Breathing Parameters Research Articles

Evaluation of the penetration capacity of bacteria through layers of different face mask types and wearing conditions.

The aim of this study was to quantify the number of non-airborne bacteria that can passively penetrate the layers of four mask types (surgical mask, community face mask type 1 (CFM1), biocidal CFM1 and CFM2) and to determine the influence of wearing conditions for the surgical type. A mask wearer simulator consisting of a 3D anatomical replica of the upper airway connected to a breathing pump was used. Wearing time, filtration quality of the mask, fit (loose vs. tight) and breathing parameters (tidal volume, respiratory rate) were tested. A Staphylococcus epidermidis inoculum was applied to the inner layer. After the wearing simulation, the layers were separated and the bacteria counted. After four hours, no or only a few bacteria were present in the middle and outer layers. Most remained in the inner layer. Surgical mask and CFM1 retained more bacteria and provided a breeding ground for germs. The biocidal CFM1 rapidly reduced the number in the inner layer. The breathing parameters had no influence, in contrast to fit and wearing time. These results confirm that the standard test for bacterial filtration efficiency, which includes the active penetration of airborne bacteria into aerosol droplets, is the most objective measure of the ability of bacteria to penetrate through the mask layers, as the passive penetration ability of non-airborne bacteria is insignificant.

Racial and ethnic and sex differences in at-home estimates of sleep-disordered breathing parameters among Mexican American, Black, and Non-Hispanic White adults.

Background Racial and ethnic and sex differences in sleep may exist, but there are limited data directly comparing objective estimates of sleep-disordered breathing (SDB), particularly in rapid eye movement (REM) versus non-rapid eye movement (NREM) sleep, among Black, Mexican American (MA) and non-Hispanic White (NHW) men and women. Our goal is to investigate health disparities in SDB in a new, diverse cohort of older adults. Research Question Do SDB parameters during REM and NREM sleep differ by race and ethnicity or sex in community-dwelling older adults?. Methods The Dormir Study conducted a comprehensive sleep examination among eligible participants enrolled in the ongoing community-based Health and Aging Brain Study-Health Disparities (HABS-HD) cohort (2020-4), among Black, MA, and NHW adults aged 50 years and older. Here we characterize racial and ethnic and sex differences in SDB indices assessed by an FDA-approved Peripheral Arterial Tonometry (PAT)-based home sleep testing system. Results We examined 821 participants, including 543 (66.1%) women, and 284 (34.6%) MA and 174 (21.2%) Black individuals, with a mean age of 66.6±8.5 years. Around half (50.5%) of the participants had moderate to severe SDB as defined by the respiratory event index (REI based on 3% desaturations) of ≥15/ hour, 72.7% with moderate to severe REM SDB (REM-REI ≥ 15/hour) and 39.5% with moderate to severe NREM SDB (NREM-REI ≥15/hour). The prevalence of SDB did not differ by race or sex. However, significant racial and ethnic and sex differences were observed for REM-specific SDB metrics. Overall, Black women had the highest REM REI, and NHW men had the lowest REM REI and REM ODI. After controlling for age, sex, education, income, employment status, cognitive status, BMI, history of hypertension, diabetes, stroke, and coronary heart disease, and sleep medication use, Black participants had a REM-REI that was 3 events per hour higher than that of NHW adults, while NREM-REI were similar. MA individuals had similar REM or NREM SDB parameters compared to NHW adults but exhibited higher average blood oxygen levels. Conclusions In this community-based cohort of middle- to older-aged NHW, MA, and Black adults, PAT-based measures of in-home sleep indicate a higher prevalence of REM SDB in Black adults, particularly Black women, compared to their NHW counterparts; this contrasts with the similar NREM parameters observed across racial and ethnic groups. Given the close link between REM SDB and adverse health outcomes, clinicians should pay more attention to this sleep apnea phenotype, especially in minoritized populations.

The relationship between positive end-expiratory pressure (PEEP) and intra-abdominal pressure (IAP) in mechanically ventilated patients: A prospective observational study.

Positive end-expiratory pressure is a crucial mechanical breathing parameter. Intra-abdominal hypertension is well defined as a sustained increase in the intra-abdominal pressure ≥12 mmHg. There are still controversies about mechanical ventilation's effect and use of positive end-expiratory pressure on intra-abdominal pressure. We aimed to delineate the relationship between positive end-expiratory pressure and intra-abdominal pressure in mechanically ventilated patients admitted to the intensive care units of a large tertiary hospital in Upper Egypt. This study was a prospective observational study. The study was conducted at a university hospital from October 2023 to February 2024. The enrolled adult patients were allocated into two groups based on their positive end-expiratory pressure: group I, low pressure (<8 cm H2O) and group II, high pressure (8-10 cm H2O). A total of 120 patients were enrolled, 60 patients in each group. The most commonly encountered diagnoses were pneumonia (32/120, 26.7%) and acute respiratory distress syndrome (ARDS) (31/120, 25.8%), respectively. There was a significant difference between the intra-abdominal pressure mean values of the two patient groups, 18.9 ± 3.3 versus 24.4 ± 5.9 mmHg in the group of low versus high pressure (correlation value of .454, p < .001), respectively. There were highly significant correlations between intra-abdominal pressure categories and the patient groups (correlation value of .495, p < .001). There were 24 (40%) versus 0 (0%) patients of high pressure versus low pressure within the category IV group of intra-abdominal hypertension (>25 mmHg). We observed a significant relationship between positive end-expiratory pressure and intra-abdominal pressure in mechanically ventilated patients. The patient group with high pressure had higher mean values compared with the group with low pressure. The study highlights the importance of closely monitoring intra-abdominal pressure in mechanically ventilated patients who receive positive end-expiratory pressure. Further studies are warranted. The relationship between positive end-expiratory pressure and intra-abdominal pressure is an essential issue in daily critical care nursing clinical practice. Considering the occurrence of multiple organ dysfunction as a result of a non-detected increase in intra-abdominal pressure, critical care nurses should pay attention to measuring this pressure to maintain intra-abdominal pressures that are safe for mechanically ventilated and critically ill intensive care unit patients, thereby preventing these undue effects.

Respiratory and Neurodevelopmental Outcomes at 3 Years of Age of Neonates Diagnosed with Sleep-Disordered Breathing.

Objectives: Understanding the long-term consequences of sleep-disordered breathing (SDB) in neonates is crucial. A lack of consensus on diagnostic and treatment thresholds has resulted in limited research in this area. Our study aims to describe the trajectory of SDB in a cohort of high-risk neonates and their respiratory and neurodevelopmental outcomes at 3 years of age, and explore the relationship between SDB during early infancy and neurocognitive outcomes. Methods: A retrospectively identified cohort of neonates with moderate-severe SDB were prospectively followed at 3 years of age. Data collected included last polysomnography (PSG) parameters up to the age of 3 years and sleep physician's recommendations, duration of CPAP use, compliance with treatment, timing of SDB resolution, and neurodevelopmental outcomes. Univariate and multivariate logistic regression analyses were performed to evaluate the association between important respiratory and sleep breathing parameters with the developmental outcomes. Results: Eighty neonates were included. Respiratory and developmental outcomes were available for 58 (72.5%) and 56 (70%) patients, respectively. In most patients (47/58, 81%), SDB had resolved by 3 years of age. Survival without major developmental delay was seen in 32/56 (57%), but a significant proportion (21/56, 37.5%) demonstrated global developmental delay. Following univariate analysis, primary diagnosis, apnoea-hypopnoea index (AHI) at the time of last PSG and SDB outcome was significantly associated with developmental delay. However, these associations were not seen in multivariate analysis. Conclusions: Despite severity at baseline, SDB resolved in the majority of patients with time and treatment. Although statistically insignificant, logistic regression analysis identified some clinically important associations between neonatal SDB and neurodevelopmental outcomes.

THE INFLUENCE OF EVENING TWILIGHT ON THE ATTENTION OF DRIVERS OF DIFFERENT AGES IN CITY CONDITIONS

The article examines the issue of driver safety in cities in the evening twilight. A group of drivers aged 20 to 40 years with a total driving experience of 3 to 16 years was studied. Drivers with 3-5 years of driving experience had an average age of 25 years, and drivers with 10-16 years of driving experience had an average age of 34 years. Drivers drove along known routes at dusk and after dark. We measured drivers’ attention with a Pupil Labs headset, as well as functional state shifts with a respiratory rate monitor. The "Neulog Respiration Monitor Belt" device was used to determine the parameters of external breathing of drivers. Previously, we measured breathing parameters when the driver was in a calm state. Since the morning, the drivers’ breathing rate has been 10-12 breathing cycles. The results of the research indicate a significant difference in the shifts in the functional state during the movement along the routes for both groups. When the lighting changes from the beginning of the evening twilight, the energy consumption by drivers increases by 40%. At the same time, the maximum rate of energy consumption for the driver is 12.6 kJ/min, i.e. 2.9 kcal/min. Also, drivers with less driving experience were less attentive and more emotionally stressed. At the same time, the drivers of both groups experienced significant difficulties in reducing the lighting in the event of conflicting situations while driving. At the same time, energy expenditure significantly exceeded the limit indicators, and attention indicators worsened. This fact was observed after 15-20 minutes of driving in the evening twilight. The experimentally obtained data on changes in the driver’s attention index in the conditions of evening twilight can be used to build multifactorial models taking into account traffic parameters on different categories of streets. In the conditions of the evening twilight, the driver’s attention is significantly reduced. When the illumination changes from 50 lux (driving time 15-20 min.) and less, the driver experiences visual fatigue from constantly searching for objects on the road. At the same time, the number of fixations is significantly reduced, as the driver spends more time recognizing and searching for the necessary elements of the road environment, pedestrians, etc. Danger in the driver causes a state of stress, which is reflected in an increase in the driver’s breathing rate and, as a consequence, a change in the functional state. The main factor affecting the amount of energy spent in such conditions is the interaction of the driver with the road conditions. These factors require the driver to take certain actions when driving a car: acceleration, braking, maintaining speed and certain reactions in the event of a traffic hazard. The results of the analysis of parameters of the functional state of drivers with different years of work showed significant differences between electrophysiological indicators, both when moving in conditions of evening twilight and in background conditions. In the background conditions, lower values of electrophysiological indicators are primarily related to the different age of the drivers. Drivers with 3-5 years of driving experience had an average age of 25 years, and drivers with 10-16 years of driving experience had an average age of 34 years. Keywords: driver attention, traffic flow, human factor.

Evidence-informed approach of sighs in the scope of osteopathic practice

Osteopathic practice attaches great importance to the respiratory function in theoretical models, in the approach to respiratory disorders and in the use of breathing techniques for therapeutic purposes. The study of different parameters of breathing would be a way to deepen the application of breathing to osteopathic practice. In this respect, the sigh is a clinical element of interest.The osteopathic grey literature is rich in examples of the use of sighing in an empirical framework with interpretations during the anamnesis, the diagnostic and the therapeutic phases. Osteopaths' empirical experiences of sighing should be compared with available experimental data to improve the quality of osteopathic care. We are not aware of any study specifically related to sighing in an osteopathic context, but the psycho-physiological data on sighing is growing.This narrative review presents scientific data on the phenomenon of sighing. The physiological and pathophysiological conditions of sighing are presented in the context of the reasons for consultation encountered in osteopathic practice. The sigh as a diagnostic tool for various conditions is discussed. Therapeutic avenues explore how sighing could be an element in controlling the effects of osteopathic treatment, or an active element in the treatment itself. Finally, the place of the sigh as an element of communication within the consultation is described. In these different fields, the contribution of scientific data leads to several contradictions with the osteopathic empirical experience. This review describes avenues of future research needed to clarify the role that sighing might play in osteopathic practice.

The pontine Kölliker-Fuse nucleus is important for reduced post-inspiratory airflow elicited by stimulation of the ventral respiratory parafacial region.

Considering that the retrotrapezoid nucleus/respiratory parafacial region (RTN/pFRG) would be an important center in the central nervous system involved in the maintenance and modulation of respiratory activity, we hypothesized that neurons in this nucleus would also be involved in the postinspiratory phase of the respiratory cycle through a connection with the pontine Kölliker-Fuse (KF) region. Here we performed pharmacogenetic manipulation (AAV-hM3D(Gq)-mCherry or AAV-hM4D(Gi)-mCherry) in VGlut2-cre, Ai6 conscious mice to evaluate breathing parameters through whole body plethysmography under baseline conditions (normoxia: FiO2 = 0.21) or under hypercapnia or hypoxia challenges (FiCO2 = 0.07 or FiO2 = 0.08). Under normoxia, selective stimulation of RTN/pFRG resulted in a smaller increase in VE (1,272 ± 102.5, vs. RTN/pFRG stimulation: 1,878 ± 122.1 ml/kg/min), due to a smaller increase in VT (5.4 ± 0.35, vs. RTN/pFRG stimulation: 7.77 ± 0.21 ml/kg) without changing fR in a condition of KF inhibition. However, inhibition of the VGlut2 neurons in the KF did affect the TE1 produced by selective activation of RTN/pFRG (119.9 ± 2.53, vs. RTN/pFRG stimulation: 104 ± 2.46 ms). Both the hypercapnia and hypoxia ventilatory response were reduced after inhibition of VGlut2-expressing KF neurons. Therefore, consistent with anatomical projections RTN/pFRG neurons regulate lung ventilation by controlling all aspects of breathing, i.e breathing frequency, inspiration, postinspiration and active expiration. All the modulation seems to be dependent on the integrity of the glutamatergic neurons in the KF region.

Phrenic nerve stimulation for central sleep apnea: a single institution experience

PurposePhrenic nerve stimulation (PNS) was approved by the Food and Drug Administration (FDA) to treat moderate to severe central sleep apnea. We report here, results of a retrospective study regarding our institutional outcomes at one year. In this study we evaluated the change in the apnea hypopnea index, epworth sleepiness score, and functional outcomes of sleep score at one year post implant.MethodsThis is a retrospective analysis of patients ≥ 18 years of age who had PNS implanted for moderate to severe CSA at the Ohio State University Wexner Medical Center apnea between Feb 1, 2018 to July 1, 2021. Sleep disordered breathing parameters and objective sleepiness as measured by the Epworth Sleepiness Scale (ESS) scores, and Functional Outcomes of Sleep Questionnaire (FOSQ) scores were assessed at baseline and one-year post-implant.ResultsTwenty-two patients were implanted with PNS at OSU between February 1, 2018 and May, 31, 2022. The AHI showed a statistically significant decrease from a median of 40 events/hour at baseline to 18 at follow-up (p-value = 0.003). The CAI decreased from 16 events/hour to 2 events/hour (p-value of 0.001). The obstructive apnea index, mixed apnea index, and hypopnea index did not significantly change. The ESS scores had a statistically significant improvement from a median score of 12 to 9 (p-value = 0.028). While the FOSQ showed a trend to improvement from 15.0 to 17.8, it was not statistically significant (p-value of 0.086).ConclusionOur study found that PNS therapy for moderate to severe CSA improves overall AHI and CAI. Objective sleepiness as measured by the ESS also improved at one-year post implant.

Breath assessment at with post-tuberculosis patients suffered new coronavirus infection

BACKGROUND: The possibility of mutual aggravation of post-tuberculosis and post-COVID respiratory pathologies requires additional consideration. AIM: To study some subjective breathing parameters at patients with post-tuberculosis pulmonary residual changes after a new coronavirus infection recovering. MATERIALS AND METHODS: The study included two groups: the main group — 14 patients with cured pulmonary tuberculosis, who had recovered from a new coronavirus infection, a comparison group — 52 patients with post-tuberculosis changes non-sick new coronavirus infection who were admitted to the tuberculosis sanatorium “Glukhovskaya” in 2020–2021. The severity of shortness of breath using the Modified Medical Research Council (mMRC) and Borg scales was assessed upon admission to the sanatorium and a month later. Results: The mMRC scale was 1.5 ± 1.4 and 2.1 ± 0.2 and the Borg scale was 1.5 ± 1.4 and 2.9 ± 0.2 before treatment respectively in the main group and the comparison group. According to the mMRC scale initially 14.3 and 11.5% of patients with pulmonary tuberculosis and the comparison group did not complain of shortness of breath and 50% of pulmonary tuberculosis patients and 42.4% of the comparison group defined it as severe. After a month there were 3 or 4 points on the mMRC scale among pulmonary tuberculosis patients. In the comparison group 3-point shortness of breath decreased by 11.2 times most often indicated shortness of breath with 2 score. According to the Borg scale dyspnea was initially assessed as 3 points at 71.5% pulmonary tuberculosis patients. In the comparison group 67.3% patients had grade 3 dyspnea and 11.5% noted 4–6 grade shortness of breath. After a month the proportion of patients with mild shortness of breath at the pulmonary tuberculosis and comparison groups increased by 4.5 and 3.3 times, respectively, and the frequency of 3-grade shortness of breath decreased by 5 and 3.9 times. CONCLUSIONS: Major post-tuberculosis changes, smoking and chronic obstructive pulmonary disease determine the severity of breathing discomfort to a greater extent than the experience of new coronavirus infection but rehabilitation treatment are leveled out these differences. It is advisable to study the state of the respiratory system at patients cured of pulmonary tuberculosis.

Quality of life assessment in children with dental arch constriction and impaired nasal breathing

Relevance. Malocclusion often cause morphofunctional and aesthetic disturbances in the dentoalveolar system, and the lack of nasal breathing in children exacerbates existing deviations.Purpose. To assess morphofunctional parameters and quality of life indicators in children with impaired nasal breathing.Materials and methods. Photometric facial analysis, cephalometric and anthropometric calculations, anterior active rhinomanometry, and an oral health-related quality of life questionnaire for children (OHRQoL) were conducted.Results. In patients with impaired nasal breathing, social and family well-being parameters were reduced in the quality of life assessment.Conclusion. An orthodontist can determine the causes and degree of nasal breathing impairment by analyzing teleradiographs, orthopantomograms, and studying the quality of life in children. This aids in interdisciplinary planning for early diagnosis and treatment of children with maxillary constriction.

Mechanisms of cerebrospinal fluid secretion by the choroid plexus epithelium: Application to various intracranial pathologies.

The choroid plexus (CP) is a small yet highly active epithelial tissue located in the ventricles of the brain. It secretes most of the CSF that envelops the brain and spinal cord. The epithelial cells of the CP have a high fluid secretion rate and differ from many other secretory epithelia in the organization of several key ion transporters. One striking difference is the luminal location of, for example, the vital Na+-K+-ATPase. In recent years, there has been a renewed focus on the role of ion transporters in CP secretion. Several studies have indicated that increased membrane transport activity is implicated in disorders such as hydrocephalus, idiopathic intracranial hypertension, and posthemorrhagic sequelae. The importance of the CP membrane transporters in regulating the composition of the CSF has also been a focus in research in recent years, particularly as a regulator of breathing and hemodynamic parameters such as blood pressure. This review focuses on the role of the fundamental ion transporters involved in CSF secretion and its ion composition. It gives a brief overview of the established factors and controversies concerning ion transporters, and finally discusses future perspectives related to the role of these transporters in the CP epithelium.

Physiological Effects and Tolerance of Wearing Surgical and N95 Masks during Sleep in Normal Individuals and Patients with Mild-Moderate Obstructive Sleep Apnea: A Randomized Crossover Trial

BackgroundIn certain situations, masks are worn during sleep to prevent respiratory infections. However, the effects of mask wearing on cardiopulmonary function during sleep are unknown. This study aimed to determine whether wearing masks during sleep has an impact on cardiopulmonary function, including in patients with obstructive sleep apnea. MethodsThis was a prospective, randomized crossover-controlled trial. The effects of wearing surgical masks or N95 respirators on cardiopulmonary function were measured in healthy subjects and patients with mild-moderate obstructive sleep apnea. Sleep breathing parameters were monitored during nocturnal sleep using a sleep monitor, and subjective feelings about mask wearing were assessed using a questionnaire. ResultsWearing masks during sleep at night did not significantly impact sleep breathing parameters. Furthermore, there were no significant differences in heart rate, blood oxygenation, and blood pressure before and after wearing masks. However, wearing masks, especially the N95 mask, had an adverse impact on sleep quality, and masks were found to be subjectively uncomfortable. ConclusionWearing masks during sleep at night does not adversely affect cardiopulmonary function but they can be uncomfortable, especially the N95 mask. Thus, in circumstances where wearing N95 masks during nocturnal sleep proves intolerable, we recommend the use of surgical masks as a more comfortable alternative.

Knowledge and Attitudes towards Medical Emergencies among Dentists in Iași, Romania.

The aim of this study was to evaluate the level of knowledge of resident dentists and new graduates regarding the etiology, clinical diagnosis, and treatment of the main medical emergency conditions. The study included a sample of 152 new graduates and residents in the first, second, and third year of training in Prosthodontics and General Dentistry from the Faculty of Dental Medicine in Iasi, Romania. Their level of knowledge and the attitudes were assessed using a questionnaire with 24 questions, divided into four sections. The differences among groups were identified using the chi-square test (p < 0.05). A high level of knowledge was found among the three groups of subjects for the questions regarding the recognition of clinical signs in hypoglycemic crisis (88-100%), in anaphylactic shock (83.3-94.5%), and the treatment of angina pectoris (76.2-84.2%). In contrast, a low level of knowledge was found for the questions regarding pulse evaluation in the case of an emergency (26.3-35.7%), the parameters of normal breathing (28.9-43%), and the treatment of hypoglycemic crisis (27.8-44.8%). The study indicated that the dentists had a moderate understanding of dental office medical emergencies and preferred practical training over theoretical courses.

Возрастные особенности аэробных возможностей организма у спортсменов с разной направленностью физических нагрузок

The purpose of this study was to identify age-related features of aerobic capacity in athletes working on their endurance or speed-strength qualities. Materials and methods. The research involved 103 male athletes, who were divided into groups according to the type of physical activity (endurance (n = 58) and strength-speed (n = 45)) and age (12–15, 16–18 and 19–26 years). Their aerobic capacity was determined using cardiorespiratory exercise testing. Results. It was shown that the increase in relative peak oxygen consumption (VO2peak) was influenced not so much by age as by the type of physical activity (ANOVA: F = 18.1, p = 0.00004). At the same time, respiratory coefficient (F = 5.6, p = 0.007), heart rate at anaerobic threshold (F = 4.9, p = 0.009), tidal volume (F = 7.5, p = 0.01) and minute ventilation (F = 6.6, p = 0.002) were influenced mainly by age. In athletes aged 12–15 years, factor analysis established a negative correlation of type of physical activity with oxygen pulse, while physical working capacity was positively correlated with breathing parameters. Subjects aged 16–18 years showed no significant correlations between the variables and type of physical activity; at the same time, the number of correlations between ergometry parameters and physical working capacity factor increased with age. In athletes aged 19–26, the variables correlated strongly with the type of physical activity; the contribution of VO2peak to the physical working capacity factor is clearly demonstrated. The development of aerobic capacity is mainly influenced by the type of physical activity. However, in athletes aged 12–15 years, aerobic loads do not lead to a significant increase in VO2peak. The greatest increase in VO2peak is observed in 16–18-year-olds, while after 18 years of age, its growth halts.

Adverse respiratory patterns in near-term spontaneously breathing newborn lambs with elevated airway liquid volumes at birth.

Recent evidence indicates that respiratory distress (RD) in near-term infants is caused by elevated airway liquid (EL) volume at the beginning of air-breathing after birth. While the adverse effects EL volumes on newborn lung function are known, the effects on respiratory control and breathing patterns shortly after birth (<4 h) are unknown. We investigated the effects of EL volumes on cardiorespiratory function and breathing patterns in spontaneously breathing near-term newborn lambs in the first hours after birth. At 137-8 days gestation (2-3 days prior to delivery; term ∼147 days), sterile surgery was performed on fetal sheep (n = 17) to implant catheters and blood flow probes. At 140 days, lambs were delivered via caesarean section under spinal anaesthesia. Airway liquid volumes were adjusted to mimic the level expected following vaginal delivery (∼10 ml/kg; Controls; n = 7), or elective caesarean section (∼30 ml/kg; elevated airway liquid group; EL; n = 10). Spontaneous breathing and cardiorespiratory parameters were recorded over four hours after birth. Non-invasive respiratory support with supplemental oxygen was provided if required. EL lambs required higher inspired oxygen levels (p = 0.0002), were less active (p = 0.026), fed less (p = 0.008) and had higher respiratory morbidity scores than Controls (p < 0.0001). EL lambs also displayed higher rates of breathing patterns associated with RD, such as expiratory braking and tachypnoea. These patterns were particularly evident in male EL lambs who displayed higher levels of severe respiratory morbidity (e.g., expiratory braking) than female EL lambs. The study demonstrates that EL volumes at birth trigger respiratory behaviour and breathing patterns that resemble clinically recognised features of RD in term infants.

Comparison of Two Different Alfaxalone Concentrations Combined with Midazolam to Anesthetize Cynomolgus Macaques (Macaca fascicularis) for Plethysmography.

Plethysmography is employed in nonhuman primates (NHPs) to calculate respiratory minute volume and determine the exposure time required to deliver an aerosol at the target dose. Anesthetic drugs can impact breathing parameters like steady-state minute volume (SSMV) central to aerosol dosing. Alfaxalone-midazolam mixtures (AM) provide superior parameters for plethysmography in cynomolgus macaques. An obstacle to the use of AM is the volume required to anesthetize via intramuscular injection. A more concentrated formulation of alfaxalone will reduce injection volumes and refine AM protocols. The purpose of this study was to compare AM using the Indexed 10-mg/mL (AM10) formulation compared with an investigational 40-mg/mL (AM40) formulation for IM administration in cynomolgus macaques undergoing plethysmography. We hypothesized that AM10 and AM40 would show no difference in quality of anesthesia (QA), duration of anesthesia, SSMV, accumulated minute volume (AMV), and side effects. We also hypothesized that female macaques would have a longer duration of anesthesia compared with males using both formulations. The study used 15 cynomolgus macaques comprised of 8 females and 7 males. NHPs were compared between 2 separate and randomized anesthetic events no less than one week apart. Each animal served as its own control and animals were randomized by random number generation. Anesthetized NHPs were placed in a sealed plethysmography chamber, and minute volume measurements were calculated every 10 s to determine SSMV. Once SSMV was achieved for 20 min, the trial ended. There were no statistically significant differences between AM10 and AM40 for duration of anesthesia, SSMV, AMV, side effects, or QA. AM40 had a significantly smaller injection volume. Females did not show a significantly longer median duration of anesthesia using either of the alfaxalone formulations. Overall, AM40 offers a more humane anesthetic than AM10 for plethysmography in cynomolgus macaques.

Unobtrusive Sensors for Synchronous Monitoring of Different Breathing Parameters in Care Environments.

Respiratory problems are common amongst older people. The rapid increase in the ageing population has led to a need for developing technologies that can monitor such conditions unobtrusively. This paper presents a novel study that investigates Wi-Fi and ultra-wideband (UWB) antenna sensors to simultaneously monitor two different breathing parameters: respiratory rate, and exhaled breath. Experiments were carried out with two subjects undergoing three breathing cases in breaths per minute (BPM): (1) slow breathing (12 BPM), (2) moderate breathing (20 BPM), and (3) fast breathing (28 BPM). Respiratory rates were captured by Wi-Fi sensors, and the data were processed to extract the respiration rates and compared with a metronome that controlled the subjects' breathing. On the other hand, exhaled breath data were captured by a UWB antenna using a vector network analyser (VNA). Corresponding reflection coefficient data (S11) were obtained from the subjects at the time of exhalation and compared with S11 in free space. The exhaled breath data from the UWB antenna were compared with relative humidity, which was measured with a digital psychrometer during the breathing exercises to determine whether a correlation existed between the exhaled breath's water vapour content and recorded S11 data. Finally, captured respiratory rate and exhaled breath data from the antenna sensors were compared to determine whether a correlation existed between the two parameters. The results showed that the antenna sensors were capable of capturing both parameters simultaneously. However, it was found that the two parameters were uncorrelated and independent of one another.

Aerosol Delivery to Simulated Spontaneously Breathing Tracheostomized Adult Model With and Without Humidification.

Optimal aerosol delivery methods for spontaneously breathing patients with a tracheostomy remain unclear. Thus, we aimed to assess the impact of nebulizer placement, flow settings, and interfaces on aerosol delivery by using a vibrating mesh nebulizer and a jet nebulizer in line with unheated humidification. An 8.0-mm tracheostomy tube was connected to the lung model that simulates adult breathing parameters via a collecting filter. Albuterol sulfate (2.5 mg/3 mL) was administered via a vibrating mesh nebulizer and a jet nebulizer, which was placed in line with unheated humidification provided by a large-volume nebulizer, with FIO2 set at 0.28, with gas flows of 2 L/min versus 6 L/min. Nebulizers were placed in line distal and proximal to the lung model by using a tracheostomy collar and a T-piece. Conventional nebulization was tested using a vibrating mesh nebulizer and a jet nebulizer directly connected to the tracheostomy tube bypassing the humidification device. The drug was eluted from the collecting filter and assayed with ultraviolet spectrophotometry (276 nm). During in-line nebulizer placement with unheated humidification, the inhaled dose was 2-4 times higher with a gas flow of 2 L/min than 6 L/min, regardless of nebulizer type, placement, or interface (all P < .05). At 6 L/min, the inhaled dose was higher with proximal than distal placement when using both interfaces, but, at 2 L/min, the inhaled dose was lower with proximal placement. With a jet nebulizer, the tracheostomy collar generated a higher inhaled dose at proximal placement compared with the T-piece, whereas the T-piece resulted in a higher inhaled dose than the tracheostomy collar with distal placement, regardless of the flow settings. Compared with conventional nebulization using a vibrating mesh nebulizer, an in-line vibrating mesh nebulizer with a large-volume nebulizer at 2 L/min had a similar inhaled dose, regardless of nebulizer placement and interface. In contrast, the in-line jet nebulizer was influenced by both placement and interface. Aerosol delivery with an in-line vibrating mesh nebulizer and jet nebulizer with unheated humidification was affected by nebulizer placement, interface, and gas flow settings.

Comparative study of the inhalation parameters of COPD patients through NEXThaler® and Ellipta® dry powder inhalers

The deposition of dry powder aerosol drugs depends on the inhalation parameters of the patients through the inhaler. These data are not directly measured in clinical practice. Their prediction based on the routinely measured spirometric data could help in choosing the appropriate device and optimizing the therapy. The aim of this study was to perform inhalation experiments to find correlations between inhalation parameters of COPD patients through two DPI devices and their native spirometric data, gender, age and disease severity. Another goal was to establish relationships between peak inspiratory flows through NEXThaler® and Ellipta® inhalers and their statistical determinants. Breathing parameters of 113 COPD patients were measured by normal spirometry and while inhaling through the two DPIs. Statistical analysis of the measured data was performed. The average values of peak inspiratory flow through the devices (PIFdev) were 68.4 L/min and 78.0 L/min for NEXThaler® and Ellipta®, respectively. PIFdev values were significantly higher for males than for females, but differences upon age, BMI and disease severity group were not significant. PIFdev values correlated best with their native spirometric counterparts (PIF) and linear relationships between them were revealed. Current results may be used in the future to predict the success of inhalation of COPD patients through DPI devices, which may help in the inhaler choice. By choosing the appropriate device-drug pair for each patient the lung dose can be increased and the efficiency of the therapy improved. Further results of the clinical study will be the subject of a next publication.

Dynamics of parameters of human cardiovascular and respiratory systems under the influence of speleoclimat

Speleotherapy uses the conditions of salt mines and caves to treat diseases of the skin and respiratory systems, to restore patients after illnesses, to maintain health, and stimulate the immune system. The purpose of this study is to study the dynamics of the parameters of the cardiovascular and respiratory systems of a person under the influence of speleoclimate. The study involved studens of 1–2 courses of the Voronezh State Medical University. N.N. Burdenko. Every day for 10 days of speleotherapy after the end of speleotherapy, blood pressure, pulse, oxygen saturation, respiratory rate, and lung capacity were measured. The analysis of the obtained data was carried out using Excel and StatPlus Pro programs. It was revealed that human adaptation to the speleoclimate occurs both due to the frequency and strength of the heart contraction. The dynamics of the parameters of the respiratory system under the influence of speleoclimate reflects the adaptation of the study participants to the speleoclimate mainly due to the depth of breathing, to a lesser extent – due to the frequency of breathing. Mobilization of adaptive resources and the state of tension of the cardiovascular and respiratory systems during the development of the anxiety stage under the influence of speleoclimate is formed mainly due to intersystem mechanisms. Tension in the cardiovascular system persists after the 10th speleo procedure. It is shown that the speleoclimate has the ability to restore the vegetative status of a person. Differences in the dynamics of breathing parameters in girls and boys under the influence of speleoclimate were revealed.