Search Results (899)

Chronic respiratory diseases claim nearly four million lives annually, making them the third leading cause of death worldwide. Extracorporeal membrane oxygenation (ECMO) is often the last line of support for patients with severe lung failure. Still, its performance is limited by an incomplete understanding of gas exchange in hollow fiber membrane (HFM) oxygenators. Computational fluid dynamics (CFD) has become a robust oxygenator design and optimization tool. However, most models oversimplify O₂ and CO₂ transport by ignoring their physiological coupling, instead relying on fixed saturation curves or constant-content assumptions. For the first time, this study introduces a novel physiologically informed CFD model that integrates the Bohr and Haldane effects to capture the coupled transport of oxygen and carbon dioxide as functions of local pH, temperature, and gas partial pressures. The model is validated against in vitro experimental data from the literature and assessed against established CFD models. The proposed CFD model achieved excellent agreement with experiments across blood flow rates (100–500 $\mathrm{mL}/\min$ ), with relative errors below 5% for oxygen and 10–15% for carbon dioxide transfer. These results surpassed the accuracy of all existing CFD approaches, demonstrating that a carefully formulated single-phase model combined with physiologically informed diffusivities can outperform more complex multiphase simulations. This work provides a computationally efficient and physiologically realistic framework for oxygenator optimization, potentially accelerating device development, reducing reliance on costly in vitro testing, and enabling patient-specific simulations. Full article

Purpose: The pulmonary function test holds significant clinical value in assessing the severity, prognosis, and treatment efficacy of respiratory diseases. However, the test is limited by patient compliance, thereby limiting its practical application. Moreover, it only reflects the current state of the patient and cannot directly indicate future health trends or prognosis. Computational fluid dynamics (CFD), combined with airway models built from medical image data, can assist in analyzing a patient’s ventilation function, thus addressing the aforementioned issues. However, current airway models have shortcomings in accurately representing the structural features of a patient’s airway. Additionally, these models exhibit geometric defects such as low smoothness, topological errors, and noise, which further reduce their usability. This study generates airway skeletons based on CT data and, in combination with convolutional surface technology, proposes an individualized airway modeling method to solve these deficiencies. This study also provides a method for predicting a patient’s lung function based on the constructed airway model and using CFD simulation technology. This study also explores the application of this method in preoperative prediction of the required extent of airway expansion for patients with large airway stenosis. Methods: Based on airway skeleton data extracted from patient CT images, a personalized airway model is constructed using convolutional surface technology. The airway model is simulated according to the patient’s clinical statistical values of pulmonary function to obtain airway simulation data. Finally, a regression equation is constructed between the patient’s measured pulmonary function values and the airway simulation data to predict the patient’s pulmonary function values based on the airway simulation data. Results: To preliminarily demonstrate the above method, this study used the prediction of FEV1 in patients with large airway stenosis as an example for a proof-of-concept study. A linear regression model was constructed between the outlet flow rate from the simulation of the stenosed airway and the patient’s measured FEV1 values. The linear regression model achieved a prediction result of RMSE = 0.0246 and R² = 0.9822 for the test set. Additionally, preoperative predictions were made for the degree of airway dilation needed for patients with large airway stenosis. According to the linear regression model, the proportion of airway radius expansion required at the stenotic position to achieve normal FEV1 was calculated as 72.86%. Conclusions: This study provides a method for predicting patient pulmonary function based on CFD simulation technology and convolutional surface technology. This approach addresses, to some extent, the limitations in pulmonary function testing and accuracy caused by patient compliance. Meanwhile, this study provides a method for preoperative evaluation of airway dilation therapy. Full article

Objectives: We sought to document interim methodologic improvements and preliminary results for pulmonary suffusion. Methods: A Phase I/II trial of thoracoscopic lung suffusion for resectable sarcoma and colorectal carcinoma metastases followed a pilot study on oligometastatic lung malignancy at a comprehensive cancer center. Primary-specific chemotherapy doses (cisplatin, oxaliplatin, doxorubicin, or gemcitabine) suffused unilaterally for 30 min were escalated to amplify regional deliveries three-fold. Drug delivery was measured with tissue, blood samples, and ⁹⁹Tc; pulmonary function tests and clinical adverse events (AEs) assessed safety and tolerance. Results: From 2008–2025, 31 ECOG 0–2 patients (10 male) aged 33–75 years had unilateral lung suffusion (16 right, 14 left, 1 aborted, and 8 sides selected randomly). Vascular occlusion intolerance was immediate or delayed (25 min) in two cases. Two catheter-positioning grade 3 AEs occurred: hypotension with troponin leak (1) and atrial fibrillation (1). Patients averaged 1.3 ± 1.2 metastasectomies (17 sub-lobar, 8 lobar resections, and 2 intentional open cytoreductive metastasectomies). Hospitalizations were brief (1–4 days) except for 6–7 day stays in the only two open cases and one doxorubicin (grade 4 hypoxic respiratory failure) case. Ninety-day survival was 100%, and the Phase I delivery goal of 12.75 mg/m² 65 (15% systemic) was achieved for oxaliplatin. Lung function was preserved according to ⁹⁹Tc differentials within 6.1 ± 7.1% of the predicted reductions at 30 days. Sampling delays, tracer discordances, and atypical pharmacokinetics reduced tissue drug detections. Recent pulmonary artery snaring cases (two) demonstrated in-flow control more stable than that of balloon occlusions. Conclusions: Suffusion for metastatic malignancies appears safe and warrants further investigation. Full article

Aim: This study aimed to evaluate the nutritional status of children with cystic fibrosis (CF) and investigate the correlation between malnutrition and the decline of pulmonary function in this population. Methods: We retrospectively analyzed the clinical data of children with CF admitted to four large tertiary centers in Upper Egypt. We compared clinical characteristics among children with different nutritional statuses and evaluated the correlation between malnutrition and pulmonary functions. Results: A total of 104 children with CF, including 54 males (52%), aged 3 to 18 years, were analyzed. Respiratory symptoms were present in all cases (100%). Malnutrition was observed in 72% (75/104) of the participants, with affected children exhibiting significantly lower body weight and serum albumin levels. Pulmonary function tests showed that vital capacity (VC) and the predicted values for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), FEV₁/FVC, and expiratory flow at 25%, 50%, and 75% of FVC were all lower in the malnourished group compared to children with normal nutrition. Correlation analysis demonstrated that the body mass index (BMI) Z-score was positively correlated with these pulmonary function indicators. Conclusions: Malnutrition is highly prevalent among Egyptian children with CF and is associated with decreased pulmonary function. Improving nutritional status may enhance lung function in this population. Full article

Background/Objectives: Hormonal contraceptives are widely used, but their effects on respiratory health remain underexplored. This systematic review examined the impact of oral contraceptive pills (OCPs) on pulmonary function, with an emphasis on asthma-related outcomes and underlying mechanisms. Methods: MEDLINE (PubMed), EMBASE (Ovid), CINAHL, AMED, SPORTDiscus, and PEDro were searched from January 2000 to December 2024. Pulmonary outcomes assessed included PEFR, FEV₁, airway hyperresponsiveness, and exhaled nitric oxide levels. Results: Twelve peer-reviewed studies were included. Most studies reported that OCPs do not impair lung function and may even improve respiratory parameters. Women using OCPs showed enhanced peak expiratory flow and reduced symptom variability, particularly in asthma and cystic fibrosis. Potential mechanisms include the stabilization of airway reactivity and modulation of inflammatory pathways. Heterogeneity across study populations and contraceptive types limited a meta-analysis, and few studies stratified outcomes by hormonal composition or comorbidities. Conclusions: Hormonal contraceptives may provide protective or regulatory effects on pulmonary function in specific populations. Larger precision-based studies are needed to clarify mechanisms and guide contraceptive counseling for women with respiratory conditions. Full article

In this study, a prototype system was developed as a potential alternative to lockdown measures against the spread of airborne infectious diseases such as COVID-19. The system integrates real-time estimation functions for respiratory flow and mask leakage into a low-cost powered air-purifying respirator (PAPR) designed for the general public. Using only a single differential-pressure sensor (SDP810) and a controller (Arduino UNO R4 WiFi), the respiratory flow (Q_3e) is estimated from the differential pressure (ΔP) and battery voltage (V_b), and both the wearing status and leak status are transmitted to and displayed on a smartphone application. For evaluation, a testbench called the Respiratory Airflow Testbench was constructed by connecting a cylinder–piston drive to a mannequin head to simulate realistic wearing conditions. The estimated respiratory flow Q_3e, calculated solely from ΔP and V_b, showed high agreement with the measured flow Q_3m obtained from a reference flow sensor, confirming the effectiveness of the estimation algorithm. Furthermore, an automatic leak detection method based on the time-integrated value of Q_3e was implemented, enabling the detection of improper wearing. This system thus achieves respiratory flow estimation and leakage detection based only on ΔP and V_b. In the future, it is expected to be extended to applications such as pressure control synchronized with breathing activity and health monitoring based on respiratory and coughing analysis. This platform also has the potential to serve as the foundation of a PAPR Wearing Status Network Management System, which will contribute to societal-level infection control through the networked sharing of wearing status information. Full article

Background: Frailty syndrome significantly worsens the prognosis of elderly people. Sarcopenia and malnutrition are integral parts of aging, but there is a lack of knowledge about the overlap of these states, as well as their diagnostic methods and treatments. This study aimed to assess the malnutrition and sarcopenia scale in patients with frailty syndrome and the viability of evaluating the concentrations of the following potential biomarkers: albumin, total protein, and fibrinogen. Methods: A total of 170 patients >65 years were assessed for frailty using the Fried frailty scale. The risk of sarcopenia was measured using the SARC-F scale, and the risk of malnutrition was measured using the Mini Nutritional Assessment (MNA) scale. Serum albumin, protein, and fibrinogen levels were measured. The following fat-free body mass and respiratory parameters were measured: peak expiratory flow (PEF) and forced expiratory volume-one second (FEV1). Results: A total of 53 patients were classified as robust (31%), 96 as prefrail (57%), and 21 as frail (12%) according to Fried frailty criteria. Frail patients had significantly reduced serum albumin and increased fibrinogen compared to the prefrail and robust groups (p < 0.05). A total of 38% of frail patients were at risk of sarcopenia, and 52% were at risk of malnutrition. Frail patients had lower PEF and FEV1 values, with decreases in respiratory parameters correlating with fat-free body mass and muscle strength. Conclusions: Frail patients are at substantial risk of malnutrition and sarcopenia. The MNA and SARC-F scales, combined with routine screening of elderly patients with frailty, may effectively identify patients with the highest risk. Full article

Micromeria graeca (L.) Benth. ex Rchb. (Lamiaceae) is a promising medicinal plant valued for its antioxidant, anti-hyperglycemic, anti-hypertensive, antimicrobial, and anti-aflatoxigenic properties. It is rich in phenolic and flavonoid compounds, supporting its traditional use for digestive, respiratory, cardiovascular, and dermatological conditions. Plant tissue culture facilitates controlled in vitro propagation to study plant growth and bioactive properties. The effects of activated charcoal and varying subculture intervals on multiplication and biomass production in M. graeca shoot cultures were investigated. The phenolic composition of methanolic extracts from in vitro-grown plants was characterized using high-performance liquid chromatography (HPLC), identifying rosmarinic, caffeic, and syringic acids as the primary phenolic compounds. Antimicrobial activity against selected microbial strains was evaluated using a micro-well dilution assay. Anticancer activity of selected extracts was assessed in human hepatocellular carcinoma cell line HepG2, with flow cytometry (Annexin-V/PI staining) used to analyze cell death mechanisms, and compared to pure rosmarinic acid (RA). Activated charcoal showed no beneficial effects on multiplication or biomass production, but significantly increased phenolic acid content (up to 4-fold). RA dominated the phenolic profiles, with other phenolic acids present in lower amounts. Methanolic extracts exhibited negligible antimicrobial activity compared to reference antibiotics and fungicide. Extracts from 4-week-old shoot cultures displayed modest anti-hepatoma activity (IC50 values of CV assay ranging from 193 to 274 µg mL⁻¹), inducing HepG2 cell apoptosis via oxidative stress, independent of RA. Our results suggest that the metabolic output of M. graeca shoot cultures and consequently their biological activity can be modulated by varying in vitro culture conditions. These findings underscore the potential of their methanolic extracts for biotechnological production and therapeutic applications. Full article

Recent documents from leading international pediatric respiratory societies have strongly encouraged the use of lung function tests in clinical practice and research. These tests can explore ventilatory function across its volumetric and temporal domains, providing information on the intrapulmonary location and extent of damage caused by respiratory diseases. The choice of which test to use in each case to investigate presenting respiratory symptoms depends on the patient’s symptoms and the diagnostic–therapeutic phase being addresse d. In the most common and representative chronic pediatric condition—bronchial asthma—lung function tests play an especially important role due to the disease’s complexity and the fluctuating nature of airway obstruction. This review aims to examine the potential of various lung function tests in asthma, helping clinicians and researchers to optimize diagnosis and follow-up with the most appropriate methodology. While spirometry and flow resistance measurements using the interrupter technique have historically been the cornerstones of diagnosis and clinical monitoring in childhood asthma, the advent of new technologies—such as multiple breath nitrogen washout (MBNW) and the forced oscillation technique (FOT)—is opening up the door to a more nuanced view of the disease. These tools allow for an evaluation of asthma as a structurally complex and topographically and temporally disorganized condition. FOT, in particular, facilitates measurement acceptability in less cooperative subjects, both in respiratory physiology labs and even at the patient’s home. Full article

Glaesserella parasuis (G. parasuis) is a bacterial respiratory pathogen from pigs, which can cause high morbidity and mortality in weaned piglets in piggery. An accurate and rapid detection for G. parasuis is crucial for the effective control of Glässer’s disease. In the present study, two distinct Recombinase-Aided Amplification (RAA) techniques, utilizing fluorescence and lateral flow dipstick, were developed for the detection of G. parasuis. The two RAA assays, namely the fluorescent RAA (Fluo-RAA) and lateral flow dipstick RAA (LFD-RAA) assays, prioritize specificity and are capable of detecting G. parasuis with sensitivities of 10 copies and 100 copies, respectively. Both assays are capable of utilizing boiled nasal swab samples as DNA templates, demonstrating sensitivity comparable to that of commercial DNA extraction kits. Sensitivity tests had revealed that the Fluo-RAA assay exhibited greater sensitivity than the LFD-RAA assay. While the Fluo-RAA assay is more sensitive than the LFD-RAA assay, it is also more labor-intensive and better-suited for laboratory use than for field conditions. The entire process for the LFD-RAA assay can be completed within one hour without the need for professional equipment, making it more suitable for field use. Full article

Background and Clinical Significance: Anaerococcus tetradius (A. tetradius) and Gardnerella vaginalis (G. vaginalis) are rare etiological factors for postpartum endometritis and are typically associated with bacterial vaginosis. However, in some cases, G. vaginalis and A. tetradius can cause serious postpartum endometritis with complications such as sepsis. Case Presentation: 26-year-old pregnant woman expecting monochorionic diamniotic twins presented to the hospital at 35 weeks and 3 days of gestation and two male infants were delivered via the Cesarean section. On the fifth day after delivery, the patient began to complain of intense abdominal pain, a fever of 37.9 °C, and overall weakness. Blood tests revealed neutrophilic leukocytosis, increased C-reactive protein (CRP) of 225.4 mg/L. Upon examination, abdominal distension, tenderness on palpation, and positive symptoms of peritoneal irritation were present and the site of the abdominal incision was inflamed with flowing foul-smelling greenish pus. Ultrasound examination revealed free fluid collection in the peritoneal cavity, under the liver, and around the uterus. Later, the condition of the patient worsened with progressing hypotension and respiratory distress. As a result, suppurative peritonitis and sepsis was suspected and the patient underwent urgent total hysterectomy without oophorectomy. Acute endometritis, focal myometritis, and chronic cervicitis were concluded from histopathological examination of the removed uterus. Microbiological tests showed the most abundant growth of A. tetradius in the wound cultures and great abundance of G. vaginalis in the abdominal cavity cultures. After trying three different treatment schemes and difficulties with determining the antibiotic sensitivity tests for pathogens, the antibacterial therapy was escalated to Meropenem, which was found to be effective, and the patient was discharged home. Conclusions: This case report highlights the severity of complications of postpartum endometritis that can be caused by rare pathogens (such as G. vaginalis and A. tetradius), and strategies for how to manage it. The clinical presentation of a patient should be monitored closely for several days after Cesarean section and if endometritis is suspected, microbiological cultures are necessary to determine the cause of infection and implement an appropriate treatment. Full article

Background: Patients undergoing head and neck surgery with free flap reconstruction are at a high risk for postoperative respiratory complications, including hypoxemia. Conventional oxygen therapy (COT) and non-invasive ventilation (NIV) may be poorly tolerated or contraindicated due to anatomical limitations. High-Flow Nasal Cannula (HFNC) therapy represents a promising alternative, offering better humidification, comfort, and oxygenation. Methods: This retrospective single-center study included 50 adult patients admitted to the ICU after head and neck oncologic surgery with flap reconstruction from January 2022 to November 2024. All patients received HFNC immediately after extubation. Hypoxemia was defined as a PaO₂/FiO₂ (P/F) ratio of < 300 mm Hg. The primary outcome was the incidence of postoperative hypoxemia. Secondary outcomes included reintubation rates and patient compliance. Data were collected at 1, 6, 12, and 24 h following HFNC initiation. Results: Out of 59 patients screened, 9 were excluded per predefined criteria. Among the 50 included, only 2 patients (4%) developed hypoxemia, with P/F ratios remaining above 250. No patients required reintubation. The respiratory rate–oxygenation index (ROX index) improved steadily during the first 24 h. HFNC was well tolerated; only three patients required minor adjustments due to discomfort. Conclusions: HFNC use in the immediate postoperative period after head and neck surgery was associated with a low incidence of hypoxemia and no reintubations. These findings suggest that HFNC is a safe and effective strategy for postoperative respiratory support in this high-risk population. Further prospective studies are warranted to confirm the benefit of HFNC in reducing hypoxemia and preventing reintubation in high-risk surgical populations. Full article

Porcine reproductive and respiratory syndrome virus (PRRSV), an enveloped single-stranded positive-sense RNA virus, poses a significant threat to global swine production. Despite the availability of modified live virus and inactivated vaccines, their limited efficacy and safety concerns highlight the urgent need for novel antiviral therapeutics. This study aimed to investigate the molecular mechanisms by which lycopene inhibits PRRSV replication. Initial assessments confirmed that lycopene did not adversely affect cellular viability, cell cycle progression, or apoptosis. Using fluorescence microscopy, flow cytometry, immunoblotting, quantitative real-time PCR (qRT-PCR), and viral titration assays, lycopene was shown to exhibit potent antiviral activity against PRRSV. Mechanistic studies revealed that lycopene suppresses reactive oxygen species (ROS) production, which is critical for PRRSV proliferation. Additionally, lycopene attenuated PRRSV-induced inflammatory responses, as demonstrated by immunoblotting, ELISA, and qRT-PCR assays. These findings suggest that lycopene inhibits PRRSV replication by modulating ROS levels and mitigating inflammation, offering a promising avenue for the development of antiviral therapeutics. This study provides new insights and strategies for combating PRRSV infections, emphasizing the potential of lycopene as a safe and effective antiviral agent. Full article

Lower respiratory tract infections remain a leading cause of morbidity and mortality among Intensive Care Unit patients, with severe cases often progressing to acute respiratory distress syndrome (ARDS). This life-threatening syndrome results from alveolar–capillary membrane injury, causing refractory hypoxemia and respiratory failure. Early detection and management are critical to treat the underlying cause, provide protective lung ventilation, and, eventually, improve patient outcomes. The 2012 Berlin definition standardized ARDS diagnosis but excluded patients on non-invasive ventilation (NIV) or high-flow nasal cannula (HFNC) modalities, which are increasingly used, especially after the COVID-19 pandemic. By excluding these patients, diagnostic delays can occur, risking the progression of lung injury despite ongoing support. Indeed, sustained, vigorous respiratory efforts under non-invasive modalities carry significant potential for patient self-inflicted lung injury (P-SILI), underscoring the need to broaden diagnostic criteria to encompass these increasingly common therapies. Recent proposals expand ARDS criteria to include NIV and HFNCs, lung ultrasound, and the SpO₂/FiO₂ ratio adaptations designed to improve diagnosis in resource-limited settings lacking arterial blood gases or advanced imaging. However, broader criteria risk overdiagnosis and create challenges in distinguishing ARDS from other causes of acute hypoxemic failure. Furthermore, inter-observer variability in imaging interpretation and inconsistencies in oxygenation assessment, particularly when relying on non-invasive measurements, may compromise diagnostic reliability. To overcome these limitations, a more nuanced diagnostic framework is needed—one that incorporates individualized therapeutic strategies, emphasizes lung-protective ventilation, and integrates advanced physiological or biomarker-based indicators like IL-6, IL-8, and IFN-γ, which are associated with worse outcomes. Such an approach has the potential to improve patient stratification, enable more targeted interventions, and ultimately support the design and conduct of more effective interventional studies. Full article

Nasal obstruction is a common symptom of nasal conditions, with nasal resistance being a crucial physiological indicator for assessing severity. However, traditional rhinomanometry faces challenges with interference, limited automation, and unstable measurement results. To address these issues, this research designed a nasal resistance measurement system based on multi-sensor fusion of pressure and flow. The system comprises lower computer hardware for acquiring raw pressure–flow signals in the nasal cavity and upper computer software for segmenting and filtering effective respiratory cycles and calculating various nasal resistance indicators. Meanwhile, the system’s anti-interference capability was assessed using recall, precision, and accuracy rates for respiratory cycle recognition, while stability was evaluated by analyzing the standard deviation of nasal resistance indicators. The experimental results demonstrate that the system achieves recall and precision rates of 99% and 86%, respectively, for the recognition of effective respiratory cycles. Additionally, under the three common interference scenarios of saturated or weak breaths, breaths when not worn properly, and multiple breaths, the system can achieve a maximum accuracy of 96.30% in identifying ineffective respiratory cycles. Furthermore, compared to the measurement without filtering for effective respiratory cycles, the system reduces the median within-group standard deviation across four types of nasal resistance measurements by 5 to 18 times. In conclusion, the nasal resistance measurement system developed in this research demonstrates strong anti-interference capabilities, significantly enhances the automation of the measurement process and the stability of the measurement results, and offers robust technical support for the auxiliary diagnosis of related nasal conditions. Full article