AIMS:This study aimed to evaluate the acute effects of cannabidiol plus tetrahydrocannabinol (CBD+THC) and tetrahydrocannabinol (THC) oils on cardiovascular haemodynamics, respiratory muscle activity and peripheral tissue perfusion in healthy adults. METHODS:In this randomized, double-blind, crossover trial, participants received orally administered CBD+THC oil (12.5 mg + 12.5 mg), THC oil (12.5 mg) or placebo. Cardiovascular haemodynamics, respiratory muscle electromyography and peripheral tissue perfusion were evaluated during breathing tasks. RESULTS:Eighteen individuals were evaluated (26 ± 5 years). Both oils significantly increased heart rate (HR) (p < 0.05). Cardiac index significantly increased in I-THC at 60 and 150 min postdose (p < 0.05). The vascular resistance index was lower in the I-THC, with significant differences during respiratory overload and recovery (p < 0.05). A significant increase in activity of the sternocleidomastoid (SCM) and parasternal (PARA) muscles was observed in the I-THC during inspiratory loading at 60 and 150 min after dose (p < 0.05). In the I-CBD+THC, increased activation was observed in the scalene (ESC) and PARA muscles (p ≤ 0.021). HHb levels showed a descriptive decrease, particularly during inspiratory loading and recovery in the I-THC group, without reaching statistical significance, whereas O2Hb showed a significant increase during inspiratory loading in the I-THC group (p < 0.05). CONCLUSIONS:Acute administration of THC and CBD+THC oils induced distinct cardiorespiratory responses in healthy individuals, affecting cardiovascular haemodynamics, respiratory muscle activation and peripheral tissue oxygenation. THC produced more pronounced physiological responses, while CBD+THC was associated with a more attenuated pattern.

OBJECTIVE:To describe age-related differences in Sit-to-Stand Test (STST) performance (5 repetitions, 30 s, and 1 min) and their association with PA levels. DESIGN:We estimated age-related trajectories for 3 STST across physical activity (PA) strata defined by self-reported IPAQ-SF (low, moderate, high) and quantified the PA effects. In a multicenter cross-sectional study from 12 cities in three BLINDED countries (n=1283; 56% women; 18 to 80 y), performance was assessed with 5rep-STST (seconds), 30s-STST (repetitions), and 1min-STST (repetitions). Primary analyses used generalized additive models with a common age spline, adjusted for sex, BMI, and smoking; multiplicity-adjusted pairwise contrasts were computed. An age-equivalent advantage (high vs. low PA) was derived using a parametric bootstrap; distribution-aware models were tested for robustness. STST performance declined nonlinearly with age. RESULTS:Higher PA was associated with better performance in repetition-based tests; 5rep-STST effects were small. In 1min-STST, high exceeded low by ~2.5 repetitions, yielding an age-equivalent advantage of ~5 to 7 years; for 30s-STST, advantages were ~3 to 5 years. Sensitivity analyses corroborated these findings. CONCLUSIONS:In this Latin American cohort, STST performance declined nonlinearly with age but was consistently better in those with higher habitual PA, regardless of sex, BMI, or smoking.

Roberto Vera-Uribe,1 Rodrigo Torres-Castro,1 Mat&iacute;as Otto-Y&aacute;&ntilde;ez2 1Department of Physical Therapy, University of Chile, Santiago, Chile; 2Health, Functionality, and Physical Activity Research Group (GISFAF), School of Kinesiology, Faculty of Health Sciences, Autonomous University of Chile, Santiago, ChileCorrespondence: Rodrigo Torres-Castro, Email rodritorres@uchile.cl

Mat&iacute;as Otto-Y&aacute;&ntilde;ez,1 Rodrigo Torres-Castro,2 Jordi Vilar&oacute;3 1Health, Functionality, and Physical Activity Research Group (GISFAF), School of Kinesiology, Faculty of Health Sciences, Autonomous University of Chile, Santiago, Chile; 2Department of Physical Therapy, University of Chile, Santiago, Chile; 3Blanquerna School of Health Sciences, Global Research on Wellbeing, Ramon Llull University, Barcelona, SpainCorrespondence: Mat&iacute;as Otto-Y&aacute;&ntilde;ez, Email matias.otto@uautonoma.cl

Background: Amyotrophic lateral sclerosis (ALS) is a fatal heterogeneous neurodegenerative disease characterized by the degeneration of both upper and lower motor neurons and spinal cord. Measurement of respiratory muscle strength has been shown to be an important assessment in the decision-making process and can be assessed by maximum inspiratory (P Imax ) and expiratory pressures (P Emax ), sniff nasal inspiratory (SNIP) and expiratory (SNEP) pressures. Body position appears to have a significant effect on respiratory muscle strength. The aim of this study was to observe the difference in peak values of SNIP and SNEP of the respiratory muscles measured in 2 different positions (seated and supine with 45° elevation) in subjects with ALS and a group of matched healthy subjects. Methods: This is a case–control study of subjects with ALS and healthy subjects. Spirometry and surface electromyography (EMG) of the sternocleidomastoid, scalene, rectus abdominis, and external oblique muscles were assessed during P Imax and P Emax maneuvers in the seated position, and SNIP and SNEP in the seated and supine positions at 45° elevation (randomized). Results: SNEP values in the 45° elevation were lower than in the sitting position in ALS (70.3 ± 26.7 vs 57.3 ± 22.8 cm H 2 O, P = .041). SNIP and SNEP were lower in ALS in the 45° elevation compared with healthy subjects (69.1 ± 27.2 vs 95.5 ± 23.5 cm H 2 O; 57.3 ± 22.5 vs 92.7 ± 26.4 cm H 2 O, P = .041). In subjects with ALS, baseline electromyographic activity of the sternocleidomastoid muscle at rest was higher than in healthy subjects in both positions ( P = .041). No significant differences in electrical activity were found for other variables and measurements. Conclusions: In ALS, nasal pressure may be affected by reduced diaphragm and abdominal muscle effectiveness in the supine position. The sternocleidomastoid muscle showed increased electrical activity in the supine position with 45° elevation compared with controls, which may indicate muscle weakness.

BACKGROUND:The six-minute walk distance (6MWD) is widely used to assess functional status and prognosis in interstitial lung disease (ILD). As exertional desaturation is common, indices combining distance and peripheral oxygen saturation (SpO₂) may improve mortality prediction. OBJECTIVES:To evaluate the 5-year prognostic performance of the desaturation-distance ratio (original DDR), a new DDR, and the distance-saturation product (DSP). METHODS:Retrospective cohort of adults with ILD completing a 6-min walk test (6MWT). Predictors included original DDR, new DDR, DSP, 6MWD, resting and end-exercise SpO₂, and ΔSpO₂. ROC analyses included patients with known 5-year follow-up; survival analyses included all patients with censoring. Multivariable Cox models adjusted for age, sex, forced vital capacity (FVC) %pred, and carbon monoxide lung diffusing capacity (DLCO) %pred. RESULTS:We studied 183 patients (47% female; age 65±12 years); 166 (110 survivors, 56 non-survivors) were included in ROC analyses. AUCs were moderate (0.674-0.732), with original DDR and new DDR showing the highest discrimination (0.732 and 0.730, respectively). Exploratory cut-offs were original DDR>0.168, new DDR<29.06, DSP<377 m%, 6MWD<467 m, end-exercise SpO₂≤85%, resting SpO₂≤95%, and ΔSpO₂≥9%. Dichotomized Cox models showed increased mortality risk across all high-risk strata. In continuous Cox models, original DDR and new DDR had the highest C-indices (0.706 and 0.705), slightly higher than 6MWD (0.652). In adjusted models, DSP and original DDR remained associated with mortality, with small increases in C-index over the base clinical model. CONCLUSIONS:Composite desaturation-distance indices provided moderate discrimination and modest prognostic gain beyond 6MWD and warrant external validation.

BACKGROUND:Peak oxygen uptake (VO2 peak) is essential for assessing exercise capacity and mortality risk in chronic respiratory diseases. Due to limited accessibility, VO2 peak is often estimated using prediction equations from the 6-min walk test (6MWT). We evaluate the accuracy of VO2 peak prediction equations from the 6-min walk distance (6MWD) in patients with pulmonary hypertension (PH) and/or chronic obstructive pulmonary disease (COPD), and risk assessment. METHODS:Patients with PAH, COPD with PH (COPD-PH), and COPD without PH were followed at Hospital Clinic, Barcelona, Spain. All underwent the 6MWT and direct VO2 peak measurement via CPET. Estimated VO2 peak from 6MWD-based equations was compared with measured values. Reliability and agreement were assessed using intraclass correlation coefficients (ICC) and Bland-Altman analysis. We also evaluated the accuracy of VO2 peak estimation in identifying high-risk patients. RESULTS:A total of 225 patients participated: 81 with PAH, 64 with COPD-PH, and 80 with COPD without PH. ICC values showed moderate reliability for VO2 peak prediction in all groups, and despite moderate overall agreement, variability indicated inconsistencies. The equations consistently underestimated mortality risk. CONCLUSIONS:Our findings revealed moderate reliability, poor agreement, and a high bias, with 6MWD-based equations overestimating VO2 peak and underestimating risk classification. While the 6MWT is useful when CPET is unavailable, clinicians should interpret these equations cautiously for risk stratification and decision-making.

INTRODUCTION:Respiratory diseases represent a significant global health burden, and inhaled drug therapy remains a central component in their management. Despite the availability of effective medications, suboptimal device selection, poor inhaler technique, and limited patient education substantially compromise treatment effectiveness. The expanding diversity of inhaler devices, spacers, and valved holding chambers (VHCs) has enabled more individualized care but has also increased clinical complexity. AREAS COVERED:This review synthesizes current evidence on inhaler device selection and use, with particular emphasis on pressurized metered-dose inhalers combined with spacers or VHCs, chamber characteristics, and dry powder inhalers. It also addresses common inhaler technique errors, hygiene, and maintenance, and the role of educational programs. Evidence from bench studies, clinical trials, pharmacokinetic investigations, and guideline documents is integrated to highlight how device design, patient-related factors, and training interact to determine drug delivery and clinical outcomes. EXPERT OPINION:Optimizing inhaled therapy requires viewing each inhaler-patient pairing as a specific delivery system rather than interchangeable components. Durable antistatic VHCs, appropriate interfaces, and regular technique assessment with targeted education should be the standard of care. Future efforts should prioritize device-specific guidance, scalable education strategies, and implementation research to close the persistent gap between evidence and real-world practice.

BACKGROUND AND AIMS:Guillain-Barré syndrome (GBS) is the leading cause of acute flaccid paralysis. A Chilean study for 2001-2012 reported an age-standardized incidence of 2.10 per 100 000. We updated nationwide GBS incidence for 2013-2022 by sex, age, and macrozone. METHODS:We conducted a retrospective, population-based analysis of the Chilean Department of Statistics and Health Information (DEIS) hospital-discharge database. Cases were identified with the ICD-10 code G61.0 and deduplicated. Incidence rates (IRs) per 100 000, using official mid-year populations, were age-standardized to the World Health Organization standard and stratified by sex, 10-year age groups, and five macrozones. RESULTS:We identified 5096 discharges. The period crude IR was 2.73, and the age-standardized IR was 2.60 per 100 000. Annual standardized IRs ranged from 3.15 (2013) to 2.03 (2020). Men comprised 58.6% of cases; period IRs were 3.25 in males versus 2.34 in females. Age-specific IRs rose from 2.47 at 0-9 years to 5.76 at 70-79, then declined (3.63 at 80-89; 1.04 at ≥ 90). Regionally, IRs were lowest in the Far North (1.86) and North (2.26), intermediate in the Central zone (2.51), and highest in the South (4.55) and Far South (4.86). INTERPRETATION:In 2013-2022, Chile's GBS incidence remained high by international standards and higher than in 2001-2012, with persistent male predominance, a peak among older adults, and a southward gradient. These updated background rates inform service planning, surveillance, and vaccine-safety assessment, and support integrated epidemiologic-microbiologic studies across macrozones.

INTRODUCTION:Pulmonary hypertension (PH) is characterized by exertional dyspnea and reduced exercise capacity. This study aims to synthesize current evidence to guide more effective exercise-based interventions. METHODS:This overview included systematic reviews (SRs) of randomized controlled trials in adults with PH that performed an exercise intervention as exercise training (ET), inspiratory muscle training (IMT) or combined training (CT). The main outcome was exercise capacity measured (e.g. six-minute walk test (6MWT) or cardiopulmonary exercise test (CPET). The searches were conducted in seven databases. Two independent reviewers conducted the analysis, with a third resolving disagreements. Methodological quality and certainty of evidence were assessed using AMSTAR-2 and GRADE, along with overlap analysis. RESULTS:A total of 14 SRs were included, categorized into ET, IMT, and CT. All three interventions demonstrated improvements in functional capacity, with increases in 6MWT distance of >48.5 m (ET), 39.1 m (IMT), and 49.5 m (CT). VO2peak improved in ET and CT groups by >2.07 and >3.0 mL/kg/min, respectively. Only one study performed IMT, with gains. Overall, methodological quality was rated as critically low, with significant overlap across studies. CONCLUSION:These findings suggest a clinically significant benefit of exercise-based interventions, with a slight superiority of CT.Protocol registration: http://www.crd.york.ac.uk/prospero identifier is CRD42025643615.

IntroductionSpeaking valves (SVs) restore phonation and may support airway protection in people with a tracheostomy, yet tolerance varies widely in neurological rehabilitation. We aimed to identify clinical factors associated with SV use and duration in a neurological rehabilitation setting.MethodsWe retrospectively analyzed 117 adults with neurological conditions and tracheostomy admitted to a rehabilitation center. Two internally validated multivariable models were developed: logistic regression for SV use (yes/no) and a quasi-Poisson regression for target daytime SV duration (hours/day), using routinely available bedside clinical variables.ResultsOf 117 patients, 64 (54.7%) used an SV during hospitalization. In the multivariable logistic model, higher level of consciousness (eMCS vs VS/MCS; OR 6.26, 95% CI 1.53-23.14), a positive blue dye test (OR 0.05, 95% CI 0.01-0.30), and endotracheal suction requirement (vs spontaneous cough; OR 0.07, 95% CI 0.003-0.879) were independently associated with SV use. Model performance was strong (AUC 0.856; accuracy 79.5%). Among SV users, longer daytime duration for SV use was associated with younger age, greater inspiratory and expiratory muscle strength, higher consciousness level, mild dysphagia, spontaneous cough, and neuromuscular or spinal cord injury diagnoses. In contrast, moderate-to-abundant secretions were associated with fewer hours.ConclusionIn a single-center neurological rehabilitation cohort, SV adoption and sustained tolerance were associated with bedside indicators of neurological responsiveness, secretion management, swallowing safety, and respiratory muscle strength. Findings should be interpreted as predictive associations and warrant external validation in contemporary multicenter cohorts.

Advanced respiratory diseases, particularly chronic obstructive pulmonary disease (COPD) and interstitial lung diseases (ILD), constitute an increasing challenge for healthcare systems due to their high prevalence, substantial symptom burden, and significant resource use. This consensus document, developed jointly by the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) and the Spanish Society of Palliative Care (SECPAL), provides recommendations for a multidisciplinary, integrated model of care. Using the SIGN methodology and a systematic literature review, a multidisciplinary panel developed 70 evidence-based recommendations addressing key domains: identification of patients with palliative care needs; management of respiratory symptoms; strategies to improve quality of life; communication and shared decision-making; caregiver support; and coordination across care settings. A needs-based approach, rather than reliance on prognosis alone, is recommended to facilitate earlier recognition of patients with advanced COPD and ILD and to enable the timely integration of palliative care alongside disease-directed therapies. Adoption of these recommendations is expected to improve quality of life, reduce symptom burden and suffering, and optimize care for patients with advanced respiratory diseases.

Sleep apnea is a common breathing disorder that affects nearly one billion people worldwide. Despite its high prevalence and clinical impact, it remains underdiagnosed and undertreated, particularly in middle-income countries. AIM:To determine the prevalence and risk of obstructive sleep apnea (OSA) and associated symptoms in the Chilean population. METHODS:A systematic review was conducted across seven databases to identify studies reporting the prevalence, risk, or symptoms of OSA in Chile. Prevalence estimates were synthesized using a random-effects meta-analysis. RESULTS:Fifteen studies involving 13,157 participants were included. The STOP-Bang questionnaire and the Epworth Sleepiness Scale were the most frequently used tools. Other instruments, such as the Berlin Questionnaire and sleep quality indices, were used less often. Only three studies employed respiratory polygraphy. The pooled prevalence of moderate-to-high risk of OSA, defined by a STOP-Bang score >3, was 25% (95% CI: 16-34%, I2= 98.4%). The most frequently reported symptoms were snoring, excessive daytime sleepiness, and witnessed apneas. CONCLUSION:The findings reveal a substantial burden of OSA risk and related symptoms in the Chilean population, based chiefly on screening questionnaires. Objective diagnostic methods were limited. These results underscore the need for population-based research using standardized and objective assessment tools to estimate OSA prevalence and inform public health strategies accurately.

Background: Pulmonary rehabilitation is effective for people with chronic obstructive pulmonary disease (COPD), but access remains limited. Telerehabilitation with telemonitoring may improve access to home-based care; however, feasibility data are currently scarce. This study assessed the feasibility, acceptability, and occurrence of adverse effects in a videoconference-based pulmonary telerehabilitation program supported by wearable devices in individuals with COPD. Methods: Our one-group pre-post feasibility study evaluated an 8-week intervention comprising two supervised exercise sessions and one education session per week. Telemonitoring included wearable-device data capture (heart rate, peripheral oxygen saturation, step count) and symptom severity reporting. Feasibility outcomes included recruitment rate, study completion, dropout rate, session attendance, data-submission compliance, adverse events, and participant satisfaction. Exploratory clinical outcomes were assessed pre- and post-intervention. Results: Of 32 eligible individuals, 15 consented and attended baseline assessment (recruitment rate: 47%), and nine completed the study (completion: 60%; dropout: 40%). Among completers, median age was 67 years (interquartile range [IQR] 62-73), and seven (78%) were women. Mean session attendance was 94 ± 6.6%. Data submission rates averaged 86 ± 7.7% for the O2 ring and 97 ± 6.4% for symptom severity reporting, while smartwatch data were submitted by all participants (100%). No adverse events were reported, and participant satisfaction was high. No statistically significant pre-post changes were observed in clinical outcomes. Mean 6-min walk test distance increased by 29 m, a potentially clinically relevant but exploratory finding. Conclusions: A videoconference-based pulmonary telerehabilitation program supported by wearable devices appears to be operationally deliverable among participants who remained engaged, with no adverse events observed in this small, selected group of participants with COPD. Findings should be interpreted cautiously due to the small sample size, one-group design, and attrition.

BACKGROUND:Mechanical insufflation-exsufflation (MI-E) consists of increasing expiratory air flow, thereby promoting an increase in cough peak flow (CPF) and secretion clearance. Respiratory impairment, characterized by reduced lung volumes and ineffective cough, is the major cause of morbidity and mortality in patients with amyotrophic lateral sclerosis (ALS). This study aimed to assess the acute effects of MI-E on CPF and chest wall compartmental and operational volumes in patients with ALS. METHODS:Ten ALS subjects (6 males) were studied by optoelectronic plethysmography (OEP) to assess the immediate effects of MI-E on CPF, chest wall volume variations and their distribution in the chest wall compartments, breathing pattern, and shortening velocity of the respiratory muscles before, during, and after the application of MI-E. RESULTS:No differences were observed in the CPF analysis between time points (pre, MI-E, post). A significant increase in CPF (P = .01) was obtained immediately after the application of MI-E in subjects with spinal-onset ALS (n = 7). No significant differences in total and compartmental lung volumes and chest wall operational volumes were observed between pre MI-E (quiet breathing), during MI-E (after coughs 1, 2, and 3), and post MI-E time points. CONCLUSIONS:The application of the MI-E technique may increase CPF in individuals with spinal ALS. However, no significant changes in total thoracic volumes, total and compartmental chest wall volumes, or changes in breathing patterns in the participants in our sample after the application of the technique were observed.

BackgroundProgressive respiratory muscle weakness in neuromuscular diseases (NMD) impairs cough effectiveness and increases respiratory morbidity. We compared peak cough flow (PCF) and vital capacity (VC) across airway clearance/cough augmentation techniques in adolescents and young adults using home noninvasive ventilation (NIV).MethodsIn this cross-sectional physiological study, adolescents and young adults with NMD receiving home NIV were evaluated at home. PCF and VC were measured at baseline and immediately after manual assisted cough (MAC), NIV at usual settings, NIV at inspiratory positive airway pressure of 30 cmH2O, air stacking (AS), glossopharyngeal breathing (GPB), and mechanical insufflation-exsufflation (MI-E). Techniques were tested alone and in combination with MAC; the sequence was randomized within participants.ResultsTwenty-four participants (70.8% male; age 17.5 ± 2.4 years) were included. Baseline PCF was 211.2 ± 89.4 L/min. Compared with baseline, PCF increased with MAC, AS, NIV at usual settings, NIV at 30 cmH2O, and MI-E (all p < 0.05), whereas GPB showed no significant change. When combined with MAC, all techniques further increased PCF (e.g., AS + MAC, 306.7 ± 98.4; NIV-30 + MAC, 297.1 ± 94.0 L/min; all p < 0.001), with no between-technique differences. VC increased after AS, MI-E, and NIV (all p < 0.005), but not after GPB.ConclusionsIn adolescents and young adults with NMD using home NIV, AS, NIV, and MI-E improved cough effectiveness and lung volume, and adding MAC produced additional PCF gains.

INTRODUCTION:Chronic respiratory diseases are a major global health burden, and oxygen therapy remains a cornerstone treatment for chronic hypoxemia. However, the effectiveness of long-term oxygen therapy (LTOT) depends not only on indication but also on the interaction between device performance, patient physiology, and real-world use. Variability in delivery systems, inadequate titration, and poor adherence often lead to mismatches between prescribed and delivered oxygen doses. AREAS COVERED:This review synthesizes current evidence on LTOT as a drug-delivery system, focusing on device characteristics, delivery performance, and patient-device matching across rest, exertion, and sleep. It examines stationary and portable systems, as well as home high-flow nasal cannula (HFNC). Key challenges such as pulse-dose variability, device limitations, adherence, and safety are addressed. Evidence from clinical trials, physiological studies, registries, and guidelines is integrated to show how delivery systems and patient factors influence effectiveness. EXPERT OPINION:LTOT should be reframed as a precision drug delivery system rather than a simple flow-based prescription. Device-specific titration, confirmation of adequate oxygenation with the prescribed device under the intended conditions of use, and individualized matching are essential. Future strategies should prioritize objective monitoring, advanced technologies, and scalable education to reduce the gap between prescription and real-world effectiveness.