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Journal of Physiotherapy Jul 2015Does inspiratory muscle training improve inspiratory muscle strength in adults receiving mechanical ventilation? Does it improve the duration or success of weaning? Does... (Review)
Review
QUESTION
Does inspiratory muscle training improve inspiratory muscle strength in adults receiving mechanical ventilation? Does it improve the duration or success of weaning? Does it affect length of stay, reintubation, tracheostomy, survival, or the need for post-extubation non-invasive ventilation? Is it tolerable and does it cause adverse events?
DESIGN
Systematic review of randomised trials.
PARTICIPANTS
Adults receiving mechanical ventilation.
INTERVENTION
Inspiratory muscle training versus sham or no inspiratory muscle training.
OUTCOME MEASURES
Data were extracted regarding: inspiratory muscle strength and endurance; the rapid shallow breathing index; weaning success and duration; duration of mechanical ventilation; reintubation; tracheostomy; length of stay; use of non-invasive ventilation after extubation; survival; readmission; tolerability and adverse events.
RESULTS
Ten studies involving 394 participants were included. Heterogeneity within some meta-analyses was high. Random-effects meta-analyses showed that the training significantly improved maximal inspiratory pressure (MD 7 cmH2O, 95% CI 5 to 9), the rapid shallow breathing index (MD 15 breaths/min/l, 95% CI 8 to 23) and weaning success (RR 1.34, 95% CI 1.02 to 1.76). Although only assessed in individual studies, significant benefits were also reported for the time spent on non-invasive ventilation after weaning (MD 16 hours, 95% CI 13 to 18), length of stay in the intensive care unit (MD 4.5 days, 95% CI 3.6 to 5.4) and length of stay in hospital (MD 4.4 days, 95% CI 3.4 to 5.5). Weaning duration decreased in the subgroup of patients with known weaning difficulty. The other outcomes weren't significantly affected or weren't measured.
CONCLUSION
Inspiratory muscle training for selected patients in the intensive care unit facilitates weaning, with potential reductions in length of stay and the duration of non-invasive ventilatory support after extubation. The heterogeneity among the results suggests that the effects of inspiratory muscle training may vary; this perhaps depends on factors such as the components of usual care or the patient's characteristics.
Topics: Humans; Inhalation; Intensive Care Units; Physical Therapy Modalities; Respiration, Artificial; Respiratory Muscles; Ventilator Weaning
PubMed: 26092389
DOI: 10.1016/j.jphys.2015.05.016 -
Journal of the American Heart... Jul 2021Background High-resistance inspiratory muscle strength training (IMST) is a novel, time-efficient physical training modality. Methods and Results We performed a... (Randomized Controlled Trial)
Randomized Controlled Trial
Time-Efficient Inspiratory Muscle Strength Training Lowers Blood Pressure and Improves Endothelial Function, NO Bioavailability, and Oxidative Stress in Midlife/Older Adults With Above-Normal Blood Pressure.
Background High-resistance inspiratory muscle strength training (IMST) is a novel, time-efficient physical training modality. Methods and Results We performed a double-blind, randomized, sham-controlled trial to investigate whether 6 weeks of IMST (30 breaths/day, 6 days/week) improves blood pressure, endothelial function, and arterial stiffness in midlife/older adults (aged 50-79 years) with systolic blood pressure ≥120 mm Hg, while also investigating potential mechanisms and long-lasting effects. Thirty-six participants completed high-resistance IMST (75% maximal inspiratory pressure, n=18) or low-resistance sham training (15% maximal inspiratory pressure, n=18). IMST was safe, well tolerated, and had excellent adherence (≈95% of training sessions completed). Casual systolic blood pressure decreased from 135±2 mm Hg to 126±3 mm Hg (<0.01) with IMST, which was ≈75% sustained 6 weeks after IMST (<0.01), whereas IMST modestly decreased casual diastolic blood pressure (79±2 mm Hg to 77±2 mm Hg, =0.03); blood pressure was unaffected by sham training (all >0.05). Twenty-four hour systolic blood pressure was lower after IMST versus sham training (=0.01). Brachial artery flow-mediated dilation improved ≈45% with IMST (<0.01) but was unchanged with sham training (=0.73). Human umbilical vein endothelial cells cultured with subject serum sampled after versus before IMST exhibited increased NO bioavailability, greater endothelial NO synthase activation, and lower reactive oxygen species bioactivity (<0.05). IMST decreased C-reactive protein (=0.05) and altered select circulating metabolites (targeted plasma metabolomics) associated with cardiovascular function. Neither IMST nor sham training influenced arterial stiffness (>0.05). Conclusions High-resistance IMST is a safe, highly adherable lifestyle intervention for improving blood pressure and endothelial function in midlife/older adults with above-normal initial systolic blood pressure. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03266510.
Topics: Aged; Biomarkers; Blood Pressure; Breathing Exercises; Cells, Cultured; Colorado; Double-Blind Method; Endothelium, Vascular; Female; Human Umbilical Vein Endothelial Cells; Humans; Hypertension; Inhalation; Male; Middle Aged; Nitric Oxide; Oxidative Stress; Respiratory Muscles; Time Factors; Treatment Outcome
PubMed: 34184544
DOI: 10.1161/JAHA.121.020980 -
Respiratory Care Apr 2020Inspiratory muscle training (IMT) has been widely applied to different populations, including the general population of older adults. In addition to increasing... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Inspiratory muscle training (IMT) has been widely applied to different populations, including the general population of older adults. In addition to increasing inspiratory muscle strength, other benefits of IMT in the health of this population have been reported. The primary aim of this study was to review the effects of IMT on the general parameters of health (eg, respiratory, functional, physical, and other variables) in older adults (≥ 60 y), and the secondary aim was to analyze the main IMT protocol used in the studies.
METHODS
We searched the MEDLINE, PEDro, SciELO, and LILACS databases to identify relevant randomized controlled clinical trials, and we assessed their methodological quality according to the PEDro scale. The Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guidelines were used to guide the development of the protocol for this systematic review.
RESULTS
The search yielded 7 studies involving 248 participants from 917 titles. The main outcomes investigated in response to IMT were related to the respiratory, functional, and physical variables. The results indicate that IMT promotes an increase of inspiratory muscle strength and diaphragmatic thickness in older adults. There was heterogeneity in the protocols described for this population with respect to the total training time (4-8 weeks), intensity (30-80% of the maximum inspiratory pressure), and weekly frequency (5 or 7 sessions).
CONCLUSIONS
The reviewed studies revealed a positive trend for the effectiveness of IMT in improving inspiratory muscle performance in elderly subjects. More randomized studies are needed to evaluate other outcomes (eg, functional capacity, exercise capacity, cardiac autonomic control, quality of life, and others) to provide robust evidence that this training modality can promote improvements in health parameters in this population. In addition, the usual IMT prescription in this population is based on sets and repetitions, of mild to moderate intensity, performed on most days of the week, for ≥ 4 weeks.
Topics: Aged; Aged, 80 and over; Breathing Exercises; Female; Humans; Inhalation; Male; Muscle Strength; Quality of Life; Respiratory Muscles
PubMed: 31662444
DOI: 10.4187/respcare.06945 -
PloS One 2021Although, pre-operative inspiratory muscle training has been investigated and reported to be an effective strategy to reduce postoperative pulmonary complications, the... (Randomized Controlled Trial)
Randomized Controlled Trial
Effect of postoperative high load long duration inspiratory muscle training on pulmonary function and functional capacity after mitral valve replacement surgery: A randomized controlled trial with follow-up.
OBJECTIVES
Although, pre-operative inspiratory muscle training has been investigated and reported to be an effective strategy to reduce postoperative pulmonary complications, the efficacy of postoperative inspiratory muscle training as well as the proper load, frequency, and duration necessary to reduce the postoperative pulmonary complications has not been fully investigated. This study was designed to investigate the effect of postoperative high-load long-duration inspiratory muscle training on pulmonary function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.
DESIGN
Prospective randomized controlled trial.
METHODS
A total of one hundred patients (mean age 38.3±3.29years) underwent mitral valve replacement surgery were randomized into experimental (n = 50) and control (n = 50) groups. The control group received conventional physiotherapy care, while experimental group received conventional care in addition to inspiratory muscle training, with 40% of the baseline maximal inspiratory pressure targeting a load of 80% by the end of the 8 weeks intervention protocol. Inspiratory muscle training started on the patient's first day in the inpatient ward. Lung functions, inspiratory muscle strength, and functional capacity were evaluated using a computer-based spirometry system, maximal inspiratory pressure measurement and 6MWT respectively at 5 time points and a follow-up assessment was performed 6 months after surgery. Repeated measure ANOVA and post-hoc analyses were used (p <0.05).
RESULTS
Group-time interactions were detected for all the studied variables (p<0.001). Between-group analysis revealed statistically significant postoperative improvements in all studied variables in the experimental group compared to the control group (p <0.001) with large effect size of η2 ˃0.14. Within-group analysis indicated substantial improvements in lung function, inspiratory pressure and functional capacity in the experimental group (p <0.05) over time, and these improvements were maintained at follow-up.
CONCLUSION
High intensity, long-duration postoperative inspiratory muscle training is highly effective in improving lung function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.
Topics: Adult; Breathing Exercises; Cardiac Surgical Procedures; Female; Humans; Inhalation; Lung; Male; Middle Aged; Mitral Valve; Muscle Strength; Myocardium; Respiratory Muscles; Respiratory Physiological Phenomena; Rheumatic Heart Disease; Spirometry; Young Adult
PubMed: 34449776
DOI: 10.1371/journal.pone.0256609 -
Journal of Applied Physiology... Nov 2022The purpose of this study was to determine the cardiovascular consequences elicited by activation of the inspiratory muscle metaboreflex in patients with heart failure...
The purpose of this study was to determine the cardiovascular consequences elicited by activation of the inspiratory muscle metaboreflex in patients with heart failure with preserved ejection fraction (HFpEF) and controls. Patients with HFpEF ( = 15; 69 ± 10 yr; 33 ± 4 kg/m) and controls ( = 14; 70 ± 8 yr; 28 ± 4 kg/m) performed an inspiratory loading trial at 60% maximal inspiratory pressure (P) until task failure. Mean arterial pressure (MAP) was measured continuously. Near-infrared spectroscopy and bolus injections of indocyanine green dye were used to determine the percent change in blood flow index (%ΔBFI) from baseline to the final minute of inspiratory loading in the vastus lateralis and sternocleidomastoid muscles. Vascular resistance index (VRI) was calculated. Time to task failure was shorter in HFpEF than in controls (339 ± 197 s vs. 626 ± 403 s; = 0.02). Compared with controls, patients with HFpEF had a greater increase from baseline in MAP (16 ± 7 vs. 10 ± 6 mmHg) and vastus lateralis VRI (76 ± 45 vs. 32 ± 19%) as well as a greater decrease in vastus lateralis %ΔBFI (-32 ± 14 vs. -17 ± 9%) (all, < 0.05). Sternocleidomastoid %ΔBFI normalized to absolute inspiratory pressure was higher in HFpEF compared with controls (8.0 ± 5.0 vs. 4.0 ± 1.9% per cmHO·s; = 0.03). These data indicate that patients with HFpEF exhibit exaggerated cardiovascular responses with inspiratory muscle metaboreflex activation compared with controls. Respiratory muscle dysfunction is thought to contribute to exercise intolerance in heart failure with preserved ejection fraction (HFpEF); however, the underlying mechanisms are unknown. In the present study, patients with HFpEF had greater increases in leg muscle vascular resistance index and greater decreases in leg muscle blood flow index compared with controls during inspiratory resistive breathing (to activate the metaboreflex). Furthermore, respiratory muscle blood flow index responses normalized to pressure generation during inspiratory resistive breathing were exaggerated in HFpEF compared with controls.
Topics: Humans; Heart Failure; Inhalation; Leg; Respiratory Muscles; Stroke Volume; Case-Control Studies
PubMed: 36227167
DOI: 10.1152/japplphysiol.00141.2022 -
Respiratory Medicine Sep 2016Inhaled drugs are the mainstay of treatment for lung diseases such as asthma and chronic obstructive pulmonary disease. However, failure to use inhalation devices... (Review)
Review
BACKGROUND
Inhaled drugs are the mainstay of treatment for lung diseases such as asthma and chronic obstructive pulmonary disease. However, failure to use inhalation devices correctly can lead to a poorly controlled status. A vast number of inhalation devices exist and each device has specific requirements to achieve optimum inhalation of the drug. Currently, there is no overview of inhalation requirements considering all devices. This article presents a review of the literature on different inhalation device requirements and incorporates the data into a new inhalation flow algorithm.
METHODS
Data from literature on commercially available inhalation devices were evaluated and parameters, such as inhalation flow rate, flow acceleration, inhalation volume, and inspiration time assessed for the required inhalation maneuver specific to the device. All agreed upon data points were used to develop an inhalation flow algorithm.
RESULTS
The literature analysis revealed availability of robust data for the required inhalation flow characteristics for most devices and thus for the development of an algorithm. For those devices for which these parameters are not published, the minimum required flow criteria were defined based on published data regarding individual aspects of aerosol quality.
CONCLUSIONS
This review provides an overview of inhalation devices available on the market regarding requirements for an acceptable inhalation maneuver and shows which goals should be achieved in terms of inhalation flows. The presented algorithm can be used to develop a new computer based measurement system which could help to test and train patients' individual inhalation maneuvers with their inhalation devices.
Topics: Administration, Inhalation; Aerosols; Algorithms; Asthma; Drug Delivery Systems; Equipment Design; Humans; Inhalation; Nebulizers and Vaporizers; Pulmonary Disease, Chronic Obstructive
PubMed: 27578473
DOI: 10.1016/j.rmed.2016.07.013 -
Frontiers in Immunology 2020Polarization of immune cells is commonly observed in host responses associated with microbial immunity, inflammation, tumorigenesis, and tissue repair and fibrosis. In... (Review)
Review
Polarization of immune cells is commonly observed in host responses associated with microbial immunity, inflammation, tumorigenesis, and tissue repair and fibrosis. In this process, immune cells adopt distinct programs and perform specialized functions in response to specific signals. Accumulating evidence indicates that inhalation of micro- and nano-sized particulates activates barrier immune programs in the lung in a time- and context-dependent manner, including type 1 and type 2 inflammation, and T helper (Th) 17 cell, regulatory T cell (Treg), innate lymphoid cell (ILC), and myeloid-derived suppressor cell (MDSC) responses, which highlight the polarization of several major immune cell types. These responses facilitate the pulmonary clearance and repair under physiological conditions. When exposure persists and overwhelms the clearance capacity, they foster the chronic progression of inflammation and development of progressive disease conditions, such as fibrosis and cancer. The pulmonary response to insoluble particulates thus represents a distinctive disease process wherein non-infectious, persistent exposures stimulate the polarization of immune cells to orchestrate dynamic inflammatory and immune reactions, leading to pulmonary and pleural chronic inflammation, fibrosis, and malignancy. Despite large variations in particles and their associated disease outcomes, the early response to inhaled particles often follows a common path. The initial reactions entail a barrier immune response dominated by type 1 inflammation that features active phagocytosis by M1 macrophages and recruitment of neutrophils, both of which are fueled by Th1 and proinflammatory cytokines. Acute inflammation is immediately followed by resolution and tissue repair mediated through specialized pro-resolving mediators (SPMs) and type 2 cytokines and cells including M2 macrophages and Th2 lymphocytes. As many particles and fibers cannot be digested by phagocytes, resolution is often extended and incomplete, and type 2 inflammation becomes heightened, which promotes interstitial fibrosis, granuloma formation, and tumorigenesis. Recent studies also reveal the involvement of Th17-, Treg-, ILC-, and MDSC-mediated responses in the pathogenesis caused by inhaled particulates. This review synopsizes the progress in understanding the interplay between inhaled particles and the pulmonary immune functions in disease pathogenesis, with focus on particle-induced polarization of immune cells and its role in the development of chronic inflammation, fibrosis, and cancer in the lung.
Topics: Animals; Cytokines; Dendritic Cells; Humans; Immune Tolerance; Immunity, Cellular; Inflammation; Inhalation; Lung; Lymphocytes; Macrophages; Myeloid-Derived Suppressor Cells; Particulate Matter; Signal Transduction; T-Lymphocyte Subsets
PubMed: 32625201
DOI: 10.3389/fimmu.2020.01060 -
Respiratory Care Sep 2017Dynamic hyperinflation is a common cause of dyspnea and functional limitation in patients with emphysema. Dynamic hyperinflation occurs in individuals with air-flow... (Review)
Review
Dynamic hyperinflation is a common cause of dyspnea and functional limitation in patients with emphysema. Dynamic hyperinflation occurs in individuals with air-flow limitation when expiratory time is decreased during periods of relative tachypnea (such as during exercise or agitation, for example). In this setting, patients with emphysema develop lung hyperinflation, impairment of inspiratory respiratory muscles, and an increase in work of breathing. The associated decrease in inspiratory capacity results in the stimulation of several receptors, including chemoreceptors and pulmonary receptors, which signal the brain to increase tidal volume. The inability of the respiratory system to respond to signals of increased demand (eg, by enlarging tidal volume and increasing inspiratory flow) results in a dissociation between afferent and efferent signaling thereby intensifying breathing discomfort, or what clinicians term dyspnea. A thorough understanding of the physiology of dyspnea and pathophysiology of dynamic hyperinflation informs the interventions used to mitigate sensations of dyspnea and the physiologic effects of dynamic hyperinflation, respectively. Pharmacotherapy, pulmonary rehabilitation, breathing techniques, positive airway pressure, and lung volume reduction are well-studied interventions that target pathways to dyspnea in patients with dynamic hyperinflation.
Topics: Dyspnea; Humans; Inhalation; Inspiratory Capacity; Lung; Pulmonary Emphysema; Pulmonary Ventilation; Respiratory Physiological Phenomena
PubMed: 28655742
DOI: 10.4187/respcare.05198 -
Respiratory Physiology & Neurobiology Nov 2013Diaphragm pacing is a clinically useful modality providing artificial ventilatory support in patients with ventilator dependent spinal cord injury. Since this technique... (Review)
Review
Diaphragm pacing is a clinically useful modality providing artificial ventilatory support in patients with ventilator dependent spinal cord injury. Since this technique is successful in providing full-time ventilatory support in only ~50% of patients, better methods are needed. In this paper, we review a novel method of inspiratory muscle activation involving the application of electrical stimulation applied to the ventral surface of the upper thoracic spinal cord at high stimulus frequencies (300 Hz). In an animal model, high frequency spinal cord stimulation (HF-SCS) results in synchronous activation of both the diaphragm and inspiratory intercostal muscles. Since this method results in an asynchronous pattern of EMG activity and mean peak firing frequencies similar to those observed during spontaneous breathing, HF-SCS is a more physiologic form of inspiratory muscle activation. Further, ventilation can be maintained on a long-term basis with repetitive stimulation at low stimulus amplitudes (<1 mA). These preliminary results suggest that HF-SCS holds promise as a more successful method of inspiratory muscle pacing.
Topics: Animals; Diaphragm; Humans; Inhalation; Intercostal Muscles; Spinal Cord Injuries; Spinal Cord Stimulation
PubMed: 23751522
DOI: 10.1016/j.resp.2013.06.001 -
The Journal of Physiology Sep 2019The female diaphragm fatigues at a slower rate compared to that of males, with blunted cardiovascular consequences (i.e. inspiratory muscle metaboreflex). It is unclear...
KEY POINTS
The female diaphragm fatigues at a slower rate compared to that of males, with blunted cardiovascular consequences (i.e. inspiratory muscle metaboreflex). It is unclear if these findings are a function of relative or absolute diaphragmatic work. We asked if sex differences in diaphragm fatigue and the inspiratory muscle metaboreflex persisted during inspiratory loading performed at equal absolute intensities. We found that matching men and women for absolute diaphragmatic work resulted in an equal degree of diaphragm fatigue, despite women performing significantly greater work relative to body mass. Metabolite-induced reflex influences in sympathetic outflow originating from the diaphragm are attenuated in women, with potential implications for blood flow distribution during exercise.
ABSTRACT
In response to inspiratory pressure-threshold loading (PTL), women have greater inspiratory muscle endurance time, slower rate of diaphragm fatigue development, and a blunted pressor response compared to men. It is unclear if these differences are due to discrepancies in absolute diaphragm force output. We tested the hypothesis that following inspirations performed at equal absolute intensities, females would develop a similar level of diaphragm fatigue and an attenuated cardiovascular response relative to men. Healthy young men (n = 8, age = 24 ± 3 years) and women (n = 8, age = 23 ± 3 years) performed PTL whilst targeting a transdiaphragmatic pressure (P ) of 92 cmH O for 5 min. Diaphragm fatigue was assessed via twitch P (P ) using cervical magnetic stimulation. Heart rate (HR) and mean arterial blood pressure were monitored continuously. During PTL, the absolute amount of diaphragm work was not different between men (13,399 ± 2019 cmH O s) and women (12,986 ± 1846 cmH O s; P > 0.05); however, women performed the PTL task at a higher relative /P . Following inspiratory PTL, the magnitude of reduction in P was similar between men (-27.1 ± 7.2%) and women (-23.8 ± 13.8%; P > 0.05). There were significant increases in HR over time (P < 0.05), but this did not differ on the basis of sex (P > 0.05). Mean arterial blood pressure increased significantly over time in both men and women (P < 0.05); however, the rate of change was higher in men (6.24 ± 2.54 mmHg min ) than in women (4.15 ± 2.52 mmHg min ) (P < 0.05). We conclude that the female diaphragm is protected against severe fatigue when inspiratory work is excessive and as a result does not evoke overt sympathoexcitation.
Topics: Adult; Arterial Pressure; Cardiovascular System; Diaphragm; Exercise; Female; Heart Rate; Humans; Inhalation; Male; Muscle Fatigue; Reflex; Respiration; Respiratory Mechanics; Respiratory Muscles; Young Adult
PubMed: 31348520
DOI: 10.1113/JP278380