Effect of exercise on endothelial function in heart transplant recipients: systematic review and meta-analysis.

Endothelial dysfunction is associated with increased cardiovascular risk and death in heart transplant recipients (HTx). Although the measurement of peripheral endothelial function is considered a significant predictor of cardiovascular events in several populations, few studies have investigated this outcome after therapeutic strategies, including different exercise types, duration, and intensity. This systematic review and meta-analysis aimed to investigate the effects of continuous moderate exercise (CON) or high-intensity interval training (HIIT) to improve endothelial function (EF) in HTx. The search was conducted in Cochrane Central Registry of Controlled Trials (CENTRAL), MEDLINE (via PubMed), Web of Science and Scopus/Elsevier, CINAHL/Ebsco, Physiotherapy Evidence Database (PEDro), LILACS/BIREME, and SciELO databases. Quality of the evidence was assessed using the Grading of Recommendations Assessment Development and Evaluation (GRADE). The search strategy retrieved 5192 titles. A total of four articles met the inclusion criteria and were included for the qualitative analysis. Meta-analysis showed that exercises improved EF ([mean difference-MD] 3.48 95% CI - 0.29 to 7.25, p = 0.007) when compared with the control. However, there was a poor quality of evidence to demonstrate that CON or HIIT is better than usual care to improve EF. Exercise training provides benefits to patients, but the poor quality of evidence does not allow us to state that exercise is related to endothelial function improvement in HTx.

Noninvasive Ventilation Before Maximum Exercise Test Increases Exercise Tolerance in Subjects With Heart Failure: A Crossover Study.

OBJECTIVE: To evaluate the effect of noninvasive ventilation (NIV) on exercise performance in individuals with heart failure (HF). DESIGN: Crossover, blind, randomized controlled trial with allocation concealment. SETTING: University-based research laboratory. PARTICIPANTS: Participants (N=24) with New York Heart Association class II and III left heart failure and with a mean age of 51.8±10.2 years (women: n=8; men: n=16). INTERVENTIONS: Ventilatory support attached to the face of the individual via a facemask prior to cardiopulmonary exercise test (CPET) was administered at 2 pressure levels for 30 minutes. Inspiratory pressure of 15cmH2O and expiratory pressure of 5cmH2O were applied. MAIN OUTCOME MEASURES: Maximal oxygen uptake, maximum heart rate, variation between the initial and maximum heart rates, CPET duration, and recovery time oxygen consumption. RESULTS: Differences were observed in maximal oxygen consumption (nonintervention phase: 18.3±4.4mL·kg-1·min-1 vs NIV phase: 20.6±4.9mL·kg-1·min-1, P=.01), heart rate (nonintervention phase: 127.3±20.9 beats per minute vs NIV phase: 134.7±19.5 beats per minute, P=.04), and heart rate variation (nonintervention phase: 63.3%±19.3% vs NIV phase: 69.7%±16.6%, P=.02). Moreover, differences in cardiopulmonary exercise time (nonintervention phase: 7.4±1.5min vs NIV phase: 8.3±1.7min, P=.01) and oxygen consumption recovery time (nonintervention phase: 2.8±1.0min vs NIV phase: 2.4±0.8min, P=.01) were observed. CONCLUSIONS: NIV elicited beneficial effects in the HF population that included increased exercise tolerance, recovery time optimization, and improved chronotropic and respiratory reserves.

Correlation between peripheral endothelial function, oxygen consumption and ventilatory efficiency in heart transplantation recipients.

BACKGROUND: Endothelial dysfunction and peak oxygen uptake (VO2peak) are also predictors of increased risk of cardiovascular events in heart transplantation (HTx) recipients. The preservation of endothelial function may contribute to exercise tolerance. OBJECTIVE: To investigate the correlation between peripheral endothelial function and exercise tolerance through VO2peak and ventilation to carbon dioxide production slope (VE / VCO2 slope) in HTx recipients. METHODS: A pilot cross-sectional study was conducted with adult individuals aged 18-65 years, HTx ≥ six months after surgery, who had a stable medical condition and no changes over the last three months of immunosuppressive treatment. The patients underwent an assessment of endothelial function through PAT (EndoPAT-2000®) and performed a cardiopulmonary exercise test (CPET). RESULTS: A total of 41% of the studied population presented endothelial dysfunction. The individuals were divided into two groups: the endothelial dysfunction (GED; n=9) group and the normal endothelial function (GNEF; n=13) group according to the logarithm of the reactive hyperemia index (LnRHI). There was a positive and moderate correlation between the LnRHI and VO2 peak (r=0.659, p=0.013) and a negative and moderate correlation between the LnRHI and VE/VCO2 slope (r= -0.686, p= 0.009) in the GNEF. However, no significant correlations were found in the GED. CONCLUSION: The results showed that the preservation of peripheral endothelial function is significantly correlated with an increase in exercise tolerance in individuals after HTx. These findings bring important considerations for cardiovascular risk prevention and emphasize that therapeutic strategies with physical training programs must be implemented early.

Influence of Mechanical Ventilation Modes on the Efficacy of Nebulized Bronchodilators in the Treatment of Intubated Adult Patients with Obstructive Pulmonary Disease.

BACKGROUND: Little has been reported in terms of clinical outcomes to confirm the benefits of nebulized bronchodilators during mechanical ventilation (MV). Electrical Impedance Tomography (EIT) could be a valuable method to elucidate this gap. OBJECTIVE: The purpose of this study is to evaluate the impact of nebulized bronchodilators during invasive MV with EIT by comparing three ventilation modes on the overall and regional lung ventilation and aeration in critically ill patients with obstructive pulmonary disease. METHOD: A blind clinical trial in which eligible patients underwent nebulization with salbutamol sulfate (5 mg/1 mL) and ipratropium bromide (0.5 mg/2 mL) in the ventilation mode they were receiving. EIT evaluation was performed before and after the intervention. A joint and stratified analysis into ventilation mode groups was performed, with p < 0.05. RESULTS: Five of nineteen procedures occurred in controlled MV mode, seven in assisted mode and seven in spontaneous mode. In the intra-group analysis, the nebulization increased total ventilation in controlled (p = 0.04 and ⅆ = 2) and spontaneous (p = 0.01 and ⅆ = 1.5) MV modes. There was an increase in the dependent pulmonary region in assisted mode (p = 0.01 and ⅆ = 0.3) and in spontaneous mode (p = 0.02 and ⅆ = 1.6). There was no difference in the intergroup analysis. CONCLUSIONS: Nebulized bronchodilators reduce the aeration of non-dependent pulmonary regions and increase overall lung ventilation but there was no difference between the ventilation modes. As a limitation, it is important to note that the muscular effort in PSV and A/C PCV modes influences the impedance variation, and consequently the aeration and ventilation values. Thus, future studies are needed to evaluate this effort as well as the time on ventilator, time in UCI and other variables.

Mapping peripheral and abdominal sarcopenia acquired in the acute phase of COVID-19 during 7 days of mechanical ventilation.

Our aim was to map acquired peripheral and abdominal sarcopenia in mechanically ventilated adults with COVID-19 through ultrasound measurements. On Days 1, 3, 5 and 7 after admission to critical care, the muscle thickness and cross-sectional area of the quadriceps, rectus femoris, vastus intermedius, tibialis anterior, medial and lateral gastrocnemius, deltoid, biceps brachii, rectus abdominis, internal and external oblique, and transversus abdominis were measured using bedside ultrasound. A total of 5460 ultrasound images were analyzed from 30 patients (age: 59.8 ± 15.6 years; 70% men). Muscle thickness loss was found in the bilateral anterior tibial and medial gastrocnemius muscles (range 11.5-14.6%) between Days 1 and 3; in the bilateral quadriceps, rectus femoris, lateral gastrocnemius, deltoid, and biceps brachii (range 16.3-39.1%) between Days 1 and 5; in the internal oblique abdominal (25.9%) between Days 1 and 5; and in the rectus and transversus abdominis (29%) between Days 1 and 7. The cross-sectional area was reduced in the bilateral tibialis anterior and left biceps brachii (range 24.6-25.6%) between Days 1 and 5 and in the bilateral rectus femoris and right biceps brachii (range 22.9-27.7%) between Days 1 and 7. These findings indicate that the peripheral and abdominal muscle loss is progressive during the first week of mechanical ventilation and is significantly higher in the lower limbs, left quadriceps and right rectus femoris muscles in critically ill patients with COVID-19.

Endothelial function, arterial stiffness and heart rate variability of patients with cardiovascular diseases hospitalized due to COVID-19.

BACKGROUND: The novel coronavirus disease (COVID-19) may cause vascular (e.g., endothelial dysfunction, and arterial stiffness), cardiac, autonomic (e.g., heart rate variability [HRV]), and systemic inflammatory response via direct viral attack, hypoxia-induced injury, or immunological dysregulation, especially in those patients with pre-existing cardiovascular diseases (CVD). However, to date, no study has shown prevalence of endothelial dysfunction, arterial stiffness and heart rate variability assessed by bedside peripheral arterial tonometry in patients with previous CVD hospitalized in the acute phase of COVID-19. OBJECTIVE: This study aimed to assess the prevalence of endothelial dysfunction, arterial stiffness, and altered HRV in patients with CVD hospitalized due to COVID-19. METHODS: This cross-sectional study was conducted from July 2020 to February 2021. Included male and female adult patients aged 40 to 60 years with previous CVD and diagnosed with COVID-19. Anthropometric data, comorbidities, and blood tests were analyzed. Endothelial function, arterial stiffness, and HRV were assessed using peripheral arterial tonometry (PAT), and the statistical significance was set at 5%. RESULTS: Fourteen (51.8%) patients presented endothelial dysfunction (reactive hyperemia index = 1.2 ± 0.3) and enhancement in the high-frequency component of HRV (p < 0.05). There was a high prevalence of endothelial dysfunction, especially in patients with chronic heart failure (10 (71.4%)). Patients with preserved endothelial function showed a high augmentation index normalized to a heart rate of 75 bpm (p < 0.01), suggesting arterial stiffness. CONCLUSION: Patients with CVD hospitalized due to COVID-19 presented endothelial dysfunction assessed using PAT, which could be used as a biomarker for arterial stiffness and altered HRV. The possibility of detecting vascular and autonomic changes during phase II of COVID-19 may help to prevent possible long-term complications.

Effects of continuous aerobic training associated with resistance training on maximal and submaximal exercise tolerance, fatigue, and quality of life of patients post-COVID-19.

BACKGROUND AND PURPOSE: Dyspnea, fatigue, and reduced exercise tolerance are common in post-COVID-19 patients. In these patients, rehabilitation can improve functional capacity, reduce deconditioning after a prolonged stay in the intensive care unit, and facilitate the return to work. Thus, the present study verified the effects of cardiopulmonary rehabilitation consisting of continuous aerobic and resistance training of moderate-intensity on pulmonary function, respiratory muscle strength, maximum and submaximal tolerance to exercise, fatigue, and quality of life in post-COVID-19 patients. METHODS: Quasi-experimental study with a protocol of 12 sessions of an outpatient intervention. Adults over 18 years of age (N = 26) with a diagnosis of COVID-19 and hospital discharge at least 15 days before the first evaluation were included. Participants performed moderate-intensity continuous aerobic and resistance training twice a week. Maximal and submaximal exercise tolerance, lung function, respiratory muscle strength, fatigue and quality of life were evaluated before and after the intervention protocol. RESULTS: Cardiopulmonary rehabilitation improved maximal exercise tolerance, with 18.62% increase in peak oxygen consumption (VO2peak) and 29.05% in time to reach VO2 peak. VE/VCO2 slope reduced 5.21% after intervention. We also observed increased submaximal exercise tolerance (increase of 70.57 m in the 6-min walk test, p = 0.001), improved quality of life, and reduced perceived fatigue after intervention. DISCUSSION: Patients recovered from COVID-19 can develop persistent dysfunctions in almost all organ systems and present different signs and symptoms. The complexity and variability of the damage caused by this disease can make it difficult to target rehabilitation programs, making it necessary to establish specific protocols. In this work, cardiopulmonary rehabilitation improved lung function, respiratory muscle strength, maximal and submaximal exercise tolerance, fatigue and quality of life. Continuous aerobic and resistance training of moderate intensity proved to be effective in the recovery of post-COVID-19 patients.

Agreement between two methods for assessment of maximal inspiratory pressure in patients weaning from mechanical ventilation.

BACKGROUND: Respiratory muscle strength in patients with an artificial airway is commonly assessed as the maximal inspiratory pressure (MIP) and is measured using analogue or digital manometers. Recently, new electronic loading devices have been proposed to measure respiratory muscle strength. This study evaluates the agreement between the MIPs measured by a digital manometer and those according to an electronic loading device in patients being weaned from mechanical ventilation. METHODS: In this prospective study, the standard MIP was obtained using a protocol adapted from Marini, in which repetitive inspiratory efforts were performed against an occluded airway with a one-way valve and were recorded with a digital manometer for 40 seconds (MIPDM). The MIP measured using the electronic loading device (MIPELD) was obtained from repetitively tapered flow resistive inspirations sustained for at least 2 seconds during a 40-second test. The agreement between the results was verified by a Bland-Altman analysis. RESULTS: A total of 39 subjects (17 men, 55.4±17.7 years) was enrolled. Although a strong correlation between MIPDM and MIPELD (R=0.73, P<0.001) was observed, the Bland-Altman analysis showed a high bias of -47.4 (standard deviation, 22.3 cm H2O; 95% confidence interval, -54.7 to -40.2 cm H2O). CONCLUSIONS: The protocol of repetitively tapering flow resistive inspirations to measure the MIP with the electronic loading device is not in agreement with the standard protocol using one-way valve inspiratory occlusion when applied in poorly cooperative patients being weaned from mechanical ventilation.

Association between performance on the Glittre ADL-test and the functional capacity of patients with HF: A cross-sectional study.

Background: The Weber classification based on peak VO2 is a well-established method for categorizing patients with heart failure (HF) regarding severity. However, other submaximal tests such as the Glittre ADL-Test have been gaining prominence in practice due to a coherent and more comprehensive correlation with limitations for performing activities of daily living in patients with heart failure.Objective: To investigate the correlation between the time required to perform the Glittre ADL-Test and the peak VO2 in patients with HF.Methods: A cross-sectional study conducted with 40 adult individuals (21 to 65 years) diagnosed with HF of all etiologies, with LVEF<50% and NYHA II and III.Results: The average time for performing the Glittre ADL-Test was 284.9 seconds, and a significant difference was found between Weber classification classes A and C (p = .01). Significant correlations with peak VO2 were also found (r = -0.424 - p < .01). Thirty (30) patients performed a second test, and the ICC found in the reproducibility analysis was 0.75 (95% CI 0.14-0.91) and p < .01.Conclusion: The Glittre ADL-Test was able to reflect the functional performance of individuals with HF, suggesting that it represents an evaluation tool which can be safely used in clinical practice.

Heliox and forward-leaning posture improve the efficacy of nebulized bronchodilator in acute asthma: a randomized trial.

BACKGROUND: Heliox and forward-leaning posture (torso inclined forward at 50-60° with the elbows resting on the thighs) are adjuncts in the administration of nebulized bronchodilator to patients with acute asthma. METHODS: We randomized 59 patients who presented to the emergency department in severe asthma crisis, into 4 treatment groups: nebulized bronchodilator + oxygen; nebulized bronchodilator + oxygen + forward-leaning posture; nebulized bronchodilator + heliox; and nebulized bronchodilator + heliox + forward-leaning posture. Before and after the bronchodilator treatments the subjects were seated with torso erect, breathing room air. Each subject received 2 doses, 20 min apart, of nebulized fenoterol (2.5 mg) plus ipratropium bromide (0.25 mg) in 3 mL of 0.9% saline, delivered with a semi-closed valved aerosol reservoir. The nebulizer was run with oxygen or 80:20 heliox. The post-treatment pulmonary function tests were performed 15 min after the second nebulization. The group's mean age was 35.1 ± 13.6 y, and there were 20 men and 39 women. RESULTS: The oxygen + forward-leaning-posture group had a greater FEV(1) improvement than the oxygen group (59% vs 38%, P = .02). The heliox + forward-leaning-posture group had a greater FEV(1) improvement than the oxygen group (103% vs 38%, P = .001) and the heliox group (103% vs 42%, P = .03). The heliox group had greater reduction in respiratory rate than the oxygen group (P = .03). The heliox + forward-leaning-posture group had significantly greater peak expiratory flow improvement than any of the other groups. CONCLUSIONS: Heliox plus forward-leaning posture during bronchodilator nebulization improves bronchodilator efficacy in patients with severe acute asthma. (ClinicalTrials.gov registration NCT00922350).

Accuracy of Algorithms and Visual Inspection for Detection of Trigger Asynchrony in Critical Patients : A Systematic Review.

OBJECTIVE: This study aimed to summarize the accuracy of the different methods for detecting trigger asynchrony at the bedside in mechanically ventilated patients. METHOD: A systematic review was conducted from 1990 to 2020 in PubMed, Lilacs, Scopus, and ScienceDirect databases. The reference list of the identified studies, reviews, and meta-analyses was also manually searched for relevant studies. The reference standards were esophageal pressure catheter and/or electrical activity of the diaphragm. Studies were assessed following the QUADAS-2 recommendations, while the review was prepared according to the PRISMA criteria. RESULTS: One thousand one hundred and eleven studies were selected, and four were eligible for analysis. Esophageal pressure was the predominant reference standard, while visual inspection and algorithms/software comprised index tests. The trigger asynchrony, ineffective expiratory effort, double triggering, and reverse triggering were analyzed. Sensitivity and specificity ranged from 65.2% to 99% and 80% to 100%, respectively. Positive predictive values reached 80.3 to 100%, while the negative predictive values reached 92 to 100%. Accuracy could not be calculated for most studies. CONCLUSION: Algorithms/software validated directly or indirectly using reference standards present high sensitivity and specificity, with a diagnostic power similar to visual inspection of experts.

Oxygen uptake efficiency slope: A submaximal test evaluation tool that provides cardiopulmonary reserve data in individuals with Parkinson's disease.

BACKGROUND: Oxygen uptake efficiency slope (OUES) is a method for investigating cardiorespiratory fitness and is proposed as an alternative to overcome the limitations of traditional measures such as peak oxygen consumption (VO2peak) for patients who do not achieve a maximum response, such as in Parkinson's disease (PD). OBJECTIVE: To assess the performance of individuals with PD during the six-minute walk test (6MWT) using the OUES. METHODS: This is an observational cross-sectional study including 12 individuals with PD and 12 healthy controls. Participants performed the 6MWT along with an analysis of exhaled gas kinetics. The OUES was determined from the last 16 s of the walk test. Multiple linear regression analyses were computed to explore associations between the independent (OUES) and the dependent variables (VO2peak) controlled by group. RESULTS: The OUES was associated to VO2peak on the 6MWT (ß=0.24, p<0.01) in individuals with PD. The PD group had low performance on the 6MWT with a shorter distance walked (mean difference: -113.1 m; 95% CI: -203.2, -59.1) and worse cardiopulmonary condition with lower OUES values (mean difference: -0.52 [l/minO2]/[l/minVE]; 95% CI: -0.83, -0.21) found in this same group. CONCLUSIONS: Our results suggest that OUES is related to VO2peak during the 6MWT, and therefore it could be used as a submaximal test evaluation tool which provides cardiopulmonary reserve data in individuals with PD.

Acute Effects of Lung Expansion Maneuvers in Comatose Subjects With Prolonged Bed Rest.

BACKGROUND: Patients with decreased consciousness are prone to prolonged bed rest and respiratory complications. If effective in reducing atelectasis, lung expansion maneuvers could be used to prevent these complications. In comatose, bedridden subjects, we aimed to assess the acute effect on regional lung aeration of 2 lung expansion techniques: expiratory positive airway pressure and the breath-stacking maneuver. Our secondary aim was to evaluate the influence of these lung expansion techniques on regional ventilation distribution, regional ventilation kinetics, respiratory pattern, and cardiovascular system. METHODS: We enrolled 10 subjects status post neurosurgery, unable to follow commands, and with prolonged bed rest. All subjects were submitted to both expansion techniques in a randomized order. Regional lung aeration, ventilation distribution, and regional ventilation kinetics were measured with electrical impedance tomography. RESULTS: Lung aeration increased significantly during the application of both expiratory positive airway pressure and breath-stacking (P < .001) but returned to baseline values seconds afterwards. The posterior lung regions had the largest volume increase (P < .001 for groups). Both maneuvers induced asynchronous inflation and deflation between anterior and posterior lung regions. There were no significant differences in cardiovascular variables. CONCLUSIONS: In comatose subjects with prolonged bed rest, expiratory positive airway pressure and breath-stacking promoted brief increases in lung aeration. (ClinicalTrials.gov registration NCT02613832.).

Addition of proprioceptive neuromuscular facilitation to cardiorespiratory training in patients poststroke: study protocol for a randomized controlled trial.

BACKGROUND: Individuals affected by stroke present with changes in cardiovascular and respiratory functions. Cardiorespiratory training (CRT) is one of the classic intervention guidelines for cardiorespiratory fitness. CRT in association with the proprioceptive neuromuscular facilitation (PNF) technique for respiratory muscles could improve the quality of life, cardiorespiratory function and gait parameters of patients after stroke. OBJECTIVE: To assess the effects of respiratory and trunk patterns of CRT associated with PNF on the quality of life, gait, oxygen consumption, respiratory muscle strength and thoracic volumes. METHODS/DESIGN: A blind, randomized clinical trial with allocation confidentiality will be performed. Forty patients will be randomized into four groups: CRT-lower limb (LL) plus PNF; CRT-LL and respiration; CRT-upper limb (UL) plus PNF; or CRT-UL and respiration. Individuals will be evaluated at three different times (pretreatment, after 20 days of treatment and 1 month after the end of treatment). The treatment protocol consists of respiratory exercises, 30 min of CRT (cycle ergometer) and then repetition of the respiratory exercises, performed three times a week over a period of 20 days. Primary outcome measures are quality of life, gait, balance, peak oxygen uptake and rib cage compartment volumes. As secondary outcomes, respiratory function and maximal inspiratory and expiratory pressures will be measured. DISCUSSION: The association of PNF with CRT may be a viable and accessible alternative to increase cardiorespiratory function in patients with stroke. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03171012. Registered on 6 June 2017.

Effects of physical exercise on the autonomic nervous system in patients with coronary artery disease: a systematic review.

BACKGROUND: Imbalance in autonomic modulation can occur after a cardiac event, which can lead to deleterious consequences. Exercise has proven to be a therapy which affects this modulation and can be assessed through heart rate variability (HRV). AREAS COVERED: The objective of this systematic review was to investigate the effects of physical exercise on heart rate variability in individuals with coronary artery disease (CAD). The PubMed, PEDro, Scielo, Lilacs and Cochrane databases were systematically searched, for articles which performed supervised exercises in phase II of cardiac rehabilitation in patients with CAD. EXPERT OPINION: Given the differences between studies on interventions and population characteristics, it is difficult to justify similarities or divergences in terms of results. In addition to the variation in sample size, intervention duration, carrying out an additional program at home, and patients with different clinical presentations, it can be inferred that responses to exercise may vary for certain types/clinical profile of individuals with CAD. Thus, it is necessary to carry out more studies with greater methodological rigor, greater standardization of the variables studied and the evaluation forms, in order to increase the veracity of the results and the consequent clinical relevance and therapeutic application.

Influence of posture, sex, and age on breathing pattern and chest wall motion in healthy subjects.

OBJECTIVE: We evaluated the effects of posture, sex, and age on breathing pattern and chest wall motion during quiet breathing in healthy participants. METHODS: Eighty-three participants aged 42.72 (SD=21.74) years presenting normal pulmonary function were evaluated by optoelectronic plethysmography in the seated, inclined (with 45° of trunk inclination), and supine positions. This method allowed to assess the chest wall in a three dimensional way considering the chest wall as three compartments: pulmonary rib cage, abdominal rib cage and abdomen. RESULTS: Posture influenced all variables of breathing pattern and chest wall motion, except respiratory rate and duty cycle. Chest wall tidal volume and minute ventilation were reduced (p<0.05) in both sexes from seated to inclined and from seated to supine positions, mainly in males. Moreover, moving from seated to supine position significantly increased the percentage contribution of the abdomen to the tidal volume in both sexes (p<0.0001). Regarding sex, women showed higher contribution of thoracic compartment compared to men (p=0.008). Aging provided reductions on rib cage contributions to tidal volume that were compensated by increases of abdomen contributions (p<0.0001). In addition, increases in end-inspiratory and end-expiratory volumes over the years were observed. CONCLUSION: The degree of contribution of chest wall compartments is dependent on posture, sex, and age. Therefore, verticalization increases expansion of pulmonary rib cage as well as horizontalization increases abdominal displacement. Women presented higher thoracic contribution to tidal volume than men. Aging reduces rib cage contributions to tidal volume that were compensated by increases of abdomen contributions.

Effectiveness of inspiratory muscle training associated with a cardiac rehabilitation program on sympathetic activity and functional capacity in patients with heart failure: a study protocol for a randomized controlled trial.

BACKGROUND: Individuals affected by heart failure (HF) may present fatigue, dyspnea, respiratory muscle weakness, and sympathetic activity hyperstimulation of the myocardium, among other symptoms. Conducting cardiac rehabilitation (CR) programs can be associated with inspiratory muscle training. The aim of this study was to evaluate the efficacy of inspiratory muscular training (IMT) associated with a CR program on modulating myocardial sympathetic activity and maximal functional capacity, submaximal functional capacity, thickness, and mobility of the diaphragm muscle in patients with HF. METHODS: We will conduct a clinical, controlled, randomized, double-blind trial that will include sedentary men and women who are 21-60 years old and who have diagnosed systolic HF and a left ventricular ejection fraction of less than 45%. Participants will be randomly assigned to one of two groups: experimental and control. The control group will follow the conventional CR protocol, and the experimental group will follow the conventional CR protocol associated with IMT 7 days a week. The two proposed exercise protocols will have a frequency of three times a week for a period of 12 weeks. The sympathetic innervation of the cardiac muscle, the maximum and submaximal functional capacity, diaphragm mobility and thickness, and the quality of life of the participants will be evaluated before and after the intervention protocol. DISCUSSION: This clinical trial will be the first study to investigate the additional effects of IMT on CR in sympathetic hyperstimulation in the myocardium. The results of this study will contribute to developing therapeutic strategies collaborating to elucidate whether the association of IMT with CR can induce clinical benefits for patients with HF. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02600000. Registered November 9, 2015. Retrospectively registered.

Patient-ventilator asynchrony in conventional ventilation modes during short-term mechanical ventilation after cardiac surgery: randomized clinical trial.

INTRODUCTION AND AIM: Studies regarding asynchrony in patients in the cardiac postoperative period are still only a few. The main objective of our study was to compare asynchronies incidence and its index (AI) in 3 different modes of ventilation (volume-controlled ventilation [VCV], pressure-controlled ventilation [PCV] and pressure-support ventilation [PSV]) after ICU admission for postoperative care. METHODS: A prospective parallel randomised trialin the setting of a non-profitable hospital in Brazil. The participants were patients scheduled for cardiac surgery. Patients were randomly allocated to VCV or PCV modes of ventilation and later both groups were transitioned to PSV mode. RESULTS: All data were recorded for 5 minutes in each of the three different phases: T1) in assisted breath, T2) initial spontaneous breath and T3) final spontaneous breath, a marking point prior to extubation. Asynchronies were detected and counted by visual inspection method by two independent investigators. Reliability, inter-rater agreement of asynchronies, asynchronies incidence, total and specific asynchrony indexes (AIt and AIspecific) and odds of AI ≥10% weighted by total asynchrony were analysed. A total of 17 patients randomly allocated to the VCV (n=9) or PCV (n=8) group completed the study. High inter-rated agreement for AIt (ICC 0.978; IC95%, 0,963-0.987) and good reliability (r=0.945; p<0.001) were found. Eighty-two % of patients presented asynchronies, although only 7% of their total breathing cycles were asynchronous. Early cycling and double triggering had the highest rates of asynchrony with no difference between groups. The highest odds of AI ≥10% were observed in VCV regardless the phase: OR 2.79 (1.36-5.73) in T1 vs T2, p=0.005; OR 2.61 (1.27-5.37) in T1 vs T3, p=0.009 and OR 4.99 (2.37-10.37) in T2 vs T3, p<0.001. CONCLUSIONS: There was a high incidence of breathing asynchrony in postoperative cardiac patients, especially when initially ventilated in VCV. VCV group had a higher chance of AI ≥10% and this chance remained high in the following PSV phases.

Reversal of bronchial obstruction with bi-level positive airway pressure and nebulization in patients with acute asthma.

Jet nebulization (JN) and non-invasive mechanical ventilation (NIMV) through bi-level pressure is commonly used in emergency and intensive care of patients experiencing an acute exacerbation of asthma. However, a scientific basis for effect of JN coupled with NIMV is unclear. Objective. To evaluate the effect of jet nebulization administered during spontaneous breathing with that of nebulization with NIV at two levels of inspiratory and expiratory pressures resistance in patients experiencing an acute asthmatic episode. Methods. A prospective, randomized controlled study of 36 patients with severe asthma (forced expiratory volume in 1 second [FEV(1)] less than 60% of predicted) selected with a sample of patients who presented to the emergency department. Subjects were randomized into three groups: control group (nebulization with the use of an unpressured mask), experimental group 1 (nebulization and non-invasive positive pressure with inspiratory positive airway pressure [IPAP] = 15 cm H(2)O, and expiratory positive airway pressure [EPAP] = 5 cm H(2)O), and experimental group 2 (nebulization and non-invasive positive pressure with IPAP = 15 cm H(2)O and EPAP = 10 cm H(2)O). Bronchodilators were administered with JN for all groups. Dependent measures were recorded before and after 30 minutes of each intervention and included respiratory rate (RR), heart rate (HR), oxygen saturation (SpO(2)), peak expiratory flow (PEF), forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and forced expiratory flow between 25 and 75% (FEF(25-75)). Results. The group E2 showed an increase of the peak expiratory flow (PEF), forced vital capacity (FVC), FEV(1) (p < 0.03) and F(25-75%) (p < 0.000) when compared before and 30 minutes after JN+NIMV. In group E1 the PFE (p < 0.000) reached a significant increase after JN+ NIMV. RR decreased before and after treatment in group E1 only (p = 0.04). Conclusion. Nebulization coupled with NIV in patients with acute asthma has the potential to reduce bronchial obstruction and symptoms secondary to augmented PEF compared with nebulization during spontaneous breathing. In reversing bronchial obstruction, this combination appears to be more efficacious when a low pressure delta is used in combination with a high positive pressure at the end of expiration.