化与动脉皮瓣不同。     

Maternal origin of transferrin receptor positive cells in venous blood of pregnant women

We studied the origin of transferrin receptor (CD71) positive cells in blood from seven women pregnant with a male fetus in order to explore if fetal cells could be detected among them. We used a technique that allows direct chromosomal analysis by in situ hybridization on immunologically and morphologically classified cells. Enrichment was performed by magnetic activated cell sorting (miniMACS)® using an anti-CD71 monoclonal antibody. The cells were immunophenotyped by alkaline phosphatase anti-alkaline phosphatase immunostaining with the same antibody. The origin of the immunophenotyped cells was studied by in situ hybridization using an X cosmid Y repeat chromosome specific probe cocktail. CD71 positive cells were found in six of the seven women at the range of 4 to 43 in respective samples. Over 90% of the CD71 positive cells were nucleated erythrocytes. None of the detected positive cells were shown to be fetal. Thus, the use of transferrin receptor antigen alone in combination with the miniMACS® may not be sufficient for enrichment of fetal cells.     

Ultrasound study of the cranial venous system in the human new-born infant and the adult

A pulsed doppler ultrasound technique has been used to measure changes in blood velocities in the superior sagittal sinus, the jugular veins and intracranial and extracranial arteries in 13 neonates, and in the jugular veins and an extracranial artery in 13 adults, during unilateral and bilateral jugular venous compressions. The results have enabled us to determine how the subject under examination functionally uses his cranial venous drainage system in the resting state, and whether or not he can shunt obstructed venous flow through other cranial venous channels. We have found great variability between the subjects. In the resting situation the range of possibilities from total dependence on one jugular vein alone to usage of both jugular veins and the vertebral veins exists. Shunting of blood on jugular compression from either or both jugular veins to the vertebral veins may occur, and contralateral shunting between the jugular veins may be possible in both directions, in one direction or not at all.     

Naloxone-provoked vaso-vagal response to head-up tilt in men

A double-blind paired protocol was used to evaluate, in eight male volunteers, the effects of the endogenous opiate antagonist naloxone (NAL; 0.05 mg· kg^–1) on cardiovascular responses to 50° head-up tilt-induced central hypovolaemia. Progressive central hypovolaemia was characterized by a phase of normotensive-tachycardia followed by an episode of hypotensive-bradycardia. The NAL shortened the former from 20 (8–40) to 5 (3–10) min (median and range; (P < 0.02). Control head-up tilt increased the means of thoracic electrical impedance [from 35.8 (SEM 2.1) to 40.0 (SEM 1.8) ; P < 0.01 of heart rate [HR; from 67 (SEM 5) to 96 (SEM 8) beats · min^–1, P < 0.02], of total peripheral resistance [TPR; from 25.5 (SEM 3.2) to 50.4 (SEM 10.5)mmHg min 1^–1,P < 0.05] and of mean arterial pressure [MAP; from 96 (SEM 2) to 101 (SEM 2)mmHg, P < 0.02]. Decreases were observed in stroke volume [from 65 (SEM 12) to 38 (SEM 9) ml, P < 0.01], in cardiac output [from 3.7 (SEM 0.7) to 2.5 (SEM 0.5) 1 · mint, P < 0.01], in pulse pressure [from 55 (SEM 4) to 37 (SEM 3)mmHg, P < 0.01] and in central venous oxygen saturation [from 73 (SEM 2) to 59 (SEM 4)%, P < 0.01]. During NAL, mean HR increased from 70 (SEM 3); n.s. compared to control) to only 86 (SEM 9) beats · min^–1 (P < 0.02 compared to control) and MAP remained stable. The episode of hypotensive-bradycardia appeared as mean control HR decreased to 77 (SEM 7)beats · min^–1, TPR to 31.4(SEM 7.7)mmHg · min · 1^–1 and MAP to 60 (SEM 5)mmHg (P < 0.01), and the volunteers were tilted supine. Cardiovascular effects of naloxone on central hypovolaemia included a reduced elevation of HR and blood pressures and provocation of the episode of hypotensive-bradycardia.     

老年患者中心静脉置管分析

目的总结对老年患者施行中心静脉置管的经验,寻找对老年患者施行中心静脉置管的最短时间和最佳部位。方法对三年来施行过中心静脉置管术的病例进行分析。结果总置管成功率为96.2%,失败率为3.8%。虽然经右颈内静脉置管的首次成功率与经右锁骨下静脉置管的首次成功率相比无显著性差异（P〉0.05）,但经右颈内静脉置管时间较经右锁骨下静脉置管时间短（P〈0.05）。结论老年患者施行中心静脉穿刺置管术条件复杂、情况多变,置管难度较大,经右颈内静脉置管较经右锁骨下静脉置管更为省时、安全、可行。     

重度烧伤患者中心静脉导管感染的原因分析及预防措施

目的探讨烧伤患者中心静脉导管感染的原因并制定有效预防措施。方法对2004年1月～2007年12月烧伤病房158例中心静脉置管患者进行监测，包括导管留置时间、置管部位、穿刺部位皮肤、置管环境及导管的病原学检查结果等。结果引起重度烧伤患者中心静脉导管感染的病原菌中，主要为真菌和表皮葡萄球菌；中心静脉置管感染与导管留置部位、留置时间等原因有关。结论严格遵守无菌操作原则，提高穿刺人员的操作技能，缩短置管时间，并保证置管环境的洁净，是预防中心静脉导管感染的有效措施。     

Near-infrared spectrophotometry determined brain oxygenation during fainting

During orthostatic hypotension we evaluated whether presyncopal symptoms relate to a reduced brain oxygenation. Nine subjects performed 50° head-up tilt for 1 h and eight subjects were followed during 2 h of supine rest and during 1 h of 10° head-down tilt. Cerebral perfusion was assessed by transcranial Doppler determined middle cerebral artery blood velocity (MCA v_mean), while brain blood oxygenation was assessed by near-infrared spectrophotometry determined concentration changes for oxygenated (ΔHbO₂) and deoxygenated haemoglobin and brain cell oxygenation by the oxidized cytochrome c concentration (ΔCytO₂). During head-up tilt, six volunteers developed presyncopal symptoms and mean arterial pressure (88 (78–103) to 68 (57–79) mmHg; median and range), heart rate (96 (72–111) to 65 (50–107) beats min^?1), MCA v_mean (59 (51–82) to 41 (29–56) cm s^?1), ΔHbO₂ (by ?5.3 (?3.0 to ?14.8) μmol l^?1) and ΔCytO₂ were reduced (by ?0.2 (?0.1 to ?0.4) μmol l^?1; P < 0.05). During tilt down the cardiovascular variables recovered immediately and ΔHbO₂ increased to 2.2 (?0.9–12.0) mmol L^?1 above the resting value and also ΔCytO₂ recovered. In the nonsyncopal head-up tilted subjects as in the controls, blood pressure, heart rate, MCA v_mean and brain oxygenation indices remained stable. The results suggest that during orthostasis, presyncopal symptoms relate not only to cerebral hypoperfusion but also to reduced brain oxygenation.     

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.