浅快呼吸指数、中心静脉血氧饱和度及其变化率对机械通气患者拔管成功率的预测价值

目的:探讨浅快呼吸指数(RSBI)、中心静脉血氧饱和度(SCVO_2)及其变化率(ΔSCVO_2)对机械通气患者拔管成功率的预测价值。方法:采用前瞻性研究方法,选取重症监护室的机械通气患者70例次,按拔管结果分成拔管成功(ES)组和拔管失败(EF)组,比较2组SCVO_2、ΔSCVO_2及RSBI。结果:2组患者性别、年龄差异无统计学意义(P0.05)。2组自主呼吸试验(SBT)30min SCVO_2、ΔSCVO_2及RSBI差异有统计学意义(P0.05)。SBT 30 min SCVO_2与拔管成功率正相关(r=0.283,P=0.025),ΔSCVO_2和RSBI与拔管成功率负相关(r=-0.425,-0.282,P=0.001,0.025)。SBT 30min SCVO_2、ΔSCVO_2和RSBI的ROC下面积分别为0.697、0.810、0.651。结论:SBT 30 min SCVO_2、ΔSCVO_2和RSBI对机械通气患者拔管成功率具有一定的预测价值,ΔSCVO_2、SBT 30 min SCVO_2优于RSBI。     

中心静脉血氧饱和度对困难脱机病人拔管失败预测价值的临床研究

目的探讨中心静脉血氧饱和度(ScvO2)对困难脱机病人拔管失败的预测价值。方法机械通气超过48 h的困难脱机病人,其中成功经历两步脱机策略后给予拔除气管插管的病人入选为进一步的研究对象。拔管失败定义为在48 h内需要重新插管。根据定义进一步分为拔管成功(ES)组和拔管失败(EF)组,测量病人自主呼吸试验(SBT)前1 min及后30 min的各项参数。结果再插管率为32%。ScvO2的ROC曲线分析显示SBT开始后30 min,ScvO2下降5.4%,敏感性93%,特异性88%。结论 ScvO2是困难脱机病人拔管失败的一个早期的预测因子,下降5.4%以上可作为预测阈值。     

中心静脉血氧饱和度对困难脱机病人拔管失败预测价值的临床研究简

目的 探讨中心静脉血氧饱和度（ScvO2）对困难脱机病人拔管失败的预测价值.方法机械通气超过48 h的困难脱机病人,其中成功经历两步脱机策略后给予拔除气管插管的病人入选为进一步的研究对象.拔管失败定义为在48 h内需要重新插管.根据定义进一步分为拔管成功（ES）组和拔管失败（EF）组,测量病人自主呼吸试验（SBT）前1 min及后30 min的各项参数.结果 再插管率为32%.ScvO2的ROC曲线分析显示SBT开始后30 min,ScvO2下降5.4%,敏感性93%,特异性88%.结论 ScvO2是困难脱机病人拔管失败的一个早期的预测因子,下降5.4%以上可作为预测阈值.     

浅快呼吸指数对机械通气脑梗死患者撤机成功率的预测价值

目的研究浅快呼吸指数(RSBI)对机械通气脑梗死患者撤机成功率的预测价值。方法采用程序化撤机策略对机械通气>24h且符合筛查试验标准的急性脑梗死患者34例,根据撤机成功与否分为成功组23例,失败组11例。应用低水平压力支持通气法进行自主呼吸试验(SBT)。SBT前和开始3min时测定呼吸频率、潮气量、心率和血氧饱和度等指标。对通过3min SBT的患者继续完成120min SBT,持续监测上述指标,每15min记录1次,血气分析分别于30、60、120min采取。结果失败组合并冠心病比例、SBT后15、30、60、90、120min的RSBI较成功组明显升高(P<0.05)。SBT前和SBT后3、15、30、60、90、120min的RSBI与撤机结果的ROC曲线下面积分别为0.581、0.745、0.658、0.838、0.925、0.889、0.881,提示SBT 60min时的RSBI预测撤机的准确性最高。SBT 60min时,以RSBI≤60次/(min·L)为标准,RSBI预测撤机成功的敏感性为100%,特异性为81.81%,准确性为84.12%。结论动态观察RSBI对机械通气脑梗死患者撤机成功率有一定的预测价值。     

下腔静脉变异度和中心静脉血氧饱和度变化率对机械通气患者撤机的预测价值

目的探讨下腔静脉变异度(ΔDIVC)和中心静脉血氧饱和度变化率(ΔSCVO 2)对机械通气患者撤机的预测价值。方法选择2012年10月~2015年10月河北省胸科医院收治进入ICU的患者268例的资料进行回顾性分析。根据患者是否撤机成功分为对照组和观察组,对照组为拔管成功,观察组为拔管失败。对比两组的一般情况、各项撤机指标。分析ΔDIVC和ΔSCVO 2对机械通气患者撤机的预测价值、ΔDIVC和ΔSCVO 2的相关性。结果在全部268例患者中,有73例撤机后再插管,对照组195例,观察组73例。观察组的改良呼吸机撤机指数、ΔDIVC、ΔSCVO 2均大于对照组(P<0.05)。利用改良呼吸机撤机指数、ΔDIVC和ΔSCVO 2对机械通气患者撤机是否能够进行预测,最佳截断值分别为21.63(分)、24.65、4.75,约登指数分别为26.06%、37.44%、34.23%。ΔDIVC和ΔSCVO 2之间呈正相关(r=0.104,P<0.05)。结论ΔDIVC和ΔSCVO 2对机械通气患者是否应该撤机具有一定的预测价值,但是在工作中,需要参考更多的指标进行全面分析后得出准确的判断。     

持续中心静脉血氧饱和度监测在围术期处理中的应用现状

<正>血氧饱和度是指血红蛋白(Hb)氧含量与氧容量的百分比。临床上常用的血氧饱和度监测指标,包括混合静脉血氧饱和度(SvO2)、中心静脉血氧饱和度(ScvO2)及经皮血氧饱和度。静脉血氧饱和度可反映组织氧合程度和组织灌注水平,也可作为评估机体氧供需平衡的工具[1]。在行较大外科手术     

观察导管补偿模式(TC)行自主呼吸试验(SBT) 对呼吸衰竭患者拔管成功率的影响

目的探讨导管补偿模式(TC)下,达到拔出气管插管指证的患者,实行自主呼吸试验(SBT),对其拔管成功率的影响。方法选取2015. 5月-2017. 9月在济宁市第一人民医院重症监护二区住院治疗的45例机械通气患者,随机分成ATC组(25例)和PSV组(20例),根据指南治疗后病情稳定,并达到拔管指证。ATC组采用自动导管补偿模式,PSV组应用低水平压力(PS 8cmH_2O),各自进行自主呼吸试验(SBT) 1h,结束后,检测并记录以下通气参数:潮气量(V_T)、气道峰压(PIP)、呼吸频率(RR)、血氧饱和度(SaO_2)、气道闭合压(P0. 1)、最大吸气压(Pimax)和呼吸浅快指数(RSBI),比较两组患者各呼吸力学参数的差异。结果 ATC组患者的P0. 1、Pimax、RSBI和RR高于PSV组,有统计学差异(P 0. 05),而PIP、V_T和SaO_2与PSV组无统计学差异(P 0. 05)。结论对于预拔管的呼吸衰竭患者,采用ATC法进行自主呼吸试验时,较应用低水平PSV试验通气模式拔管成功率更高。     

4种不同体位对机械通气危重症患者中心静脉压的影响

【】目的 分析4种不同体位对机械通气危重症患者中心静脉压(CVP)测量的影响,并探讨平卧位与其他3种体位CVP间的定量关系。方法：采用前瞻性自身对照研究,选取45例机械通气危重症患者作为研究对象,分别测量研究对象平卧位(0°)、30°、45°和60°卧位时的CVP、平均动脉压(MAP)、血氧饱和度(SpO₂)、心率(HR)、呼吸频率(RR)。采用重复测量方差分析和配对t检验比较不同体位CVP间的差异,采用简单回归分析方法探讨平卧位与其他卧位CVP间的定量关系。 结果：①平卧位、30°、45°和60°卧位CVP测量值分别为(10.71 ± 4.85)cmH₂O、(9.64 ± 4.93)cmH₂O、(9.11 ± 4.97)cmH₂O和(8.58 ± 5.06)cmH₂O,两两比较差异均有统计学意义(P<0.05)。②平卧位与30°卧位CVP间相关系数为0.99(P<0.01),线性回归方程为CVP_平卧=0.98*CVP_30°卧位 1.31；平卧位与45°卧位CVP间相关系数为0.99(P<0.01),线性回归方程为CVP_平卧=0.96*CVP_45°卧位 1.94；平卧位与60°卧位CVP间相关系数为0.98(P<0.01),线性回归方程为CVP_平卧=0.94*CVP_60°卧位 2.63。 结论：机械通气危重症患者测量体位角度越高,CVP值越低；平卧位与其他卧位间的CVP存在线性定量关系。     

中心静脉血氧饱和度、下腔静脉呼吸变异指数对脓毒症休克机械通气患者容量反应有评估作用

摘要 目的：评估中心静脉血氧饱和度（ScvO2）、下腔静脉呼吸变异指数（IVC-rvi）对脓毒症休克机械通气患者容量反应的价值，分析其与乳酸清除率（LCR）的相关性。方法： 回顾性分析78例脓毒症休克患者的临床资料，患者均进行机械通气与容量负荷试验。根据心脏指数（CI）分为有反应组37例（CI≥15%）和无反应组41例（CI<15%），分析负荷试验前、后ScvO2、IVC-rci、LCR情况，绘制受试者工作特征（ROC）曲线，评估ScvO2、IVC-rci对负荷试验有反应者的预测价值。 采用Pearson相关性分析LCR与ScvO2、IVC-rvi的相关性。 结果：有反应组负荷前、后ScvO2、乳酸低于无反应组，IVC-rvi高于无反应组（P均<0.05）。ROC曲线分析显示，ScvO2、IVC-rvi预测有反应患者的AUC为0.617、0.741；两项联合预测AUC为0.864，灵敏度91.9%，特异性78.0%。Pearson相关性分析显示LCR与ScvO2、IVC-rvi呈显著正相关（r=0.526、0.541,P均<0.05）。结论： ScvO2、IVC-rvi对预测脓毒症休克机械通气患者容量反应具有一定价值，但两者联合预测效果更好，且两指标与LCR存在明显相关性。     

脉搏灌注指数和脉搏灌注变异指数在机械通气患者撤机中的应用

目的 观察脉搏灌注指数（PI）和脉搏灌注变异指数（PVI）在机械通气患者撤机中的应用效果。方法 选取116例准备撤机的机械通气患者,通过撤机筛查后采用T-管模式进行自主呼吸试验（SBT）,以患者拔管后自主呼吸时间超过48 h为撤机成功,根据撤机结果将患者分为撤机成功组（90例）和撤机失败组（26例）,使用脉搏血氧仪Radical-7监测SBT前和SBT结束时患者PI、PVI,计算SBT前后PI和PVI的变化（ΔPI、ΔPVI）,利用ROC评估SBT前PI、PVI及ΔPI、ΔPVI对机械通气患者撤机结果的预测价值。结果 与撤机失败组比较,撤机成功组SBT前PVI、SBT后PI、SBT后PVI、ΔPI、ΔPVI增加（P均<0.05）。当SBT前PVI>14.0%时,其预测机械通气患者撤机成功的灵敏度为86.1%,特异度为79.2%,AUC为0.860,95%CI为0.766～0.953;当ΔPVI>10.5%时,其预测机械通气患者撤机成功的灵敏度为91.7%,特异度为83.3%,AUC为0.905,95%CI为0.831～0.978;当ΔPI>12.5%时,其预测机...     

Clinical Utility of Central Venous Saturation for the Calculation of Cardiac Index in Cardiac Patients

BackgroundMixed venous saturation (MVS) obtained from the distal pulmonary artery (PA) during Swan-Ganz catheterization is the criterion standard for calculating cardiac output (CO) and cardiac index (CI) with the use of the Fick method. We think that calculating CI with the use of central venous saturation (CVS) instead of PA-MVS is both feasible and accurate. Earlier studies were small, enrolled heterogeneous patient populations, and resulted in inconsistent findings.MethodsAll patients undergoing right heart catheterization from January 2011 to January 2012 in our catheterization lab with simultaneous measurements of MVS obtained from the distal PA and CVS obtained from the superior vena cava (SVC) or right atrium (RA) were included. Out of the 902 patients enrolled, we excluded patients (n = 50) who had known cardiac shunt or dialysis fistula, had duplicate medical records, or were septic. We calculated the CI with the use of the assumed Fick method using both MVS (criterion standard) and CVS (SVC or RA saturations) in the remaining 852 patients. We measured the correlation and the agreement between the 2 methods with the use of the Pearson correlation coefficient and Bland-Altman analysis.ResultsTotals of 112 patients with simultaneous PA and RA saturation measurements (group I) and 740 patients with simultaneous PA and SVC saturation measurements (group II) were included. We found an excellent linear correlation between SVC and PA saturation (r = 0.928) and between RA and PA saturation (r = 0.95). There was also an excellent correlation between CI calculated with the use of PA saturation and CI calculated with the use of SVC (r = 0.87) or RA (r = 0.93) saturation. The mean bias of CVS-derived CI compared with MVS-derived CI (criterion standard) was −0.1 (95% limits of agreement [LOA] −1 to +0.77) in the SVC group and −0.006 (LOA −0.68 to +0.69) in the RA group. Patients with low CI had stronger correlation and smaller bias between the 2 methods compared with those with normal or high CI. The presence of baseline hypoxemia, valvular heart disease, or acute coronary syndrome had no significant effect on the correlation or the bias between the 2 methods.ConclusionsIn cardiac patients, CVS can be used as a surrogate to true MVS in the calculation of CI. This method is readily available in patients who have central venous access, and may aid in early goal-directed treatment when cardiogenic shock is suspected.     

Modifications of Oxygen Saturation During Transesophageal Echocardiography

The present study was designed: (1) to establish the effects of transesophageal echocardiography (TEE) on arterial oxygen saturation (SAO(2)%); (2) to verify the possible clinical consequences of this phenomenon; and (3) to study the possibility of predicting modifications of SAO(2)% by clinical or hemodynamic variables or by specific factors related to the TEE procedure. We prospectively studied 116 unselected patients, aged 61 +/- 12 years, who underwent diagnostic TEE for various clinical indications. Thirty-seven patients had mitral valve disease, 19 aortic valve disease, 14 combined mitroaortic disease, 8 congenital heart disease, and 38 other cardiovascular diseases. Eight patients were affected by chronic obstructive pulmonary disease. Ninety-seven patients were sedated by 4 +/- 2 mg of diazepam IV SAO(2)% (5-min average) (Ohmeda Biox 3700 pulse oxymeter finger probe), heart rate (HR), and blood pressure (BP) were considered during baseline transthoracic examination, after pharmacological sedation but before the introduction of the probe, and finally during TEE. Neither clinical complications nor major arrhythmias were observed. Baseline SAO(2)%, HR and BP were, respectively, 93.6 +/- 3.3%, 76 +/- 14 beats/min, and 129 +/- 20/75 +/- 10 mmHg. Pharmacological sedation did not modify SAO(2)%, HR, and BP (P > 0.1). During TEE a small but significant reduction in SAO(2)% by an average of 1.2 +/- 3.2% was observed (P < 0.005), as well as a small and significant increase in HR by an average of 3 +/- 10 beats/min (P < 0.01). BP did not change significantly (P > 0.1 for both systolic and diastolic). The changes of SAO(2)% and HR were not interrelated and were not related to the duration of the procedure and to any of the clinical and hemodynamic variables taken into consideration. TEE can induce a small but significant drop in SAO(2)% and a small increase in HR even without any clinical relevance. No clinical or hemodynamic variable or specific factors related to the TEE procedure were related to these changes.     

脐静脉血浆胃动素浓度测定及其意义

本文测定了４５例足月正常新生儿脐静脉血浆胃动素浓度，并与４５例正常产妇进行比较，结果表明脐静脉血浆平均胃动素浓度为３９６．００±８５．５０ｎｇ／Ｌ，与产妇血浆平均胃动素浓度（３９３．５３±５５．０３ｎｇ／Ｌ）基本相等（Ｐ＞０．０５），但明显高于正常育龄非孕妇女（３６１．１２±９６．２３ｎｇ／Ｌ），Ｐ＜０．０１；不同性别的新生儿，其胃动素浓度无明显差异（Ｐ＞０．０５）。提示新生儿脐静脉血胃动素浓度较高，其意义可能有助于新生儿胃肠道结构和功能的进一步发育和成熟。     

Intact Megakaryocytes in the Venous Blood as a Marker for Thrombopoiesis

A total of 110 children, aged 0–15 years, were investigated for circulating megakaryocytes in cubital venous blood using the saponin-haemolysis leucoconcentration technique. The average number of megakaryocytes decreased from 17.8 per ml blood in the first year of life to 5.5 after the 6th year, which is the same value as in adult humans. The intact thrombo-cytogenic megakaryocyte value decreases from about 40 % in the first year of life to only a few percent (< 5 %) after the 10th year, the same value as in adult humans. There was a significantly higher number of megakaryocytes in children aged 0–6 years than in those aged 7–15 years. We concluded that occurrence of intact megakaryocytes ≥ 25 % in the venous blood is a sign of a normal thrombopoietic activity in the bone marrow, and the percentage of intact megakaryocytes in cubital venous blood reflects the decrease in thrombopoiesis in the bone marrow of fingers, hands and forearms during childhood. The decline in thrombopoietic activity is concentrated in three periods: 1–3, 6–7 and 10–11 years. An occurrence of intact megakaryocytes > 5 % in venous blood draining organs or bone marrow is a sign of some thrombopoietic activity.     

Evaluation of Bronchial Hyperresponsiveness by Monitoring of Transcutaneous Oxygen Tension and Arterial Oxygen Saturation during Methacholine Challenge in Asthmatic Children

Background. Bronchial hyperresponsiveness (BHR) is a key feature of asthma, but the measurement of BHR is hampered by the fact that most tests of airway caliber are difficult to conduct at a young age. Methacholine-induced bronchoconstriction is associated with significant hypoxemia, which can be assessed noninvasively by transcutaneous oxygen pressure (tcPO₂) and pulse oximetry. Evaluating BHR by monitoring tcPO₂ instead of respiratory resistance (Rrs) has been used over a wide age range in childhood.

Objective. To investigate whether there is a consistent relationship between changes in arterial oxygen saturation (SaO₂) and respiratory resistance (Rrs) similar to the relationship between tcPO₂ and Rrs during methacholine challenge in young children and to assess the usefulness of SaO₂ as a parameter for the indirect measurement of BHR.

Method. We performed methacholine inhalation challenge by monitoring SaO₂, tcPO₂ and Rrs in 37 asthmatic children 5 to 7 years of age. Consecutive doses of methacholine were doubled until a 10% decrease in tcPO₂ from the baseline was reached. We recorded the cumulative dose of methacholine (Dmin) at the inflection point of tcPO₂ (Dmin-tcPO₂), SaO₂ (Dmin-SaO₂), and Rrs(Dmin-Rrs).

Results. The mean value of Dmin-Rrs was 4.27 ± 2.02 units, the mean value of Dmin-tcPO₂ was 4.48 ± 2.01 units, and the mean value of Dmin-SaO₂ was 4.57 ± 0.20 units. Inhalation of increasing doses of methacholine raised Rrs curvilinearly and depressed tcPO₂ and SaO₂. There were no significant differences between any of the parameters. There were significant relationships between Dmin-tcPO₂ and Dmin-Rrs (r = 0.914, p < 0.001) and between Dmin-SaO₂ and Dmin-Rrs (r = 0.905, p < 0.001) and a relationship between Dmin-tcPO₂ and Dmin-SaO₂ (r = 0.949, p < 0.001).

Conclusion. We concluded that measurement of SaO₂ and/or tcPO₂ during methacholine inhalation challenge may be used to assess bronchial hyperresponsiveness. This study showed that both SaO₂ and tcPO₂ monitoring are safe, useful, and tolerable for use in children who are too young to cooperate with lung function tests.     

中心静脉氧饱和度的监测及其应用

通过中心静脉导管监测中心静脉氧饱和度(ScVO2)是一个方便、可靠的方法,它能快速反映危重患者全身氧的供需平衡的瞬时变化,能早期发现组织缺氧,且优于其它传统的血流动力学参数,是评估组织氧合充分与否的有用的间接指标,也是评估危重患者院内病死率及预后的重要指标;用ScVO2、平均动脉压和中心静脉压来指导早期目标指导性治疗,可提高严重脓毒血症或感染性休克患者的存活率.因此,ScVO2的监测对危重患者的评估和管理是非常重要和有用的.     

Use of Arterial Oxygen Saturation, Heart Rate, and Blood Pressure as Indirect Objective Physiologic Markers to Predict Aspiration

If an indirect bedside variable can reliably predict whether an objective instrumental dysphagia evaluation is needed, time and money can be saved without compromising patient care. To date, the search for a reliable indirect subjective marker of aspiration has not been successful. However, research on indirect objective markers of aspiration is alluring. The purpose of the present study was to investigate changes, if any, in the physiologic parameters of arterial oxygen saturation (SpO(2)), heart rate, and blood pressure during simultaneous objective confirmation of aspiration status with Fiberoptic Endoscopic Evaluation of Swallowing (FEES). Sixty adult subjects were divided into 4 groups of 15. Group 1 did not require supplemental oxygen and did not aspirate. Group 2 did not require supplemental oxygen and exhibited aspiration. Group 3 required supplemental oxygen and did not aspirate. Group 4 required supplemental oxygen and exhibited aspiration. Simultaneous SpO(2), heart rate, and blood pressure measurements were collected at 1-min intervals, i.e., pre-FEES baseline for 5 min; during FEES; and post-FEES for 5 min. Results indicated no significant differences in SpO(2) levels based on aspiration status or oxygen requirements for any of the 4 groups. A consistent pattern of higher heart rate values during FEES and continuing for 5 min post-FEES was observed for all 4 groups. A consistent pattern of higher blood pressure values during FEES and then lower blood pressure values post-FEES was observed for all 4 groups. It was concluded that the use of changes in SpO(2), heart rate, or blood pressure values as indirect objective markers of aspiration was not supported.     

Relation between Nocturnal Arterial Oxygen Desaturation and Morning Blood Pressure

Objective. Arterial oxygen saturation (SpO₂) in volunteers had been previously investigated, and the possibility that a decrease in SpO₂ leads to an increase in blood pressure (BP) in airline passengers experiencing oxygen desaturation at high altitudes was reported. It was also shown that mean nocturnal SpO₂ was lower in subjects with high-normal BP or mild hypertension than in those with normal BP. The present study investigated nocturnal SpO₂, evening BP, and morning BP of volunteers during daily life and examined the relation between nocturnal SpO₂ and change in BP (morning BP minus evening BP) to determine the influence of SpO₂ on BP. Methods. Sixty-two volunteers (31 men and 31 women) aged 40–87 years (mean: 55.9 ± 12 [SD] years) underwent measurement of SpO₂ and heart rate with a ring-shaped pulse oximeter during sleep at home. Evening BP and morning BP were measured by automatic BP recorder. Subjects that were classified as having high SpO₂ (mean nocturnal SpO₂ ≥ 95%; n = 23, 10 men and 13 women; mean age: 53.2 ± 12 years) or low SpO₂ (mean nocturnal SpO₂ < 94%; n = 21, 12 men and 9 women; mean age: 58.7 ± 13 years) were compared. The relation between mean nocturnal SpO₂ and morning BP and the relation between mean nocturnal SpO₂ and change in BP were investigated. Results. There was a significant negative correlation between mean nocturnal SpO₂ and morning systolic BP (SBP; r = ?0.50, p < 0.01) and between mean nocturnal SpO₂ and morning diastolic BP (DBP; r = ?0.37, p < 0.01). A significant negative correlation between mean nocturnal SpO₂ and change in SBP was observed (r = ?0.57, p < 0.01). Morning BP was significantly higher in the low nocturnal SpO₂ group than in the high nocturnal SpO₂ group (p < 0.001). Conclusion. The increase in morning BP from evening BP was significantly greater in subjects with a low nocturnal SpO₂. The decrease in SpO₂ during sleep may affect morning BP rise.