Application of intraoperative arterial pressure-based cardiac output monitoring for patients undergoing coronary artery bypass grafting surgery

Background For patients undergoing off-pump coronary artery bypass grafting （OPCABG）, it is important to establish a hemodynamic monitoring system to obtain powerful parameters for better intraoperative treatment. This study aimed to observe the clinical feasibility of arterial pressure-based cardiac output （APCO） for cardiac output （CO） monitoring and to evaluate the correlation between APCO and pulmonary artery catheter （PAC） for CO measurement for patients undergoing OPCABG intraoperatively. Methods Fifty patients of American Society of Anaesthesiologists （ASA） classification Ⅱ-Ⅲ, undergoing elective OPCABG at Beijing Anzhen Hospital were randomly enrolled into this study. All patients were assigned to CO monitoring by PAC and APCO simultaneously. Patients with pacemaker, severe valvular heart disease, left ventricular ejection fraction （EF） 〈40%, cardiac arrhythmias, peripheral vascular disease, application of intra-aortic balloon pump （IABP） and emergent diversion to cardiac pulmonary bypass were excluded. The radial artery waveform was analyzed to estimate the stroke volume （SV） and heart rate （HR） continuously. CO was calculated as SV × HR; other derived parameters were cardiac index （CI）, stroke volume index （SVI）, systemic vascular resistance （SVR）, and systemic vascular resistance index （SVRI）. PAC was placed via right internal jugular vein and the correct position was confirmed by PAC waveforms. Continuous cardiac output （CCO）, CI and other hemodynamic parameters were monitored at following 5 time points： immediate after anesthesia induction （baseline value）, anastomosis of left internal mammary artery to left anterior descending artery （LAD）, anastomosis of left circumflex （LCX）, anastomosis of posterior descending artery （PDA） and immediate after sternal closure. Results In the 50 patients, preoperative echocardiography measured left ventricular EF was （52.8±11.5）%, and 35 patients （70%） showed regional wall motion abnormalities. The correlation coefficient of CO monitored by APCO and PAC were 0.70, 0.59, 0.78, 0.74 and 0.85 at each time point. The bias range of CI monitored from both APCO and PAC were （0.39±0.06） L.minl.m2, （0.48±0.12） L.min^-1.m2, （0.26±0.06） L.min1.m-2, （0.27±0.06） L.min-l.m2, （0.30＋0.05） L.min-l.m2 at each time point. The results of SVR by two hemodynamic monitoring techniques had good correlation during OPCABG. The variation trends of SVR were opposite comparing with the results of CO. SVR collected from PAC obtained the highest value of （1220.0±254.0） dyn.s.cm5 at PDA anastomosis, but the highest value obtained from APCO was （1206.0±226.5） dyn.s.cm-5 in LCX anastomosis. Conclusions APCO is feasible in hemodynamic monitoring for patients undergoing OPCABG The results of hemodynamic monitoring derived from APCO and PAC are closely correlated. Its characterizations of timely, accurate and continuous display of hemodynamic parameters are also obviously demonstrated in the present study.

Assessment of Stroke Volume Variation Perioperatively by Using Arterial Pressure with Cardiac Output

Objective To observe the sensitivity of stroke volume variation(SVV) for assessing volume change during induction period of general anesthesia. Methods Patients who underwent orthopaedic surgery under general anesthesia and mechanical ventilation were divided into two groups randomly. Patients in the group Ⅰwere subjected to progressive central hypovolemia and correction of hypovolemia sequentially; patients in the Group Ⅱ were exposed to hypervolemia alone. Each step was implemented after 5 minutes when the hemodynamics was stable. SVV and cardiac index(CI) were recorded, and Pearson's product-moment correlation was used to analyze correlation between SVV and CI. Results Forty patients were included in this study, 20 cases in each group. For group Ⅰ patients, SVV was increased significantly along with blood volume reduction, and changes in CI were negatively correlated with changes in SVV(r=-0.605, P<0.01); SVV decreased significantly along with correction of blood volume; changes in CI were negatively correlated with changes in SVV(r=-0.651, P<0.01). For group Ⅱ patients, along with blood volume increase, SVV did not change significantly; changes in CI revealed no significant correlation with changes in SVV(r=0.067, P>0.05). Conclusion SVV is a useful indicator for hypovolemia, but not for hypervolemia.

Comparison of Cardiac Output and Hemodynamic Responses of Intubation among Different Videolaryngoscopies in Normotensive and Hypertensive Patients

Tracheal intubation with Macintosh laryngoscope（MAC） might result in severe cardiovascular complications. The results of conducted studies investigating the effects of videolaryngoscopies on hemodynamic response of tracheal intubation are conflicting. We know little about the effects of videolaryngoscopies on cardiac output changes during tracheal intubation. We compared cardiac output（COP） and hemodynamic responses in normal blood pressure（n=60） and hypertensive patients（n=60） among 3 intubation devices： the MAC, the UE videolaryngoscopy ？（UE）, and the UE video intubation stylet ？（VS）. Cardiac index（CI）, stroke volume index（SVI）, heart rate（HR）, systolic blood pressure（SBP） and diastolic blood pressure（DBP） were recorded using Lidco Rapid V2？ preinduction, preintubation, and every minute for the first 5 min after intubation. We assessed oropharyngeal and laryngeal structures injury as well. Intubation time was significantly shorter than MAC groups（P〈0.001） only in UE group of normotensive and hypertensive patients. In normotensive patients, there were no significant differences in any of COP variables or hemodynamic variables among the three devices. In hypertensive patients, SBP and DBP in the MAC group were significantly higher（P〈0.05 or 〈0.01） than the UE and VS groups at 1, 2 and 3 min after intubation, but there were no significant differences in CI, SVI and HR among the three devices. There was no significant difference in oropharyngeal and laryngeal structures injury among all groups. It was concluded that both the UE and VS attenuate only the hemodynamic response to intubation as compared with the MAC in hypertensive patients, but not in normotensive patients.

Correlation of Electric Cardiometry and Continuous Thermodilution Cardiac Output Monitoring Systems

Purpose: Impedance Cardiography (ICG) with its drawbacks to reliably estimate cardiac output (CO) when compared to reference methods has led to the development of a novel technique called Electrical Cardiometry (EC). The purpose of this study was to compare EC-CO with the Continuous CO (CCO) derived from Pulmonary Artery Catheter (PAC). Methods: 60 patients scheduled to undergo coronary artery surgery necessitating the placement of PAC were studied in the operating room. Standard ECG electrodes were used for EC-CO measurements. Simultaneous CO measurement from EC and PAC was done at three predefined time points and were correlated. Results: A significant high correlation was found between the EC-CO and CCO at the three time points. Bland and Altman analysis revealed a bias of 0.08 L/min, a precision of 0.15 L/min, with a narrow limit of agreement (-0.13 to 0.28 L/min). The percentage error between the methods was 3.59%. Conclusion: The agreement between EC-CO and CCO is clinically acceptable and these two techniques can be used interchangeably. Mediastinal opening has no effect on the correlation between these two modalities.

Comparison of Cardiac Output Measurement by Noninvasive Method with Electrical Cardiometry and Invasive Method with Thermodilution Technique in Patients Undergoing Coronary Artery Bypass Grafting

Objective: This study was conducted to compare the cardiac output by using Electrical Cardiometry (EC), a noninvasive method of continuous cardiac output monitoring during cardiac surgery with pulmonary artery catheter (PAC) derived cardiac output. Design: Prospective observational clinical study. Setting: Cardiac surgery operating room of a tertiary care cardiac center. Participants: Twenty five patients undergoing coronary artery bypass surgery with cardiopulmonary bypass. Measurements and Main Results: A total of 150 double data of cardiac output were compared with Thermodilution Cardiac Output (TDCO) and Thoracic Electrical Bioimpedance (TEBCO). The TDCO value ranges from 1.8-6.9 litre·min-1 with a mean of 4.39 ± 1.16 litre·min-1 and TEBCO ranges from 1.8-7.1 litre·min-1 with a mean of 4.21 ± 1.16 litre·min-1. The averaged Bland-Altman analysis for TDCO and TEBCO revealed that a mean bias was 0.18 and limit of agreement was -1.25 - 0.89 litre·min-1 and the percentage error (PE) ranged from 22%-32%. The precision for the TDCO was measured to be ±16.2% and the precision for TEBCO was ±19.6%. Receiver Operating Characteristic (ROC) curve analysis between TDCO and TEBCO with a cutoff of 15% shows a sensitivity of 84% and specificity of 63 and area under ROC curve of 0.80. Mountain plot between TDCO and TEBCO shows that a median percentile is 0.25 and value of 97.5 percentile is 1.525. Conclusions: The present study indicates that the electric cardiometry device yields numerically comparable results to cardiac outputs derived from the PAC during the cardiac surgery. Therefore, electrical cardiometry can be used to evaluate haemodynamic variables with clinically acceptable accuracy, when invasive methods are to be avoided or not available.

Use of venous-to-arterial carbon dioxide tension difference to guide resuscitation therapy in septic shock

The mixed venous-to-arterial carbon dioxide(CO_2)tension difference[P(v-a) CO_2]is the difference between carbon dioxide tension(PCO_2) in mixed venous blood(sampled from a pulmonary artery catheter) and the PCO_2 in arterial blood.P(v-a) CO_2 depends on the cardiac output and the global CO_2 production,and on the complex relationship between PCO_2 and CO_2 content.Experimental and clinical studies support the evidence that P(v-a) CO_2 cannot serve as an indicator of tissue hypoxia,and should be regarded as an indicator of the adequacy of venous blood to wash out the total CO_2generated by the peripheral tissues.P(v-a) CO_2 can be replaced by the central venous-to-arterial CO_2 difference(△PCO_2),which is calculated from simultaneous sampling of central venous blood from a central vein catheter and arterial blood and,therefore,more easy to obtain at the bedside.Determining the △PCO_2 during the resuscitation of septic shock patients might be useful when deciding when to continue resuscitation despite a central venous oxygen saturation(SCVO_2) > 70%associated with elevated blood lactate levels.Because high blood lactate levels is not a discriminatory factor in determining the source of that stress,an increased △PCO_2(> 6 mmHg)could be used to identify patients who still remain inadequately resuscitated.Monitoring the △PCO_2 from the beginning of the reanimation of septic shock patients might be a valuable means to evaluate the adequacy of cardiac output in tissue perfusion and,thus,guiding the therapy.In this respect,it can aid to titrate inotropes to adjust oxygen delivery to CO_2 production,or to choose between hemoglobin correction or fluid/inotrope infusion in patients with a too low ScvO_2 related to metabolic demand.The combination of P(v-a) CO_2 or △PCO_2 with oxygen-derived parameters through the calculation of the P(v-a) CO_2 or △PCO_2/arteriovenous oxygen content difference ratio can detect the presence of global anaerobic metabolism.

不同潮气量和PEEP对脉搏轮廓法与经肺热稀释法测量巴马猪心排血量的影响

【目的】探究机械通气时不同潮气量和呼气末正压(PEEP)对脉搏轮廓法与经肺热稀释法测量巴马猪心排血量的影响。【方法】选取实验用巴马猪12只,随机分为对照组(肺动脉导管热稀释法)、研究组A(经肺热稀释法)和研究组B(脉搏轮廓法),各4只。建立模型,采用不同方法测量心排出量,分析其一致性,比较不同潮气量和PEEP对心排出量的影响。【结果】脉搏轮廓法与热稀释法测定猪心排血量的相关系数为r=0.754,两者具有正相关性。经肺热稀释法与热稀释法测定猪心排血量的相关系数为r=0.771,两者具有正相关性。脉搏轮廓法、与热稀释法测定猪心排血量相对误差为13.5%,两者具有一致性。经肺热稀释法与热稀释法测定猪心排血量相对误差为12.9%,两者具有一致性。随着潮气量增加,心排出量值明显降低,差异具有统计学意义(P<0.05)。随着PEEP增加,猪心排出量明显降低,差异具有统计学意义(P<0.05)。【结论】脉搏轮廓法、经肺热稀释法与热稀释法测定猪心排血量的一致性良好;当机械通气潮气量或PEEP增加时猪心排血量逐渐下降。

冠状动脉旁路移植术后低心排血量综合征的危险因素分析及预测模型构建

目的探讨冠状动脉旁路移植术(CABG)后发生低心排血量综合征(LCOS)的危险因素并构建预测LCOS发生风险的列线图模型。方法选择2019年10月至2022年5月于河南省人民医院心脏中心行CABG手术的231例冠状动脉粥样硬化性心脏病(CAHD)患者为研究对象,将患者按照7:3的比例随机分为训练集(n=162)和验证集(n=69)。比较训练集与验证集患者的各项参数,以明确训练集与验证集患者的可比性。根据CABG术后是否发生LCOS,将训练集患者分为LCOS组(n=33例)和非LCOS组(n=129例),并对训练集中的样本参数进行单因素和多因素logistic回归分析,得出CABG术后发生LCOS的独立危险因素,构建CABG术后LCOS发生风险的列线图预测模型,使用受试者操作特征曲线、校准曲线和决策曲线分析评估模型的区分度、校准度和临床适用性。结果训练集和验证集患者的LCOS发生率分别为20.37%(33/162)和18.84%(13/69)。训练集和验证集患者的各项参数比较差异均无统计学意义(P>0.05)。训练集中非LCOS组与LCOS组患者的年龄、心率、血尿素氮、血清肌酐、估测肾小球滤过率(eGFR)、血清N端B型钠尿肽前体(NT-proBNP)、血清肌钙蛋白T、左心室射血分数(LVEF)、二尖瓣反流面积、合并心肌梗死史、纽约心脏病学会分级Ⅲ~Ⅳ级占比、体外循环手术占比、手术时间、术中出血量以及术后血流动力学指标中心静脉压、肺动脉舒张压、肺动脉搏动指数(PAPI)比较差异有统计学意义(P<0.05)。多因素logistic回归分析显示,术前LVEF降低[比值比(OR)=0.891,95%置信区间(CI):0.832~0.954,P=0.001]、术前eGFR降低(OR=0.963,95%CI:0.934~0.994,P=0.018)、术前NT-proBNP升高(OR=1.001,95%CI:1.000~1.001,P=0.006)、手术时间增加(OR=1.013,95%CI:1.003~1.022,P=0.008)及术后PAPI降低(OR=0.094,95%CI:0.028~0.319,P=0.000)是CABG术后发生LCOS的独立危险因素。基于上述指标构建列线图模型。列线图模型在训练集中预测LCOS发生风险的曲线下曲积为0.931(95%CI:0.890~0.972),灵敏度为82.20%,特异度为90.90%;在验证集中预测LCOS发生风险的曲线下曲积为0.907(95%CI:0.813~1.000),灵敏度为96.40%,特异度为84.60%;说明该模型具有很高的区分度;校准曲线显示,在训练集和验证集中列线图模型的预测概率与实际发生概率具备良好的一致性(平均绝对误差分别为0.038、0.026);Hosmer-Lemeshow拟合优度检验显示,模型预测LCOS发生概率和实际发生概率的预测偏差均无统计学意义(χ^(2)=6.381、6.907,P>0.05),表明该模型具有良好的校准度。结论术前LVEF降低、术前eGFR降低、术前NT-proBNP升高、手术时间增加和术后PAPI降低是CABG术后CAHD患者发生LCOS的独立危险因素,基于以上5个因素建立的预测LCOS发生风险的列线图模型具有较高的区分度、良好的校准度和较好的临床适应性,可有效预测CABG术后LCOS的发生。

体外膜氧合成功救治左冠状动脉异常起源于肺动脉术后低心排血量综合征患儿1例

左冠状动脉异常起源于肺动脉(anomalous left coronary artery origin from pulmonary artery,ALCAPA)是一种发病率低、预后较差的先天性心脏畸形,常在婴儿期需要外科手术矫治。低心排血量综合征是指各种原因导致心排出量降低的一种病理异常表现,是心脏术后导致患者死亡的主要原因之一。体外膜氧合(extracorporeal membrane oxygenation,ECMO)是一种可以临时替代心肺功能的装置,在重症及急救领域应用广泛,但在ALCAPA术中及术后应用相关经验报道较少,本文分享一例ECMO成功救治ALCAPA术后低心排血量综合征的案例。

每搏连续无创血压监测系统在心脏瓣膜术后低心排血量综合征监护中的应用

目的:探讨每搏连续无创血压(continuous noninvasive arterial pressure,CNAP)监测系统在心脏瓣膜术后低心排血量综合征(low cardiac output syndrome,LCOS)监测中的应用价值。方法:选取福建省立医院2020年4月-2022年4月心脏瓣膜术后合并LCOS患者76例。随机将其分为对照组(n=44)和CNAP组(n=32)。对照组给予常规治疗,CNAP组给予CNAP指导治疗。比较两组瑞芬太尼、丙泊酚、多巴酚丁胺和去甲肾上腺素总用量,ICU住院时间,有创机械通气时间,液体平衡总量。结果:两组瑞芬太尼、丙泊酚总用量、ICU住院时间、有创机械通气时间比较,差异均无统计学意义(P>0.05)。CNAP组多巴酚丁胺总用量、去甲肾上腺素总用量、液体平衡总量均小于对照组,差异均有统计学意义(P<0.05)。结论:应用CNAP指导心脏瓣膜术后LCOS患者的治疗能够优化此类患者术后的血流动力学管理。

左西孟旦治疗冠状动脉旁路移植术后低心排出量综合征的成本-效果分析

目的从中国医疗保健体系角度,评估左西孟旦联合常规治疗方案(左西孟旦组)对比常规治疗方案(常规组)治疗冠状动脉旁路移植术(CABG)术后低心排出量综合征(LCOS)的成本-效果。方法基于一项国外多中心随机临床试验开展基础分析,成本参照新疆地区药品中标价和医疗服务收费标准,效用值参照国外已发表文献,构建决策树模型分析两方案的成本-效果,采用单因素、概率敏感性分析评估基础分析结果的稳健性。基于中国人群研究进行情景分析,分析方法同基础分析,评估两方案在中国人群中的成本-效果分析结果及其稳健性。结果基础分析表明:左西孟旦组对比常规组成本减少138.77元、效果增加0.000042个质量调整生命年(QALYs),具有绝对成本-效果优势,其敏感性分析表明某些成本及概率参数变动可能带来基础分析结果的偏差。情景分析表明:左西孟旦组对比常规组成本低(-2702.88元),效果相似(-0.000143 QALYs),未反转基础分析结果,其敏感性分析表明该情景分析结果具有稳健性。结论以中国医疗保健体系为研究角度,左西孟旦联合常规治疗方案对比常规治疗方案治疗CABG术后LCOS更有成本-效果优势,建议临床决策在考虑经济性时,优先使用左西孟旦联合常规治疗方案。

主动脉球囊反搏术对脓毒症休克合并低心排血量患者心脏指数、动脉血乳酸水平及短期预后的影响

目的探讨主动脉球囊反搏术(IABP)对脓毒症休克合并低心排血量患者心脏指数、动脉血乳酸水平及短期预后的影响。方法回顾性分析336例脓毒症休克合并低心排血量患者的临床资料,根据是否应用IABP治疗分为对照组165例和观察组171例。给予对照组患者常规治疗,给予观察组常规治疗联合IABP治疗。比较两组患者干预前后的心脏指数及动脉血乳酸水平,以及入院28 d内的病死率。结果干预后,对照组患者心脏指数低于干预前,动脉血乳酸水平高于干预前,而观察组患者心脏指数高于干预前及对照组,动脉血乳酸水平低于干预前及对照组(均P<0.05)。观察组入院28 d内的病死率低于对照组(P<0.05)。结论在常规治疗的基础上应用IABP治疗,可提高脓毒症休克合并低心排血量患者的心脏指数,降低动脉血乳酸水平,改善患者短期预后。

快速输液条件下温度稀释法与动脉压法心输出量测定的比较

目的比较温度稀释法与动脉压法心输出量(CO)测定的不同,并观察快速输液条件下血流动力学的变化。方法选择ASAⅠ或Ⅱ级的骶骨肿瘤手术患者10例,麻醉诱导后,放置Swan-Ganz导管、FloTrac传感器和Vigileo监护仪,温度稀释法间断测定心输出量(ICO),动脉压法测定心输出量(APCO)。手术开始前30min内输注10ml/kg羟乙基淀粉130/0.4注射液,测定液体输注前后HR、MAP、CVP、肺动脉楔压(PAWP)、ICO、每搏量变异度(SVV)、APCO、每搏输出量指数(SVI)。采用Bland-Altman分析,比较两种方法测量CO的差异。结果 APCO-ICO的均数为-0.10L/min,95%CI为-1.14～0.94L/min。(APCO+ICO)/2的均数为5.97L/min,与95%区间的最大绝对值1.14L/min相比临床可以接受。快速液体后,CVP、PAWP、APCO和SVI明显升高(P<0.05或P<0.01);而SVV明显低于输液前(P<0.01);HR和MAP无明显变化。结论动脉压法测定CO与温度稀释法相关性好,可为围术期提供有效的血流动力学监测。

单中心1098例冠状动脉旁路移植手术患者围手术期危险因素分析

目的:连续进行1098例冠状动脉旁路移植术(coronary artery bypass grafting,CABG),其中包括113例左室射血分数(left ventricular ejection fraction,LVEF)低于35%的病例,分析与围手术期死亡相关的危险因素。方法:回顾性采集北京大学第一医院心脏外科1999年12月至2009年12月1 098例CABG手术临床资料,对全组患者分别进行单因素分析和Logistic多因素回归分析,筛选死亡相关危险因素。结果:对全组病例进行单因素分析,影响预后的危险因素是年龄、急性冠脉综合征、急诊手术、术前慢性肾功能不全、合并周围血管病变、左室射血分数(LVEF)≤35%、左室舒张末内径(left ventricular end diastolic diameter,LVEDD)、中度以上的二尖瓣返流、室壁瘤形成、主动脉瓣返流、同期二尖瓣成形或置换、室壁瘤切除、同期主动脉瓣置换、围手术期使用主动脉内球囊反搏(in-tra-aortic balloon pump,IABP)、使用左心辅助装置(left ventricular assist device,LVAD)和非体外循环下(off-pump)CABG手术等;进行多因素回归分析时,非体外循环下off-pump CABG对于围手术期的预后倾向于是保护性因素;而年龄、性别(女性)、急诊手术、术前慢性肾功能不全和围术期使用IABP是明确的危险因素。结论:年龄、女性、急诊手术、术前慢性肾功能不全和围手术期使用IABP,对于全部患者是与预后相关的危险因素,需特别注意并谨慎处理;CABG同期合并其他非心脏手术以及同期处理中度以上的二尖瓣返流和室壁瘤切除、左室重建均不是影响围手术期预后的危险因素。

FloTrac/Vigileo_(V3.0)系统在肝移植手术中的应用

目的比较FloTrac/VigileoV3.0系统监测心排血量（APCO）在肝移植手术中与SwanGanz漂浮导管经肺动脉连续心排血量（PCCO）的一致性,探讨其在肝移植手术中应用的可行性和指导术中容量治疗的临床意义。方法随机选择肝移植手术患者30例,所有患者均同时分别应用APCO和PCCO连续监测心排血量,并于麻醉后2h（T1）、无肝期前（T2）、无肝期2min（T3）、无肝期35min（T4）、新肝期2min（T5）、新肝期30min（T6）、新肝期2h（T7）及术毕（T8）,记录患者的心排量（CO）、周围血管阻力（SVR）、每搏量变异（SVV）等血流动力学参数。Bland-Altman分析法综合分析两种方法监测结果的一致性。结果与T1时比较,T2～T5时SVV明显升高,T6时SVV明显降低;T2、T3、T6～T8时PCCO明显升高,T4、T5时明显降低;T2、T5～T8时APCO明显升高,T3、T4时明显降低（P〈0.05或P〈0.01）。T1～T4、T6～T8时PCCO均明显高于APCO,T5时明显低于APCO（P〈0.05或P〈0.01）。除T3和T5时点外,APCO与PCCO的变化趋势一致,二者的一致性较好。结论 FloTrac/VigileoV3.0监测系统与Swan-Ganz漂浮导管经肺动脉连续心排血量监测的监测结果之间有较好的一致性,用于肝移植手术中连续监测CO具有可行性,可以用于指导容量治疗。

血流动力学监测——动脉轮廓法和肺动脉导管法的对比性研究

目的探讨动脉轮廓法(PiCCO)在血流动力学监测中的准确性。方法30例危重患者因不同病因入住ICU,每例患者均同时行PiCCO和肺动脉导管法(PAC)对血流动力学进行监测,于同一时间点采集两种方法的血流动力学数据,比较两种方法的相关性。结果两种方法所测心输出量(CO)、心脏指数(CI)、每搏输出量(SV)、体循环阻力(SVR)有很好的相关性,r值分别是0.865、0.879、0.824、0.833,差异有统计学意义(P<0.001)。结论PiCCO可以及时、快捷、连续地反映血流动力学状态。

被动抬腿试验预测感染性休克患者容量反应性的临床研究

目的评价被动抬腿试验（PLR）联合外周动脉压心排量监测（arterialpressurewaveformaJlalysisofcardiacoutput，APCO）技术预测感染性休克患者容量反应性的价值。方法本研究采用前瞻性、观察性队列研究的设计方法，选择2011—04～2012—03我院重症医学科（ICU）的感染性休克患者纳入研究。所有患者均先后进行PLR和扩容，并用APCO持续监测PLR前后和扩容前后各项血流动力学指标的变化。根据对扩容的反应（扩容后SV增加≥15％为有反应）将患者分为有反应组和无反应组，用受试者工作特征曲线（ROC曲线）评价PLR预测容量反应性的价值。结果共有47例感染性休克患者纳入本研究，扩容后有反应者占55．3％（26／47）。反应组PLR后SV较之前明显增加[（76．5±23．4）mL比（65．1±20．5）mL，P〈0．05]，而无反应组PLR前后SV无明显变化（P〉0．05）；PLR期间ASV与扩容后ASV呈显著正相关（r=0．653，P=0．024）；PLR预测容量反应性的ROC曲线下面积（AUC）为0．945±0．047，以PLR-△SV≥13％预测容量反应性的敏感性和特异性分别为83．0％和92．5％。结论用APCO测量由PLR所引起的SV变化能精确预测感染性休克患者液体治疗时的容量反应性，可用来指导临床液体治疗。

心率、左心室功能指数和冠状动脉强化CT值的相关性研究

目的：探讨心率、心输出量、每搏输出量和射血分数在冠状动脉CT血管造影（coronary computed tomography angiography,CCTA）检查中与冠状动脉强化CT值的相关性。方法：选择连续进行CCTA的患者74例,对比剂注射参数相同,所得数据按R-R间期的0%～90%以10%为间隔进行重建,所得数据进行左心室功能定量分析,包括心输出量、每搏输出量和射血分数,并比较左心功能参数和心率与冠状动脉强化CT值的相关性。结果：心率与冠状动脉强化CT值呈负相关,并有统计学意义（R=-0.454,P=0.000）。心功能指数中,心输出量和冠状动脉强化CT值呈负相关,并有统计学意义（R=-0.498,P=0.000）,而射血分数和每搏输出量与冠状动脉强化CT值没有相关性（R=-0.089,P=0.451和R=-0.195,P=0.096）。结论：在对比剂注射参数相同的情况下,冠状动脉强化CT值随着心率和心输出量的增加而下降。

FloTrac/Vigileo系统用于冠状动脉搭桥术中血流动力学监测

目的:观察FloTrac/Vigileo系统在非体外循环冠状动脉旁路移植术(OPCABG)血流动力学监测中应用的可行性,分析其与肺动脉导管(PAC)心排量监测(CCO)结果的相关性。方法:随机选择50例择期OPCABG的患者,所有患者同时应用连续心排出量(APCO)和CCO进行心排量(CO)监测,分别在切皮前、吻合左冠状动前降支、吻合回旋支、吻合后降支、关胸后5个时间点,测定2种方法监测的CO、心排指数(CI)及其他血流动力学参数。结果:术中在固定器放置、改变心脏位置、血管活性药物及使用正性肌力药情况下,APCO监测结果均有所改变,变化趋势与PAC监测结果一致。2种监测方法在各时间点监测的CO值的相关系数(r)分别为0.70,0.59,0.78,0.74及0.85,各时间点CI差值的偏倚范围分别为:(0.39±0.06)L.min-1.m-2、(0.48±0.12)L.min-1.m-2、(0.26±0.06)L.min-1.m-2、(0.27±0.06)L.min-1.m-2及(0.30±0.05)L.min-1.m-2,提示2种方法监测结果有较好的相关性。2种监测方法所得(SVR)在吻合血管时变化趋势与各自监测所得CO变化趋势相反。结论:APCO用于OP-CABG术中连续CO监测具有可行性,与PAC监测法所得CO结果相关,监测结果体现了较好的即时性和动态性。

慢性肝病原位肝移植围术期肺血流变化的研究

目的 研究原位肝移植围术期肺血流的变化。方法 经Swan Ganz漂浮导管和桡动脉导管监测原位肝移植围术期血流动力学参数 ,并与术前比较。结果 心率在无肝期开始增快 ;血压在新肝早期明显下降 ,术后有增高的趋势 ;肺动脉压在新肝期开始有显著增高 ,术后仍继续增高 ;肺动脉楔压与肺动脉压变化基本一致 ;术前心输出量高于正常 ,术中转流期有明显下降 ,术后 4 8h内趋于术前水平 ;体循环阻力在转流期中显著增高 ,新肝期始恢复 ,术后 4 8h趋于术前水平。肺循环阻力术前低于正常 ,术中无明显变化 ;术毕及术后 4 8h显著增高。结论 监测原位肝移植围术期患者肺血流的改变对预防和控制肺部并发症、心功能不全具有重要意义。