Effect of pulse pressure on the predictability of stroke volume variation for fluid responsiveness in patients with coronary disease

Purpose

We hypothesized that the predictability of stroke volume variation (SVV) on fluid responsiveness would be reduced in patients with coronary disease who have wide pulse pressure (PP).

Methods

Sixty-six patients undergoing coronary surgery were divided into 2 groups according to the PP measured 1 day before surgery: normal PP (n = 33, PP ≤ 60 mm Hg) or wide PP (n = 33, PP > 60 mm Hg). After applying mechanical ventilation, hemodynamic parameters (including SVV measured by the FloTrac/Vigileo system [Edwards Lifesciences, Irvine, Calif]) were recorded before and 10 minutes after fluid replacement in a closed-chest condition. Prediction of fluid responsiveness was tested by calculating the area under the receiver operating characteristic curves.

Results

Twenty-one patients in the normal PP and 16 patients in the wide PP condition were fluid responders. The area under the receiver operating characteristic curves of SVV to predict fluid responsiveness were 0.808 (P = .022) and 0.609 (P = .288) in the normal PP and wide PP patients, respectively. In the normal PP condition, a SVV value of 13% discriminated between fluid responders and nonresponders with a sensitivity of 76% and a specificity of 67%.

Conclusions

In contrast to patients with normal PP, SVV does not predict fluid responsiveness in patients with coronary disease who have wide PP.     

Measurement of pulse wave velocity using pulse wave Doppler ultrasound: comparison with arterial tonometry

Pulse wave velocity (PWV), the speed of propagation of arterial pressure waves through the arterial tree, is related to arterial stiffness and is an important prognostic marker for cardiovascular events. In clinical practice PWV is commonly determined by arterial tonometry, with a noninvasive pressure sensor applied sequentially over carotid and femoral arteries. The electrocardiogram (ECG) is used as a timing reference to determine the time delay or "transit time" between the upstroke of carotid and femoral pulse waveforms. Commercially available vascular ultrasound scanners provide a pulsed wave (PW) Doppler velocity signal, which should allow determination of carotid-femoral transit time and hence PWV. We compared carotid-femoral PWV measured by tonometry and by PW Doppler ultrasound (Seimens, Apsen scanner with 7 MHz linear transducer) in asymptomatic subjects (n = 62, 26 male, aged 21 to 72 y). To test for intra-subject and inter-observer variation, ten subjects were scanned by one observer on two occasions 2 wk apart and by two observers on same day. PWV by tonometry ranged from 5.3 to 15.0 m/s. There was no significant difference between mean values of PWV obtained by the two techniques (mean difference: 0.3 m/s, standard deviation of difference: 1.5 m/s), which were closely correlated (r = 0.83). The coefficient of variation for repeated measures on the same subject by the same observer was 10.1% and the inter-observer coefficient of variation was 5.8%. These results suggest a commercial ultrasound scanner can be used to measure PWV, giving results that are reproducible and closely correlated with those obtained by arterial tonometry. (E-mail: ben_yu.jiang@kcl.ac.uk).     

高血压病患者脉压与脑卒中初发及再发关系的临床研究

目的　探讨高血压病患者脉压对脑卒中发生的预测价值。方法　回顾性分析 785例高血压性脑卒中患者的脉压水平 ,并与同期住院的 10 0例非脑卒中高血压病患者作对照。结果　①脑卒中组与对照组的脉压有显著差异 (P <0 .0 5 ) ;②出血性与缺血性脑卒中的脉压无统计学差异 (P >0 .0 5 ) ;③再发与初发脑卒中组收缩压与脉压有显著差异 (P <0 .0 5 )。结论　脉压增大与脑卒中的发生有关 ,是引起脑卒中发生及再发的重要危险因素     

脉搏波传导速度评价动脉僵硬度的应用进展

动脉脉搏波传导速度（PWV）是反映动脉僵硬度的可靠指标,为临床评估动脉硬化提供了重要信息。近年来,随着科学技术的发展,PWV作为能够定量评价动脉僵硬度的指标,其检测效能和应用价值得到不断的提升,已被越来越多的临床工作者所认可。本文就PWV评价动脉僵硬度的研究进展进行综述。     

维持性血液透析患者脉压及相关因素分析

目的探讨维持性血液透析（MHD）患者的脉压水平及其相关因素。方法对北京大学人民医院血液净化中心90例MHD患者采用WelchAllyn血压计测定非内瘘侧上肢肱动脉血压并记录。脉压（PP）和平均动脉压（MAP）分别根据收缩压（SBP）-舒张压（DBP）和（SBP＋2DBP）/3计算得出。检测患者血生化指标和全段甲状旁腺素（iPTH）水平。采用Complior SP脉搏波速度（PWV）测定仪测定其单次透析前颈动脉-股动脉脉搏波速度（CFPWV）。对MHD患者PP与相关因素进行多元逐步回归。对糖尿病透析患者和非糖尿病透析患者进行独立样本t检验。36例性别、年龄匹配的健康成人作为对照。结果MHD患者PP（59.8±16.8）mmHg（1mmHg=0.133kpa）,SBP（140.9±20.4）mmHg,MAP（101.1±14.7）mmHg,CFPWV（13.22±3.23）m/s,均高于正常对照（P〈0.05）。多元逐步回归发现,年龄、糖尿病和CFPWV是MHD患者PP的独立影响因素。糖尿病患者SBP、PP及CFPWV明显高于非糖尿病患者（P〈0.05）,DBP低于非糖尿病患者,但差异无统计学意义。结论维持性血液透析患者脉压明显增加,SBP增高是其主要原因。年龄、糖尿病和CFPWV是脉压的独立影响因素。     

非透析慢性肾脏病患者大动脉僵硬度的临床研究

目的评估非透析慢性肾脏病（CKD）患者大动脉僵硬度并进行相关因素分析,探讨其意义。方法选取2006年4月～2007年10月在北京大学第三医院肾内科门诊随访的非透析CKD患者378例,测量颈股动脉脉搏波速度（CF-PWV）,生化指标并记录一般情况,进行相关分析。结果378例CKD患者的CF-PWV与年龄（r=0.494,P〈0.001）、收缩压（r=0.419,P〈0.001）、脉压（r=0.471,P〈0.001）、血糖（r=0.220,P〈0.001）、24h尿蛋白（r=0.245,P=0.003）、代谢综合征（r=0.220,P=0.001）正相关,与肌酐清除率（r=-0.261,P〈0.001）血HDL-C（r=-0.136,P=0.018）负相关,没有发现CKD患者CF-PWV与性别（r=0.100,P=0.052）、体重指数（r=-0.082,P=0.156）、血TG（r=0.004,P=0.951）、血钙磷乘积（r=-0.005,P=0.932）相关。回归分析时PWV的独立正相关因素是年龄（B=0.063,P〈0.001）,脉压（B=0.047,P=0.004）,24h尿蛋白量（B=0.6,P=0.001）。结论非透析CKD患者的CF-PWV与传统心血管危险因素及尿蛋白,肌酐清除率相关,可成为早期预测CKD患者CVD发生的检查方法,动脉硬化可能在CKD患者CVD发生中起重要作用。     

Ability of pulse contour and esophageal Doppler to estimate rapid changes in stroke volume

OBJECTIVE: Two technologies to acquire beat-to-beat stroke volume values exist, pulse contour analysis and esophageal Doppler monitoring. Pulse contour analysis assumes fixed aortic impedance. Esophageal Doppler assumes a constant proportional descending aortic flow and diameter. These assumptions may not be correct as arterial tone or myocardial contractility vary. We tested these relationships in the setting of rapidly changing stroke volumes and different cardiovascular states over a period of 10-15 cardiac cycles. DESIGN AND SETTING: In a university research facility we compared beat-to-beat changes in stroke volume as measure by aortic root flow probe or conductance catheter to pulse contour analysis and stroke distance as measured by esophageal Doppler. SUBJECTS: Five purpose-bred research hounds. INTERVENTIONS: To obtain a wide range of rapidly changing stroke volumes measurements were made during transient inferior vena cava occlusion. Data were gathered under baseline conditions and during norepinephrine, nitroprusside, and dobutamine infusions. MEASUREMENTS AND RESULTS: The pulse contour stroke volumes and esophageal Doppler stroke distance paralleled flow probe stroke volumes under all conditions (R(2)=0.89 for all measures). However, the absolute changes and proportional changes and the absolute values for both surrogate measures differed from absolute stroke volumes. Bland-Altman analysis showed no consistent bias or degree of precision across all animals under any given cardiovascular state. CONCLUSIONS: Both pulse contour stroke volumes and esophageal Doppler derived stroke distance estimates yield significant correlations with aortic root flow probe. However, the absolute values, absolute changes, or proportional changes may not reflect actual stroke volumes as cardiovascular state varies, making their use in estimating absolute changes in stroke volume potentially inaccurate.     

腹膜透析患者血尿酸与动脉僵硬度的相关性研究

目的动脉僵硬是心血管疾病的重要危险因素。本研究探讨腹膜透析患者血尿酸和动脉僵硬度的关系。方法采集158名稳定腹膜透析患者的临床和生化数据,测定其颈-股动脉脉搏波速度(CF-PWV)作为动脉僵硬度的指标。结果根据血尿酸浓度,患者被分为4组。在组间有显著性差异的指标有C反应蛋白(CRP)(P<0.05)和CF-PWV(P<0.01)。Pearson相关分析显示,和CF-PWV明显相关的因素包括收缩压(P<0.05)和尿酸浓度(P<0.01)。多元逐步回归分析显示,血尿酸浓度(β=-0.300,P=0.001)和钙磷乘积(β=0.179,P=0.027)是CF-PWV的独立影响因素。结论血尿酸水平和动脉僵硬度有独立的相关关系。血尿酸浓度升高和动脉僵硬度增加有关,可能参与了心血管事件的发生。     

动脉弹性功能参数与脉压的关系

目的:分析3种动脉弹性功能参数[脉搏波传导速度(PWV)、大、小动脉弹性指数(C1和C2)、压力反射波增强指数(AI)]与脉压(PP)间的关系,寻找能敏感反映动脉弹性改变的指标。方法:选择429例高血压患者,同时检测PWV、C1和C2、AI,根据PP水平分成4组,然后分析PP与动脉弹性功能参数间的相关性,比较不同PP水平组动脉弹性功能参数的差异。观察60例PP≥60mmHg高血压患者,治疗后PP下降程度与各动脉弹性功能参数改善间的相关性。结果:PP与PWV正相关,与C1负相关。在不同脉压水平4组间,PWV、C1﹑C2均有显著性差异(P<0.05),AI值仅在脉压≥60mmHg与<60mmHg间差异有显著性(P<0.05)。PP减小与PWV降低呈正相关,与C1升高呈负相关,而与C2﹑AI改变无显著相关。结论:PWV、C1是敏感反映动脉弹性改善与PP减小的大动脉弹性功能指标。     

2型糖尿病患者动态动脉僵硬指数和24h脉压的相关性研究

目的:探讨2型糖尿病患者动态动脉僵硬指数(AASI)与24 h脉压(24hPP)的相关关系.方法:入选2型糖尿病患者共100例,按照是否合并高血压分为:非合并高血压组(n=32例)和合并高血压组(68例).记录患者临床情况,包括性别、年龄、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、糖化血红蛋白(HbA1C)和尿微量白蛋白与肌酐的比值(ACR),记录患者24 h动态血压参数,包括24h平均收缩压(24hSBP)、24h平均舒张压(24hDBP)、24h脉压(24hPP)、夜间平均收缩压/白昼平均收缩压比值(nSBP/dSBP)、夜间平均舒张压/白昼平均舒张压比值(nDBP/dDBP).然后按AASI=1-舒张压对收缩压的回归斜率计算每个个体的AASI值.结果:两组患者在ACR、24hSBP、24hDBP、24hPP和AASI差异有显著性(均P＜0.05).AASI与年龄、ACR、24hPP、nSBP/dSBP和nDBP/dDBP有显著性相关性(均P＜ 0.05).结论:糖尿病患者,无论是否合并存在高血压,AASI均与24 h脉压存在密切的相关性,可以反映动脉的僵硬度.     

The effects of vasoactive drugs on pulse pressure and stroke volume variation in postoperative ventilated patients

Introduction

Although pulse pressure variation (PPV) and stroke volume variation (SVV) during mechanical ventilation have been shown to predict preload responsiveness, the effect of vasoactive therapy on PPV and SVV is unknown.

Methods

Pulse pressure variation and SVV were measured continuously in 15 cardiac surgery patients for the first 4 postoperative hours. Pulse pressure variation was directly measured from the arterial pressure waveform, and both PPV and SVV were also calculated by LiDCO Plus (LiDCO Ltd, Cambridge, United Kingdom) before and after volume challenges or changes in vasoactive drug infusions done to sustain cardiovascular stability.

Results

Seventy-one paired events were studied (38 vasodilator, 10 vasoconstrictor, 14 inotropes, and 9 volume challenges). The difference between the measured and LiDCO-calculated PPV was 1% ± 7% (1.96 SD, 95% confidence interval, r² = 0.8). Volume challenge decreased both PPV and SVV (15% to 10%, P < .05 and 13% to 9%, P = .09, respectively). Vasodilator therapy increased PPV and SVV (13% to 17% and 9% to 15%, respectively, P < .001), whereas increasing inotropes or vasoconstrictors did not alter PPV or SVV. The PPV/SVV ratio was unaffected by treatments.

Conclusion

Volume loading decreased PPV and SVV; and vasodilators increased both, consistent with their known cardiovascular effects. Thus, SVV and PPV can be used to drive fluid resuscitation algorithms in the setting of changing vasoactive drug therapy.     

维持性血液透析患者贫血与动脉硬化的关系

目的探讨维持性血液透析（maintenance hemodialysis,MHD）患者贫血与动脉硬化的关系。方法选取82名病情稳定的非糖尿病肾病MHD患者为研究对象,根据血红蛋白（Hb）浓度分组,A组,Hb浓度〈100g/L,45例;B组,Hb浓度≥100g/L,37例。应用高分辨二维超声测量透析患者颈动脉内膜-中层厚度（IMT）。记录各患者的临床观察指标,透前采血测定患者循环丙二醛（MDA）、超氧化物歧化酶（SOD）及其他生化指标,评估两组患者的Kt/V值,进行相关及多元回归分析以判断相应指标之间的关系,筛选颈动脉IMT的影响因素。结果A组患者颈动脉IMT、收缩压、脉压及MDA水平高于B组（P〈0.01）,A组SOD及白蛋白水平低于B组（P〈0.01）。Pearson相关分析显示MDA（r=-0.567,P=0.000）及SOD水平（r=0.482,P=0.000）与Hb浓度显著相关;颈动脉IMT与年龄（r=0.658,P=0.000）、收缩压（r=0.441,P=0.000）、Hb浓度（r=-0.398,P=0.000）、白蛋白（r=-0.483,P=0.000）及MDA（r=0.278,P=0.011）水平显著相关。多元线性逐步回归分析显示,Hb浓度、年龄、收缩压、白蛋白水平是影响颈动脉IMT的危险因素（R2=0.646,P〈0.001）。结论贫血与颈动脉IMT增厚密切相关,贫血是MHD患者颈动脉IMT增厚的独立危险因素。贫血可能通过氧化应激加重动脉硬化的发生。     

Effectiveness of yoga on arterial stiffness: A systematic review

ObjectivesArterial stiffness is a major cardiovascular (CV) risk and an independent strong predictor of CV morbidity and mortality. The aim of this systematic review is to evaluate the clinical or interventional studies that assessed the effectiveness of yoga on arterial stiffness in participants of any age or sex, healthy or with any conditions.DesignSystematic review of clinical trials or interventional studies.Data sourcesCochrane Library, Medline/PubMed, Scopus, and Google Scholar databases.Review methodsDatabases were searched till July 2019 for clinical trials or interventional studies whether controlled or uncontrolled, randomized or non-randomized studies assessing the effects of yoga on arterial stiffness. Quality of the studies was assessed by using Physiotherapy Evidence Database (PEDro) Scale.ResultsSeven full-text articles (total number of participants = 362) that evaluated the effect of yoga on arterial stiffness were included in this review. There were three randomized controlled studies and four were non-controlled studies (single group studies). Four studies have shown significant reduction in arterial stiffness, while three studies did not find any significant change in arterial stiffness. The beneficial effects of yoga intervention on arterial stiffness in young adults and elderly hypertensive patients are encouraging. Methodological quality was good for one study, moderate for two studies and poor for four studies.ConclusionsThis review shows that yoga practice is effective in preventing or reducing the arterial stiffness in young healthy and obese, and elderly hypertensive patients. As the methodology of many studies is of low quality and safety measures were not reported, there is a need of quality randomized controlled trials of yoga effects on arterial stiffness among high risk individuals.     

彩色三维多普勒超声在心搏出量计算方面的实验性研究

目的探讨彩色三维多普勒超声在心搏出量计算方面的应用价值.方法运用彩色三维多普勒超声对10只犬先后在三种状态下,即静息状态下正常心搏出量、注射多巴酚丁胺时的高心搏出量和结扎左冠状动脉前降支后出现的低心搏出量进行检查,测定犬在不同状态下通过主动脉瓣口横断面血流积分及心搏量的变化,并与热稀释法测定的数值比较.结果彩色三维超声计算犬在不同心功能状态下的每搏量与生理仪热稀释法测得相应的数值相关显著,其中①静息状态下正常心搏出量时两种方法测值分别为(13.45±5.56)ml与(13.90±4.02)ml,r=0.85;②注射多巴酚丁胺后高心搏出量时分别为(18.49±4.73)ml与(19.10±4.37)ml,r=0.90;③结扎冠脉后低心搏出量时分别为(10.24±4.13)ml与(11.31±3.92)ml,r=0.92.彩色三维超声与生理仪热稀释法两种方法所测定的心搏出量非常接近,总相关系数r=0.93,t检验差别无显著性意义.结论彩色三维多普勒超声在理论上不存在几何学方面的假设,可直接测量经过瓣口的血流量,是一项很具潜力的超声新技术.     

低钠透析对血液透析患者大动脉僵硬度的影响

目的大动脉僵硬度的金标准--腹主动脉脉搏波传导速度(pulse wave velocity,PWV)是终末期肾脏病患者全因死亡和心血管死亡的独立危险因素。在非透析人群,饮食钠摄入增多可升高PWV;反之,限盐可降低PWV。本研究旨在观察应用低钠透析液增加透析钠清除对血液透析患者大动脉僵硬度的影响。方法选择处于干体质量的稳定血液透析患者16名。先应用标准透析液(钠浓度138mmol/L)透析一1个月,再将透析液钠浓度降为136mmol/L透析4个月(低钠透析)。研究期间未对饮食钠进行限制和干预,并且每个月应用生物电阻抗仪对干体质量进行调节,以保持透析后容量状态稳定。同时测量PWV、44h动态血压,记录透析间期体质量增长、每月透析中低血压和肌肉痉挛的发生率。结果随着低钠透析,腹主动脉PWV显著下降(12.61±2.30比11.74±2.65m/s,P=0.005);44h动态收缩压和舒张压分别较基线水平下降10mmHg和6mmHg(1mmHg=0.133kpa),而透析后容量状态无明显变化;透析间期体重增长轻度下降(2.89±0.66比2.67±0.63kg,P=0.051)。低血压和肌肉痉挛的发生率无明显变化。结论降低透析液钠浓度可显著改善透析患者的大动脉僵硬度。     

对称动态动脉硬化指数对原发性高血压患者早期肾功能损害的预测

目的：探讨对称动态动脉硬化指数（S-AASI）对原发性高血压患者早期肾功能损害的预测价值。方法：选择原发性高血压患者300例,测量患者的动态血压参数并计算S-AASI,检测尿N-乙酰-β-D-氨基葡萄糖苷酶（NAG）/肌酐（NAG/Cr）,化验血清肌酐并计算Ccr。根据S-AASI的四分位数将受试者分为A、B、C、D 4组。比较4组患者各参数的差别,并行S-AASI与尿NAG/Cr等参数的多元相关回归分析。结果：①4组的年龄随S-AASI水平的增高依次增高（P〈0.05）。A、B组高血压病程差异无统计学意义（P〉0.05）,B、C、D组高血压病程依次延长,各组间比较差异有统计学意义（P〈0.05）。②4组之间的血清肌酐比较差异无统计学意义（P〉0.05）,但4组尿NAG/Cr及微量蛋白尿阳性率均依次增高,而Ccr依次降低,组间比较差异有统计学意义（P〈0.05）。③多元线性回归分析显示S-AASI与尿NAG/Cr（β=0.470,P〈0.001）、Ccr（β=-0.322,P〈0.05）具有相关性。尿NAG/Cr每增加1 IU/g,S-AASI相应增加0.005;Ccr每降低1 ml/（min.1.73 m2）,S-AASI相应增加0.003。结论：S-AASI可作为高血压早期肾功能损害的预测指标。     

New monitors of intravascular volume: a comparison of arterial pressure waveform analysis and the intrathoracic blood volume

Objective: Two new monitoring techniques, the analysis of arterial pressure waveform during mechanical ventilation and the determination of intrathoracic blood volume, were evaluated for preload assessment in a model of graded hemorrhage. Design: 8 anesthetized dogs bled of 10, 20, and 30 % of their blood volume, then retransfused and volume loaded with plasma expander. Central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), cardiac output, parameters of the arterial pressure waveform analysis [systolic pressure variation (SPV) and delta down (dDOWN)], and intrathoracic blood volume (ITBV) were measured at baseline and after each stage of hemorrhage and volume expansion. Results: The stroke volume index decreased significantly from 1.3 ± 0.4 ml/kg at baseline to 0.7 ± 0.2 ml/kg at 30 % hemorrhage and then increased after retransfusion and volume loading. The changes in the filling pressures during the various stages of hemorrhage were in the range of 1–2 mmHg. CVP decreased from 5.5 ± 0.9 to 3.1 ± 1.7 mmHg and PCWP from 8.0 ± 0.8 to 5.1 ± 1.2 mmHg at 30 % hemorrhage. Both filling pressures responded significantly to retransfusion; PCWP also changed in response to a volume load. SPV and dDOWN (expressed as percent of the systolic blood pressure during a short apnea) increased significantly from 6.7 ± 1.7 and 5.6 ± 3.2 %, respectively, at baseline, to 9.7 ± 2.6 and 8.1 ± 2.9 % after 10 % blood loss and to 13.1 ± 3.9 and 11.1 ± 3.8 % after 30 % hemorrhage. ITBV decreased significantly from 29.7 ± 4.5 to 26.8 ± 5.3 ml/kg after 10 % blood loss and to 23.1 ± 3.0 ml/kg after 30 % hemorrhage. ITBV, SPV, and dDOWN responded significantly to retransfusion and volume load. Significant correlations were found between the degree of volume change and dDOWN (r = 0.93), SPV (r = 0.96), ITBV (r = 0.95), CVP (r = 0.82), and PCWP (r = 0.90). Conclusions: The parameters of arterial pressure waveform analysis (SPV and dDOWN) and ITBV were sensitive estimates of cardiac preload during the early stages of hemorrhage. Measurement of SPV and dDOWN, being both sensitive and relatively noninvasive, has advantages over other methods of preload assessment but is limited to patients on controlled mechanical ventilation. ITBV, which supplies quantitative information about cardiac preload, is more invasive but can also be used in patients who are breathing spontaneously or who are on partial ventilatory support. Received: 6 June 1996 Accepted: 27 February 1977     

呼气末正压对每搏量变异评价容量准确性的影响

目的 探讨机械通气时呼气末正压(PEEP)对血流动力学及每搏量变异(SVV)评价容量状态准确性的影响.方法 将30只健康家猪充分镇静肌松,给予机械通气,并按随机数字表法均分为正常容量、低容量和高容量组3组,5 min内逐步释放20％家猪血容量建立低容量模型,输注相当于家猪20％血容量的羟乙基淀粉建立高容量模型,正常容量组不予任何处理.每组均按照随机顺序调节PEEP水平为0(PEEP0)、5(PEEP5)、10 (PEEP10)和15 cm H2O (PEEP15,1 cm H2O=0.098 kPa).采用脉搏指示连续心排血量(PiCCO)监测心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、心排血指数(CI)、每搏量指数(SVI)、外周血管阻力指数(SVRI)、胸腔内血容量指数(ITBVI)等血流动力学指标和SVV的变化.结果 正常容量组中随PEEP水平升高,HR、CVP、SVRI、SVV呈逐渐增加趋势,CI、SVI、ITBVI则呈逐渐降低趋势,均于PEEP15时达峰值或谷值,与PEEP0时比较差异有统计学意义[HR(次/min):124±18比88±12,CVP(mmHg,1 mm Hg=0.133 kPa):11±1比8±3,SVRI (kPa·s·L-1·m-2):289.6±81.5比215.0±79.1,SVV:(23±6)％比(11±2)％,CI (L·min-1·m-2):3.10.8比4.3±1.4,SVI(ml·min-1·m-2):26±7比41±4,ITBVI(ml/m2):440±43比49147,均P＜0.05];而MAP无明显变化.低容量组中随PEEP水平升高,HR、CVP、SVV逐渐升高,MAP、CI、SVI、ITBVI呈下降趋势,均于PEEP15时达峰值或谷值,与PEEP0时比较差异有统计学意义[HR(次/min):146±31比115±27,CVP(mmHg):11±2比5±1,SVV:(28±4)％比(20±5)％,MAP (mm Hg):90±26比115±19,CI (L·min-1·m-2):2.3±0.6比3.4±1.1,SVI(ml·min-1·m-2):20±6比31±9,ITBVI(ml/m2):355±34比396±53,均P＜0.05];而SVRI无明显变化.高容量组中随PEEP水平升高,SVV呈逐渐增加趋势,CI、SVI、ITBVI则呈降低趋势,均于PEEP15时达峰值或谷值,与PEEP0时比较差异有统计学意义[SVV:(18±4)％比(6±2)％,CI(L·min-1·m-2):4.5±0.9比5.0±1.2,SVI(m1·min-1 ·m-2):37±9比49±7,ITBVI (ml/m2):473±71比565±94,均P＜0.05];而HR、MAP、CVP、SVRI无明显变化.低容量组SVV较正常容量组显著升高,而高容量组SVV则较正常容量组显著下降.正常容量组不同PEEP水平时SVV与CI呈显著负相关(rPEE0P0=-0.831,rPEEP5=-0.790,rPEEP10=-0.875,rPEEP5=-0.560,P＜0.05或P＜0.01).结论 SVV能准确反映容量状态,高PEEP可能影响血流动力学及SVV监测的准确性.     

血液透析患者跟骨骨量减少与大动脉僵硬的关系

目的本研究旨在探讨血液透析患者低骨量与大动脉僵硬的关系。方法选择首都医科大学附属朝阳医院血液净化中心维持性血液透析患者41例。应用跟骨超声骨密度测定仪进行跟骨密度测定,同时测量颈总动脉僵硬度:采用日本Aloka Prosound α 10型彩色多普勒超声诊断仪,高分辨血管探头(频率7.5～13MHz),Echo-tracking技术(血管壁回声跟踪技术)测量颈总动脉僵硬度,以颈总动脉硬化参数β表示。β=[In(Ps/Pd)]/[(Ds-Dd)/Dd](Ds:血管收缩期内径,Dd:血管舒张期内径,Ps:收缩压,Pd:舒张压)。同时测定血清25-羟维生素D3、钙、磷、全段甲状旁腺素(intact parathyroid hormone,iPTH),C-反应蛋白、白蛋白、血脂水平。结果患者平均(57.0±12.3)岁。跟骨密度为(-2.1±0.8),14.6%的患者存在骨质疏松,58.5%的患者存在骨量减少;Pearson相关分析显示颈总动脉硬化参数β与跟骨密度呈负相关(r=-0.453,P=0.002);与血25-羟维生素D3呈负相关(r=-0.337,P=0.031);与血磷呈正相关(r=0.391,P=0.022);与平均动脉压呈正相关(r=0.298,P=0.043);与年龄呈正相关(r=0.477,P=0.002);而与校正后血钙、iPTH、C-反应蛋白、白蛋白、血脂水平无相关性。多元逐步回归分析显示,年龄(β=0.311,P=0.008)、跟骨密度(β=-0.218,P=0.043)是颈总动脉硬化参数β的独立影响因素。跟骨密度与25-羟维生素D3呈正相关(r=0.315,P=0.049);与年龄呈负相关(r=-0.381,P=0.014);与血磷呈负相关(r=-0.323,P=0.046),而与校正后血钙、iPTH无相关性。结论血液透析患者普遍存在低骨量,而低骨量与大动脉僵硬度增加独立相关。