体位改变对高位脊髓损伤患者大脑中动脉血流的影响

目的分析比较高位脊髓损伤患者不同体位下大脑中动脉 (MCA)血流动力学变化特征。方法采用经颅彩色多普勒超声 (TCCD)技术 ,对 48例高位脊髓损伤的患者分别于平卧位、斜立位 (3 0°、60°、80°)检测MCA的峰值流速 (PSV )、舒张期末流速(EDV)及平均流速 (MV )。结果斜立 3 0°与平卧位比较PSV无显著性差异 (P >0 0 5 ) ,EDV、MV有非常显著性差异 (P <0 0 1)。斜立 60°、80°与平卧位所测PSV、EDV、MV均有非常显著性差异 (P <0 0 1)。结论脊髓损伤患者的体位变化影响MCA血流动力学的变化。     

妊娠晚期孕妇体位对彩色多普勒超声检测胎儿脐动脉和大脑中动脉血流影响

目的探讨妊娠晚期孕妇体位对彩色多普勒超声检测胎儿脐动脉和大脑中动脉血流影响及彩色多普勒超声检测预测胎儿宫内缺氧价值。方法应用彩色多普勒超声检测67例妊娠晚期孕妇仰卧位、左侧卧位及右侧卧位胎儿脐动脉和大脑中动脉血流动力学参数[收缩期峰值(PSV)、舒张期末最大血流速度(EDV)、阻力指数(RI)、搏动指数(PI)、PSV与EDV之比(S/D)],比较各体位时参数变化,并与胎儿出生后1 min Apgar评分结果作比较,评估彩色多普勒超声检测预测胎儿宫内缺氧的价值。结果妊娠晚期孕妇不同体位时胎儿脐动脉血流动力学参数比较,仰卧位PSV、RI和PI均高于左、右侧卧位,EDV均低于左、右侧卧位,S/D高于右侧卧位,差异有统计学意义(P0.01);左侧卧位EDV高于右侧卧位,差异有统计学意义(P0.01)。妊娠晚期孕妇不同体位时胎儿大脑中动脉血流动力学参数比较,左侧卧位RI和PI均低于右侧卧位,差异有统计学意义(P0.01);仰卧位PSV、RI、PI和S/D均高于左、右侧卧位,EDV均低于左、右侧卧位,差异有统计学意义(P0.01)。本组新生儿出生后1 min Apgar评分8~10分者61例,4~8分者6例;仰卧位与左、右侧卧位时彩色多普勒超声检测胎儿大脑中动脉与脐动脉RI比值均1,轻度窒息6例均未能在彩色多普勒超声检测中被预测。结论妊娠晚期孕妇不同体位对彩色多普勒超声检测胎儿脐动脉和大脑中动脉血流动力学参数有明显影响,胎儿脐动脉和大脑中动脉血流动力学参数难以预测新生儿轻度窒息。     

彩超对胎儿大脑中动脉与脐动脉血流动力学的相关性研究

目的:探讨彩超对胎儿大脑中动脉(MCA)与脐动脉(UA)血流动力学之间的关系.方法:检查分析300例中、晚孕胎儿的MCA和UA的血流动力学参数,研究其间的关系.结果:(1)随着孕龄的增加,MCA和UA的峰值流速与舒张末期流速比值(S/D),阻力指数(RI),搏动指数(PI)均相应减小,MCA的各血流参数均相应大于UA的各血流参数(P＜0.01),(2)不论孕龄如何变化,MCA和UA的S/D、RI、PI关系密切,均呈直线正相关(P＜0.01),(3)收缩期峰值流速(PSV),舒张末期流速(EDV)相关性不明显(P>0.05).结论:UA血流动力学异常是造成脑血流动力学异常的重要因素,进一步证明了检测胎儿UA血流动力学变化对评价胎儿宫内生长发育的重要意义.     

脊髓损伤后体位性低血压的临床研究

目的:探讨高位脊髓损伤患者发生体位性低血压(OH)的临床机制。方法:对45例高位脊髓损伤患者进行30°、60°、80°斜立试验,测量斜立后血压、脉搏、大脑中动脉血流(CBF)速度。根据斜立后是否出现体位性低血压症状,将患者分为有症状组和无症状组,进行对比性分析。结果:第1组24例患者无OH症状,能完成全部的测试;第2组21例患者均出现OH症状,18例因不能耐受体位性低血压症状而完成部分试验,3例完成全部试验。统计表明,无症状组平卧位与斜立位的血压差异有非常显著性意义,平卧位与斜立30°的脉搏、CBF速度差异无显著性意义,与斜立60°、80°差异有显著性意义。有症状组平卧位与斜立30°的CBF差异无显著性意义,斜立各角度间的CBF差异有显著性意义。两组在斜立30°时收缩压差异有显著性,而脉搏、CBF速度差异无显著性意义。结论:①脊髓损伤后早期,斜立30°15min不影响CBF速度,不出现OH症状;②血压下降并不是引起OH出现症状的直接原因,CBF速度下降是引起OH症状的直接原因。     

E-Flow成像技术对原发性高血压患者指端微血管血流动力学变化的评价

目的 探讨原发性高血压患者指端微血管病变的血流动力学变化与高血压程度的相关性.方法 应用E-Flow成像技术观察39例原发性高血压患者右手无名指末节指腹动脉和甲床动脉的收缩期峰值流速(PSV)、舒张期峰值流速(EDV)及阻力指数(RI),并与35例健康人作对照.结果 与彩色及能量多普勒相比,E-Flow能更清晰地显示指端微血管的分布及走行,且随着病程的加重,原发性高血压患者指腹动脉、甲床动脉PSV、EDV的测量值均减低(P＜0.05),RI则升高(P＜0.05).结论 指端微血管血流动力学的变化可作为衡量原发性高血压外周阻力变化的指标.E-Flow成像技术可作为一种新的方法对指端微血管血流动力学进行评价.     

过床板在预防髋关节置换术后体位改变时对血流动力学影响的作用

[目的]探讨采用过床板预防髋关节置换术后病人因体位改变对血流动力学影响的效果.[方法]选择2011年3月-2013年1月行髋关节置换手术病人80例,按住院先后顺序分为观察组和对照组各40例,对照组病人术毕由侧卧90°直接改为平卧位.观察组病人术毕采用过床板使病人由侧卧位90°改为45°,2min后再改为平卧位,观察两组血流动力学变化.[结果]侧卧位90°直接改为平卧位时病人血压有不同程度的下降,尤其在体位改变1min时血压下降最明显;采用过床板使侧卧位90°改为侧卧位45°再改为平卧位,体位逐步缓慢地改变,病人血压无明显变化.[结论]髋关节置换病人术毕由侧卧位90°直接改变为平卧位时血压有明显波动,尤其是老年病人.采用过床板将病人逐步缓慢放平的方法可减小血压的波动.     

超声评价单侧颈内动脉闭塞者颈部动脉血流动力学改变

目的应用超声评价单侧颈内动脉闭塞患者颈部其他动脉血流动力学改变。方法 50例单侧颈内动脉闭塞患者(闭塞组)及50例体检健康者(对照组),超声检查其颈总动脉、颈内动脉、颈外动脉及椎动脉的内径、收缩期峰值血流速度(PSV)、舒张末期血流速度(EDV)、平均血流速度(MV)、搏动指数(PI)及阻力指数(RI),并计算颈总动脉与同侧颈外动脉的PSV比值、PI比值及RI比值。结果①闭塞组患侧颈总动脉的PSV、EDV及MV较健侧及对照组降低,PI和RI增加(P﹤0.05);患侧及健侧颈外动脉的PSV及MV较对照组增加(P﹤0.05);患侧椎动脉的内径、EDV、MV较健侧及对照组增加(P﹤0.05);健侧颈内动脉的PSV及MV较对照组增加(P﹤0.05)。②与健侧及对照组相比,患侧颈总动脉与颈外动脉的PSV比值、EDV比值及MV比值减小(P﹤0.01),PI比值和RI比值增大(P﹤0.05)。结论超声不仅可直接诊断颈内动脉闭塞,也可评价单侧颈内动脉闭塞后颈部其他动脉的血流动力学改变。     

腹腔镜精索静脉高位结扎术对睾丸动脉血流参数的影响

目的 应用彩色多普勒血流成像(CDFI)技术观察腹腔镜左侧精索静脉高位结扎术对该侧睾丸内动脉(ITA)和包膜动脉(CA)血流参数的影响.方法 选择29例左侧精索静脉曲张并行同侧腹腔镜精索静脉高位结扎术的患者,使用CDFI技术在术前1周和术后3、6个月检测双侧CA和ITA向心支的收缩期峰值流速(PSV)、舒张末期流速(EDV)、阻力指数(RI)及搏动指数(PI).结果 手术前后比较,患者左侧ITA和CA的RI、PI及PSV值均降低,差异有统计学意义(P＜0.05),其中RI、PI的改变较PSV降低更明显(P＜0.01).术后6个月各指标较术后3个月下降更明显,差异有统计学意义(P＜0.05),但EDV无明显变化,差异无统计学意义.患者右侧ITA和CA的各血流参数值手术前后比较差异均无统计学意义.结论 腹腔镜精索静脉高位结扎术后患者患侧ITA和CA的血流动力学参数均有显著改善;ITA和CA的RI、PI值可作为检测腹腔镜精索静脉结扎术后患者手术效果的一项重要指标.     

重型颅脑损伤病人体位变化对颅内压及脑灌注压的影响

[目的]分析重型颅脑损伤病人体位变化对颅内压(ICP)和脑灌注压(CPP)的影响.[方法]取12种不同体位,统计比较各种体位变化前后ICP、CPP变化.[结果]仰卧位头部抬高45°、仰卧屈膝位30°及45°可使颅内压明显降低,而左侧卧位头部抬高15°、右侧卧位头部抬高15°后颅内压则明显升高.左侧卧位头部抬高30°脑灌注压明显下降.[结论]不同体位可显著影响重型颅脑损伤病人颅内压和脑灌注压的变化.     

体位及头高位对重型颅脑损伤病人颅内压和脑灌注压的影响

[目的]探讨体位及头高位对重型颅脑损伤病人颅内压和脑灌注压的影响。[方法]收集2016年10月—2017年12月某三级甲等医院颅脑外伤病区50例住院病人为研究对象。在静息状态下,依次将病人置于仰卧位合并头位抬高0°、30°、45°,左半侧卧位合并头位抬高0°、30°、45°,右半侧卧位合并头位抬高0°、30°、45°,每种体位保持15 min。记录每种体位保持15 min时的颅内压、平均动脉压、心率、血氧饱和度,并计算得出相应脑灌注压。[结果]同一头高位,病人三种卧位下颅内压、平均动脉压、脑灌注压比较差异无统计学意义(P0. 05);同一体位,病人颅内压、平均动脉压、脑灌注压随头部抬高角度增加呈下降趋势,除脑灌注压在头高位30°与45°时差异无统计学意义(P0. 05)外,其余指标同一卧位不同头高位数据两两比较,差异均有统计学意义(P0. 05)。同一体位,病人头高位0°与45°相比,心率差异有统计学意义(P0. 05),同一体位不同头高位、同一头高位不同体位,病人血氧饱和度比较差异均无统计学意义(P0. 05)。[结论]重型颅脑损伤病人床头抬高30°,有利于控制颅内压、平均动脉压,保持脑灌注压水平的稳定,且对病人生命体征没有影响。     

Wheelchair propulsion technique at different speeds

To study wheelchair propulsion technique at different speeds, five well-trained subjects propelled a wheelchair on a treadmill. Measurements were made at four belt speeds of 0.56-1.39 m/s and against slopes of 2 and 3 degrees. Cardiorespiratory data were collected. Three consecutive strokes were filmed. Using markers on subject, wheelchair and treadmill frame a kinematic analysis was performed. Considerable inter-individual differences in propulsion style were found, but also general changes relative to speed occurred in the group as a whole. Cycle time decreased with speed, predominantly as the result of a shorter push time while push angle remained constant and the movement ranges of trunk and arms shifted with speed. It is concluded that despite different propulsion styles, general and continuous adaptations to speed changes occurred, mainly by flexion of the trunk and arms.     

Haemodynamic changes at different lung volumes

In 17 healthy males pulmonary blood flow distribution (PBFD), pulmonary artery pressure (PAP), wedge pressure (Pw), and cardiac output were measured at different lung volumes and body positions. The PBFD became more even and PAP increased at RV in the sitting position as compared to at FRC. PAP also increased at TLC, but PBFD became more uneven.In the lateral position the increased PAP at RV caused only a minor change in PBFD. In both erect and lateral position at RV the Pw close to the diaphragm increased more than did PAP.     

Sit-to-stand at different periods of pregnancy

OBJECTIVE: This study was performed to determine the biomechanics of chair rising by pregnant women. DESIGN: Relative body joint position and ground reaction forces were measured by a motion analysis system and one force plate. BACKGROUND: Physiological and psychological changes during pregnancy impose postural demands and limit the performance of daily living activities such as rising from sitting to standing position. METHODS: Twenty-four pregnant women, divided into three groups, were studied performing sit-to-stand transition from an armless and adjustable chair. By kinematic and kinetic analysis, the angles and moments of hip, knee and ankle joints were investigated. RESULTS: The chair height has great influence on knee joint and hip joint moments, but less on ankle joints. In the third trimester for all chair heights, because of a marked increase in abdominal depth, the maximum hip moment is significantly less than that in first trimester, while the maximum knee moment is significantly larger. Pregnant women in third trimester produced larger knee moment during sit-to-stand transition from lower chair height. CONCLUSIONS:The mechanism of sit-to-stand is affected by the physical changes of pregnant women at different periods of pregnancy, e.g. increased loading of knee joint and decreased hip joint moment, especially in the last trimester period of pregnancy.     

Stability of lactate dehydrogenase at different storage temperatures

The effect of storing human serum, cord blood serum or heparinized plasma at 25 degrees C, 4 degrees C & -20 degrees C on the activity and isoenzyme distribution of lactate dehydrogenase (LD) was studied. Cellulose acetate and agarose electrophoresis, as well as an immunochemical inhibition technique, were used for isoenzyme quantification. In contrast to previous reports, cryo-instability was found only in specimens stored at 4 degrees C. Serum specimens stored at 25 degrees C and -20 degrees C retained 74% and 87% of total activity after 45 days of storage. LD-1 was stable at all three temperatures, with a maximum loss of 10%. LD-2, LD-3, LD-4, & LD-5 were most labile at 4 degrees C. Specimens that are to be analyzed for total LD or LD isoenzymes should be stored frozen or, if necessary, at room temperature, but not in a refrigerator. Thus, separate storage of specimens for cardiac isoenzymes (LD & creatine kinase) is not necessary. This may eliminate a possible source of falsely elevated LD-1/LD-2 ratios, as well as reducing the labor factor and the corresponding cost of cardiac isoenzyme determinations.     

Pharmacokinetics of intravenous ciprofloxacin at three different doses

The pharmacokinetics of ciprofloxacin were evaluated after single iv bolus injections of 50, 100 and 250 mg in eight young, healthy male volunteers. Concentrations were determined by high-performance liquid chromatography. The mean terminal half-life was 3.33, 3.73 and 3.45 h for 50, 100 and 250 mg doses, respectively. No significant differences between the three dose levels were noted for terminal half-life, total and renal clearances, distribution volume (Vd(ss] and percentage of dose recovered in urine over 24 h. The areas under the serum concentration curves were proportional to the given dose. We conclude that distribution and elimination of ciprofloxacin is not dose dependent.