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Cardiovascular Toxicology Oct 2019The use of electronic cigarettes has increased exponentially since its introduction onto the global market in 2006. However, short- and long-term health effects remain... (Randomized Controlled Trial)
Randomized Controlled Trial
The use of electronic cigarettes has increased exponentially since its introduction onto the global market in 2006. However, short- and long-term health effects remain largely unknown due to the novelty of this product. The present study examines the acute effects of e-cigarette aerosol inhalation, with and without nicotine, on vascular and pulmonary function in healthy volunteers. Seventeen healthy subjects inhaled electronic cigarette aerosol with and without nicotine on two separate occasions in a double-blinded crossover fashion. Blood pressure, heart rate, and arterial stiffness measured by pulse wave velocity and pulse wave analysis were assessed at baseline, and then at 0 h, 2 h, and 4 h following exposure. Dynamic spirometry and impulse oscillometry were measured following vascular assessments at these time points, as well as at 6 h following exposure. e-Cigarette aerosol with nicotine caused a significant increase in heart rate and arterial stiffness. Furthermore, e-cigarette aerosol-containing nicotine caused a sudden increase in flow resistance as measured by impulse oscillometry, indicating obstruction of the conducting airways. Both aerosols caused an increase in blood pressure. The present study indicates that inhaled e-cigarette aerosol with nicotine has an acute impact on vascular and pulmonary function. Thus, chronic usage may lead to long-term adverse health effects. Further investigation is warranted.
Topics: Administration, Inhalation; Adult; Aerosols; Airway Obstruction; Airway Resistance; Blood Pressure; Cardiovascular System; Cross-Over Studies; Double-Blind Method; Electronic Nicotine Delivery Systems; Female; Healthy Volunteers; Heart Rate; Hemodynamics; Humans; Lung; Male; Nicotine; Nicotinic Agonists; Risk Assessment; Time Factors; Vaping; Vascular Stiffness; Young Adult
PubMed: 30963443
DOI: 10.1007/s12012-019-09516-x -
Frontiers in Physiology 2023The primary impact of ventilation and ventilatory efforts on left ventricular (LV) function in left ventricular dysfunction relate to how changes in intrathoracic... (Review)
Review
The primary impact of ventilation and ventilatory efforts on left ventricular (LV) function in left ventricular dysfunction relate to how changes in intrathoracic pressure (ITP) alter the pressure gradients for venous return into the chest and LV ejection out of the chest. Spontaneous inspiratory efforts by decreasing ITP increase both of these pressure gradients increasing venous blood flow and impeding LV ejection resulting in increased intrathoracic blood volume. In severe heart failure states when lung compliance is reduced, or airway resistance is increased these negative swings in ITP can be exacerbated leading to LV failure and acute cardiogenic pulmonary edema. By merely reversing these negative swings in ITP by the use of non-invasive continuous positive airway pressure (CPAP), these profoundly detrimental forces can be immediately reversed, and cardiovascular stability can be restored in moments. This forms the clinical rationale for the immediate use of CPAP for the treatment of acute cardiogenic pulmonary edema. Increasing ITP during positive pressure ventilation decreases the pressure gradients for venous return and LV ejection decreasing intrathoracic blood volume. In a hypovolemic patient even with LV dysfunction this can result in hypotension due to inadequate LV preload. Minor increases in ITP as occur using pressure-limited positive-pressure ventilation primarily reverse the increased LV afterload of negative swings in ITP and if fluid overload was already present, minimally alter cardiac output. The effect of changes in lung volume on LV function are related primarily to its effects on right ventricular (RV) function through changes in pulmonary vascular resistance and overdistention (hyperinflation). In acute lung injury with alveolar collapse, positive pressure ventilation may reduce pulmonary vascular resistance if alveolar recruitment predominates. Hyperinflation, however, impedes diastolic filling while simultaneously increasing pulmonary vascular resistance. Thus, increasing lung volume can reduce RV afterload by reversing hypoxic pulmonary vasoconstriction or increase afterload by overdistention. Hyperinflation can also impede RV filling. All of these processes can be readily identified at the bedside using echocardiography.
PubMed: 37614756
DOI: 10.3389/fphys.2023.1237741 -
Cureus Jul 2023Airway suctioning is routinely performed in the majority of care circumstances, including acute care, subacute care, home-based settings, and long-term care. Using an... (Review)
Review
Airway suctioning is routinely performed in the majority of care circumstances, including acute care, subacute care, home-based settings, and long-term care. Using an artificial airway to suction the patient allows for the mobilization and evacuation of secretions. When a patient can't independently remove all of the secretions from their respiratory tract, suction is used. This can occur when the body produces excessive secretion or it is not eliminated quickly enough, causing the respiratory system's upper and lower respiratory secretions to accumulate. Airway blockage and inadequate breathing may result from this. Ultimately, this leads to a shortage of oxygen and carbon dioxide from the air, both of which are necessary for ideal cellular activity. Artificial airway suctioning is one of the most crucial components of airway care and a core competency for medical professionals trying to ensure airway patency. Artificial airway suctioning is a standard treatment carried out every day globally and is frequently done in both outpatient and inpatient patients. Therefore, specialists must know the safest and most efficient ways to perform surgery and any potential side effects. In ventilated infants and children, the removal of obstructive secretions by endotracheal suctioning is frequently done. It is unknown how suctioning affects the mechanics of breathing. This study used a prospective observational clinical design to examine the immediate impact of airway resistance in endotracheal suctioning, tidal volume, and dynamic lung regulation in mechanically ventilated adult patients and mechanically ventilated pediatric patients. The preparation, process, and indications for intraoperative fusion treatment in various circumstances are covered in this systematic review.
PubMed: 37641766
DOI: 10.7759/cureus.42579 -
The Journal of Allergy and Clinical... Nov 2023Global warming has direct and indirect effects, as well as short- and long-term impacts on the respiratory and skin barriers. Extreme temperature directly affects the... (Review)
Review
Global warming has direct and indirect effects, as well as short- and long-term impacts on the respiratory and skin barriers. Extreme temperature directly affects the airway epithelial barrier by disrupting the structural proteins and by triggering airway inflammation and hyperreactivity. It enhances tidal volume and respiratory rate by affecting the thermoregulatory system, causing specific airway resistance and reflex bronchoconstriction via activation of bronchopulmonary vagal C fibers and upregulation of transient receptor potential vanilloid (TRPV) 1 and TRPV4. Heat shock proteins are activated under heat stress and contribute to both epithelial barrier dysfunction and airway inflammation. Accordingly, the frequency and severity of allergic rhinitis and asthma have been increasing. Heat activates TRPV3 in keratinocytes, causing the secretion of inflammatory mediators and eventually pruritus. Exposure to air pollutants alters the expression of genes that control skin barrier integrity and triggers an immune response, increasing the incidence and prevalence of atopic dermatitis. There is evidence that extreme temperature, heavy rains and floods, air pollution, and wildfires increase atopic dermatitis flares. In this narrative review, focused on the last 3 years of literature, we explore the effects of global warming on respiratory and skin barrier and their clinical consequences.
Topics: Humans; Dermatitis, Atopic; Global Warming; Respiratory Rate; Rhinitis, Allergic; Inflammation
PubMed: 37689250
DOI: 10.1016/j.jaci.2023.09.001 -
Critical Care (London, England) Aug 2023The effects of awake prone position on the breathing pattern of hypoxemic patients need to be better understood. We conducted a crossover trial to assess the... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The effects of awake prone position on the breathing pattern of hypoxemic patients need to be better understood. We conducted a crossover trial to assess the physiological effects of awake prone position in patients with acute hypoxemic respiratory failure.
METHODS
Fifteen patients with acute hypoxemic respiratory failure and PaO/FiO < 200 mmHg underwent high-flow nasal oxygen for 1 h in supine position and 2 h in prone position, followed by a final 1-h supine phase. At the end of each study phase, the following parameters were measured: arterial blood gases, inspiratory effort (ΔP), transpulmonary driving pressure (ΔP), respiratory rate and esophageal pressure simplified pressure-time product per minute (sPTP) by esophageal manometry, tidal volume (V), end-expiratory lung impedance (EELI), lung compliance, airway resistance, time constant, dynamic strain (V/EELI) and pendelluft extent through electrical impedance tomography.
RESULTS
Compared to supine position, prone position increased PaO/FiO (median [Interquartile range] 104 mmHg [76-129] vs. 74 [69-93], p < 0.001), reduced respiratory rate (24 breaths/min [22-26] vs. 27 [26-30], p = 0.05) and increased ΔP (12 cmHO [11-13] vs. 9 [8-12], p = 0.04) with similar sPTP (131 [75-154] cmHO s min vs. 105 [81-129], p > 0.99) and ΔP (9 [7-11] cmHO vs. 8 [5-9], p = 0.17). Airway resistance and time constant were higher in prone vs. supine position (9 cmHO s arbitrary units [4-11] vs. 6 [4-9], p = 0.05; 0.53 s [0.32-61] vs. 0.40 [0.37-0.44], p = 0.03). Prone position increased EELI (3887 arbitrary units [3414-8547] vs. 1456 [959-2420], p = 0.002) and promoted V distribution towards dorsal lung regions without affecting V size and lung compliance: this generated lower dynamic strain (0.21 [0.16-0.24] vs. 0.38 [0.30-0.49], p = 0.004). The magnitude of pendelluft phenomenon was not different between study phases (55% [7-57] of V in prone vs. 31% [14-55] in supine position, p > 0.99).
CONCLUSIONS
Prone position improves oxygenation, increases EELI and promotes V distribution towards dependent lung regions without affecting V size, ΔP, lung compliance and pendelluft magnitude. Prone position reduces respiratory rate and increases ΔP because of positional increases in airway resistance and prolonged expiratory time. Because high ΔP is the main mechanistic determinant of self-inflicted lung injury, caution may be needed in using awake prone position in patients exhibiting intense ΔP. Clinical trail registeration: The study was registered on clinicaltrials.gov (NCT03095300) on March 29, 2017.
Topics: Humans; Prone Position; Respiration; Respiratory Insufficiency; Tidal Volume; Wakefulness; Cross-Over Studies
PubMed: 37592288
DOI: 10.1186/s13054-023-04600-9 -
Respiratory Physiology & Neurobiology Oct 2023Oscillometry has been around for almost 70 years, but there are still many unknowns. The test is performed during tidal breathing and is therefore free from... (Review)
Review
Oscillometry has been around for almost 70 years, but there are still many unknowns. The test is performed during tidal breathing and is therefore free from patient-dependent factors that could influence the results. The Forced Oscillation Technique (FOT), which requires minimal patient cooperation, is gaining ground, particularly with elderly patients and children. In pulmonology, it is a valuable tool for assessing obstructive conditions (with a distinction between central and peripheral obstruction) and restrictive disorders (intrapulmonary and extrapulmonary). Its sensitivity allows the assessment of bronchodilator and bronchoconstrictor responses. Different lung diseases show different patterns of changes in FOT, especially studied in asthma and chronic obstructive pulmonary disease. Because of these differences, many studies have analysed the usefulness of this technique in different areas of medicine. In this paper, the authors would like to present the basics of oscillometry with the areas of its most recent clinical applications.
Topics: Child; Humans; Aged; Airway Resistance; Oscillometry; Asthma; Pulmonary Disease, Chronic Obstructive; Respiratory Function Tests; Spirometry; Forced Expiratory Volume
PubMed: 37536553
DOI: 10.1016/j.resp.2023.104135 -
Respiratory Research Mar 2020The mechanism for symptomatic improvement after bronchial thermoplasty (BT) is unclear, since spirometry reveals little or no change. In this study, the effects of BT on...
BACKGROUND
The mechanism for symptomatic improvement after bronchial thermoplasty (BT) is unclear, since spirometry reveals little or no change. In this study, the effects of BT on airway resistance were examined using two independent techniques.
METHODS
Eighteen consecutive patients, with severe asthma (57.6 ± 14.2 years) were evaluated by spirometry and plethysmography at three time points: (i) baseline, (ii) left lung treated but right lung untreated and (iii) 6 weeks after both lungs were treated with BT. At each assessment, total and specific airway resistance (Raw, sRaw) were measured. High resolution CT scans were undertaken at the first two assessments, and measurements of lobar volume, airway volume and airway resistance were made. The Asthma Control Questionnaire (ACQ) was administered at each assessment.
RESULTS
The baseline ACQ score was 3.5 ± 0.9, and improved progressively to 1.8 ± 1.2 (p < 0.01). At baseline, severe airflow obstruction was observed, FEV1 44.8 ± 13.7% predicted, together with gas trapping, and elevated Raw at 342 ± 173%predicted. Following BT, significant improvements in Raw and sRaw were observed, as well as a reduction in Residual Volume, increase in Vital Capacity and no change in FEV1. The change in Raw correlated with the change in ACQ (r = 0.56, p < 0.05). CT scans demonstrated reduced airway volume at baseline, which correlated with the increased Raw determined by plethysmography (p = - 0.536, p = < 0.05). Following BT, the airway volume increased in the treated lung, and this was accompanied by a significant reduction in CT-determined local airway resistance.
CONCLUSION
Symptomatic improvement after BT is mediated by increased airway volume and reduced airway resistance.
Topics: Adult; Aged; Airway Resistance; Asthma; Bronchial Thermoplasty; Female; Humans; Male; Middle Aged; Plethysmography; Respiratory Function Tests
PubMed: 32228586
DOI: 10.1186/s12931-020-1330-5 -
Chest Sep 2022Patients with eosinophilic asthma often report poor symptomatic control and quality of life. Anti-IL-5 therapy, including anti-IL-5Rα (benralizumab), rapidly depletes... (Clinical Trial)
Clinical Trial
BACKGROUND
Patients with eosinophilic asthma often report poor symptomatic control and quality of life. Anti-IL-5 therapy, including anti-IL-5Rα (benralizumab), rapidly depletes eosinophils in the blood and airways and also reduces asthma exacerbations and improves quality of life scores. In patients with severe asthma, eosinophilic inflammation-driven airway mucus occlusions have been measured using thoracic x-ray CT imaging. Pulmonary Xe MRI ventilation defect percentage (VDP) also sensitively measures asthma airway dysfunction caused by airway hyperresponsiveness, remodeling, and luminal mucus occlusions. Using Xe MRI and CT imaging together, it is feasible to measure both airway luminal occlusions and airway ventilation in relationship to anti-IL-5 therapy to ascertain the direct impact of therapy-induced eosinophil depletion on airway function.
RESEARCH QUESTION
Does Xe MRI detect airway functional responses to eosinophil depletion after a single benralizumab dose and do airway mucus occlusions mediate this response?
STUDY DESIGN AND METHODS
MRI, eosinophil count, spirometry, oscillometry, Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire (AQLQ), and St. George's Respiratory Questionnaire were completed on day 0 and 28 days after a single 30-mg subcutaneous benralizumab dose. CT scan mucus plugs were scored on day 0, and MRI VDP was quantified on days 0 and 28.
RESULTS
Twenty-nine participants (27 with baseline CT imaging) completed day 0 and day 28 visits. On day 28 after a single benralizumab dose, significantly improved blood eosinophil counts, VDP, ACQ 6 scores, AQLQ scores (all P < .001), and peripheral airway resistance (P = .04) were found in all participants. On day 28, significantly improved VDP and ACQ 6 scores also were found in the subgroup of nine participants with five or more mucus plugs, but not in the subgroup (n = 18) with fewer than five mucus plugs. Based on univariate relationships for change in ACQ 6 score, multivariate models were generated and showed that day 0 VDP (P < .001) and day 0 CT scan mucus score (P < .001) were significant variables for change in ACQ 6 score on day 28 after benralizumab injection.
INTERPRETATION
Xe ventilation significantly improved in participants with uncontrolled asthma and in those with significant mucus plugging after a single dose of benralizumab.
TRIAL REGISTRY
ClinicalTrials.gov; No.: NCT03733535; URL: www.
CLINICALTRIALS
gov.
Topics: Airway Management; Airway Obstruction; Anti-Asthmatic Agents; Antibodies, Monoclonal, Humanized; Asthma; Eosinophils; Humans; Magnetic Resonance Imaging; Mucus; Pulmonary Eosinophilia; Quality of Life; Respiration
PubMed: 35283104
DOI: 10.1016/j.chest.2022.03.003