Portable High-Flow Nasal Oxygen during Walking in Patients with Severe Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial.

BACKGROUND: High-flow nasal oxygen (HFNO) improves exercise capacity, oxygen saturation, and symptoms in patients with chronic obstructive pulmonary disease (COPD). Due to the need of electricity supply, HFNO has not been applied during free ambulation. OBJECTIVE: We evaluated whether HFNO delivered during walking by a battery-supplied portable device was more effective than usual portable oxygen in improving exercise capacity in patients with COPD and severe exercise limitation. The effects on 6-min walking tests (6MWTs) were the primary outcome. METHODS: After a baseline 6MWT, 20 stable patients requiring an oxygen inspiratory fraction (FiO2) <0.60 during exercise, randomly underwent 2 6MWT carrying a rollator, under either HFNO with a portable device (HFNO test) or oxygen supplementation by a Venturi mask (Control) at isoFiO2. Walked distance, perceived dyspnea, pulse oximetry, and inspiratory capacity at end of the tests as well as patients' comfort were compared between the tests. RESULTS: As compared to baseline, walked distance improved significantly more in HFNO than in the control test (by 61.1 ± 37.8 and 39.7 ± 43.8 m, respectively, p = 0.01). There were no significant differences between the tests in dyspnea, peripheral oxygen saturation, or inspiratory capacity, but HFNO test was appreciated as more comfortable. CONCLUSION: In patients with COPD and severe exercise limitation, HFNO delivered by a battery-supplied portable device was more effective in improving walking distance than usual oxygen supplementation.

Respiratory rehabilitation for patients with COVID-19 infection and chronic respiratory failure: a real-life retrospective study by a Lombard network.

The Lombardy region has been one of the areas most affected by the COVID-19 pandemic since the first months of 2020, providing real-life experiences in the acute phase. It is unclear how the respiratory rehabilitation network responded to this emergency. The aims of this retrospective study were: i) to analyze clinical, functional, and disability data at admission; ii) describe assessment tools and rehabilitative programs; iii) evaluate improvement after rehabilitation. The study was conducted on data collected from ten pulmonary rehabilitation centers in Lombardy, between the period of March 1st 2020 to March 1st 2021, in patients with respiratory failure recovering from COVID-19 both at admission and discharge. The study included demographics, comorbidities, nutritional status, risk of falls, disability status (Barthel index; Short Physical Performance Battery (SPPB); 6 minutes walking test (6MWT), symptoms (dyspnoea with Barthel Dyspnoea and MRC Dyspnoea Scale), length of stay, discharge destination, need for mechanical ventilation, respiratory function, assessment/outcomes indices, and prescribed rehabilitative programs. 413 patients were analyzed. Length of stay in acute and rehabilitative units was less than 30 days. Fifty % of patients used non-invasive ventilation during their stay. Functional status was mildly compromised for forced volumes and oxygenation, while severely compromised for diffusion capacity. Independency was low while physical performance status very low.  At discharge, 318 (77%) patients were sent home, 83 (20.1%) were transferred to an acute unit and 12 (2.9%) passed away. Barthel Index and 6MWT were the most used, while MRC score was the least used outcome parameter. The 5 main rehabilitative activities were walking (90.8 %), transfer from bed to armchair (77.5%), limb mobilization in bed (76%), balance (71.2%), and cycle-ergometer or treadmill (43.1%). A huge difference was found in admission, discharge, and delta change among different rehabilitative centers. When available, all outcomes showed a significant improvement. With the limitation of a retrospective study with a clear amount of missing data, COVID-19 subjects admitted to rehabilitative centers presented a reduced physical performance, symptoms of dyspnoea, and severe disability. The 6MWT and Barthel index were the most used measurement.

Italian suggestions for pulmonary rehabilitation in COVID-19 patients recovering from acute respiratory failure: results of a Delphi process.

There is a need of consensus about the pulmonary rehabilitation (PR) in patients with COVID-19 after discharge from acute care. To facilitate the knowledge of the evidence and its translation into practice, we developed suggestions based on experts' opinion. A steering committee identified areas and questions sent to experts. Other international experts participated to a RAND Delphi method in reaching consensus and proposing further suggestions. Strong agreement in suggestions was defined when the mean agreement was >7 (1 = no agreement and 9 = maximal agreement). Panelists response rate was >95%. Twenty-three questions from 4 areas: Personnel protection equipment, phenotypes, assessments, interventions, were identified and experts answered with 121 suggestions, 119 of which received high level of concordance. The evidence-based suggestions provide the clinicians with current evidence and clinical experts opinion. This framework can be used to facilitate clinical decision making within the context of the individual patient. Further studies will evaluate the clinical usefulness of these suggestions.

Bioimpedance Phase Angle as a Prognostic Tool in Late-Onset Pompe Disease: A Single-Centre Prospective Study With a 15-year Follow-Up.

Background: Late-onset Pompe disease (LOPD) is an autosomal-recessive metabolic myopathy caused by deficiency of the lysosomal enzyme Acid Alpha-Glucosidase (GAA), leading to glycogen accumulation in proximal and axial muscles, and in the diaphragm. Enzyme Replacement Therapy (ERT) with recombinant GAA became available in 2006. Since then, several outcome measures have been investigated for the adequate follow-up of disease progression and treatment response, usually focusing on respiratory and motor function. Prognostic factors predicting outcome have not been identified till now. Methods: In this single Centre, prospective study, we evaluate the response to enzyme replacement therapy in 15 patients (7 males) with LOPD in different stages of disease, aged 49.4 ± 16.1, followed-up for 15 years. Treatment response was measured by the 6-min walking test, vital capacity in supine and upright position, respiratory muscle strength, muscle MRI, manual muscle testing. We investigated the usefulness of Body Impedance Vectorial Analysis for serial body composition assessment. Results: Although most patients with LOPD benefit from long-term treatment, some secondary decline may occur after the first 3-5 years. Some nutritional (lower body mass index, higher fat free mass, higher phase angle) and disease parameters (higher creatinine and shorter disease duration at the beginning of treatment) seem to predict a better motor outcome. Lower Phase Angle, possibly reflecting loss of integrity of skeletal muscle membranes and thus treatment mis-targeting, seems to correlate with worse treatment response on long-term follow-up. Conclusion: Body Impedance Vectorial Analysis is a fast, easily performed and cheap tool that may be able to predict long-term treatment response in patients with LOPD. Low Phase angle may serve as a marker of muscle quality and may be used to predict the response to a muscle-targeted intervention such as ERT, thus improving the identification of patients needing a closer follow-up due to higher fragility and risk of deterioration.

Pilot study of a new device to titrate oxygen flow in hypoxic patients on long-term oxygen therapy.

BACKGROUND: The O(2) Flow Regulator (Dima, Bologna, Italy) is a new automated oxygen regulator that titrates the oxygen flow based on a pulse-oximetry signal to maintain a target S(pO(2)). We tested the device's safety and efficacy. METHODS: We enrolled 18 subjects with chronic lung disease, exercise-induced desaturation, and on long-term oxygen therapy, in a randomized crossover study with 2 constant-work-load 15-min cycling exercise tests, starting with the patient's previously prescribed usual oxygen flow. In one test the oxygen flow was titrated manually by the respiratory therapist, and in the other test the oxygen flow was titrated by the O(2) Flow Regulator, to maintain an S(pO(2)) of 94%. We measured S(pO(2)) throughout each test, the time spent by the respiratory therapist to set the device or to manually regulate the oxygen flow, and the total number of respiratory-therapist titration interventions during the trial. RESULTS: There were no differences in symptoms or heart rate between the exercise tests. Compared to the respiratory-therapist-controlled tests, during the O(2) Flow Regulator tests S(pO(2)) was significantly higher (95 ± 2% vs 93 ± 3%, P = .04), significantly less time was spent below the target S(pO(2)) (171 ± 187 s vs 340 ± 220 s, P < .001), and the O(2) Flow Regulator tests required significantly less respiratory therapist time (5.6 ± 3.7 min vs 2.0 ± 0.1 min, P = .005). CONCLUSIONS: The O(2) Flow Regulator may be a safe and effective alternative to manual oxygen titration during exercise in hypoxic patients. It provided stable S(pO(2)) and avoided desaturations in our subjects.

Polymorphism in exercise genes and respiratory function in late-onset Pompe disease.

Genetic polymorphisms influencing muscle structure and metabolism may affect the phenotype of metabolic myopathies. We here analyze the possible influence of a wide panel of "exercise genes" on the severity and progression of respiratory dysfunction in late-onset Pompe disease (LOPD). We stratified patients with comparable age and disease duration according to the severity of their respiratory phenotype, assessed by both upright FVC% and postural drop in FVC%. We included 43 patients with LOPD (25 males, age 50.8 ± 13.6 yr) with a 2-yr follow-up since the beginning of enzyme replacement therapy (ERT). Twenty-two patients showed a postural drop >25% T0, seven other patients developed it during the follow-up. We analyzed the relationship between the progression of respiratory dysfunction and genetic polymorphisms affecting muscle function and structure [angiotensin converting enzyme (ACE), α-actinin 3 (ACTN3), peroxisome proliferator-activated receptor α (PPR-α), angiotensin (AGT)], glycogen metabolism [glycogen synthase (GYS), glycogen synthase kinase-3 isoform ß (GSK3ß)], and autophagy [sirtuin 1 (SIRT1), autophagy-related gene 7 (ATG7)]. Individuals carrying two copies of the ACE D-allele shared a 24-fold increase in the risk of severe respiratory dysfunction and progression during the 2-yr follow-up. ACTN3-XX polymorphism was also associated with worse respiratory outcome. The study of exercise genes is of particular interest in respiratory muscles, due to their peculiar features, that is, continuous, low-intensity contraction and prominent recruitment of type I fibers. In line with previous observations on skeletal muscles, ACE-DD and ACTN3-XX genotypes were associated with indirect evidence of more severe respiratory phenotypes. On the contrary, polymorphisms related to autophagy and glycogen metabolism did not seem to influence respiratory muscles.NEW & NOTEWORTHY Previous reports evaluated the role of exercise genes in influencing skeletal muscle phenotype and response to ERT in LOPD. Here, we investigate the role of polymorphisms in several exercise gene, focusing on respiratory muscles. ACE-DD and ACTN3-XX polymorphisms, possibly influencing muscle properties and fiber composition, were associated with more severe respiratory phenotypes.

Minimal Clinically Important Difference in Barthel Index Dyspnea in Patients with COPD.

Background: The Barthel Index dyspnea (BId) is responsive to physiological changes and pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD). However, the minimum clinically important difference (MCID) has not been established yet. Aim: To identify the MCID of BId in patients with COPD stratified according to the presence of chronic respiratory failure (CRF) or not. Materials and Methods: Using the Medical Research Council (MRC) score as an anchor, receiver operating characteristic curves and quantile regression were retrospectively evaluated before and after pulmonary rehabilitation in 2327 patients with COPD (1151 of them with CRF). Results: The median post-rehabilitation changes in BId for all patients were -10 (interquartile range = -17 to -3, p<0.001), correlating significantly with changes in MRC (r = 0.57, 95% CI = 0.53 to 0.59, p<0.001). Comparing different methods of assessment, the MCID ranged from -6.5 to -9 points for patients without and -7.5 to -12 points for patients with CRF. Conclusion: The most conservative estimate of the MCID is -9 points in patients with COPD, without and -12 in those with CRF. This estimate may be useful in the clinical interpretation of data, particularly in response to intervention studies.

High-Flow Oxygen Therapy During Exercise Training in Patients With Chronic Obstructive Pulmonary Disease and Chronic Hypoxemia: A Multicenter Randomized Controlled Trial.

OBJECTIVE: The study aimed to evaluate whether high-flow oxygen therapy (HFOT) during training was more effective than oxygen in improving exercise capacity in hypoxemic chronic obstructive pulmonary disease (COPD). METHODS: A total of 171 patients with COPD and chronic hypoxemia were consecutively recruited in 8 rehabilitation hospitals in a randomized controlled trial. Cycle-ergometer exercise training was used in 20 supervised sessions at iso inspiratory oxygen fraction in both groups. Pre- and post-training endurance time (Tlim), 6-minute walking distance (6MWD), respiratory and limb muscle strength, arterial blood gases, Barthel Index, Barthel Dyspnea Index, COPD Assessment Test, Maugeri Respiratory Failure questionnaire, and patient satisfaction were evaluated. RESULTS: Due to 15.4% and 24.1% dropout rates, 71 and 66 patients were analyzed in HFOT and Venturi mask (V-mask) groups, respectively. Exercise capacity significantly improved after training in both groups with similar patient satisfaction. Between-group difference in post-training improvement in 6MWD (mean: 17.14 m; 95% CI = 0.87 to 33.43 m) but not in Tlim (mean: 141.85 seconds; 95% CI = -18.72 to 302.42 seconds) was significantly higher in HFOT. The minimal clinically important difference of Tlim was reached by 47% of patients in the V-mask group and 56% of patients in the HFOT group, whereas the minimal clinically important difference of 6MWD was reached by 51% of patients in the V-mask group and 69% of patients in the HFOT group, respectively. CONCLUSION: In patients with hypoxemic COPD, exercise training is effective in improving exercise capacity. IMPACT STATEMENT: The addition of HFOT during exercise training is not more effective than oxygen through V-mask in improving endurance time, the primary outcome, whereas it is more effective in improving walking distance.

Physiological response to intrapulmonary percussive ventilation in stable COPD patients.

Intrapulmonary percussive ventilation (IPV) is a ventilatory technique that delivers bursts of high-flow respiratory gas into the lung at high rates, intended for treating acute respiratory failure and for mobilization of secretions. We performed a study, aimed at assessing the physiological response to IPV, on patients' breathing pattern, inspiratory effort, lung mechanics and tolerance to ventilation. Ten COPD patients underwent randomized trials of IPV through a face mask at different pressure/frequency combinations (1.2 bar/250 cycles/min; 1.8/250; 1.2/350; 1.8/350), separated by return to baseline (SB), using the IMP2 ventilator. In 5 patients we have also compared the physiological changes of IPV with those obtained during pressure support ventilation (PSV). Minute ventilation did not vary among the trials, but tidal volumes (VT) were significantly greater during 1.2/250, 1.2/350 and 1.8/350 compared to SB. The pressure time product of the diaphragm per minute (PTPdi/min) estimate of the diaphragm oxygen expenditure was also significantly reduced during 1.2/250 and 1.8/250 (209 cmH2O x s/min for SB vs. 143 and 125 for 1.2/250 and 1.8/250, respectively P < 0.05), as well as dynamic intrinsic end-expiratory pressure (PEEPi,dyn). Similar reduction in PTPdi/min were obtained also during PSV. Tolerance to ventilation and oxygen saturation were satisfactory and did not change during the different trials. In 5 normal subjects a prolonged apnea trial lasting > 2 min was also performed, without any significant decrease in SaO2 or subjective discomfort. In conclusion, IPV was able to guarantee an adequate ventilation, while inducing a significant unloading of the diaphragm during the "low-frequency" trials.

Effects of heated and humidified high flow gases during high-intensity constant-load exercise on severe COPD patients with ventilatory limitation.

INTRODUCTION: High flow nasal cannula (HFNC) was shown to washout the anatomical dead space, permitting a higher fraction of minute ventilation to participate in gas pulmonary exchanges. Moreover, it is able to guarantee the desired inhaled oxygen fraction (FiO2) even at high level of patient's minute ventilation by minimizing the room air entrainment. The effect of HFNC has never been investigated on stable severe COPD patients in term of endurance capacity with standardised laboratory tests. METHOD/DESIGN: We performed, in a randomized crossover study, two constant load exercise tests at the 75% of maximum workload achieved at a previous incremental exercise test on cycle-ergometer: with (HFNC-test) and without HFNC (Control-test). Both constant load tests were fulfilled at the same inhaled oxygen fraction (isoFiO2). RESULTS: The endurance time significantly increased in the HFNC-test compared to the Control-test (the mean difference between the two groups was 109 ± 104 s, p < 0.015). At iso-time, HFNC-test showed a better oxygen saturation (95 ± 3% vs 89 ± 3%, respectively, p < 0.005) either in the subgroup of patients who used supplemental oxygen and in the subgroup who did not. Moreover, a significantly lower dyspnea (median of 5.5 vs 10, respectively, p = 0.002) and leg fatigue score (median of 5 vs 9.5, p = 0.002) was recorded at iso-time during HFNC-test. CONCLUSION: HFNC may improve the exercise performance in severe COPD patients with ventilatory limitation. This effect is associated to an improvement of SaO2 and perceived symptoms at iso-time. In a Pulmonary Rehabilitation program HFNC may allow a given high intensity load to be sustained for a longer time with less symptoms.

Efficacy of Bilevel-auto Treatment in Patients with Obstructive Sleep Apnea Not Responsive to or Intolerant of Continuous Positive Airway Pressure Ventilation.

BACKGROUND: Ventilation with continuous positive airway pressure (CPAP) is the gold standard therapy for obstructive sleep apnea (OSA). However, it was recently suggested that a novel mode of ventilation, Bilevel-auto, could be equally effective in treating patients unable to tolerate CPAP. The aim of this study was to investigate the ability of Bilevel-auto to treat OSA patients whose nocturnal ventilatory disturbances are not completely corrected by CPAP. METHODS: We enrolled 66 consecutive OSA patients, not responsive to (group A) or intolerant of (group B) CPAP treatment, after a full night of manual CPAP titration in a laboratory. Full polysomnography data and daytime sleepiness score were compared for each group in the three different conditions: basal, during CPAP, and during Bilevel-auto. RESULTS: The apnea-hypopnea index decreased significantly during CPAP in both groups; however, in the group A, there was a further significant improvement during Bilevel-auto. The same trend was observed for oxygenation indices, while the distribution and the efficiency of sleep did not differ following the switch from CPAP to Bilevel-auto. CONCLUSIONS: This study confirmed the role of Bilevel-auto as an effective therapeutic alternative to CPAP in patients intolerant of this latter mode of ventilation. Moreover, extending the use of Bilevel-auto to those OSA patients not responsive to CPAP, we showed a significantly better correction of nocturnal respiratory disturbances.