评价膈肌功能指导慢性阻塞性肺疾病患者撤机的可行性研究

目的 探讨神经机械耦联指数(NMC)和神经通气耦联指数(NVC)对慢性阻塞性肺疾病(COPD)患者撤机的指导价值.方法 以2008年12月至2009年12月入住东南大学附属中大医院重症医学科行机械通气超过24 h,且考虑撤机的COPD患者为研究对象.根据患者撤机成功与否分为撤机成功组与撤机失败组.具备撤机条件后行自主呼吸试验(SBT)30 min,监测SBT0、5、30 min时膈肌电活动(Edi)、NMC、NVC、NVC × NMC、呼吸浅快指数(f/Vt)及口腔闭合压(P0.1).结果 16例患者纳入本研究,其中撤机成功组6例,撤机失败组10例.(1)Edi对撤机失败的预测价值:SBT30 min时,撤机失败组Edi明显高于撤机成功组,其预测撤机失败的接受者操作特征(ROC)曲线下面积(AUC)为0.817(P＜0.05).(2)NVC、NMC对撤机的判断:SBT 5、30 min时撤机成功组NVC、NMC均高于撤机失败组.SBT 30 min时,NVC预测撤机失败的AUC为0.850(P＜0.05),NMC预测撤机失败的AUC为0.800(P＞0.05).(3)NVC×NMC对撤机失败的预测:SBT 30 min时预测撤机失败的AUC为0.850(P＜0.05),以NVC×NMC＜39 em H2O·ml·μV-2(1 em H2O=0.098 kPa)为临界值时,其灵敏度为100.0%,特异度为83.3%.(4)f/Vt、f/Vt×P0.1对撤机的预测:SBT 时,f/Vt、f/Vt×P0.1均不能预测撤机失败.结论 Edi、NVC、NVC×NMC对COPD患者撤机具有良好的预测价值.

Abstract：

Objective To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). Methods Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi) , NMC, NVC, NVC ×NMC, index of rapid shallow breathing (f/Vt) , airway occlusion pressure (P0.1) and f/Vt ×P0.1 at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. Results Successful weaning(S group) was observed in 6 patients while weaning failure(F group) in 10 patients. (1)The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P ＜ 0. 05), the area under the ROC curves(AUC) was 0. 817(P ＜0. 05). (2) The predictive capacity of NVC and NMC:at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P ＜0. 05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0. 822, P ＜ 0. 05), while the AUC of NMC was 0. 800 (P ＞ 0. 05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0. 864, P ＜ 0. 05) , showing greater sensitivity (100. 0%) and specificity (83. 3%) .(4) The predictive capacity of f/Vt and P0.1: f/Vt and f/Vt × P0.1 presented poor predictive performance in the failed patients. Conclusions Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.     

评价膈肌功能指导慢性阻塞性肺疾病患者撤机的可行性研究

Objective To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). Methods Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi) , NMC, NVC, NVC ×NMC, index of rapid shallow breathing (f/Vt) , airway occlusion pressure (P0.1) and f/Vt ×P0.1 at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. Results Successful weaning(S group) was observed in 6 patients while weaning failure(F group) in 10 patients. (1)The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P ＜ 0. 05), the area under the ROC curves(AUC) was 0. 817(P ＜0. 05). (2) The predictive capacity of NVC and NMC:at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P ＜0. 05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0. 822, P ＜ 0. 05), while the AUC of NMC was 0. 800 (P ＞ 0. 05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0. 864, P ＜ 0. 05) , showing greater sensitivity (100. 0%) and specificity (83. 3%) .(4) The predictive capacity of f/Vt and P0.1: f/Vt and f/Vt × P0.1 presented poor predictive performance in the failed patients. Conclusions Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.     

评价膈肌功能指导慢性阻塞性肺疾病患者撤机的可行性研究

Objective To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). Methods Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi) , NMC, NVC, NVC ×NMC, index of rapid shallow breathing (f/Vt) , airway occlusion pressure (P0.1) and f/Vt ×P0.1 at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. Results Successful weaning(S group) was observed in 6 patients while weaning failure(F group) in 10 patients. (1)The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P ＜ 0. 05), the area under the ROC curves(AUC) was 0. 817(P ＜0. 05). (2) The predictive capacity of NVC and NMC:at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P ＜0. 05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0. 822, P ＜ 0. 05), while the AUC of NMC was 0. 800 (P ＞ 0. 05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0. 864, P ＜ 0. 05) , showing greater sensitivity (100. 0%) and specificity (83. 3%) .(4) The predictive capacity of f/Vt and P0.1: f/Vt and f/Vt × P0.1 presented poor predictive performance in the failed patients. Conclusions Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.     

评价膈肌功能指导慢性阻塞性肺疾病患者撤机的可行性研究

Objective To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). Methods Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi) , NMC, NVC, NVC ×NMC, index of rapid shallow breathing (f/Vt) , airway occlusion pressure (P0.1) and f/Vt ×P0.1 at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. Results Successful weaning(S group) was observed in 6 patients while weaning failure(F group) in 10 patients. (1)The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P ＜ 0. 05), the area under the ROC curves(AUC) was 0. 817(P ＜0. 05). (2) The predictive capacity of NVC and NMC:at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P ＜0. 05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0. 822, P ＜ 0. 05), while the AUC of NMC was 0. 800 (P ＞ 0. 05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0. 864, P ＜ 0. 05) , showing greater sensitivity (100. 0%) and specificity (83. 3%) .(4) The predictive capacity of f/Vt and P0.1: f/Vt and f/Vt × P0.1 presented poor predictive performance in the failed patients. Conclusions Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.     

膈肌功能对慢性阻塞肺疾病加重期插管患者撤机的指导价值分析

目的探讨膈肌功能对慢性阻塞性肺病加重期(AECOPD)插管患者撤机的指导价值。方法选取行机械通气并考虑撤机的AECOPD插管患者为研究对象,根据患者撤机成功与否分为撤机成功组与撤机失败组。具备撤机条件后行自主呼吸试验(SBT)30 min,监测SBT 0、5、30 min时膈肌电活动(Edi)、呼吸浅快指数(f/Vt)及口腔闭合压(P0.1)。结果 37例患者纳入本研究,其中撤机成功组25例,撤机失败组12例。撤机失败组患者血Pa CO2高于另一组患者(P0.05)。撤机成功与失败组患者的年龄、Pa O2、MAP等各方面均无显著差异(P0.05)。SBT 30 min时两组患者Edi均显著高于SBT 0 min;在SBT 30 min撤机成功组Edi低于撤机失败组,以Edi12V为临界值,撤机失败预测的灵敏度为100.0%和特异度为66.7%。在SBT 5、30min时撤机成功组患者f/Vt较撤机失败组低,两组患者P0.1无明显差别(P0.05)。结论 Edi对AECOPD患者撤机具有良好的预测价值。     

膈肌超声对重症患者机械通气撤机的预测价值

目的:评价膈肌超声对机械通气(MV)患者撤机结果的预测价值。方法:选取行MV时间 48h的重症患者41例,在符合撤机条件后使用T管进行自主呼吸试验(SBT),于SBT 30min时使用床旁超声测量患者右侧躯体的膈肌移动度(DE)和膈肌厚度,并计算膈肌增厚率(DTF),根据撤机成败与否将患者分为撤机成功组(26例)和撤机失败组(15例)。采用受试者工作特征(ROC)曲线评价膈肌功能超声指标对撤机的指导价值。结果:撤机成功组患者DE及DTF高于撤机失败组(均P 0. 05)。分别选取1. 08 cm和30%作为DE和DTF的截断值,其预测撤机成功的敏感度分别为80. 77%和65. 38%,特异度分别为80. 00%和60. 00%,ROC曲线下面积分别为0. 751(95%CI:0. 571～0. 932)和0. 668(95%CI:0. 484～0. 852)。结论:膈肌功能超声监测可作为重症医学科MV患者撤机能力的预测指标,对撤机具有较好的指导价值。     

膈肌电活动对慢性阻塞性肺疾病急性加重期插管患者成功撤机的预测价值

目的 探究膈肌电活动对慢性阻塞性肺疾病急性加重期(AECOPD)插管患者撤机的预测价值.方法 选择2013年5月至2015年5月在哈尔滨医科大学附属第一医院行机械通气治疗并考虑撤机的AECOPD插管患者55例作为研究对象,根据患者是否撤机成功将55例AECOPD患者分为撤机成功组与撤机失败组2组.符合撤机条件后,分别对2组患者行自主呼吸试验(SBT) 30 min,分别监测、记录并比较行SBT后0、10及30 min时2组患者膈肌电活动(Edi)、口腔闭合压(P0.1)及呼吸浅快指数(f/Vt),并监测比较2组患者PaCO2、PaO2、MAP及HR等一般情况.结果 55例患者中,撤机成功者35例,占63.6％,撤机失败者20例,占36.4％,2组患者的年龄、PaO2、MAP等一般情况差异均无统计学意义(t=0.078、1.669、1.150,P＞0.05);与撤机失败组相比,撤机成功组患者的PaCO2均明显偏低,差异有统计学意义(t=2.454,P=0.017);行SBT后10 min及30 min时2组患者Edi均显著高于SBT后0 min时相应组别患者的Edi,差异有统计学意义(P＜0.05);行SBT 30 min时,与撤机失败组相比,撤机成功组患者Edi明显偏低,差异有统计学意义(t=3.505,P=0.001);行SBT后10 min及30 min时撤机失败组患者f/Vt较撤机成功组患者高,差异有统计学意义(t=2.624、2.170,P值均＜0.05);与撤机失败组相比,撤机成功组患者P0.1无明显差异,且差异无统计学意义(P＞0.05).结论 Edi对AECOPD插管患者撤机具有较好的预测价值.     

序贯健肌操联合床旁B超监测膈肌预测老年慢性阻塞性肺疾病急性加重期患者机械通气撤机的临床观察

目的 探讨序贯健肌操联合床旁B超监测膈肌预测老年慢性阻塞性肺疾病(慢阻肺)急性加重期患者机械通气撤机情况的效果.方法 60例老年慢阻肺急性加重期患者,所有患者接受序贯健肌操联合床旁B超监测膈肌,观察分析其机械通气撤机成功率及撤机指标〔膈肌电活动(Edi)、口腔闭合压(P0.1)及呼吸浅快指数(f/Vt)〕情况.结果 6...     

神经电活动辅助通气:一种新的机械通气模式

机械通气是呼吸衰竭患者重要的支持手段,但传统的机械通气存在明显人机不同步,可能导致机械通气时间延长、呼吸机相关肺损伤等相关并发症.神经电活动辅助通气,通过监测膈肌电活动.根据自身吸气驱动,成比例地持续辅助通气.目前研究表明神经电活动辅助通气明显改善有创及无创机械通气人机同步性;减轻呼吸肌肉负载;能自动调节通气支持水平,具有一定的肺保护作用;利用膈肌电活动,发挥独特的监测功能.     

超声膈肌功能评估对重症肺炎伴呼吸衰竭患者机械通气撤机的指导意义

目的 分析超声膈肌功能评估对重症肺炎伴呼吸衰竭患者机械通气撤机的指导意义。方法 选择2019年8月至2022年8月我院接受机械通气治疗的重症肺炎伴呼吸衰竭患者98例,根据撤机结局分为撤机成功为观察组72例和撤机失败者为对照组26例;筛查影响撤机失败的危险因素,对膈肌移动度和膈肌增厚率对重症肺炎伴呼吸衰竭患者机械通气撤机失败的预测。结果 急性生理与慢性健康指数(APACHEⅡ)评分升高、腹胀、通气时间延长、膈肌移动度降低、膈肌增厚率降低是重症肺炎伴呼吸衰竭患者撤机失败的危险因素(P<0.05)。ROC分析结果膈肌移动度、膈肌增厚率单一及联合预测重症肺炎伴呼吸衰竭患者机械通气撤机失败的AUC分别为0.709(95%CI:0.591～0.827)、0.716(95%CI:0.598～0.834)、0.782(95%CI:0.675～0.889)。结论 超声膈肌功能可用于分析重症肺炎伴呼吸衰竭患者机械通气后的撤机结局,膈肌增厚率、膈肌移动率对患者机械通气后撤机失败率预测具有意义。     

A study on the mechanism of twitch potentiation by hypertonic solution in the frog atrial muscle

Hypertonic solutions were found to exhibit both positive and negative inotropic effects on the contraction of the isolated atrial myocardium of bullfrog. The optimum tonicity for twitch potentiation was about 1.5 T. The mechanism for the positive inotropic action was investigated. The possibility of involvement of an increase in calcium influx during each action potential was excluded, since both the overshoot and the plateau of action potential were strongly depressed by perfusion of hypertonic solution. The effect on the time course of twitch potentiation was similar to that of muscle shrinkage, regardless of the type solute (sucrose, NaCl or LiCl) used for elevating the tonicity, except that excess sodium showed an initial rapid inhibitory phase of contraction. A marked post-rest potentiation was observed even after "zero" calcium perfusion, provided that the tonicity of the bathing medium was elevated previously. Potassium contracture occurred during the prolonged hypertonic perfusion in "zero" calcium condition. In addition, caffeine contracture was strongly augmented in hypertonic solution. The results suggest that an elevation in both the [Ca2+]i and amount of calcium bound intracellularly may play an important role in the positive inotropic action.     

A concise, total synthesis of the TMC-95A/B proteasome inhibitors

A concise, total synthesis of the proteasome inhibitors TMC-95A/B has been accomplished. The synthesis features the use of an L-serine-derived E-selective modified Julia olefination reaction to ultimately control the stereochemical outcome of the highly oxidized tryptophan fragment. Additionally, the limited use of protecting groups at a late stage of the total synthesis allowed for its completion in an efficient manner.     

Ventricular-arterial coupling in patients with heart failure treated with cardiac resynchronization therapy: may we predict the long-term clinical response?

Objective: To evaluate the effects of cardiac resynchronization therapy(CRT) on ventricular-arterial coupling (VAC) in patients withrefractory congestive heart failure (HF), left bundle brunchblock, and sinus rhythm. Background: The ratio between arterial elastance (Ea) and left ventricularend-systolic elastance (Ees), the so-called VAC, defines theefficiency of the myocardium in pumping blood. Methods: Seventy-eight patients were studied with echocardiography beforeCRT, and 1 year later. End-systolic elastance was calculatedaccording to the method of Chen. Arterial elastance (ratio ofthe systolic pressure to the stroke volume), end-systolic volume(ESV), and quality of life (QoL) (Minnesota Living with HeartFailure Questionnaire) were assessed at the baseline and after1 year. Patients with a reduction >15% of ESV or a decrease>33% in QoL score were considered responders to CRT. Results: QRS duration and interventricular delay were significantly reducedwith CRT compared with baseline (156 ± 2 vs. 195 ±3 ms, P < 0.001; and 25 ± 2 vs. 55 ± 3 ms,P < 0.001, respectively). Arterial elastance/Ees decreasedsignificantly on CRT (2.47 ± 1.48 vs. 1.41 ± 0.87,P < 0.0001). The lowering of Ea/Ees was congruent to a decreasein intraventricular delay (83.1 ± 55.7 vs. 28.4 ±49.5 ms, P < 0.0001) and an increase in ejection fraction(26 ± 6.3 vs. 36.9 ± 8.0%, P < 0.0001). Respondersto CRT were 74 and 71% of the overall patient population, consideringas endpoint QoL or ESV, respectively. The analysis of VAC showeda baseline cut-off value of 2, above which 88% and 69% of patientsresponded to CRT, considering as endpoint QoL or ESV, respectively. Conclusions: The non-invasive assessment of VAC may be proposed as an immediate,easy, and optimal tool for quantifying the effect of CRT inpatients with HF.     

Homologation and functionalization of carbon monoxide by a recyclable uranium complex

Carbon monoxide (CO) is in principle an excellent resource from which to produce industrial hydrocarbon feedstocks as alternatives to crude oil; however, CO has proven remarkably resistant to selective homologation, and the few complexes that can effect this transformation cannot be recycled because liberation of the homologated product destroys the complexes or they are substitutionally inert. Here, we show that under mild conditions a simple triamidoamine uranium(III) complex can reductively homologate CO and be recycled for reuse. Following treatment with organosilyl halides, bis(organosiloxy)acetylenes, which readily convert to furanones, are produced, and this was confirmed by the use of isotopically (13)C-labeled CO. The precursor to the triamido uranium(III) complex is formed concomitantly. These findings establish that, under appropriate conditions, uranium(III) can mediate a complete synthetic cycle for the homologation of CO to higher derivatives. This work may prove useful in spurring wider efforts in CO homologation, and the simplicity of this system suggests that catalytic CO functionalization may soon be within reach.     

Calcium and pancreatic beta-cell function. 6. Glucose and intracellular 45Ca distribution.

Glucose stimulates the uptake of 45Ca into beta-cell-rich pancreatic islets isolated from ob/ob-mice. The distribution of the incorporated radioactivity was analysed by labelling the organelles with 45Ca in their cellular environment. The radioactive content of the organelles was measured after homogenization and fractionation of the islets under conditions preventing 45Ca redistribution. The 45Ca taken up in response to glucose appeared essentially in the secretory granule fraction and in that enriched in mitochondria. Modification of the 45Ca loading procedure, involving reduction of the oxygen tension and incubation volume, resulted in the disappearance of the glucose effect on the mitochondrial fraction whereas part of the stimulatory effect on the secretory granules persisted. Buffering of calcium by the secretory granules and mitochondria may be important for regulating the cytoplasmic Ca2+ involved in stimulus-secretion coupling.     

Ephaptic conduction in a cardiac strand model with 3D electrodiffusion

We study cardiac action potential propagation under severe reduction in gap junction conductance. We use a mathematical model of cellular electrical activity that takes into account both three-dimensional geometry and ionic concentration effects. Certain anatomical and biophysical parameters are varied to see their impact on cardiac action potential conduction velocity. This study uncovers quantitative features of ephaptic propagation that differ from previous studies based on one-dimensional models. We also identify a mode of cardiac action potential propagation in which the ephaptic and gap-junction-mediated mechanisms alternate. Our study demonstrates the usefulness of this modeling approach for electrophysiological systems especially when detailed membrane geometry plays an important role.