Lung Compliance Research Articles

Polystyrene microplastic induced airway hyper-responsiveness, and pulmonary inflammation are mitigated by bronchom treatment in murine model of lung disease.

Polystyrene microplastic induced airway hyper-responsiveness, and pulmonary inflammation are mitigated by bronchom treatment in murine model of lung disease.

Identifying micron-scale fatigue crack initiation by correlating temporal dynamic compliance with Computed Tomography

Identifying micron-scale fatigue crack initiation by correlating temporal dynamic compliance with Computed Tomography

Measurement device and derivation formula for static ocular compliance

To introduce a device for measuring static ocular compliance (SOC) and propose a best-fit formula. An observational experimental study involving patients with age-related cataracts was conducted between May 2024 and September 2024. Pearson’s correlation analysis was used to screen for potential variables that were significantly associated with the SOC. Then, the SOC at six different height differences (recorded as “Δh”) was compared, and the best-fit equations for SOC were screened by linear regression analysis. CΔh was defined as SOC at height difference of Δh mm. A total of 47 eyes of 47 patients (22 males [46.8%] and 25 females [53.2%]) were enrolled. The mean SOC was (0.846 ± 0.274) µL/cmH2O, with a 95% confidence interval of (0.813–0.879) µL/cmH2O, with ocular axial length (AL) of (23.74 ± 1.83) mm and central corneal thickness of (541.13 ± 35.34) µm. Furthermore, Pearson’s correlation analysis revealed a significant correlation between SOC and AL (all P < 0.001). Using our device, the best-fit formula can be expressed as SOC = 0.948 x C600 + 0.067 x AL (R2 = 0.985; P = 0.000), with an optimal height difference of 600 mm. The designed in vivo measurement device can accurately measure SOC and derive a best-fit formula.

Inductance Plethysmography in Preterm Newborns Under Volume Guarantee Ventilation: A Crossover Study.

The diaphragm of preterm newborns is flat, weak and horizontally inserted in the rib cage. Consequently, it hampers the lever mechanism during muscle contraction, reduces the efficiency of pulmonary ventilation and chest expansion and increases energy expenditure. Primary outcome was to assess chest expansion using inductance plethysmography in preterm newborns during assist-control ventilation and inspiratory pressure control with and without volume guarantee (AC-PC and VG, respectively) and secondary outcomes were to assess ventilatory and autonomic outcomes. Chest expansion, as well as ventilatory (peak pressure, minute volume, dynamic compliance and airway resistance) and autonomic outcomes (heart rate, respiratory rate and peripheral oxygen saturation), were measured at 0, 30 and 60 min after initiation of ventilation in a crossover clinical trial study. A 30-min wash-out was performed between changes in ventilation modes. We analysed 450 respiratory cycles of preterm newborns between 27 and 32 gestational age (weighted 964 ± 167.1 g). Chest expansion was higher in VG in T0 (p = 0.01), T30 (p < 0.01) and T60 (p = 0.04). Ventilatory outcomes are similar between two modes. Heart rate in VG mode was lower than AC-PC at T60 (p < 0.01), whereas peripheral oxygen saturation (SpO2) was higher at the three moments, being significant at T30 (p = 0.02). Although nonsignificant, respiratory rate was lower for VG when compared to AC-PC. VG may increase chest expansion and peripheral oxygen saturation compared with AC-PC mode, and reduce heart rate.

Quantifying the Effect of Albuterol on Tracheal and Lung Compliance

Quantifying the Effect of Albuterol on Tracheal and Lung Compliance

Application and calculation methods of dynamic compliance in anaesthetised dogs, a scoping review.

Application and calculation methods of dynamic compliance in anaesthetised dogs, a scoping review.

The pulmonary resistance-compliance relationship: Real or mathematical artifact?

Pulmonary vascular resistance (PVR) and arterial compliance (PAC) have been reported to share an inverse hyperbolic relationship, with their product-the pulmonary vascular time constant (τ)-remaining more or less constant across disease states. However, PAC is often estimated as stroke volume (SV) divided by pulse pressure (PACclinical = SV/PP), introducing potential mathematical coupling with PVR, which is dependent on SV. This inherent relationship may artificially produce hyperbolic correlations. We conducted joint density analysis (JDA) and hemodynamic simulations using data from patients with pulmonary hypertension due to left-sided disease. PACclinical was calculated as SV/PAPP, and PVR as (PAM - PCWP)/CO. Log-transformed values were analyzed to assess the PVR-PACclinical relationship. JDA demonstrated a strong inverse correlation between PVR and PACclinical (Spearman's R = -0.88, CI -0.92 to -0.82), increasing to -0.92 with bootstrapping. Hemodynamic simulations confirmed a first-order hyperbolic decay (PAC = τavg/PVR; r2 = 0.86, p < 0.001). The relationship shifted downward with increasing PCWP. Our findings replicate the reported PVR-PACclinical relationship, highlighting its mathematical dependence. Further studies using more accurate PAC estimation methods are needed to determine whether this association is truly physiological or an artifact of calculation.

The Relationship of Computed Tomography-Derived Pulmonary Artery to Aorta Ratio to Pulmonary Artery Compliance and Pulmonary Vascular Resistance in PVDOMICS Participants With COPD and/or Interstitial Lung Disease

The Relationship of Computed Tomography-Derived Pulmonary Artery to Aorta Ratio to Pulmonary Artery Compliance and Pulmonary Vascular Resistance in PVDOMICS Participants With COPD and/or Interstitial Lung Disease

Static Compliance of the Respiratory System Is a Genetically Regulated Quantitative Trait in Sepsis-Associated Acute Hypoxemic Respiratory Failure

Static Compliance of the Respiratory System Is a Genetically Regulated Quantitative Trait in Sepsis-Associated Acute Hypoxemic Respiratory Failure

Preclinical Testing of a New Dry Powder Aerosol Synthetic Lung Surfactant Formulation and Device Combination for the Treatment of Neonatal Respiratory Distress Syndrome.

Background: This study advanced the preclinical development of a new dry powder aerosol synthetic lung surfactant (SLS) product for neonatal respiratory distress syndrome (RDS) by integrating a multiple-actuation device and scalable spray-dried formulation, evaluating physicochemical and in vitro aerosol performance, and then comparing biological efficacy with the current clinical standard of high-volume liquid bolus instillation. Methods: A new high-dose air-jet dry powder inhaler was developed that was characterized by a variable-volume aerosolization chamber (D3 device) with the goal of unifying aerosol quality and emitted dose (ED) over multiple actuations. The SLS excipient enhanced growth dry powder formulation was advanced through production on a scalable nozzle-based spray dryer system (Mini Spray Dryer; MSD2 formulation). Physicochemical characterization of the formulation was performed along with in vitro aerosol testing of the new D3-MSD2 device and formulation combination. The optimized D3-MSD2 aerosol therapy was then evaluated in a rabbit model of severe RDS. Results: The new D3-MSD2 combination produced a small-particle aerosol with high fine particle fraction (FPF<5 µm = 87.9%; FPF<2.5 µm = 61.6%) and percent ED (77.4% of loaded). Additional in vitro testing highlighted consistent particle size (Dv50 = 1.6 µm) and ED across multiple actuations. In the animal model experiments, a total device-loaded formulation mass of 60 mg (delivered as 2x30 mg) produced a total phospholipid (PL) dose of 24 mg-PL/kg and a device ED of 18 mg-PL/kg compared with the 200 mg-PL/kg clinical dose of Curosurf liquid. In vivo response rate for the D3-MSD2 aerosol therapy was considerably more rapid with arterial oxygenation recovering 5-12 times faster than for liquid Curosurf. Biological response for the D3-MSD2 aerosol therapy was also superior with 2-fold improvement in final lung compliance compared with liquid Curosurf. Conclusions: The new D3-MSD2 aerosol therapy was found to be superior to clinical-practice liquid bolus instillation in the critical areas of required dose (order-of-magnitude reduction), delivery time, biological response rate, and efficacy.

Slow releasing sulphide donor GYY4137 protects mice against ventilator-induced lung injury

BackgroundCyclic stretching of the lung during mechanical ventilation induces inflammation that contributes to the development of ventilator induced lung injury. Hydrogen sulphide (H2S) is an endogenous gasotransmitter known for its anti-inflammatory properties. However, the administration of exogenous H2S is constrained by its narrow therapeutic window, rapidly leading to potentially toxic peak concentrations. Alternatively, slow-release sulphide donors, such as GYY4137, offer a more controlled delivery. The primary aim of this study is to assess the efficacy and safety of GYY4137 in mitigating VILI.MethodsAnaesthetised male C57BL/6 J mice were pretreated with an intraperitoneal injection of GYY4137 (50 mg/kg, n = 14) or an equivalent volume of phosphate-buffered saline (controls, n = 13) and were then subjected to high tidal volume ventilation (VT 40–42.5 ml/kg) for a maximum of 4 h.ResultsGYY4137 pretreatment led to a notable 50% increase in survival rates compared to controls (p = 0.0025). It also improved arterial oxygenation after high VT ventilation, with arterial partial pressure of oxygen (PaO2) of 64 mmHg (IQR 49–125 mmHg) vs. 44 mmHg (IQR 42–51 mmHg) in controls (p < 0.001). Additionally, GYY4137 reduced total protein concentration in bronchoalveolar lavage fluid by 30% (p = 0.024) and lowered IL-1β levels by 40% (p = 0.006). GYY4137 mitigated the decline in dynamic respiratory system compliance caused by high VT ventilation, showing values of 24 μl/cmH2O (IQR 22–27) compared to 22 μl/cmH2O (IQR 22–24) in controls (p = 0.017). GYY4137 had minimal effects on antioxidant gene expression related to the erythroid nuclear factor 2, and it did not affect glutathione metabolism, the nuclear factor kappa B pathway, or the endoplasmic reticulum stress response.ConclusionsIn this mouse model of VILI, pretreatment with GYY4137 showed protective effects. GYY4137 significantly improved survival. It also improved arterial blood oxygenation and dynamic respiratory system compliance, and mitigated the development of lung oedema and inflammation.

A Quantitative Legal Support System for Transnational Autonomous Vehicle Design

One of the key expectations of AI product manufacturers for their products is the ability to scale to larger markets, especially across legal systems, with fewer prototypes and lower adaptation costs. This paper focuses on the increasingly dynamic legal compliance challenges faced by designers of AI products in achieving this goal. Based on non-monotonic reasoning, we design an automated reasoning tool to help them better understand the legal implications of their designs in a transnational context and, ultimately, adjust the design of AI products more flexibly. This tool supports the quantitative representation of the strength of legal significance to help designers better understand the reasons for their decisions from their own perspective. To illustrate this functionality, a case study on traffic regulations across the UK, France, and Japan demonstrates the system’s ability to resolve legal conflicts—such as driving-side mandates and speed radar detector prohibitions—through quantitative evaluation.

Effect of individualized end-inspiratory pause guided by driving pressure on respiratory mechanics during prone spinal surgery: a randomized controlled trial.

The prone position is commonly used in spinal surgery, but it can lead to decreased lung compliance and increased airway pressure. This study aimed to evaluate the effect of individualized end-inspiratory pause guided by driving pressure on respiratory mechanics in patients undergoing prone spinal surgery. A randomized controlled trial was conducted from August to October 2023. Patients scheduled for elective prone spinal surgery were randomly assigned to either a study group, receiving individualized end-inspiratory pause, or a control group, receiving a fixed end-inspiratory pause (10% of total inspiratory time). Mechanical ventilation parameters, including tidal volume, plateau pressure, driving pressure, and peak pressure, were recorded at different time points. Arterial blood gases were collected at baseline and at specified intervals. Data from 36 subjects (18 in each group) were included in the final analysis. The study group exhibited a significant increase in respiratory system compliance (P < 0.05) and improved intraoperative oxygenation (P < 0.05). In addition, the individualized end-inspiratory pause significantly decreased plateau pressure (P < 0.05) and driving pressure (P < 0.05) compared to the control group. The individualized end-inspiratory pause guided by driving pressure effectively optimized pulmonary compliance and improved oxygenation during prone spinal surgery. These findings suggest that this ventilation strategy may enhance respiratory mechanics and reduce the risk of postoperative pulmonary complications.

Nationwide Assessment of Pulmonary Function Testing Practices and Safety Compliance During the COVID-19 Pandemic

Coronavirus disease-2019 (COVID-19) presented considerable challenges to health services, particularly for a routine assessment method, the pulmonary function tests (PFTs), which can generate aerosols and require sharing common surfaces. Despite these risks, there is a need to continue testing, especially for vulnerable patient groups. An online survey was conducted from June 1 to June 26, 2020, to assess pulmonologists’ practices regarding PFTs before and during the pandemic’s first peak in Türkiye (March 11-May 20, 2020). The survey included 30 anonymized questions and received ethical committee approval. Statistical analysis was performed using the IBM Statistical Package for the Social Sciences statistical package. Two hundred and forty-three respondents across 59 cities participated in the study. 93% were pulmonologists. 77.4% of PFT labs have adequate ventilation by having a window enabling room direct air exchange. 27.2% of the PFT labs continued testing during the first peak of the pandemic. 83.3% of the responding centers applied triage before testing. Ongoing tests included spirometry (100%), bronchodilator reversibility testing (62.1%), and carbon-monoxide diffusion testing (16.7%). 49% of the PFT labs conducted fewer than four tests daily, while 21.2% performed more than eight. PFT technicians used personal protective equipment, with 67.7% using eye protection and 75.3 % wearing FFP3 or FFP2 masks. The survey found that pulmonologists have acted quickly and made moderate success in making preparations in PFT labs for the COVID-19 pandemic. Nevertheless, safer practice in PFT units still needs to be implemented.

Redefining Marketplace Payment On boarding: A Unified Global Payment Framework for Marketplace Scalability

This article presents a comprehensive examination of a transformative project that reimagined marketplace payment onboarding through the implementation of a unified global payment framework. The initiative addressed critical challenges faced by marketplace platforms operating across borders, including fragmented user experiences, technical debt accumulation, inconsistent security controls, operational inefficiencies, and limited scalability. Through a carefully architected solution built on React JS, Spring Boot microservices, and Kubernetes orchestration, the article implemented key innovations including universal payment provider integration, enhanced multi-factor authentication, and dynamic compliance management. The phased deployment strategy minimized disruption while validating system performance, resulting in dramatic improvements in seller onboarding time, support requirements, completion rates, and fraud prevention. The article examines technical challenges overcome during implementation, including integration complexity, data migration, and scalability under load, while detailing the multi-layered security approach that protected sensitive financial information through encryption, tokenization, behavioral analysis, and automated compliance controls. This work advances industry understanding of how unified payment frameworks can enable marketplace scalability in an increasingly global commercial landscape.

Analysis of heterogeneous traffic flow model integrating dynamic time headway and driver compliance uncertainty-aware

Analysis of heterogeneous traffic flow model integrating dynamic time headway and driver compliance uncertainty-aware

The in-vitro performance of a modern portable respirator in different lung models and as an alternative intensive care respirator: A simulation based cohort study.

Transporting ventilated patients safely and without loss of efficacy is a challenge. Portable ventilators are generally used to transport critically ill patients, but their performance is often limited. This study aimed to compare the in-vitro performance of a modern portable respirator with a modern intensive care respirator for different lung settings. An in-vitro testing of a portable and an intensive care respirator. Anaesthesia Department at the University Children's Hospital Zurich. The portable respirator Hamilton T1 was compared with the established intensive care respirator bellavista1000 (BV) while applying different settings with the ASL 5000 (ASL) device. The ASL can simulate neonatal, paediatric, and adult lung settings with normal or impaired lung function. Accuracy of delivered tidal volumes, proximal and distal airway pressures and mechanical lung properties were assessed. Bland-Altman analyses showed higher accuracy for applied tidal volumes delivered by the portable respirator, 12.6% [95% confidence interval (CI) -8.9 to 34.2], compared with the intensive care respirator, 15.9% (95% CI -18.5 to 50.3). In neonatal and infant lung models particularly, the accuracy of delivered tidal volumes by the portable respirator, 13.2% (95% CI -8.9 to 35.3) was superior to those delivered by the intensive care respirator, 20.9% (95%CI -15.9 to 57.7). Lung compliance estimation was performed more accurately by the intensive care respirator, whereas the portable respirator measured airway resistance more accurately. However, both respirators showed only moderate overall accuracy when assessing lung mechanics. The tested portable respirator proved to be a useful device for invasive ventilation of critically ill patients. The overall performance is non-inferior to a conventional intensive care respirator.

Experimental and clinical perspectives on glycocalyx integrity and its relation to acute respiratory distress syndrome.

Experimental and clinical perspectives on glycocalyx integrity and its relation to acute respiratory distress syndrome.

Clinical Profile and Outcome of High Flow Nasal Cannula Therapy in Children with Acute Respiratory Distress: A Single Centre Retrospective Cohort Study from Southern India

Introduction: High Flow Nasal Cannula (HFNC) therapy is being widely used as a treatment option for acute respiratory support prior to tracheal intubation or invasive ventilation. HFNC is a form of therapy in which high concentrations of oxygen, with adequate humidity and temperature, are administered non invasively via a nasal cannula. This approach has been shown to reduce airway resistance and improve lung compliance. While there are studies in Western literature regarding the efficacy of HFNC therapy in children in developed countries, there is still a paucity of data on the outcomes and efficacy of HFNC therapy in children in developing countries. Aim: To describe the clinical profile and outcomes of HFNC therapy in children admitted to a Paediatric Intensive Care Unit (PICU) with acute respiratory distress, as well as to identify the risk factors for failure of HFNC therapy in these children. Materials and Methods: This was a retrospective cohort study conducted by analysing the case records of children admitted with severe respiratory distress to the PICU of a tertiary care hospital in Southern India during the period from January 1, 2023, to December 31, 2023. The results were analysed over a threemonth period from January 1, 2024, to March 31, 2024. In this study, 55 children aged between one month and 18 years were included if they had received HFNC therapy for acute respiratory distress during the study period. Clinical and demographic data were collected and analysed with regard to the aetiology of acute respiratory distress, the indication for HFNC therapy, and the outcome. Results: During the study period, 55 (23.6%) of the 233 children admitted to the PICU required HFNC oxygen therapy for acute distress. Of these, 24 (43.6%) were children less than one year of age. The most common indication for HFNC therapy was bronchiolitis in acute respiratory distress (58.2%). In this study, 43 (78.2%) of the 55 children improved with HFNC; however, 12 children (21.8%) required escalation to invasive mechanical ventilation, which was considered a treatment failure. The reasons for treatment failures were analysed and found to include desaturation with worsening of the primary pathology and discontinuation of HFNC due to nasal discomfort, particularly in older children. Conclusion: This study concluded that HFNC therapy is beneficial, offering favourable outcomes and alleviating the need for more invasive forms of ventilation.

Head-To-Head Comparison of Biologic Efficacy in Asthma: What Have We Learned?

We performed an in-depth appraisal of indirect head-to-head comparisons of biologics approved for asthma, including anti-IL5/5Rα (mepolizumab, benralizumab), anti-IL4Rα (dupilumab), anti-TSLP (tezepelumab) and anti-IgE (omalizumab), which was neither a systematic review nor a meta-analysis. A crude evaluation of 95% CI's for rate ratios which excluded unity revealed greater overall reductions in annualised exacerbations with dupilumab versus either mepolizumab or benralizumab and also with tezepelumab versus benralizumab. Furthermore in patients with eosinophils ≥ 300/μL exacerbation rates were lower for tezepelumab, dupilumab and mepolizumab versus benralizumab; and with eosinophils< 150/μL for tezepelumab versus dupilumab. For lung function, no overall differences in FEV1 response were observed between drugs where there was considerable heterogeneity of overlapping 95% CI's. Dupilumab was superior to benralizumab for oscillometry-derived peripheral lung resistance and compliance, as well as for attenuation of mannitol airway hyperresponsiveness. There were no differences in asthma control or quality of life scores where the effect sizes were small, along with wide overlaps in 95% CI's. There is an unmet need for prospective pragmatic randomised controlled trials to directly compare biologics, especially to assess clinical remission in both type 2 high and low asthma patients. Real-life studies might also evaluate complete remission with different biologics to include outcomes such as inhaled corticosteroid sparing, small airways dysfunction using oscillometry, abolition of airway hyperresponsiveness and to assess mucus plugging and remodelling as wall thickening with imaging.