J. Respir., Volume 6, Issue 1 (March 2026) – 6 articles

Background: Accessory ostia (AOs) can notably alter maxillary sinus ventilation, yet configuration-specific effects remain unclear. This study quantified how AO location and orientation regulate sinus ventilation using in vitro measurements and numerical analyses. Methods: One patient-specific sinonasal geometry (control) was used to reconstruct five models with varying AO numbers, locations, and orientations (AO-F, AO-FC, AO-F30, AO-B, AO-FB). E-vapor was used as a visual tracer for sinus clearance under breath-hold and quiet breathing conditions. Complementary simulations characterized flow dynamics and sinus ventilation rates. Results: Both inhalation and AO presence accelerate e-vapor clearance for all conditions considered. The e-vapor clearance time in AO-FB decreases from 51 s under breath-hold to 29 s under quiet breathing (1 m/s). Configuration-wise, posterior AO ventilates the sinus faster than anterior AO, with dual anterior–posterior ostia (AO-FB) consistently performing the best. Among the three anterior AO, an uptilt AO ventilates the sinus faster than a parallel one, which is in turn faster than an AO located closer to the natural ostium (NO), i.e., AO-F30 > AO-F > AO-FC. CFD predictions provide a mechanistic understanding of the configuration-specific differences observed in vitro. Flow patterns in the ostium–sinus region, as well as the ventilation rate and driving pressure, show high sensitivities to AO location and orientation. At 1 m/s, the predicted AO-NO pressure drop ranges 2–18 mPa, with the lowest in AO-FC and highest in AO-B. Conclusions: The high sensitivity of sinus ventilation to AO configurations underscores the clinical importance of examining NO-adjacent openings in surgical planning and physiological interpretation. Full article

Background/Objective: Post-COVID survivors present significant respiratory deficiency that has been associated with ongoing shortness of breath and impaired lung function. Inspiratory muscle training (IMT) is increasingly used in survivors of COVID-19 rehabilitational programs as a means to facilitate recovery of the respiratory system. Yet, its home-based effectiveness across clinically relevant outcomes remains unclear. This systematic review aimed to present current evidence on home- or tele-delivered IMT in the post-COVID-19 population. Methods: PubMed, Scopus, Cochrane library and Science Direct were systematically searched for studies evaluating home-based (or telerehabilitation) IMT, alone or as part of a respiratory muscle training program, in adults with post-COVID-19 symptoms. The primary outcome was inspiratory muscle strength. Secondary outcomes included dyspnea, pulmonary function, exercise capacity and health-related quality of life. The methodological quality of the included studies was assessed via the PEDro scale. Owing to clinical and methodological heterogeneity, we performed only a qualitative synthesis. Results: Eight studies met the inclusion criteria. Two included both inspiratory and expiratory muscles training and three included physical training as well. The methodological quality was found to be good. IMT consistently increased inspiratory muscle strength across trials. Respiratory muscle training (RMT) programs that combined inspiratory and expiratory training also improved maximal expiratory pressure. IMT reduced dyspnea versus control/sham or baseline and several studies reported improvements in exercise capacity and physical function. Spirometry/DLCO changes were small or null in most cohorts. HRQoL gains were domain-specific in anxiety and depression. Adherence was generally good. No serious adverse events attributable to IMT were reported. Conclusions: Home-based IMT for adults with post-COVID-19 conditions is safe and seems to improve inspiratory muscle strength and dyspnea, with signs of benefit for exercise capacity, physical function, and selected HRQoL domains. Effects on ventilatory efficiency and conventional lung function appear limited. Future multicenter, sham-controlled RCTs should further explore the characteristics of IMT, employ core outcome sets, include longer follow-up, and predefine phenotype-based subgroups. Full article

Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can cause persistent, multisystem complications collectively termed long COVID. Cardiovascular sequelae are among the most clinically significant yet remain incompletely characterized. This review aimed to synthesize current evidence on objective cardiovascular outcomes in long COVID and explore underlying mechanisms. Methods: A systematic review was conducted using PubMed, Scopus, and Web of Science for studies published between January 2020 and March 2024. Search terms included “COVID-19,” “long COVID,” “post-acute sequelae,” “cardiovascular,” “echocardiography,” “biomarkers,” and “imaging.” Only studies reporting at least one cardiovascular outcome, defined as either objectively measured parameters (e.g., echocardiography, cardiac biomarkers, ECG findings, or vascular function indices) or clinically relevant cardiovascular symptoms during follow-up, were included. From 412 identified records, ten recent, high-quality studies with a primary cardiovascular focus were selected. This systematic review was conducted in accordance with the PRISMA 2020 guidelines. Results: Long COVID is associated with subclinical myocardial dysfunction, arrhythmias, endothelial injury, vascular stiffness, and a prothrombotic state. Reported findings included reduced left ventricular ejection fraction, impaired global longitudinal strain, increased arterial stiffness, elevated cardiac biomarkers, new-onset hypertension, and persistent ECG changes, even in non-hospitalized patients without prior cardiovascular disease. Proposed mechanisms include myocardial inflammation, endothelial dysfunction, renin–angiotensin–aldosterone system dysregulation, autonomic imbalance, and chronic inflammation. Secondary bacterial and fungal infections were noted in critically ill survivors but did not fully explain the breadth or persistence of symptoms. Conclusions: Long COVID is a heterogeneous entity with substantial cardiovascular implications across all levels of acute disease severity. Early detection through longitudinal monitoring, standardized definitions, and multidisciplinary care is essential to reduce long-term cardiovascular risk. Full article

Urinothorax, the presence of urine in the pleural space, is an exceptionally rare cause of pleural effusion, with fewer than 100 cases described in the literature. It most often follows trauma or urological procedures, though obstructive uropathy is also a recognized mechanism. We report an 83-year-old man with chronic kidney disease and benign prostatic hyperplasia who presented with acute dyspnea and a massive right-sided pleural effusion. Thoracentesis yielded clear yellow fluid with an ammonia-like odor, while imaging revealed chronic bladder outlet obstruction with bilateral hydroureteronephrosis. Despite inconclusive scintigraphy, the effusion resolved completely after urinary decompression with Foley catheterization, confirming the diagnosis. This case underscores the diagnostic challenges of urinothorax, which may be overlooked due to its rarity and variable biochemical profile, and highlights the importance of correlating clinical, radiologic, and pleural fluid findings. Early recognition is crucial, as timely relief of urinary obstruction provides both definitive diagnosis and curative treatment. Full article

Background: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity, mortality, and healthcare utilization. Lung volume reduction surgery improves outcomes in a select cohort but portends high morbidity. Bronchoscopic lung volume reduction (BLVR) is a less invasive, reversible manner of lung volume reduction, using one-way valves to improve lung function, quality of life, and exercise capacity. Nevertheless, knowledge gaps persist regarding factors that predict procedural success. Methods: We retrospectively reviewed 142 patients who underwent BLVR at the University of Chicago between December 2018 and July 2024 to assess the relationship between comorbidities and procedural outcomes. Using logistic and multinomial regression, we determined odds ratios (ORs) for a binary outcome of success and failure and relative risk ratios (RRRs) for failure sub-categories relative to procedural success. Results: We observed a procedural success rate of 48.1% and pneumothorax prevalence of 21.8%. After adjusting for age, sex, race, and body mass index (BMI), comorbidities associated with procedural failure included chronic kidney disease (CKD), congestive heart failure (CHF), anemia, and a BMI, Obstruction, Dyspnea and Exercise (BODE) Index of 5 or greater. Obstructive sleep apnea (OSA) was associated with procedural success. Conclusions: Comorbidities associated with dyspnea appear to have a significant effect on procedural success in BLVR. Full article

(1) Background: Indwelling pleural catheters (IPCs) with vacuum-based drainage can cause pain, especially in patients with a non-expandable lung (NEL). This evaluation assessed whether the Passio™ digital drainage system offers a viable alternative for patients experiencing pain during IPC drainage. (2) Methods: All IPC patients between November 2023 and April 2024 completed questionnaires assessing pain severity on a 10-point visual analogue scale (VAS) at four points during drainage. Patients reporting drainage-related pain at the 2-week post-IPC appointment had their existing valve replaced with a Passio™ valve (n = 5). (3) Results: Twenty-seven patients (59% male) were included in this analysis. The mean VAS scores for pain with a standard vacuum bottle were not statistically different at mid-drainage and the end of drainage compared with pre-drainage. Patients who experienced pain with the vacuum bottle (n = 5) had higher mean VAS scores at mid-drainage (51.68 mm ± 16.29; p = 0.13), end of drainage (46.68 mm ± 19.45; p = 0.19), and 10 min post-drainage (61.38 mm ± 9.81; p = 0.06) compared with pre-drainage (9.16 mm ± 4.01). Post-Passio™ valve replacement (n = 5), patients had a lower VAS pain score mid-drainage (20.15 mm ± 9.34; p = 0.25), end of drainage (27.28 mm ± 12.69; p = 0.84), and 10 min post-drainage (14.81 mm ± 3.33; p = 0.0079) when compared with vacuum bottle drainage. There were no complications with the Passio™ drainage system. (4) Conclusions: Controlled pleural drainage using a digital drainage device such as Passio™ may have a role in IPC patients who experience pain with vacuum bottle drainage, especially in those with an NEL. Full article