Cardiopulmonary effects of phosphine poisoning: A preliminary evaluation of milrinone.

Exposure to phosphine (PH3) presents with a host of diverse, non-specific symptoms that span multiple organ systems and is characterized by a high mortality rate. While a comprehensive mechanism for PH3 poisoning remains inconclusive, prior studies have implicated cardiac failure and circulatory compromise as potential pathways central to PH3-induced mortality. In this study, milrinone (MLR), a phosphodiesterase-3 inhibitor used to treat cardiac failure, was investigated as a potential countermeasure for PH3 poisoning. Lethality, physiological responses, and behavioral changes were evaluated in telemetrized female rats pretreated with water (sham) or one of three doses of MLR (40, 200, or 600 µg/kg) and exposed to PH3 (660 ppm for 25-40 min; 16,500-26,400 ppm × min). Animals receiving prophylactic administration of 600 µg/kg of MLR had nominally improved survivability compared to sham animals, although median lethal concentration-time and time of death did not differ substantially between treatment groups. Changes in respiration and behavior induced by PH3 appeared largely unaffected by MLR pretreatment, regardless of dose. Conversely, MLR pretreatment alleviated some aspects of PH3-induced cardiac function impairment, with slight dose-dependent effects observed for cardiac contractility, mean arterial pressure, and QRS duration. Together, these results illustrate the importance of circulatory compromise in PH3 poisoning and highlight the potential viability of MLR as a potential countermeasure option or part of a countermeasure regimen when administered prophylactically at 600 µg/kg.

Effects of alternate nostril breathing exercise on cardiorespiratory functions in healthy young adults.

Introduction: Alternate nostril breathing (ANB) is an effective breathing exercise with therapeutic benefits on cardiorespiratory functions for healthy and diseased individuals. This study was conducted to assess the effects of ANB exercise on cardiorespiratory tasks in healthy adults. Materials and Methods: This randomized experimental study was conducted in the Department of Physiology, Chittagong Medical College, Chattogram, from July 2017 to June 2018. A total of 100 1st-year students, aged between 18 and 20 years, were included by a random sampling method. Fifty participants (25 males and 25 females) were enrolled in the experimental group, while age- and body mass index-matched another 50 participants (25 males and 25 females) served as the control group. Experimental group participants performed ANB exercise for 4 weeks. Cardiorespiratory parameters (pulse rate, blood pressure, forced vital capacity, forced expiratory volume in 1st s [FEV1], and peak expiratory flow rate [PEFR] were measured. Data were taken at the start and after 4 weeks in both groups. Results: Independent t-test showed no significant differences in the cardiorespiratory functions between the experimental and control groups among the male and female participants, except for the females' PEFR which showed small differences. On the other hand, repeated measure ANOVA shows significant improvement in the experimental groups among males (P < 0.001-0.028) and females (P < 0.001-0.001) in all the cardiorespiratory functions measured, except for the FEV1 and PEFR among males. Conclusion: The results of this study suggest that cardiorespiratory functions were improved after breathing exercise, and therefore, ANB can be recommended for increasing cardiorespiratory efficiency.

RésuméIntroduction: La respiration nasale alternée (ANB) est un exercice de respiration efficace avec des avantages thérapeutiques sur les fonctions cardiorespiratoires pour les individus sains et malades. Cette étude a été menée pour évaluer les effets de l'exercice ANB sur les tâches cardiorespiratoires chez des adultes en bonne santé. Matériels et méthodes: Cette étude expérimentale randomisée a été menée au Département de physiologie, Chittagong Medical College, Chattogram, de juillet 2017 à juin 2018. Un total de 100 étudiants de 1ère année, âgés de 18 à 20 ans, ont été inclus par un échantillonnage aléatoire. méthode. Cinquante participants (25 hommes et 25 femmes) ont été inscrits dans le groupe expérimental, tandis que l'âge et l'indice de masse corporelle correspondaient à 50 autres participants (25 hommes et 25 femmes) servant de groupe témoin. Les participants du groupe expérimental ont effectué des exercices ANB pendant 4 semaines. Les paramètres cardiorespiratoires (fréquence du pouls, pression artérielle, capacité vitale forcée, volume expiratoire forcé en 1ère s [VEMS] et débit expiratoire de pointe [PEFR] ont été mesurés. Les données ont été recueillies au début et après 4 semaines dans les deux groupes. Résultats: Le test t indépendant n'a montré aucune différence significative dans les fonctions cardiorespiratoires entre les groupes expérimentaux et témoins parmi les participants masculins et féminins, à l'exception du PEFR des femmes qui présentait de petites différences.D'autre part, l'ANOVA à mesures répétées montre une amélioration significative dans les groupes expérimentaux chez les hommes (P < 0,001 à 0,028) et les femmes (P < 0,001 à 0,001) dans toutes les fonctions cardiorespiratoires mesurées, à l'exception du VEMS et du DEP chez les hommes Conclusion: Les résultats de cette étude suggèrent que les fonctions cardiorespiratoires ont été améliorées après un exercice respiratoire , et par conséquent, l'ANB peut être recommandé pour augmenter l'efficacité cardiorespiratoire.

The retrotrapezoid nucleus and the neuromodulation of breathing.

Breathing is regulated by a host of arousal and sleep-wake state-dependent neuromodulators to maintain respiratory homeostasis. Modulators such as acetylcholine, norepinephrine, histamine, serotonin (5-HT), adenosine triphosphate (ATP), substance P, somatostatin, bombesin, orexin, and leptin can serve complementary or off-setting functions depending on the target cell type and signaling mechanisms engaged. Abnormalities in any of these modulatory mechanisms can destabilize breathing, suggesting that modulatory mechanisms are not overly redundant but rather work in concert to maintain stable respiratory output. The present review focuses on the modulation of a specific cluster of neurons located in the ventral medullary surface, named retrotrapezoid nucleus, that are activated by changes in tissue CO2/H+ and regulate several aspects of breathing, including inspiration and active expiration.

Ansa Cervicalis Stimulation: A New Direction in Neurostimulation for OSA.

BACKGROUND: Hypoglossal nerve stimulation (HNS) is an alternative treatment option for patients with OSA unable to tolerate positive airway pressure but implant criteria limit treatment candidacy. Previous research indicates that caudal tracheal traction plays an important role in stabilizing upper airway patency. RESEARCH QUESTION: Does contraction of the sternothyroid muscle with ansa cervicalis stimulation (ACS), which pulls the pharynx caudally via thyroid cartilage insertions, increase maximum inspiratory airflow (VImax)? STUDY DESIGN AND METHODS: Hook-wire percutaneous electrodes were used to stimulate the medial branch of the right hypoglossal nerve and right branch of the ansa cervicalis innervating the sternothyroid muscle during propofol sedation. VImax was assessed during flow-limited inspiration with a pneumotachometer. RESULTS: Eight participants with OSA were studied using ACS with and without HNS. Compared with baseline, the mean VImax increase with isolated ACS was 298%, or 473 mL/s (95% CI, 407-539). Isolated HNS increased mean VImax from baseline by 285%, or 260 mL/s (95% CI, 216-303). Adding ACS to HNS during flow-limited inspiration increased mean VImax by 151%, or 205 mL/s (95% CI, 174-236) over isolated HNS. Stimulation was significantly associated with increase in VImax in both experiments (P < .001). INTERPRETATION: ACS independently increased VImax during propofol sedation and drove further increases in VImax when combined with HNS. The branch of the ansa cervicalis innervating the sternothyroid muscle is easily accessed. Confirmation of the ansa cervicalis as a viable neurostimulation target may enable caudal pharyngeal traction as a novel respiratory neurostimulation strategy for treating OSA.

The Effects Of Slow Breathing Exercise On Heart Rate Dynamics And Cardiorespiratory Coherence In Preschool Children: A Prospective Clinical Study.

BACKGROUND: Slow breathing has been used to improve psychophysiological regulation due to positive action on the autonomic nervous system. PRIMARY STUDY OBJECTIVE: We evaluated the effects of slow breathing on heart rate autonomic control in preschool-aged children. METHODS/DESIGN: Prospective clinical study. SETTING: Campinas, Brazil. PARTICIPANTS: We included 42 children in the experimental group (age 5.7 ± 0.3) and 33 children in the control group (age 6.2 ± 0.3). INTERVENTION: Children received a daily training of eight weeks duration for practicing a slow breathing technique. Primary Outcome Measures • We analyzed heart rate variability (HRV) and cardiorespiratory coherence at rest under spontaneous breathing and during respiratory sinus arrhythmia (RSA) at the end of the 1st, 4th, and 8th weeks of training. RESULTS: The percentage of high coherence ratio increased (P < .0001), HRV reduced (SDNN, P = .0066; RMSSD, P = .0015; pNN50, P < .0001; SD1, P = .0015; SD2, P = .0166) and the complexity of HRV increased (ApEn, P = .0004; MSE area, P < .0001; DFAαl, P = .0001; ShanEnt, P = .0106; Lmean, P = .0066) during RSA compared to spontaneous breathing after slow breathing training period. CONCLUSION: Slow breathing training exercise induced increased cardiorespiratory coherence and increased nonlinear behavior of heart rate dynamics suggesting improvements in health status. Increased cardiorespiratory coherence reinforces the importance of including respiratory exercises in strategies that aim to promote physical health and self-regulation skills in educational settings.

Safety and feasibility of inspiratory muscle training for hospitalized patients undergoing hematopoietic stem cell transplantation: a randomized controlled study.

PURPOSE: Patients undergoing hematopoietic stem cell transplantation (HSCT) usually experienced respiratory muscle weakness. Inspiratory muscle training (IMT) at HSCT has not been studied yet. Thus, it is important to evaluate the safety, feasibility, and preliminary effectiveness of IMT for hospitalized patients undergoing HSCT with an unstable and acute clinical condition. METHODS: This is a randomized controlled feasibility study. Thirty-one hospitalized patients undergoing HSCT were randomized to the conventional physical rehabilitation (CON) or to the IMT group (conventional physical rehabilitation + IMT). IMT was carried out at 40% of maximal inspiratory pressure (MIP), 5 sessions weekly, 10-20 min/session. Primary outcomes were safety and feasibility (recruitment, adherence, and attrition rates) of IMT. Secondary outcomes were respiratory strength, respiratory rate, oxygen saturation, and frequency of patients with oxygen desaturation, bleeding, dyspnea, and acute pulmonary edema. RESULTS: Patients were allocated to the IMT (N = 15; 43.6 years) or to the CON group (N = 16; 46.6 years). The recruitment rate was 100%, the adherence rate was 91%, and attrition was 13% to IMT. Two events were observed in 126 IMT sessions (1.5%). MIP increased in the IMT group (P < 0.01). No differences were observed in respiratory rate and oxygen saturation between groups. Trends to negative outcomes were observed in the CON in comparison to IMT group for a need of oxygen therapy (18% vs. 6%), bleeding (12% vs. 6%), dyspnea (25% vs. 13%), and acute pulmonary edema (6% vs. 0%). CONCLUSIONS: IMT is safe, feasible, and improves the inspiratory muscle strength in hospitalized patients undergoing HSCT. TRIAL REGISTRATION: Clinical trial registration: NCT03373526.

Investigation into Deep Breathing through Measurement of Ventilatory Parameters and Observation of Breathing Patterns.

In this protocol, two deep breathing patterns were shown to 15 participants to determine an easy yet effective method of breathing exercise for future application in a clinical setting. The women in their twenties were seated comfortably in a chair with back support. They were fitted with an airtight mask connected to a gas analyzer. Three electrodes were placed on the chest connected to a wireless transmitter for relaying to the electrocardiograph. They executed a 5 min rest phase, followed by 5 min of deep breathing with a natural breathing pattern, terminating with a 5 min rest phase. This was followed by a 10 min intermission before commencing the second instruction phase of substituting the natural breathing pattern with the diaphragmatic breathing pattern. Simultaneously, the following took place: a) continuous collection, measurement and analysis of the expired gas to assess the ventilatory parameters on a breath-by-breath basis; b) measurement of the heart rate by an electrocardiograph; and c) videotaping of the participant's thoracoabdominal movement from a lateral aspect. From the video capture, the investigators carried out visual observation of the fast-forward motion-images followed by classification of the breathing patterns, confirming that the participants had carried out the method of deep breathing as instructed. The amount of oxygen uptake revealed that, during deep breathing, the work of breathing decreased. The results from the expired minute ventilation, respiration rate and tidal volume confirmed increased ventilatory efficiency for deep breathing with the natural breathing pattern compared to that with the diaphragmatic breathing pattern. This protocol suggests a suitable method of instruction for assessing deep breathing exercises on the basis of oxygen consumption, ventilatory parameters, and chest wall excursion.

Prospective Effects of Manual Diaphragmatic Release and Thoracic Lymphatic Pumping in Childhood Asthma.

BACKGROUND: Manual noninvasive respiratory techniques have traditionally been used to treat respiratory pathologies. The aim of this study was to analyze the effects of the diaphragmatic release technique and the thoracic lymphatic pump technique versus conventional respiratory retraining in children with asthma. METHODS: Using a quasi-experimental design, 60 children with asthma were allocated to undergo the diaphragmatic release technique (n = 20), thoracic lymphatic pump technique (n = 20), or conventional respiratory retraining (n = 20) in this study. Serum immunoglobulin E levels, diaphragmatic mobility, pulmonary function, and P(A-a)O2 were assessed before and after 12 treatment sessions that were conducted over nonconsecutive days in a 4-week program. RESULTS: After 12 treatments, the changes in the serum immunoglobulin E level for each group was not significantly different from the other groups. Compared with conventional respiratory retraining, the diaphragmatic release technique was associated with a significant improvement in FVC (P = .001) and FEV1 (P = .002); the thoracic lymphatic pump technique showed no differences. With regard to diaphragmatic mobility, both the diaphragmatic release technique and the thoracic lymphatic pump technique yielded significantly favorable effects when compared with conventional respiratory retraining (P < .001 and P = .01, respectively). Further, no significant between-group differences were detected in terms of the P(A-a)O2 (P = .07). CONCLUSIONS: The thoracic lymphatic pump technique and conventional respiratory retraining approaches were helpful interventions that could be used to alleviate the symptoms of childhood asthma. Nevertheless, the diaphragmatic release technique was a potentially more effective intervention.

Effect of Expiratory Muscle Strength Training on Swallowing and Cough Functions in Patients With Neurological Diseases: A Meta-analysis.

OBJECTIVE: The aim of this review was to evaluate and summarize the results of published studies exploring the effects of expiratory muscle strength training on swallowing and cough functions in patients with neurological diseases. DATA SOURCES: The study used Embase, PubMed, and the Cochrane Library as data sources. REVIEW METHODS: Randomized controlled trials or pretest/posttest studies of adults with neurological diseases were included. The data included basic population characteristics, penetration-aspiration scores, peak expiratory flow rate, cough volume acceleration, and maximum expiratory pressure. RESULTS: Ten studies were included in this meta-analysis. Compared with the control groups, expiratory muscle strength training in patients with neurological diseases significantly reduced the penetration-aspiration scores (risk ratio = -0.94, 95% confidence interval = 1.27 to -0.61, P < 0.01) but did not increase the voluntary cough peak expiratory flow rate (risk ratio = 0.57, 95% confidence interval = 0.62 to 1.77, P = 0.35), cough volume acceleration (risk ratio = 33.87, 95% confidence interval = 57.11 to 124.85, P = 0.47), or maximum expiratory pressure (risk ratio = 14.78, 95% confidence interval = 16.98 to 46.54, P = 0.36). CONCLUSIONS: Expiratory muscle strength training might improve swallowing function in patients with neurological diseases. However, conclusive evidence supporting the use of this approach in isolation for improving cough function is unavailable. Additional multicenter, randomized clinical trials performed using reliable and valid cough function outcome measures are required to explore the effects of expiratory muscle strength training on cough function.

Inspiratory muscle training improves pulmonary functions and respiratory muscle strength in healthy male smokers.

The aim of the present study is to investigate the effects of inspiratory muscle training (IMT) on pulmonary function and respiratory muscle strength of both healthy smokers and nonsmokers. Forty-two healthy males (16 in the IMT smokers group [IMTS], 16 in the IMT nonsmokers group [IMTN], and 10 in the placebo group) participated in the present study. Using a randomized, double-blind, placebo-controlled design, IMTS and IMTN underwent 4 weeks of 30 breaths twice daily at 50% (+5% increase each week) of maximum inspiratory pressure (MIP), while the placebo group maintained 30 breaths twice daily at 15% MIP using an IMT device. The data were analyzed with repeated measures for one-way analysis of variance, 3 × 2 mixed factor analysis of variance, and least significant difference tests. Respiratory muscle strength (MIP and maximal expiratory pressure [MEP]) and pulmonary functions significantly improved after a 4-week period (between the pre and posttests) in the IMTN and IMTS groups (p < 0.05). The mean difference and percentage differences showed significant alterations in the respiratory muscle strength, forced and slow pulmonary capacities, and pulmonary volume between the IMTN and IMTS groups (p < 0.05). There were significant changes in the expiratory muscle strength (MEP), slow vital capacity (SVC), and forced pulmonary measurements (forced expiratory volume after 1 s and maximal voluntary ventilation) between IMTN and IMTS groups in favor of smokers (p < 0.05). These results show that greater improvements occurred in smokers after IMT. Increased respiratory muscle strength may be the underlying mechanism responsible for this improvement. Additionally, the benefits of IMT were greater in smokers than nonsmokers. This difference between smokers and nonsmokers may potentially be explained by higher influence of exercise on smokers' lung microbiome, resulting in greater reversal of negative effects.

The influence of respiration on brainstem and cardiovagal response to auricular vagus nerve stimulation: A multimodal ultrahigh-field (7T) fMRI study.

BACKGROUND: Brainstem-focused mechanisms supporting transcutaneous auricular VNS (taVNS) effects are not well understood, particularly in humans. We employed ultrahigh field (7T) fMRI and evaluated the influence of respiratory phase for optimal targeting, applying our respiratory-gated auricular vagal afferent nerve stimulation (RAVANS) technique. HYPOTHESIS: We proposed that targeting of nucleus tractus solitarii (NTS) and cardiovagal modulation in response to taVNS stimuli would be enhanced when stimulation is delivered during a more receptive state, i.e. exhalation. METHODS: Brainstem fMRI response to auricular taVNS (cymba conchae) was assessed for stimulation delivered during exhalation (eRAVANS) or inhalation (iRAVANS), while exhalation-gated stimulation over the greater auricular nerve (GANctrl, i.e. earlobe) was included as control. Furthermore, we evaluated cardiovagal response to stimulation by calculating instantaneous HF-HRV from cardiac data recorded during fMRI. RESULTS: Our findings demonstrated that eRAVANS evoked fMRI signal increase in ipsilateral pontomedullary junction in a cluster including purported NTS. Brainstem response to GANctrl localized a partially-overlapping cluster, more ventrolateral, consistent with spinal trigeminal nucleus. A region-of-interest analysis also found eRAVANS activation in monoaminergic source nuclei including locus coeruleus (LC, noradrenergic) and both dorsal and median raphe (serotonergic) nuclei. Response to eRAVANS was significantly greater than iRAVANS for all nuclei, and greater than GANctrl in LC and raphe nuclei. Furthermore, eRAVANS, but not iRAVANS, enhanced cardiovagal modulation, confirming enhanced eRAVANS response on both central and peripheral neurophysiological levels. CONCLUSION: 7T fMRI localized brainstem response to taVNS, linked such response with autonomic outflow, and demonstrated that taVNS applied during exhalation enhanced NTS targeting.

Upper cervical and upper thoracic spine mobilization versus deep cervical flexors exercise in individuals with forward head posture: A randomized clinical trial investigating their effectiveness.

BACKGROUND: Although commonly utilized treatments, no study has directly compared the effectiveness of joint mobilization and stabilization exercise in individuals with forward head posture (FHP). OBJECTIVE: This study aimed to investigate the effects of upper cervical and upper thoracic spine mobilization versus deep cervical flexors exercise (DCFE) in individuals with FHP. METHODS: Thirty-one participants with FHP were randomized into the mobilization (n= 15) or exercise (n= 16) group. The treatment period was 4 weeks with follow-up assessment at 4 weeks and 6 weeks after the initial examination. Outcomes assessed included the craniovertebral angle (CVA), numeric pain rating scale (NPRS), respiratory function, and the global rating of change (GRC). RESULTS: Participants in the mobilization group demonstrated significant improvements (p< 0.05) in CVA, NPRS, and respiratory function, as compared to those in the exercise group. In addition, 9 of 15 (60%) participants in the mobilization group, as compared to 4 of 16 participants (25%) in the exercise group, had a GRC score of +4 or higher. CONCLUSIONS: The combination of upper cervical and upper thoracic spine mobilization indicated better overall short-term outcomes in CVA, NPRS, respiratory function, and GRC compared with DCFE in individuals with FHP.

Effects of Diaphragmatic Breathing With and Without Pursed-Lips Breathing in Subjects With COPD.

BACKGROUND: Breathing exercises, such as diaphragmatic breathing and pursed-lips breathing, play a role in some individuals with COPD and might be considered for those patients who are unable to exercise. However, in the literature are reports of some adverse effects of diaphragmatic breathing in patients with COPD. Thus, the purpose of this study was to assess the effects of diaphragmatic breathing and diaphragmatic breathing combined with pursed-lips on chest wall kinematics, breathlessness, and chest wall asynchrony in subjects with COPD, and also to assess whether the combination of both exercises reduces the adverse effects of diaphragmatic breathing while maintaining its benefits. METHODS: Seventeen subjects with COPD, mean ± SD, 65 ± 7 y of age, with a history of smoking and clinical stability without hospitalization or symptoms of exacerbation in the past 4 wk, were evaluated. On day 1, participants' characteristics were collected, and they learned diaphragmatic breathing and its combination with pursed-lips breathing. On day 2, the participants were evaluated by optoelectronic plethysmography with the participants in the seated position while performing breathing exercises. RESULTS: Diaphragmatic breathing and diaphragmatic breathing plus pursed-lips breathing promoted a significant increase in chest wall tidal volume and its compartments as well as a reduction in breathing frequency compared with quiet breathing. No significant changes were observed in dyspnea or end-expiratory volume of the chest wall. A significant increase in asynchrony (inspiratory-expiratory phase ratio) was observed during diaphragmatic breathing and diaphragmatic breathing plus pursed-lips breathing compared with quiet breathing, with no differences observed between the exercises. CONCLUSIONS: Despite the increase in asynchrony, both breathing exercises were able to improve chest wall volumes without affecting dyspnea. The combination of exercises maintained the benefits but did not reduce the adverse effects of diaphragmatic breathing.

Breath Versus Emotions: The Impact of Different Foci of Attention During Mindfulness Meditation on the Experience of Negative and Positive Emotions.

Mindfulness meditation yields beneficial effects on the processing of emotions. However, it is still unclear whether the focus of attention during meditation influences these effects. In the present study we aimed at comparing the effects of breathing meditation and emotion-focused meditation on the immediate and delayed processing of negative and positive emotions. The study included 65 adult novice meditators who were exposed to positively and negatively valenced film clips. Participants were randomly assigned to three conditions. While watching the films at t1, they were asked to mindfully focus on their breath (condition 1), on emotions (condition 2), or on nothing in particular (condition 3). Ten minutes later at t2, comparable film clips were shown but all participants watched them without taking up a mindful attitude. Dependent measures were emotional states at t1 and t2. Participants of both meditation conditions particularly showed a more preferable delayed emotional reaction to negative stimuli than participants of the control condition. Breathing meditation and emotion-focused meditation may constitute effective emotion regulation strategies to deal with negatively valenced emotional states.

Spirometry and oxidative stress after rebreather diving in warm water.

INTRODUCTION: Hyperbaric oxygen (HBO2) therapy and use of enriched air can result in oxidative injury affecting the brain, lungs and eyes. HBO2 exposure during diving can lead to a decrease in respiratory parameters. However, the possible effects of acute exposure to oxygen-enriched diving on subsequent spirometric performance and oxidative state in humans have not been recently described recently. We aim to investigate possible effects of acute (i) hyperbaric and (ii) hyperbaric hyperoxic exposure using scuba or closed-circuit rebreather (CCR) on subsequent spirometry and to assess the role of oxidative state after hyperoxic diving. METHODS: Spirometry and urine samples were obtained from six well-trained divers (males, mean ± SD, age: 43.33 ± 9.16 years; weight: 79.00 ± 4.90 kg; height: 1.77 ± 0.07 meters) before (CTRL) and after a dive breathing air, and after a dive using CCR (PO2 1.4). In the crossover design (two dives separated by six hours) each subject performed a 20-minute session of light underwater exercise at a depth of 15 meters in warm water (31-32°C). We measured urinary 8-isoprostane and 8-OH-2-deoxyguanosine evaluating lipid and DNA oxidative damages. RESULTS: Different breathing conditions (air vs. CCR) did not significantly affect spirometry. A significant increase of 8-OH-dG (1.85 ± 0.66 vs. 4.35 ± 2.12; P ⟨ 0.05) and 8-isoprostane (1.35 ± 0.20 vs. 2.59 ± 0.61; P ⟨ 0.05) levels after CCR dive with respect to the CTRL was observed. Subjects did not have any ill effects during diving. CONCLUSIONS: Subjects using CCR showed elevated oxidative stress, but this did not correlate with a reduction in pulmonary function.

Effects of respiratory muscle training on endothelium and oxidative stress biomarkers in hemodialysis patients: A randomized clinical trial.

INTRODUCTION: Hemodialysis (HD) patients have altered pulmonary function and this is associated with impaired endothelial function and cardiovascular events. Respiratory muscle training (RMT) has the potential to improve cardiovascular outcomes in patients undergoing maintenance HD. Here, we evaluated the effects of RMT on endothelium/glycocalyx, oxidative stress biomarkers and pulmonary function test in HD patients. METHODS: This is a randomized controlled clinical trial including 41 patients undergoing thrice-weekly maintenance HD. Patients were randomly assigned at a 2:1 ratio to receive or not RMT during HD sessions for 8 weeks. Main outcomes were changes in levels of the biomarkers related to endothelium activation (vascular cell adhesion molecule 1, VCAM-1, and intercellular adhesion molecule 1, ICAM-1), glycocalyx derangement (syndecan-1), aberrant angiogenesis (angiopoietin-2) and oxidative stress (malondialdehyde) compared to baseline. Also, maximal inspiratory/expiratory pressure (MIP, MEP), Forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) were evaluated. Other outcomes included changes in functional capacity and pulmonary function test. We also performed a post-hoc analysis of plasma endothelin-1 levels. RESULTS: Of 56 randomly assigned patients, 41 were included in the primary final analyses. RMT increased all pulmonary function parameters evaluated and significantly reduced plasma syndecan-1 levels at 8 weeks compared to placebo (between-group difference: -84.5; 95% CI, -148.1 to -20.9). Also, there was a reduction in plasma levels of angiopoietin-2 (between-group difference: -0.48; 95% CI, -1.03 to -0.097). Moreover, there was a significant reduction in mean blood pressure at rest (between-group difference: -12.2; 95%CI, -17.8 to -6.6) associated with a reduction in endothelin-1 levels (between-group difference: -0.164; 95% CI, -0.293 to -0.034). There was no difference regarding biomarkers of endothelial activation or oxidative stress. CONCLUSION: A short-term RMT program ameliorate FVC, FEV1 and reduces syndecan-1 and angiopoietin-2 biomarker levels. Finally, better blood pressure control was attained during training and it was associated with a reduction in endothelin-1 levels.

The effects of breathing techniques training on the duration of labor and anxiety levels of pregnant women.

OBJECTIVE: To assess the effects of breathing techniques training on anxiety levels of pregnant women and the duration of labor. MATERIALS AND METHODS: The study utilizes a randomized controlled trial design. The pregnant women were divided into control (n = 35) or experimental group (n = 35) randomly. The experimental group received breathing techniques training in the latent phase and these techniques were applied in the following phases accordingly. The anxiety levels of pregnant women were evaluated three times in total. The duration of labor was considered as the duration of the first stage of labor and the duration of the second stage of labor. RESULTS: There were significant differences between the two groups regarding the mean State Anxiety Inventory (SAI) and the mean duration of labor. CONCLUSIONS: This study concludes that breathing techniques are an effective method in the reduction of anxiety and influence the duration of delivery during labor.

Respiratory Muscle Training Improves Diaphragm Citrate Synthase Activity and Hemodynamic Function in Rats with Heart Failure.

INTRODUCTION:: Enhanced respiratory muscle strength in patients with heart failure positively alters the clinical trajectory of heart failure. In an experimental model, respiratory muscle training in rats with heart failure has been shown to improve cardiopulmonary function through mechanisms yet to be entirely elucidated. OBJECTIVE:: The present report aimed to evaluate the respiratory muscle training effects in diaphragm citrate synthase activity and hemodynamic function in rats with heart failure. METHODS:: Wistar rats were divided into four experimental groups: sedentary sham (Sed-Sham, n=8), trained sham (RMT-Sham, n=8), sedentary heart failure (Sed-HF, n=7) and trained heart failure (RMT-HF, n=7). The animals were submitted to a RMT protocol performed 30 minutes a day, 5 days/week, for 6 weeks. RESULTS:: In rats with heart failure, respiratory muscle training decreased pulmonary congestion and right ventricular hypertrophy. Deleterious alterations in left ventricular pressures, as well as left ventricular contractility and relaxation, were assuaged by respiratory muscle training in heart failure rats. Citrate synthase activity, which was significantly reduced in heart failure rats, was preserved by respiratory muscle training. Additionally, a negative correlation was found between citrate synthase and left ventricular end diastolic pressure and positive correlation was found between citrate synthase and left ventricular systolic pressure. CONCLUSION:: Respiratory muscle training produces beneficial adaptations in the diaphragmatic musculature, which is linked to improvements in left ventricular hemodynamics and blood pressure in heart failure rats. The RMT-induced improvements in cardiac architecture and the oxidative capacity of the diaphragm may improve the clinical trajectory of patients with heart failure.

Respiratory muscle training improves diaphragm citrate synthase activity and hemodynamic function in rats with heart failure

Abstract INTRODUCTION: Enhanced respiratory muscle strength in patients with heart failure positively alters the clinical trajectory of heart failure. In an experimental model, respiratory muscle training in rats with heart failure has been shown to improve cardiopulmonary function through mechanisms yet to be entirely elucidated. OBJECTIVE: The present report aimed to evaluate the respiratory muscle training effects in diaphragm citrate synthase activity and hemodynamic function in rats with heart failure. METHODS: Wistar rats were divided into four experimental groups: sedentary sham (Sed-Sham, n=8), trained sham (RMT-Sham, n=8), sedentary heart failure (Sed-HF, n=7) and trained heart failure (RMT-HF, n=7). The animals were submitted to a RMT protocol performed 30 minutes a day, 5 days/week, for 6 weeks. RESULTS: In rats with heart failure, respiratory muscle training decreased pulmonary congestion and right ventricular hypertrophy. Deleterious alterations in left ventricular pressures, as well as left ventricular contractility and relaxation, were assuaged by respiratory muscle training in heart failure rats. Citrate synthase activity, which was significantly reduced in heart failure rats, was preserved by respiratory muscle training. Additionally, a negative correlation was found between citrate synthase and left ventricular end diastolic pressure and positive correlation was found between citrate synthase and left ventricular systolic pressure. CONCLUSION: Respiratory muscle training produces beneficial adaptations in the diaphragmatic musculature, which is linked to improvements in left ventricular hemodynamics and blood pressure in heart failure rats. The RMT-induced improvements in cardiac architecture and the oxidative capacity of the diaphragm may improve the clinical trajectory of patients with heart failure.