Respiratory Measurements Research Articles

Physiotherapy-led, community-based airway clearance services for people with chronic lung conditions: a retrospective descriptive evaluation of an existing model of care

ObjectivesAirway clearance interventions are recommended for people with chronic lung conditions and mucus hypersecretion, but there are few published models of care or descriptions of airway clearance service provision. This evaluation describes a dedicated, physiotherapy-led, community-based airway clearance service in a metropolitan local health network.DesignRetrospective evaluation using existing airway clearance service administrative database.ParticipantsAll first referrals to the airway clearance service in a 5-year period (1/1/2017 to 31/12/2021).Main outcome measuresAvailable service data grouped into four domains: participant demographics, referral demographics, service provision and outcomes.ResultsOf the 1335 first referrals eligible for inclusion, 1157 (87%) people attended. Bronchiectasis was the commonest condition (n = 649/1135, 49%). A total of 2996 occasions of service (face to face clinic n = 2108, 70%, phone n = 736, 25%, telehealth n = 99, 3%, home visit n = 53, 2%) were delivered. Airway clearance devices frequently prescribed were the Aerobika (525/1157, 45%), bubble-positive expiratory pressure (263/1157, 23%) and the Acapella (127/1157, 11%). On average, initial appointment with the airway clearance service occurred within 36 days of referral and people attended the service three times. Individuals voluntarily completed both pre/post service questionnaires around a third of the time. At least half of responders reported an improvement in respiratory symptom outcome measures consistent with the minimum clinically important difference.ConclusionsThis evaluation describes an airway clearance service as it exists, providing an example from which airway clearance services can be planned, implemented and improved.

Infection prevention and control measures to reduce the transmission of mpox: A systematic review.

To make inferences regarding the effectiveness of respiratory interventions and case isolation measures in reducing or preventing the transmission of mpox based on synthesis of available literature. The WHO Clinical Management and Infection Prevention and Control 2022 guideline and droplet precautions in healthcare facilities and home isolation infection prevention control measures for patients with mpox. We conducted a systematic review that included a broad search of five electronic databases. In a two-stage process, we initially sought only randomized controlled trials and observational comparative studies; when the search failed to yield eligible studies, the subsequent search included all study designs including clinical and environmental sampling studies. No studies were identified that directly addressed airborne and droplet precautions and home isolation infection prevention control measures. To inform the review questions the review team synthesized route of transmission data in mpox. There were 2366/4309 (54.9%) cases in which investigators identified mpox infection occurring following transmission through direct physical sexual contact. There were no reported mpox cases in which investigators identified inhalation as a single route of transmission. There were 2/4309 cases in which investigators identified fomite as a single route of transmission. Clinical and environmental sampling studies isolated mpox virus in a minority of saliva, oropharangeal swabs, mpox skin lesions, and hospital room air. Current findings provide compelling evidence that transmission of mpox occurs through direct physical contact. Because investigators have not reported any cases of transmission via inhalation alone, the impact of airborne and droplet infection prevention control measures in reducing transmission will be minimal. Avoiding physical contact with others, covering mpox lesions and wearing a medical mask is likely to reduce onward mpox transmission; there may be minimal reduction in transmission from additionally physically isolating patients with mild disease at home.

Feasibility of high-frequency percussions in people with severe acquired brain injury and tracheostomy: an observational study.

People with severe acquired brain injury (pwSABI) frequently experience pulmonary complications. Among these, atelectasis can occur as a result of pneumonia, thus increasing the chance of developing acute respiratory failure. Respiratory physiotherapy contribution to the management of atelectasis in pwSABI is yet poorly understood. We conducted a retrospective analysis on 15 non-cooperative pwSABI with tracheostomy and spontaneously breathing, hospitalized and treated with high-frequency percussion physiotherapy between September 2018 and February 2021 at the Neurological Rehabilitation Unit of the IRCCS "S.Maria Nascente - Fondazione Don Gnocchi", Milan. Our primary aim was to investigate the feasibility of such a physiotherapy intervention method. Then, we assessed changes in respiratory measures (arterial blood gas analysis and peripheral night-time oxygen saturation) and high-resolution computed tomography lung images, evaluated before and after the physiotherapy treatment. The radiological measures were a modified radiological atelectasis score (mRAS) assigned by two radiologists, and an opacity score automatically provided by the software CT Pneumonia Analysis® that identifies the regions of abnormal lung patterns. Treatment diaries showed that all treatments were completed, and no adverse events during treatment were registered. Among the 15 pwSABI analyzed, 8 were treated with IPV® and 7 with MetaNeb®. After a median of 14 (I-III quartile=12.5-14.5) days of treatment, we observed a statistical improvement in various arterial blood gas measures and peripheral night-time oxygen saturation measures. We also found radiological improvement or stability in more than 80% of pwSABI. In conclusion, our physiotherapy approach was feasible, and we observed respiratory parameters and radiological improvements. Using technology to assess abnormal tomographic patterns could be of interest to disentangle the short-term effects of respiratory physiotherapy on non-collaborating people.

Safety and efficacy of sirolimus in hospitalised patients with COVID-19 pneumonia

BackgroundThere is a critical need to develop novel therapies for COVID-19. MethodsWe conducted a phase 2, multicentre, placebo-controlled, double-blind, randomised trial; hospitalised patients with hypoxemic respiratory failure due to COVID-19 and at least one poor prognostic biomarker, were given sirolimus (6 mg on Day 1 followed by 2 mg daily for 14 days or hospital discharge, whichever happens first) or placebo, in a 2:1 randomization scheme favouring sirolimus. Primary outcome was the proportion of patients alive and free from advanced respiratory support measures at Day 28. ResultsBetween April 2020 and April 2021, 32 patients underwent randomization and 28 received either sirolimus (n = 18) or placebo (n = 10). Mean age was 57 years and 75 % of the subjects were men. Twenty-two subjects had at least one co-existing condition (Diabetes, hypertension, obesity, CHF, or asthma/COPD) associated with worse prognosis. Mean FiO2 requirement was 0.35. There was no difference in the proportion of patients who were alive and free from advanced respiratory support measures in the sirolimus group (n = 15, 83 %) compared with the placebo group (n = 8, 80 %). Although patients in the sirolimus group demonstrated faster improvement in oxygenation and spent less time in the hospital, these differences were not statistically significant. There was no between-group difference in the rate of change in serum biomarkers such as LDH, ferritin, d-dimer or lymphocyte count. There was a decreased risk of thromboembolic complications in patients on sirolimus compared with placebo. ConclusionsLarger studies are warranted to evaluate the role sirolimus in COVID-19 infection.

Simultaneous Motion and Respiration Measurement in Adult Zebrafish Based on the Instantaneous Spatial Distribution of Separated Ventilatory Signals

Simultaneous Motion and Respiration Measurement in Adult Zebrafish Based on the Instantaneous Spatial Distribution of Separated Ventilatory Signals

Isolation of yeast mitochondria by differential centrifugation.

The isolation of intact and functional mitochondria is a powerful approach to characterize and study this organelle. The classical biochemical method of differential centrifugation is routinely used to isolate mitochondria. This method has several advantages, such as a high yield and easy adaptability. The isolated mitochondria are physiologically active and can be used for a variety of follow-up experiments, for example protein import and respiration measurements. Here, we describe the procedure to purify mitochondria from the budding yeast Saccharomyces cerevisiae. In addition, two approaches are introduced to assess the quality of isolated mitochondria, by limited proteinase K digestion or measurement of the membrane potential.

Longitudinal Relationship Between Physical Activity Levels and Respiratory Function in Older Individuals : A Longitudinal Study

Aging causes various physical changes, including decreased respiratory function characterized by decreased lung elasticity, reduced chest wall compliance, and weakened respiratory muscles. This study explored the longitudinal impact of daily physical activity (PA) on respiratory function in elderly individuals aged ≥50 years in England. Using data from Waves 2 (2004–2005), 4 (2008–2009), and 6 (2012–2013), we examined the influence of different levels of PA on forced expiratory volume (FEV), forced vital capacity (FVC), and other respiratory measures. Participants were classified based on self-reported PA into three categories; “hard” (vigorous activity at least 1–3 times monthly), “middle” (moderate activity 1–3 times monthly), and “nothing” (no PA). The inclusion criteria required participants to be ≥50 years and to have valid respiratory measures. The exclusion criterion was the presence of significant respiratory or cardiovascular disease at baseline. We applied the Sequential Doubly Robust Estimator and SuperLearner ensemble methods in the analysis using inverse probability weighting to address follow up bias and found that vigorous PA significantly reduced the risk of FVC by 4.10-fold compared with no exercise. In addition, vigorous exercise was associated with a 0.63-fold reduction in the risk of restrictive ventilation disorders while moderate exercise approached significance for FVC (p = 0.08). No significant effects were found with obstructive ventilation impairment (FEV). Overall, vigorous PA appears to be crucial for maintaining respiratory function in older individuals, highlighting the importance of regular exercise in preventing respiratory decline and potentially extending a healthy lifespan. These results underscore the need to promote regular PA to improve quality of life and reduce the risk of respiratory disease.

An accurate respiratory rate estimation algorithm for a rubber fiber respiratory sensor

Respiratory measurement is a crucial indicator for assessing health status; however, current methods for measuring respiratory rate and frequency are passive and not intuitive. This study investigates peak detection algorithms using a resistive strain sensor integrated into a garment for respiratory rate monitoring. The sensor, constructed with CNT material and a flexible rubber substrate, exhibits high conformity to the body’s contours. Designed for respiration measurement, the sensor maintains a low 6% strain for optimal sensitivity, demonstrating a 4% decrease after 800 repetitions of 10% elongation. Garment design emphasizes cohesion between the sensor and fabric, achieved through a piping technique. Respiratory measurement relies on a resistive sensor principle, where abdominal volume changes induce tension, altering resistance. Three peak detection algorithms are evaluated: the window size algorithm, low-pass filter, and FIR filter. The window size algorithm shows a 93% matching rate for normal breathing but requires manual adjustments based on breathing speed. The low-pass filter reduces noise but introduces lag, challenging peak matching. The FIR filter effectively detects peaks at increased speeds, achieving a matching rate exceeding 98%. The study concludes that the choice of algorithm depends on respiratory scenarios, with the window size algorithm suitable for regular cycles, the low-pass filter for real-time monitoring, and the FIR filter for accelerated respiratory rates. The study primarily explores static situations, indicating the need for future research on dynamic respiratory movements to enhance algorithm versatility.

SlipO2Chip - single-cell respiration under tuneable environments.

In disciplines like toxicology and pharmacology, oxygen (O2) respiration is a universal metric for evaluating the effects of chemicals across various model systems, including mammalian and microalgal cells. However, for these cells the common practice is to segregate populations into control and exposure groups, which assumes direct equivalence in their responses and does not take into account heterogeneity among individual cells. This lack of resolution impedes our ability to precisely investigate differences among experimental groups with small or limited sample sizes. To overcome this barrier, we introduce SlipO2Chip, an innovative glass microfluidic platform for precisely quantifying single-cell O2 respiration in the coordinated absence and presence of chemical solutes. SlipO2Chip comprises a wet-etched fused silica channel plate on the top and a dry-etched borosilicate microwell plate at the bottom. The microwells are coated with Pt(II) meso-tetra(pentafluorophenyl)porphine (PtTFPP), an O2 sensing optode material and an O2-independent reference dye. A custom 3D-printed holder facilitates the controlled horizontal movement ('slipping') of the channel plate over the microwell plate, thereby establishing or disrupting the fluid path over microwells. Collectively, these design elements enable the immobilization of single-cells in microwells, their exposure to controlled fluid flows, the coordinated opening and closing of microwells and repeated measurements of single-cell O2 respiration. Uniquely, by sequentially executing opening and closing it becomes possible to measure single-cell respiration prior to and after exposure to chemical solutes. In a proof-of-concept application, we utilized SlipO2Chip to measure the impact of increasing exposures of the marine bacterial signal 2-heptyl-4-quinolone (HHQ) on the dark respiration of the diatom Ditylum brightwellii at single-cell resolution. Results revealed a concentration-dependent decrease in per-cell O2 dark respiration, with a maximum reduction of 40.2% observed at HHQ concentrations exceeding 35.5 μM, and a half-maximal effective concentration (EC50) of 5.8 μM, consistent with that obtained via conventional bulk respiration methods. The ability of SlipO2Chip to sequentially assess the effects of chemical substances on single-cell O2 metabolism is advantageous for research where sample volumes are limited, such as clinical biopsies, studies involving rare microbial isolates, and toxicological studies aiming to address exposure effects while accounting for cell-to-cell variability.

Long-term Measurement of Soil Respiration and Environmental Drivers in Oil Palm Peat Plantations (Young and mature) and Peat Swamp Forest

Long-term Measurement of Soil Respiration and Environmental Drivers in Oil Palm Peat Plantations (Young and mature) and Peat Swamp Forest

KL-DNAS: Knowledge Distillation-Based Latency Aware-Differentiable Architecture Search for Video Motion Magnification.

Video motion magnification is the task of making subtle minute motions visible. Many times subtle motion occurs while being invisible to the naked eye, e.g., slight deformations in muscles of an athlete, small vibrations in the objects, microexpression, and chest movement while breathing. Magnification of such small motions has resulted in various applications like posture deformities detection, microexpression recognition, and studying the structural properties. State-of-the-art (SOTA) methods have fixed computational complexity, which makes them less suitable for applications requiring different time constraints, e.g., real-time respiratory rate measurement and microexpression classification. To solve this problem, we propose a knowledge distillation-based latency aware-differentiable architecture search (KL-DNAS) method for video motion magnification. To reduce memory requirements and to improve denoising characteristics, we use a teacher network to search the network by parts using knowledge distillation (KD). Furthermore, search among different receptive fields and multifeature connections are applied for individual layers. Also, a novel latency loss is proposed to jointly optimize the target latency constraint and output quality. We are able to find 2.8 × smaller model than the SOTA method and better motion magnification with lesser distortions. https://github.com/jasdeep-singh-007/KL-DNAS.

Functional Sitting Balance and Anthropometric Measures Are Related to Inspiratory Muscle Performance in People with Spinal Cord Injury.

Respiratory complications are a leading cause of mortality post spinal cord injury (SCI). Along with breathing, respiratory muscles have a role in maintaining seated balance. Postinjury breathing influences respiratory muscle function. Preliminary evidence indicates a relation between respiratory muscle function and seated balance in people with chronic SCI dwelling in the community, but the relationship between balance and body habitus has not been explored. To explore the relationships among inspiratory muscle function, functional seated balance (FSB), and body habitus in people with SCI. A convenience sample of inpatients with SCI (C5-T12) aged 18 to 60 years who were using a wheelchair was recruited from November 2022 to March 2023. Those with additional neurological disorders or respiratory support were excluded. Respiratory muscle function measures included maximal inspiratory pressure (MIP), sustained MIP (SMIP), and Fatigue Index Test (FIT). FSB was scored using the Function in Sitting Test (FIST). Body habitus was assessed using the axillary: umbilical (A:U) ratio. Spearman correlations explored the relationships. Thirty-eight of 42 screened participants were eligible and participated (male, 32). Levels of injury ranged from C5 to T12. The mean (SD) age and duration of injury of the sample was 25.61 (6.68) years and 31.03 (28.69) months, respectively. SMIP and FIT correlated significantly with FSB (r s= .441, p = .01, and r s= .434, p = .006, respectively). A significant correlation between SMIP and A:U ratio (r s= -.330, p = .043) was observed. We observed a significant correlation between inspiratory pressure parameters and both functional seated balance and body habitus, adding to evidence on postural role of respiratory muscles.

Respiratory and locomotor muscle blood flow measurements using near-infrared spectroscopy and indocyanine green dye in health and disease.

Measuring respiratory and locomotor muscle blood flow during exercise is pivotal for understanding the factors limiting exercise tolerance in health and disease. Traditional methods to measure muscle blood flow present limitations for exercise testing. This article reviews a method utilising near-infrared spectroscopy (NIRS) in combination with the light-absorbing tracer indocyanine green dye (ICG) to simultaneously assess respiratory and locomotor muscle blood flow during exercise in health and disease. NIRS provides high spatiotemporal resolution and can detect chromophore concentrations. Intravenously administered ICG binds to albumin and undergoes rapid metabolism, making it suitable for repeated measurements. NIRS-ICG allows calculation of local muscle blood flow based on the rate of ICG accumulation in the muscle over time. Studies presented in this review provide evidence of the technical and clinical validity of the NIRS-ICG method in quantifying respiratory and locomotor muscle blood flow. Over the past decade, use of this method during exercise has provided insights into respiratory and locomotor muscle blood flow competition theory and the effect of ergogenic aids and pharmacological agents on local muscle blood flow distribution in COPD. Originally, arterial blood sampling was required via a photodensitometer, though the method has subsequently been adapted to provide a local muscle blood flow index using venous cannulation. In summary, the significance of the NIRS-ICG method is that it provides a minimally invasive tool to simultaneously assess respiratory and locomotor muscle blood flow at rest and during exercise in health and disease to better appreciate the impact of ergogenic aids or pharmacological treatments.

Joint Use of a Low Thermal Resolution Thermal Camera and an RGB Camera for Respiration Measurement

Joint Use of a Low Thermal Resolution Thermal Camera and an RGB Camera for Respiration Measurement

Effects of Different Oxygen Levels and Time Points on Mitochondrial Respiratory Functional Analysis of Placental Tissue

The placenta plays an important role in fetal growth and development. The Oxygraph-2k mitochondrial function respirometer provides an accurate and realistic quantitative analysis of mitochondrial respiratory function and the energy metabolism of organisms. However, this machine is used less frequently in placental tissues, which consume do not consume as much oxygen as the heart, brain, or skeletal muscle tissues, therefore, it is crucial to develop a standard respiratory measurement protocol for placental tissues. For this, we tested varying oxygen concentrations (150–160 (ambient air), 200, 250, and 300 μM) and time tissue remains viable in respiratory medium (1.5~3, 3~4.5, 4.5~6, and 6~7.5 hour) to determine the optimal experimental conditions. As a result, we found no significant changes in mitochondrial respiratory capacity at different oxygen levels, whilst there was a decrease in mitochondrial respiratory capacity more than 3 hour after delivery.

Design and Implementation of Low-Cost Respiratory Rate Measurement Device

Design and Implementation of Low-Cost Respiratory Rate Measurement Device

Maximum abdominal excursion assessment using an abdominal excursion measuring device: Reliability and validity of a new device for simple and quantitative assessment of respiratory function

This study aimed to verify the reliability and validity of abdominal expansion and respiratory function measurements. Forty healthy adult males underwent lung capacity, effort lung capacity, respiratory muscle strength, cough strength, diaphragm ultrasound, and abdominal expansion measurements. Abdominal expansion was measured using a device developed to accurately evaluate abdominal movements and calculate maximum abdominal expansion on the ventral side (AE-max: the difference between maximal abdominal contraction at the same time as maximal-effort expiration and maximal abdominal expansion at the same time as maximal-effort inspiration). Intra- and inter-rater reliabilities of the AE-max measurements were examined, the paired t-test was used for assessing the ratios of the expansion and contraction displacement components in AE-max, and regression analysis was used to obtain equations for predicting maximum inspiratory pressure (MIP) based on AE-max. Both intra- and inter-rater reliabilities were high. Criterion-related validity showed that AE-max was associated with all respiratory function parameters, especially MIP, and a high percentage of expansion displacement. Regression analysis showed that AE-max was significantly associated with MIP. Based on its association with MIP, the large proportion of expansion displacement in AE-max, and the results of the multiple regression analysis, we conclude that AE-max is a helpful measure for estimating MIP.

POPULATION REFERENCE VALUES FOR PEAK EXPIRATORY FLOW IN OLDER US ADULTS

Abstract Respiratory function predicts physical and cognitive health outcomes in older adults. Peak expiratory flow (PEF) is simple, inexpensive, and has been validated against traditional respiratory function measures (FEV1, FVC). PEF has additional utility because it measures maximal respiratory effort without relying on spirometry equipment. However, there is a lack of epidemiological data to support PEF reference values for aging populations, especially those ≥80 years. The National Health and Aging Trends Study (NHATS) is a large, nationally representative sample of US adults ages ≥65 that offers a unique opportunity to develop PEF population reference values. Using a healthy subsample from NHATS Round 1 (N=2,082), excluding those with history of smoking, respiratory, or cardiovascular diseases, we applied NHATS sampling weights to estimate age- and sex-specific PEF percentiles. The sample was stratified by sex (68.9% female) and categorized into six, 5-year age groups: 65-69, 70-74, … ≥90 (36.6% age ≥80 years). In a secondary analysis, we estimated age- and sex-specific PEF/height3 percentiles, per current recommendations. We calculated 5th, 95th, and 10th, 20th, … 90th percentiles, by age and sex, for both absolute and height-adjusted PEF. PEF population estimates were higher in healthy males vs. females (456.8±130.1 vs. 293.9±89.9 liters/minute [mean±SD]). After adjusting for height, estimates remained higher for males (83.1±22.4 vs. 70.9±21.5 liters/m3/minute) and higher for younger (65-79 years) vs. older (≥80 years) participants (78.9±19.7 vs. 62.9±26.6 liters/m3/minute). These results may serve as PEF population reference values for healthy older adults in the US.

Ginsenoside Rb2 inhibits p300-mediated SF3A2 acetylation at lysine 10 to promote Fscn1 alternative splicing against myocardial ischemic/reperfusion injury

IntroductionGinsenosides (GS) derived from Panax ginseng can regulate protein acetylation to promote mitochondrial function for protecting cardiomyocytes. However, the potential mechanisms of GS for regulating acetylation modification are not yet clear. ObjectivesThis study aimed to explore the potential mechanisms of GS in regulating protein acetylation and identify ginsenoside monomer for fighting myocardial ischemia-related diseases. MethodsThe 4D-lable free acetylomic analysis was employed to gain the acetylated proteins regulated by GS pretreatment. The co-immunoprecipitation assay, immunofluorescent staining, and mitochondrial respiration measurement were performed to detect the effect of GS or ginsenoside monomer on acetylated protein level and mitochondrial function. RNA sequencing, site-specific mutation, and shRNA interference were used to explore the downstream targets of acetylation modificationby GS. Cellular thermal shift assay and surface plasmon resonance were used for identifying the binding of ginsenoside with target protein. ResultsIn the cardiomyocytes of normal, oxygen glucose deprivation and/or reperfusion conditions, the acetylomic analysis identified that the acetylated levels of spliceosome proteins were inhibited by GS pretreatment and SF3A2 acetylation at lysine 10 (K10) was significantly decreased as a potential target of GS. Ginsenoside Rb2 was identified as one of the active ginsenoside monomers for reducing the acetylation of SF3A2 (K10), which enhanced mitochondrial respiration against myocardial ischemic injury in in vivo and in vitro experiments. RNA-seq analysis showed that ginsenoside Rb2 promoted alternative splicing of mitochondrial function-related genes and the level of fascin actin-bundling protein 1 (Fscn1) was obviously upregulated, which was dependent on SF3A2 acetylation. Critically, thermodynamic, kinetic and enzymatic experiments demonstrated that ginsenoside Rb2 directly interacted with p300 for inhibiting its activity. ConclusionThese findings provide a novel mechanism underlying cardiomyocyte protection of ginsenoside Rb2 by inhibiting p300-mediated SF3A2 acteylation for promoting Fscn1 expression, which might be a promising approach for the prevention and treatment of myocardial ischemic diseases.

Efficacy of Marker-Based Motion Capture for Respiratory Cycle Measurement: A Comparison with Spirometry.

Respiratory rate monitoring is fundamental in clinical settings, and the accuracy of measurement methods is critical. This study aimed to develop and validate methods for assessing respiratory rate and the duration leof respiratory cycle phases in different body positions using optoelectronic plethysmography (OEP) based on a motion capture video system. Two analysis methods, the summation method and the triangle method were developed. The study focused on determining the optimal number of markers while achieving accuracy in respiratory parameter measurements. The results showed that most analysis methods showed a difference of ≤0.5 breaths per minute, with R2 ≥ 0.94 (p < 0.001) compared to spirometry. The best OEP methods for respiratory rate were the abdominal triangles and the sum of abdominal markers in all body positions. The study explored inspiratory and expiratory durations. The research found that 5-9 markers were sufficient to accurately determine respiratory time components in all body positions, reducing the marker requirements compared to previous studies. This interchangeability of OEP methods with standard spirometry demonstrates the potential of non-invasive methods for the simultaneous assessment of body segment movements, center of pressure dynamics, and respiratory movements. Future research is required to improve the clinical applicability of these methods.