Respiratory Physiology & Neurobiology最新文献_第3页

Recruitment of the diaphragm and sternocleidomastoid muscle during increasing inspiratory pressure loads in healthy young adults 健康年轻人在吸气压力负荷增加时横膈膜和胸锁乳突肌的募集。

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-11-01 DOI: 10.1016/j.resp.2024.104365

Fang Liu , Alice Y.M. Jones , Raymond C.C. Tsang , Timothy T.T. Yam , William W.N. Tsang

Background

Inspiratory muscle training (IMT) is often employed to enhance improvement in inspiratory muscle strength. However, the relationship between inspiratory muscle recruitment patterns and increasing inspiratory load remains unclear. Furthermore, the effect of breathing instructions on diaphragm activity at various inspiratory loads is unknown.

Objective

To investigate the recruitment activity of the diaphragm and sternocleidomastoid (SCM) muscle under increased inspiratory pressure loading, with and without diaphragmatic breathing instructions, in healthy young adults.

Methods

Participants were invited to breathe, in random order, 6 sets of 10 breaths at inspiratory loads of 30 % to 80 % maximal inspiratory pressure (MIP), in 10 % increments. The measurement process was repeated with a specific focus of diaphragmatic descent during inspiration. During each targeted breath, recordings of surface electromyography of the right SCM muscle and thickness of the right hemi-diaphragm measured by ultrasonography were undertaken concurrently.

Results

Sixty-two adults (31 males, age: 23±3 years) participated in the study. Irrespective of breathing instructions, computed diaphragm thickening fraction (DTf) increased with increasing inspiratory load but peaked at 50 % MIP and declined with increasing load to 80 % MIP. SCM recruitment increased with increasing inspiratory load to 80 % MIP. Forced inspiration with diaphragmatic breathing was associated with a higher DTf and lower SCM muscle activity. The above pattern was similar for both male and female participants. Female participants produced higher SCM activity compared with males but only at inspiration loads below 50 % MIP.

Conclusions

In a cohort of young healthy adults, magnitude of diaphragmatic effort was greatest at 50 % MIP but declined with increasing inspiratory load to 80 % MIP. Forced inspiration combined with focused diaphragmatic breathing accentuated diaphragm contraction and reduced SCM muscle contribution. Our findings show that diaphragmatic muscle recruitment is non-linear and that the generic clinical prescription of an IMT program may need to be reconfigured.

背景：通常采用吸气肌训练（IMT）来增强吸气肌的力量。然而，吸气肌肉募集模式与吸气负荷增加之间的关系仍不清楚。此外，呼吸指导对不同吸气负荷下横膈膜活动的影响也不清楚：研究健康年轻人在吸气压力负荷增加的情况下，在有和没有横膈膜呼吸指导的情况下横膈膜和胸锁乳突肌（SCM）的募集活动：受试者按随机顺序在 30% 至 80% 最大吸气压力 (MIP) 的吸气负荷下呼吸 6 组，每组 10 次，每次递增 10%。测量过程重复进行，重点是吸气时横膈膜的下降。在每次目标呼吸过程中，同时通过超声波测量记录右侧SCM肌表面肌电图和右侧半膈肌厚度：62 名成人（31 名男性，年龄：23±3 岁）参加了研究。无论呼吸指示如何，计算出的膈肌增厚分数（DTf）随着吸气负荷的增加而增加，但在 50%MIP时达到峰值，并随着负荷增加至 80%MIP 而下降。随着吸气负荷增加到 80%MIP，SCM 募集量增加。横膈膜呼吸时的强制吸气与较高的 DTf 和较低的 SCM 肌肉活动有关。男性和女性参与者的上述模式相似。女性参与者的 SCM 活动量高于男性，但仅限于吸气负荷低于 50%MIP 时：结论：在一群年轻健康的成年人中，50% MIP 时横膈膜努力程度最大，但随着吸气负荷增加到 80%MIP 时，横膈膜努力程度下降。强制吸气与集中横膈膜呼吸相结合，增强了横膈膜的收缩，减少了SCM肌肉的贡献。我们的研究结果表明，横膈膜肌肉募集是非线性的，IMT 计划的通用临床处方可能需要重新配置。

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引用次数: 0

Hemodynamics and vascular oxygenation measured at the forehead during changes in respiration: A SPA-fNIRS study 呼吸变化时在前额测量血液动力学和血管氧合：SPA-fNIRS 研究。

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-10-29 DOI: 10.1016/j.resp.2024.104364

Sabino Guglielmini , Elena Wiggli , Felix Scholkmann , Martin Wolf

Significance

Cerebral blood flow is influenced by respiration, primarily through changes in the CO₂ concentration of arterial blood.

Aim

The objective of this study was to investigate the effect of changes in arterial CO₂ concentration induced by respiratory changes on oxygenation and hemodynamics in the cerebral and extracerebral tissue layers of the forehead.

Approach

We used systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) to assess changes in forehead hemodynamics and oxygenation as well as systemic physiology in 20 healthy subjects. All participants performed two respiratory tasks (breath-holding and hyperventilation).

Results

In our SPA-fNIRS study we found that changes in breathing affected hemodynamics and oxygenation in both the extracerebral and cerebral tissue layers of the forehead in characteristic ways, depending on the two respiratory tasks.

Conclusion

The results show that extracerebrovascular reactivity (ECVR) exists in parallel with the well-known cerebrovascular reactivity (CVR). CVR and ECVR must be considered when performing fNIRS neuroimaging studies involving changes in respiration.

意义：目的：本研究旨在探讨呼吸变化引起的动脉二氧化碳浓度变化对前额大脑和脑外组织层氧合和血液动力学的影响：方法：我们使用系统生理学增强功能近红外光谱（SPA-fNIRS）来评估 20 名健康受试者前额血液动力学和氧饱和度以及系统生理学的变化。所有受试者都完成了两项呼吸任务（屏气和过度换气）：结果：在我们的 SPA-fNIRS 研究中，我们发现呼吸的变化以特有的方式影响着前额脑外组织和脑组织层的血液动力学和氧合，这取决于两种呼吸任务：结果表明，脑外血管反应性（ECVR）与众所周知的脑血管反应性（CVR）同时存在：在进行涉及呼吸变化的 fNIRS 神经成像研究时，必须考虑 CVR 和 ECVR。

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引用次数: 0

Two-day cardiopulmonary exercise testing in long COVID post-exertional malaise diagnosis 长 COVID 运动后瘫痪诊断中的两天心肺运动测试

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-10-28 DOI: 10.1016/j.resp.2024.104362

Chiara Gattoni, Asghar Abbasi, Carrie Ferguson, Charles W. Lanks, Thomas W. Decato, Harry B. Rossiter, Richard Casaburi, William W. Stringer

Background

Long COVID patients present with a myriad of symptoms that can include fatigue, exercise intolerance and post exertional malaise (PEM). Long COVID has been compared to other post viral syndromes, including myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), where a reduction in day 2 cardiopulmonary exercise test (CPET) performance of a two-day CPET protocol is suggested to be a result of PEM. We investigated cardiopulmonary and perceptual responses to a two-day CPET protocol in Long COVID patients.

Methods

15 Long COVID patients [n=7 females; mean (SD) age: 53(11) yr; BMI = 32.2(8.5) kg/m²] performed a pulmonary function test and two ramp-incremental CPETs separated by 24 hr. CPET variables included gas exchange threshold (GET), peak oxygen uptake (

\dot{V}

O_2peak) and peak work rate (WR_peak). Ratings of perceived dyspnoea and leg effort were recorded at peak exercise using the modified 0–10 Borg Scale. PEM (past six months) was assessed using the modified DePaul Symptom Questionnaire (mDSQ). One-sample t-tests were used to test significance of mean difference between days (p<0.05).

Results.

mDSQ revealed PEM in 80 % of patients. Lung function was normal. Responses to day 1 CPET were consistent with the presence of aerobic deconditioning in 40 % of patients (

\dot{V}

O_2peak <80 % predicted, in the absence of evidence of cardiovascular and pulmonary limitations). There were no differences between day-1 and day-2 CPET responses (all p>0.05).

Conclusion

PEM symptoms in Long COVID patients, in the absence of differences in two-day CPET responses separated by 24 hours, suggests that PEM is not due to impaired recovery of exercise capacity between days.

背景：长期慢性阻塞性肺病（COVID）患者会出现各种症状，包括疲劳、运动不耐受和劳累后乏力（PEM）。长 COVID 与其他病毒后综合征（包括肌痛性脑脊髓炎/慢性疲劳综合征（ME/CFS））进行了比较，后者在为期两天的 CPET 方案中，第 2 天的心肺运动测试（CPET）成绩下降被认为是 PEM 的结果。我们研究了 Long COVID 患者对两天 CPET 方案的心肺和知觉反应。方法：15 名 Long COVID 患者[n=7 名女性；平均（标清）年龄：53（11）岁；体重指数 = 32.2（8.5）千克/平方米]进行了肺功能测试和两次斜坡递增 CPET，每次间隔 24 小时。CPET 变量包括气体交换阈值 (GET)、VO2 峰值和 WR 峰值。在峰值运动时，使用改良的 0-10 Borg 量表记录感觉到的呼吸困难和腿部用力情况。使用改良的德保罗症状问卷（mDSQ）对过去 6 个月的 PEM 进行评估。采用单样本 t 检验来检验不同天数之间平均差异的显著性（p 结果：mDSQ 显示 80% 的患者患有 PEM。肺功能正常。第 1 天 CPET 的反应与 40% 的患者存在有氧机能减退一致（V̇O2peak 0.05）：结论：长COVID患者出现劳累后乏力症状，而相隔24小时的两天CPET反应却没有差异，这表明劳累后乏力并不是由于几天之间运动能力恢复受损所致。

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引用次数: 0

A short duration of mechanical ventilation alters redox status in the diaphragm and aggravates inflammation in septic mice 短时间的机械通气会改变膈肌的氧化还原状态，加重脓毒症小鼠的炎症。

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-10-19 DOI: 10.1016/j.resp.2024.104361

Pedro Alves Machado-Junior , Marcelo Santiago Soares Dias , Ana Beatriz Farias de Souza , Leonardo Spinelli Estevão Lopes , Tatiana Prata Menezes , André Talvani , Laurent Brochard , Frank Silva Bezerra

Background

Mechanical ventilation (MV) is a life support method used to treat patients with respiratory failure. High tidal volumes during MV can cause ventilator-induced lung injury (VILI), but also affect other organs, such as the diaphragm (Dia) causing ventilator-induced diaphragmatic dysfunction (VIDD). VIDD is often associated with a complicated course on MV. Sepsis can induce inflammation and oxidative stress, contributing to the impairment of the Dia and worsening of the prognosis. This study evaluated the additive or synergistic effects of a short course of mechanical ventilation on Dia in healthy and septic adult mice.

Methods

32 adult male C57BL/6 mice were randomly into four groups: Control (CG), non-ventilated animals instilled with saline solution (PBS1x); Lipopolysaccharide (LPS), non-ventilated animals instilled with PBS solution containing lipopolysaccharide; Mechanical Ventilation (MV) for 1 h, ventilated animals instilled with PBS solution; and Mechanical Ventilation and LPS (MV+LPS), ventilated animals instilled with PBS solution containing LPS. At the end of the experimental protocol, the animals were euthanized, then blood and diaphragm tissue samples were collected.

Results

Evaluation of leukocyte/blood parameters and diaphragm muscle showed that MV, LPS and the combination of both were able to increase neutrophil count, creatine kinase, inflammatory mediators and oxidative stress in all groups compared to the control. MV and sepsis combined had additive effects on inflammation and lipid peroxidation.

Conclusions

A short course of Mechanical ventilation promotes inflammation and oxidative stress and, its combination with sepsis further increases local and systemic inflammation.

背景：机械通气（MV）是一种用于治疗呼吸衰竭患者的生命支持方法。机械通气期间的高潮气量可导致呼吸机诱发肺损伤（VILI），但也会影响其他器官，如引起呼吸机诱发膈肌功能障碍（VIDD）的膈肌（Dia）。VIDD 通常与 MV 的复杂病程有关。脓毒症可诱发炎症和氧化应激，导致膈肌受损和预后恶化。本研究评估了短期机械通气对健康和脓毒症成年小鼠 Dia 的叠加或协同作用：方法：将32只成年雄性C57BL/6小鼠随机分为四组：对照组（CG），灌注生理盐水（PBS1x）的非通气动物；脂多糖组（LPS），灌注含有脂多糖的PBS溶液的非通气动物；机械通气1小时组（MV），灌注PBS溶液的通气动物；机械通气和LPS组（MV+LPS），灌注含有LPS的PBS溶液的通气动物。实验结束后，对动物实施安乐术，然后采集血液和膈肌组织样本：结果：对白细胞/血液参数和膈肌的评估表明，与对照组相比，中性粒细胞增多症、脓毒症和两者的结合能增加所有组的中性粒细胞计数、肌酸激酶、炎症介质和氧化应激。中压和脓毒症联合作用对炎症和脂质过氧化具有叠加效应：结论：短期机械通气会促进炎症和氧化应激，与败血症合并使用会进一步增加局部和全身炎症。

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引用次数: 0

Differential neuromotor control of the vertical and longitudinal genioglossus muscle fibers: An overlooked tongue retractor 纵向和纵向舌根肌纤维的不同神经运动控制：被忽视的缩舌器。

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-10-09 DOI: 10.1016/j.resp.2024.104354

Ron Oliven , Arie Oliven , Mostafa Somri , Alan R. Schwartz , Emilia Hardak

Introduction

The genioglossus (GG) is known to be the main tongue protrusor, and therefore plays a major role in breathing. However, due to the fan shape of the GG fibers, it could be assumed that contraction of the anterior fibers of the GG do not cause tongue protrusion. In this study, we examined the effect of contraction of the anterior-vertical fibers of the GG (GG_V) on the tongue and their EMG activity during wakefulness and sleep. The findings were compared to those of the longitudinal fibers (GG_L), which, based on their orientation, are responsible for tongue protrusion.

Methods

Fine-wire electrode pairs were placed into the GG_V and GG_L in 11 patients with untreated OSA. Movement of the tongue during electrical stimulation at each site was videoed. The same electrodes were used to record EMG from both sites during respiratory stimulation by inspiratory loading and CO₂ rebreathing during wakefulness. During sleep, repetitive flow limitation events were induced with low-level CPAP to augment GG activity.

Results

In all participants, electrical stimulation of GG_L and GG_V protruded and retracted the tongue, respectively. Respiratory stimulation increased GG activity, but GG_V reached only 39 % and 23 % of peak GG_L activity during high resistive loading and PCO₂ of 65 mmHg, respectively. Flow limitation during sleep increased GG_L to levels that were considerably higher than awake baseline, but GG_V activity remained tonic or with minimal phasic activity, reaching on average 15 % of GG_L peak activity.

Conclusions

Our electrical stimulation findings indicate that GG_V is a tongue retractor and depressor. Tongue stimulation for OSA should avoid this area. The EMG results demonstrate that the anterior part of the GG is controlled very differently from the longitudinal protrusive fibers. The GG_V responses are similar to those previously found in tongue retractors and peri-pharyngeal muscles other than the GG, in which diminished activation during sleep is likely to be involved in the failure of increasing GG_L activity to alleviate flow limitation.

简介众所周知，舌根舌骨（GG）是主要的舌前伸肌，因此在呼吸中发挥着重要作用。然而，由于舌根舌肌纤维呈扇形，可以认为舌根舌肌前纤维的收缩不会导致舌前突。在这项研究中，我们研究了 GG 前垂直纤维（GGV）的收缩对舌头的影响，以及它们在清醒和睡眠时的肌电图活动。研究结果与纵向纤维（GGL）的研究结果进行了比较：方法：在 11 名未经治疗的 OSA 患者的 GGV 和 GGL 上放置细线电极对。对每个部位进行电刺激时舌头的运动情况进行录像。在清醒时通过吸气负荷和二氧化碳回吸进行呼吸刺激时，使用相同的电极记录这两个部位的肌电图。睡眠时，用低水平 CPAP 诱导重复性血流受限事件，以增强 GG 活动：结果：在所有参与者中，对 GGL 和 GGV 的电刺激分别会使舌头伸出和缩回。呼吸刺激增加了 GG 活动，但在高阻力负荷和 PCO2 为 65mmHg 时，GGV 只分别达到 GGL 活动峰值的 39% 和 23%。睡眠期间的流量限制使 GGL 增加到比清醒基线高得多的水平，但 GGV 活动仍保持强直或阶段性活动极少，平均达到 GGL 峰值活动的 15%：结论：我们的电刺激研究结果表明，GGV 具有缩舌和压舌作用。结论：我们的电刺激研究结果表明，GGV 是舌头的牵引器和抑制器，对 OSA 的舌头刺激应避开这一区域。肌电图结果表明，GG 的前部受到的控制与纵向突出纤维截然不同。GGV 的反应与之前在除 GG 以外的缩舌肌和咽周肌肉中发现的反应类似，其中睡眠期间激活的减少很可能与 GGL 活动的增加未能缓解血流限制有关。

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引用次数: 0

Effects of sildenafil on gas exchange, ventilatory, and sensory responses to exercise in subjects with mild-to-moderate COPD: A randomized cross-over trial 西地那非对轻度至中度慢性阻塞性肺病患者运动时气体交换、通气和感觉反应的影响：随机交叉试验。

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-10-09 DOI: 10.1016/j.resp.2024.104359

Ricardo Gass , Franciele Plachi , Fernanda O.B. Silva , Talmir Nolasco , Mateus Samuel Tonetto , Leandro S. Goelzer , Paulo T. Muller , Marli M. Knorst , J. Alberto Neder , Danilo C. Berton

Excess exercise ventilation (high ventilation (V̇_E)/carbon dioxide output (V̇CO₂)) contributes significantly to dyspnea and exercise intolerance since the earlier stages of chronic obstructive pulmonary disease (COPD). A selective pulmonary vasodilator (inhaled nitric oxide) has shown to increase exercise tolerance secondary to lower V̇_E/V̇CO₂ and dyspnea in this patient population. We aimed to assess whether a clinically more practical option - oral sildenafil - would be associated with similar beneficial effects. In a randomized, placebo-controlled study, twenty-four patients with mild-to-moderate COPD completed, on different days, two incremental cardiopulmonary exercise tests (CPET) one hour after sildenafil or placebo. Eleven healthy participants performed a CPET in a non-interventional visit for comparative purposes with patients when receiving placebo. Patients (FEV₁= 69.4 ± 13.5 % predicted) showed higher ventilatory demands (V̇_E/V̇CO₂), worse pulmonary gas exchange, and higher dyspnea during exercise compared to controls (FEV₁= 98.3 ±11.6 % predicted). Contrary to our expectations, however, sildenafil (50 mg; N= 15) did not change exertional V̇_E/V̇CO₂, dead space/tidal volume ratio, operating lung volumes, dyspnea, or exercise tolerance compared to placebo (P>0.05). Due to the lack of significant beneficial effects, nine additional patients were trialed with a higher dose (100 mg). Similarly, active intervention was not associated with positive physiological or sensory effects. In conclusion, acute oral sildenafil (50 or 100 mg) failed to improve gas exchange efficiency or excess exercise ventilation in patients with predominantly moderate COPD. The current study does not endorse a therapeutic role for sildenafil to mitigate exertional dyspnea in this specific patient subpopulation.

Clinical trial registry: https://ensaiosclinicos.gov.br/rg/RBR-4qhkf4

Web of Science Researcher ID: O-7665–2019

自慢性阻塞性肺病（COPD）早期阶段以来，运动通气量过大（通气量（V鄄E）/二氧化碳排出量（VCO2）过高）在很大程度上导致了呼吸困难和运动耐受不良。有研究表明，选择性肺血管扩张剂（吸入一氧化氮）可增加早期慢性阻塞性肺疾病患者的运动耐受性，继而降低 V̇E/VÒCO2 和呼吸困难。我们旨在评估一种临床上更实用的选择--口服西地那非--是否会带来类似的有益效果。在一项随机、安慰剂对照研究中，24 名轻度至中度慢性阻塞性肺病患者在不同的日子里，在服用西地那非或安慰剂一小时后完成了两次增量心肺运动测试（CPET）。11 名健康参与者在一次非干预性访问中进行了 CPET，以便与接受安慰剂治疗的患者进行比较。与对照组（FEV1= 98.3 ±11.6% 预估值）相比，患者（FEV1= 69.4 ±13.5% 预估值）的通气需求（V.M.E./V.M.CO2）更高，肺气体交换更差，运动时呼吸困难更严重。然而，与我们的预期相反，与安慰剂相比，西地那非（50 毫克；N= 15）并未改变用力时的 V̇E/V̇CO2、死腔/潮气量比率、肺活量、呼吸困难或运动耐受性（P>0.05）。由于疗效不明显，又有九名患者接受了更高剂量（100 毫克）的试验。同样，积极干预也没有产生积极的生理或感官效应。总之，急性口服西地那非（50 毫克或 100 毫克）未能改善以中度慢性阻塞性肺病为主的患者的气体交换效率或运动过量通气。目前的研究并不认可西地那非在缓解这一特定患者亚群的运动性呼吸困难方面的治疗作用。临床试验登记：https://ensaiosclinicos.gov.br/rg/RBR-4qhkf4 Web of Science Researcher ID：O-7665-2019.

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引用次数: 0

Inspiratory muscle training improves autonomic function in myalgic encephalomyelitis/chronic fatigue syndrome and post-acute sequelae of SARS-CoV-2: A pilot study 吸气肌训练可改善肌痛性脑脊髓炎/慢性疲劳综合征和 SARS-CoV-2 急性后遗症患者的自律神经功能：一项试点研究。

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-10-06 DOI: 10.1016/j.resp.2024.104360

Heather Edgell , Tania J. Pereira , Kathleen Kerr , Riina Bray , Farah Tabassum , Lauren Sergio , Smriti Badhwar

Post-acute sequelae of SARS-CoV-2 (PASC), or Long COVID, and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are debilitating post-viral conditions with many symptomatic overlaps, including exercise intolerance and autonomic dysfunction. Both conditions are growing in prevalence, and effective safe treatment strategies must be investigated. We hypothesized that inspiratory muscle training (IMT) could be used in PASC and mild to moderate ME/CFS to mitigate symptoms, improve exercise capacity, and improve autonomic function. We recruited healthy controls (n=12; 10 women), people with PASC (n=9; 8 women), and people with mild to moderate ME/CFS (n=12; 10 women) to complete 8 weeks of IMT. This project was registered as a clinical trial (NCT05196529) with clinicaltrials.gov. After completion of IMT, all groups experienced improvements in inspiratory muscle pressure (p<0.001), 6-minute walk distance (p=0.002), resting heart rate (p=0.037), heart rate variability (p<0.05), and symptoms related to sleep (p=0.009). In the ME/CFS group only, after completion of IMT, there were additional improvements with regard to vascular function (p=0.001), secretomotor function (p=0.023), the total weighted score (p=0.005) of the COMPASS 31 autonomic questionnaire, and symptoms related to pain (p=0.016). We found that after 8 weeks of IMT, people with PASC and/or ME/CFS could see some overall improvements in their autonomic function and symptomology.

SARS-CoV-2急性后遗症（PASC）或长COVID，与肌痛性脑脊髓炎/慢性疲劳综合征（ME/CFS）都是使人衰弱的病毒后遗症，有许多症状重叠，包括运动不耐受和自主神经功能障碍。这两种疾病的发病率都在上升，因此必须研究有效安全的治疗策略。我们假设，吸气肌训练（IMT）可用于 PASC 和轻度至中度 ME/CFS，以减轻症状、提高运动能力和改善自律神经功能。我们招募了健康对照组（12 人；10 名女性）、PASC 患者（9 人；8 名女性）和轻中度 ME/CFS 患者（12 人；10 名女性）完成为期 8 周的吸气肌训练。该项目已在 clinicaltrials.gov 注册为临床试验（NCT05196529）。完成 IMT 后，所有小组的吸气肌压力都有所改善（p

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引用次数: 0

The activity of suprahyoid muscles during sevoflurane-induced gasping in mice 七氟醚诱导小鼠喘息时耳上肌的活动。

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-10-05 DOI: 10.1016/j.resp.2024.104355

Saki Taiji, Takashi Nishino, Hisayo Jin, Mayumi Hashida, Shiroh Isono

Sevoflurane-induced gasping in mice involves an enormous increase in inspiratory effort, mandibular movement, and a marked decrease in respiratory frequency (fR). We examined differences in breathing patterns and electromyogram activity (EMG_SH) of the suprahyoid muscles (SHMs) during eupnea under 3.2 % (1 MAC: minimum alveolar concentration) sevoflurane inhalation and sevoflurane-induced gasping under 6.5 % (2 MAC) sevoflurane inhalation in eight spontaneously breathing, tracheally intubated, adult mice. We found that the phasic EMG_SH is obtained only during inspiration in eupnea and gasping and that integrated EMG_SH increases more, as a percent of baseline (% baseline) than tidal volume (V_T) during gasping (median [interquartile range]; integrated EMG_SH: 720 [425–1965] vs. V_T: 300 [238–373], P < 0.05). We also found that the onset of EMG_SH precedes the start of airflow while maintaining a bell-shaped EMG_SH contour, which characterizes the EMG of upper airway dilator (UAD) muscles during eupnea and gasping. Vigorous respiratory-related mandibular movements were never observed during eupnea but were observed in seven of 8 mice during sevoflurane-induced gasping. Our observations indicate that SHMs act as a preferentially activating UAD muscle, contributing to the development of mandibular respiratory movements.

七氟醚诱导的小鼠喘气会导致吸气强度和下颌骨运动的大幅增加，以及呼吸频率（fR）的明显降低。我们研究了 8 只自主呼吸、气管插管的成年小鼠在 3.2%（1 MAC：最小肺泡浓度）七氟烷吸入条件下出现呼吸暂停和 6.5%（2 MAC）七氟烷吸入条件下出现七氟烷诱导的喘息时的呼吸模式和舌骨上肌（SHM）肌电图活动（EMGSH）的差异。我们发现，相位 EMGSH 仅在呼吸暂停和喘气时的吸气过程中获得，在喘气过程中，综合 EMGSH 在基线百分比（% 基线）上的增加幅度大于潮气量（VT）（中位数[四分位数间距]；综合 EMGSH：720 [425-1965] vs. VT：300 [238-38] ）。VT：300 [238-373]，PSH 在气流开始之前，同时保持钟形的 EMGSH 轮廓，这是呼吸暂停和喘息时上气道扩张肌 (UAD) 肌电图的特征。在呼吸暂停过程中从未观察到与呼吸相关的下颌骨剧烈运动，但在七氟醚诱导的喘息过程中，8 只小鼠中有 7 只观察到了下颌骨剧烈运动。我们的观察结果表明，SHMs 是一种优先激活的 UAD 肌肉，有助于下颌呼吸运动的发展。

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引用次数: 0

Breathing pattern alteration from weanling to old age in male Sprague-Dawley rats 雄性 Sprague-Dawley 大鼠从断奶到老年呼吸模式的改变

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-10-01 DOI: 10.1016/j.resp.2024.104357

Mehdi Eslami-Behroozi, Payam Shahsavar, Reyhaneh Vali, Mohammad Reza Raoufy

Respiratory patterns were investigated in male Sprague-Dawley rats throughout their lifespan, from weanling (1 month) to old age (24 months), under natural conditions. Both inter-breath interval (IBI) and respiratory volume (RV) were examined. Sample entropy suggested increasing irregularity in IBI but decreasing irregularity in RV until 12 months. According to detrended fluctuation analysis, alpha exponent of the IBI showed a bimodal pattern around the value 0.7. From 1–15 months, the alpha exponent for RV generally decreased to the value 0.5, but it increased again as the animals neared the end of their lifespan. Cross-sample entropy revealed increasing synchronization between IBI and RV until 12 months, then plateauing. Many measures demonstrated a transition around 12 months, potentially reflecting maturation of respiratory control mechanisms. The findings characterize complex dynamics of respiratory patterns across the rat lifespan, providing a normative foundation to identify deviations indicative of dysfunction or disease.

在自然条件下，对雄性 Sprague-Dawley 大鼠从断奶（1 个月）到老年（24 个月）的整个生命周期的呼吸模式进行了研究。对呼吸间歇（IBI）和呼吸量（RV）进行了研究。样本熵表明，在 12 个月之前，IBI 的不规则性不断增加，而 RV 的不规则性则不断减少。根据去趋势波动分析，IBI 的α指数在 0.7 值附近呈现双峰模式。从1个月到15个月，RV的α指数普遍下降到0.5，但随着动物寿命接近尾声，α指数又再次上升。跨样本熵显示，在12个月之前，IBI和RV之间的同步性不断提高，然后趋于平稳。许多测量指标在 12 个月左右出现转变，这可能反映了呼吸控制机制的成熟。这些发现描述了大鼠整个生命周期呼吸模式的复杂动态，为识别表明功能障碍或疾病的偏差提供了规范基础。

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Safety and effectiveness of acute intermittent hypoxia during a single treatment at different hypoxic severities 不同缺氧严重程度下单次急性间歇性缺氧治疗的安全性和有效性

IF 1.9 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2024-09-29 DOI: 10.1016/j.resp.2024.104358

Cory M. Smith, Owen F. Salmon

Purpose

Examine the cardiovascular, muscular function, cognitive, and neural plastic responses to determine the safety and effectiveness of acute Intermittent hypoxia (AIH) at a low, high, and control fractional inspired oxygen (FiO₂) dosage

Methods

Thirteen human participants performed 30-min of AIH in 60-s intervals at FiO2’s of 0.21 (AIH₂₁), 0.15 (AIH₁₅), and 0.09 (AIH₉). Heart rate variability (root mean squared of successive differences; RMSSD), heart rate, oxygen saturation (SpO2), blood pressure, muscular strength, neuromuscular activation, cerebral hemodynamic responses, cognition, symptomology, and brain-derived neurotrophic factor (BDNF) responses were measured before (Pre-AIH), after (post-AIH), and at 20-min of recovery (Recovery-AIH)

Results

There were no differences between AIH protocols for heart rate, RMSSD, blood pressure, or SpO2. Muscular strength improved Post-AIH for AIH₁₅ (10 %) and AIH₉ (14 %) and remained elevated (6 %) at Recovery-AIH. Neuromuscular activation increased Pre-AIH to Post-AIH for AIH15 (10 %) and AIH₉ (11 %). Cerebral hemodynamic responses were not impacted between conditions. Both AIH₁₅ and AIH9 increased BDNF Post-AIH (62 %) and Recovery-AIH (63 %)

Conclusion

Acute intermittent hypoxia is generally safe and effective at producing neural plastic responses, but further examination of co-occurring cardiovascular diseases is needed. This study provides safety focused findings which will widen the adoption and refinement of AIH protocols

目的：检查心血管、肌肉功能、认知和神经可塑性反应，以确定在低、高和控制分数吸入氧（FiO2）剂量下进行急性间歇性缺氧（AIH）的安全性和有效性方法：13 名人类参与者在 FiO2 为 0.21（AIH21）、0.15（AIH15）和 0.09（AIH9）的条件下，以 60 秒为间隔进行了 30 分钟的 AIH。测量了心率变异性（连续差值的均方根；RMSSD）、心率、血氧饱和度（SpO2）、血压、肌肉力量、神经肌肉活化、脑血流动力学反应、认知、症状和脑源性神经营养因子（BDNF）反应，分别在治疗前（Pre-AIH）、治疗后（post-AIH）和恢复 20 分钟后（Recovery-AIH）进行结果：不同的 AIH 方案在心率、RMSSD、血压或 SpO2 方面没有差异。AIH15（10%）和 AIH9（14%）在恢复-AIH 后的肌肉强度有所提高，但在恢复-AIH 时仍保持较高水平（6%）。AIH15（10%）和 AIH9（11%）的神经肌肉激活从恢复前增加到恢复后。不同条件下的脑血流动力学反应没有受到影响。AIH15和AIH9都能在AIH后（62%）和恢复期AIH（63%）增加BDNF 结论：急性间歇性缺氧在产生神经可塑性反应方面通常是安全有效的，但还需要进一步检查并发的心血管疾病。本研究提供了以安全性为重点的研究结果，这将扩大急性间歇缺氧方案的采用范围并使其更加完善。

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引用次数: 0