脑卒中偏瘫病人呼吸肌表面肌电信号特征研究

目的 探讨脑卒中恢复期偏瘫病人平静呼吸和最大用力呼吸时呼吸肌表面肌电信号特征,为脑卒中恢复期病人呼吸肌功能评估与训练提供客观依据。方法 选取2021年1月—2021年5月合肥市第二人民医院康复科收治的脑卒中偏瘫病人21例作为观察组,另外选取22名健康体检者作为健康组。检测两组受试者平静呼吸和最大用力呼吸时胸锁乳突肌、胸骨旁肋间肌、膈肌、腹直肌的sEMG信号,记录均方根值(RMS)。结果 平静呼吸时脑卒中恢复期偏瘫病人的胸骨旁肋间肌RMS值高于健康人,差异有统计学意义(P<0.05);最大用力呼吸时,脑卒中恢复期偏瘫病人的胸骨旁肋间肌、两侧胸锁乳突肌、膈肌与腹直肌的RMS值明显低于健康人,差异均有统计学意义(P<0.05)。结论 脑卒中恢复期偏瘫病人的呼吸肌收缩功能下降,呼吸肌表面肌电可作为脑卒中偏瘫病人呼吸肌功能恢复情况的评价指标。     

体表膈肌肌电评价睡眠呼吸暂停综合征患者呼吸努力的价值

目的 使用表面电极记录膈肌肌电,评价OSAHS患者的呼吸努力及呼吸中枢驱动.方法 选择2007年6月至10月因存在打鼾、嗜睡等症状,怀疑OSAHS前来广州呼吸病研究所睡眠中心行整夜(>7h)多导睡眠(PSG)监测的患者11例,PSG监测同时记录食管压力,并通过胸部表面电极记录膈肌肌电活动信号,其中5例同时记录食管膈肌肌电信号.结果 当发生阻塞性呼吸暂停(OSA)时,表面电极记录的膈肌肌电信号(8.1±7.1)μV、食管膈肌肌电信号(21.1±10.7)μV和食管压信号(18.1±6.8)cm H_2O(1cm H_2O=0.098kPa)均逐渐增加.食管压变化幅度在呼吸暂停末达到最大值(31.1±13.4)cm H_2O,气流恢复后骤然降低(21.0±8.8)cm H_2O;体表膈肌肌电和食管膈肌肌电活动在气流恢复初期[(14.9±13.9)μV、(41.6±22.1)μV]仍继续增加,表面电极记录的膈肌肌电的最大均方根与食管压变化幅度在发生OSA时呈线性相关(r=0.66),而膈肌肌电与食管膈肌肌电在发生OSA时呈线性相关(r=0.72).结论 表面电极所记录的膈肌肌电可作为判断睡眠呼吸事件时呼吸努力存在与否的辅助方法,有助于鉴别睡眠呼吸暂停的类型.     

应用电阻抗原理判断膈肌疲劳的研究

根据生物电阻抗原理研制成胸、腹电阻抗呼吸仪（包括一维图和二维图）用来检测膈肌疲劳时胸、腹非同步呼吸运动，结果２０３例正常人全部呈胸、腹同步呼吸运动；而１８９例慢性阻塞性肺疾病患者中有１１７例出现非同步呼吸运动模式（６１．９％）。非同步呼吸运动可分为三型：Ｉ型为完全矛盾呼吸运动；ＩＩ型为胸、腹呼吸运动曲线峰值错位；ＩＩＩ型为腹部呼吸运动呈双峰曲线。经用跨膈压和肌电频谱对比观察，符合率分别达８１．８％     

慢性阻塞性肺疾病患者在二氧化碳重复呼吸及运动过程中的膈肌肌电变化

研究发现，慢性阻塞性肺疾病(COPD)患者在激烈运动后，并不出现膈肌疲劳，提示COPD患者在运动时可能存在着呼吸中枢的反馈抑制以防止呼吸肌疲劳。要证明这一假设就必须准确地评价中枢驱动。膈肌肌电可能是评价中枢驱动的一个好方法。研究提示多导食道电极记录的膈肌肌电能有效地反映正常人的呼吸中枢驱动。我们运用多导食道电极记录膈肌肌电，观察COPD患者在CO2重复呼吸及运动过程中膈肌肌电的变化，以探讨其是否存在呼吸中枢反馈抑制现象。     

两种膈肌电信号处理方法对气道阻塞状态下呼吸中枢评价的准确性比较研究

目的比较膈肌肌电均方根(RMSdi)与积分肌电值(i EMGdi)两种膈肌电信号处理方法对气道阻力增加状态下呼吸中枢评价的准确性。方法选择2015年1-6月广州12名健康志愿者,接受不同程度的吸气阻力,并测量膈肌肌电以及跨膈压,膈肌肌电分别采用均方根和积分值处理,两种算法得出的结果分别与吸气跨膈压作相关性分析,比较其相关系数。结果在低、中、高水平吸气阻力时,膈肌肌电均方根与吸气跨膈压之间的相关系数分别为0.198,0.141及0.569(P=0.054),均无相关性(均P0.05);而3个阻力下的积分肌电值与吸气跨膈压之间的相关系数分别为0.896,0.885及0.876,均存在明显相关性(均P0.01)。结论吸气阻力存在时,积分肌电值比膈肌肌电均方根更能准确地评价呼吸中枢的吸气努力程度。     

磁刺激诱发的膈肌复合动作电位的多导食道电极记录及其在重症监护室患者中的应用

目的探讨在重症监护室(ICU)里,用多导食道电极是否能满意地记录由磁刺激膈神经诱发的膈肌复合肌肉动作电位(CMAP)。方法运用1根具有5个记录导联的新型多导食道电极记录由电和磁刺激膈神经诱发的膈肌CMAP。10名正常人和10例因各种原因在ICU病房治疗的患者被纳入研究。结果不论在正常人还是ICU患者均可记录到高质量的信号。在正常人,电刺激诱发的膈神经传导时间(PNCT)、膈肌CMAP幅值[(7.2±0.8)ms、(1.52±0.40)mV]与磁刺激诱发的相似[(7.1±0.8)ms、(1.56±0.38)mV,P均>0.05]。ICU患者磁刺激诱发的膈肌CMAP幅值[(0.73±0.38)mV]显著小于正常人[(1.58±0.38)mV,P<0.01]。结论这一研究提示磁刺激可取代传统的电刺激去测量膈肌CMAP和PNCT。把磁刺激和多导食道电极结合在一起能有效地评价ICU患者的膈肌功能。     

白介素15与慢性阻塞性肺疾病大鼠骨骼肌降解的相关性研究

目的 研究慢性阻塞性肺疾病(COPD)大鼠模型骨骼肌降解途径——泛素-蛋白酶体途径与白介素15(IL-15)的相关关系,为有效防治COPD患者骨骼肌蛋白高分解提供理论与依据.方法 成年雄性SD大鼠45只,分为模型组30只,健康组15只,采用反复熏香烟加气管内注入脂多糖法复制COPD大鼠动物模型.实时荧光定量PCR法和Western blot法分别检测大鼠膈肌、腓肠肌和肋间肌中E2-14K、MAFbx、Ub基因和蛋白表达.ELISA法检测大鼠血清、膈肌、腓肠和肋间肌中IL-15和肿瘤坏死因子α(TNF-α)的含量.结果 COPD模型大鼠膈肌、腓肠肌和肋间肌中E2 14K、MAFbx、Ub基因和蛋白表达分别较健康组升高.COPD模型组大鼠血清、膈肌、腓肠肌和肋间肌中IL-15、TNF-α的水平较健康组升高.大鼠血清、膈肌、腓肠肌和肋间肌中IL-15和TNF-α水平呈正相关(血清r=0.75;膈肌r =0.81;腓肠肌r=0.82;肋间肌r=0.78,P值均＜0.05).膈肌、腓肠肌和肋间肌中IL-15均与E2-14K、MAFbx、Ub相对表达量呈正相关(膈肌r=0.88、r=0.86、r=0.87;腓肠肌r=0.85、r=0.87、r=0.76;肋间肌r=0.85、r =0.80、r=0.84,P值均＜0.05).大鼠造模结束后体质量净增长与血清、膈肌、腓肠肌和肋间肌中IL-15呈负相关(血清r=-0.90,膈肌r=-0.85,腓肠肌r=-0.82,肋间肌r=-0.82,P＜0.05).结论 在COPD模型大鼠中,IL-15可能通过TNF-α共同作用于泛素-蛋白酶体途径影响骨骼肌降解的作用.     

膈肌疲劳对呼吸中枢驱动的影响

膈肌是主要的呼吸肌，我们设想膈肌疲劳可能会导致呼吸中枢驱动增高以维持正常的通气功能。为验证这一假说，我们在6名健康人身上记录膈肌疲劳前后所进行的二氧化碳重复呼吸时的食道膈肌肌电压。采用具有4个电极对的多导食道电极导管记录膈肌电压，同时用胃食道球管法记录磁刺激下的食道、胃和跨膈肌电压。     

呼吸肌与慢阻肺呼吸衰竭

关于呼吸肌在健康和疾病状态时的功能及其变化,人们做了很多工作,认识到呼吸肌疲劳是慢阻肺呼吸衰竭的一个重要因素。现就呼吸肌的一般生理解剖、功能测定和慢阻肺呼吸肌功能变化综述于下。【呼吸肌的一般生理解剖】呼吸肌包括膈肌、肋间肌、胸廓辅助呼吸肌和腹肌。不论是荧光屏下透视还是体积描记法测定,都证明在平静呼吸时,膈肌起主导作用,是完成呼吸泵工作的主要动力来源。肋间     

甲亢时呼吸肌无力的可逆性

甲状腺机能亢进(甲亢)常有呼吸因难,严重时可导致呼衰,因而作者对甲亢治疗前后呼吸肌(肋间肌和膈肌)肌强度进行了观察。7例甲亢患者均有运动性呼吸困难(按联合王国MRC 记分Ⅰ～Ⅴ度),上楼困难和近端肌无力,平均持续7(2～24)个月。应用甲亢平平均治疗10.7(6～21)周,使甲状腺功能得以恢复。观察用药前后甲状腺功能、膈肌和股四头肌的肌力等.     

The Diaphragm and Dyspnea During Chemically Stimulated Breathing in a Subset of Patients With Diabetes

In patients with insulin-dependent diabetes mellitus (IDDM) isolated peripheral airway involvement may give rise to inspiratory threshold load (ITL) contributing to dyspnea. Based on the reported evidence of a greater increase in end-expiratory lung volume (EELV) with hypoxia than with hypercapnia in IDDM, we wondered whether, and to what extent in the two conditions, EELV contribute to perception of dyspnea (PD). We studied five nonsmokers aged between 19 and 45, with IDDM under good metabolic control and five normal control subjects matched for age. In each patient, we evaluated the electromyographic activity of the diaphragm (Edi), the swings of esophageal (Pessw), gastric (Pgsw), and transdiaphragmatic (Pdisw = Pgsw-Pessw) pressures; PD was assessed by a modified Borg scale during hypercapnic-hyperoxic (HCH) and hypoxic-isocapnic (HIC) stimulation. Change in inspiratory capacity (IC) was considered the mirror image of increase in EELV, that is, dynamic hyperinflation (DH), while intrinsic positive end inspiratory pressure (PEEPi) was measured as an index of inspiratory threshold load (ITL). In controls, Edi and Pdi but not their ratio (Edi/Pdi) related to Borg. In patients the following was found: (1) with each of the two stimuli, for any given Edi, Pdi, and Edi/Pdi ratio, there was greater Borg than in controls, (2) a similar increase in ITL and DH with HCH and HIC, (3) Edi/Pdi related to Borg similarly with HCH as with HIC. In conclusion, in controls, Edi and Pdi were associated with the perception of dyspnea similarly with the two chemical stimuli. In this subset of patients with IDDM, Edi/Pdi ratio throughout increase in EELV and ITL was found to affect the perception of dyspnea in hypoxia to a similar extent as in hypercapnia.     

Short term effect of intermittent negative pressure ventilation in COPD patients with respiratory failure

Ten patients with stable chronic obstructive pulmonary disease (COPD) and hypercapnic respiratory failure were randomly submitted to intermittent negative pressure ventilation (INPV) 6 h per day for 5 consecutive days by either a cuirass or pneumo wrap ventilator. The effects were assessed by measurements of spirometry, blood gases, maximal inspiratory (MIP) and expiratory (MEP) pressures, 12 minutes walking distance test (12 mwd), sensation of dyspnoea by a visual analogue scale (VAS) and diaphragmatic electromyographic activity (Edi). Edi was recorded during INPV sessions in only 7 patients. The same measurements apart from Edi were also performed in 8 matched control patients randomly submitted to conventional physiotherapy. During INPV, Edi activity was reduced, at least temporarily down to 50% of baseline values. Comparison of baseline with post INPV values showed no changes in thoracic gas volume (TGV), forced expiratory volume in one second (FEV1), FEV1/forced vital capacity (FVC), arterial oxygen partial pressure (Pao2) and MEP; significant improvements were seen in MIP, vital capacity (VC), VAS, and 12 mwd only in patients submitted to INPV. A significant improvement in PaCO2 was observed in both groups of patients. We conclude that INPV may be effective in improving the functional reserve of the inspiratory muscles in selected COPD patients with hypercapnic respiratory failure and signs of inspiratory muscle dysfunction.     

Electrical and mechanical output of the inspiratory muscles in anesthetized dogs

In anesthetized dogs with progressive hypercapnia, the relationships between tidal volume (VT) or occluded inspiratory esophageal pressure swings (Pes) and diaphragm (Edi) or thoracic inspiratory muscle (Etm) peak electrical activity were determined after either cordotomy at C7-T1 or bilateral phrenicotomy, and used together with the Etm vs Edi relationships established in intact and vagotomized dogs to estimate the contribution of each muscle group to VT and Pes observed under the latter conditions. Etm was obtained as the mean of scalene, 2nd and 5th parasternal peak activity, the relationships between these activities being the same under all conditions. In supine and head-up phrenicotomized dogs, VT and Pes increased linearly with Etm and were unaffected by body position. After cordotomy, VT and Pes increased progressively less with increasing Edi and at any Edi were smaller in the head-up posture. Diaphragm relative contribution to VT and Pes was greater when supine than head-up and greater after than before vagotomy, but in all cases it decreased with increasing chemical drive. That of the thoracic inspiratory muscles increased with chemical drive and eventually became equal to (supine) or larger than (head-up) diaphragm contribution.     

Expiratory muscle pressure and breathing mechanics in chronic obstructive pulmonary disease.

Expiratory muscle recruitment is common in stable chronic obstructive pulmonary disease (COPD) patients. Due to airway obstruction, there is little reason to believe that active expiration in COPD would be mechanically effective in lowering operating lung volume. The physiological significance of expiratory muscle recruitment in COPD, therefore, remains unknown. The purpose of this study was to assess, in COPD patients breathing at rest, the effect of expiratory muscle contraction on force generating ability of the diaphragm. The force generating ability of the diaphragm was evaluated from its pressure swing (Pdi) for a given diaphragm electrical activity (Edi), where Edi was normalized as % of its maximal value (Pdi/Edi/Edi,max). Phasic expiratory muscle contraction was measured as the total expiratory rise in gastric pressure (Pga,exp.rise). Nineteen seated patients with moderate to severe COPD, participated in the study and 10 exhibited phasic rise in Pga during expiration with a mean Pga,exp.rise of 1.91+/-0.89 cmH2O. The patients were thus divided into passive expiration (PE) and active expiration (AE) groups. There was no significant difference in various lung function and breathing pattern parameters between the two groups. Pdi/Edi/Edi,max was 0.63+/-0.07 and 0.54+/-0.07 cmH2O/% in PE and AE groups, respectively, and was not significantly different between each other. Compared with PE group, AE group not only recruited expiratory muscles, but also preferentially recruited inspiratory rib cage muscles and derecruited the diaphragm. The results do not support a significant improvement of the force-generating ability of the diaphragm by phasic contraction of expiratory muscles at rest in chronic obstructive pulmonary disease patients.     

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.     

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.     

Diaphragmatic rest during negative pressure ventilation by pneumowrap. Assessment in normal and COPD patients

In the present study, we assessed the occurrence of respiratory muscle rest during long lasting INPV runs using a pneumowrap ventilator at different pressure levels. We measured two indices of diaphragmatic activity: transdiaphragmatic pressure and the electrical activity of the diaphragm. Five healthy volunteers and six COPD patients were studied during spontaneous breathing and during 30-minute runs of INPV at a pressure of -2, -15 and -30 cmH2O. Ventilation, rib cage and abdomen motion were measured by inductive plethysmography; Pdi was obtained as the difference between gastric and esophageal pressures; Edi was recorded with surface electrodes. About 10 minutes of INPV (adaptation phase) were needed to obtain stable values in all the variables recorded. Ventilation increased in both groups up to threefold by increasing the negative pressure applied, this being due to changes in tidal volume. Changes in Pga swings mainly accounted for the reduction in Pdi that became negative during the run at -30 cmH2O. In both groups, Edi, after adaptation, showed no change during INPV at -2 cmH2O but a progressive reduction from control, during INPV at -15 and -30 cmH2O. We conclude that INPV by a pneumowrap ventilator can induce partial respiratory muscle rest in normal subjects and COPD patients.     

Discontinuity between inspiratory and postinspiratory diaphragm activity in man and rabbit

Diaphragm activity (Edi, 20 Hz low cutoff) was recorded with great time resolution to ascertain whether there is a discontinuity between its inspiratory and postinspiratory periods in humans. We first determined in anesthetized rabbits that gaps or notches in Edi occurred within 80 msec before and after the end of mechanical inspiration in 70% of the analysable breaths in the esophageal lead and in 77% in direct leads. We then determined from the esophageal lead of 4 conscious subjects that gaps or notches in Edi occurred during the above-defined period in 45% of 682 analysable breaths. In each subject mean of moving average Edi (12 msec averaging interval) was computed out of 14-24 breaths, free of ECG artifacts within 200-250 msec before and after end inspiration. A deep indentation occurred near end-inspiration despite the lack of gaps or notches in 1/2 to 4/5 of these breaths. These results suggest that also in humans postinspiratory diaphragm activity does not represent the decay of inspiratory ramp.     

Thin-fiber phrenic afferents mediate the ventilatory response to diaphragmatic ischemia

We assessed the role of groups III and IV phrenic afferents in the ventilatory response to diaphragmatic ischemia in mechanicalldy ventilated, chloralose-anesthetized dogs using thein-situ isolated and innervated left hemidiaphragm preparation. The inspiratory motor drive to the right (Rt Edi) and left (Lt Edi) diaphragms, parasternal (Eps), and alae nasi (Ean) muscles was measured from the peak integrated EMG activities. When left diaphragmatic ischemia was produced in the control group (n = 6) by occluding the left phrenic artery for 20 min, Lt Edi increased to 158%, Rt Edi to 160%, Eps to 150% and Ean to 135% of baseline values. Left diaphragmatic tension, however, remained unchanged during the ischemia period. In the capsaicin-treated group (n = 6), we injected repeated doses of capsaicin, a selective stimulant of groups III and IV afferents, into the left phrenic artery to eliminate inputs from these afferents. Repeated injections of capsaicin are known to induce prolonged periods of afferent dysfunction. The first two injections of capsaicin (1 mg each) produced transient activation of the inspiratory muscles and higher breathing frequencies. Subsequent injections, however, failed to elicit any ventilatory changes. When diaphragmatic ischemia was induced after the last injection of capsaicin, no changes in the Right Edi, Eps and Ean were observed, whereas Left Edi and left diaphragmatic tension declined significantly. We conclude that increased inspiratory motor drive during selective diaphragmatic ischemia is mediated through the activation of groups III and IV phrenic afferents.     

解读神经调节通气辅助模式

神经调节通气辅助模式(NAVA)是利用膈肌电活动(Ed i)控制呼吸机送气的全新通气模式。在NAVA模式下,呼吸中枢可以直接控制呼吸机的辅助水平,呼吸机变成了"呼吸肌"。目前研究表明,NA-VA可实现个体化的通气支持,极大地改善人机协调性,有效减轻呼吸中枢负荷,并能防止肺过度膨胀。