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Seminars in Respiratory and Critical... Oct 2023While static mechanical forces govern resting lung volumes, dynamic forces determine tidal breathing, airflow, and changes in airflow and lung volume during normal and...
While static mechanical forces govern resting lung volumes, dynamic forces determine tidal breathing, airflow, and changes in airflow and lung volume during normal and abnormal breathing. This section will examine the mechanisms, measurement methodology, and interpretation of the dynamic changes in airflow and lung volume that occur in health and disease. We will first examine how the total work of breathing can be described by the parameters of the equation of motion, which determine the pressure required to move air into and out of the lung. This will include a detailed description of airflow characteristics and airway resistance. Next, we will review the changes in pressure and flow that determine maximal forced inspiration and expiration, which result in the maximal flow-volume loop and the clinically important forced expired volume in 1 second. We will also assess the mechanisms and interpretation of bronchodilator responsiveness, dynamic hyperinflation, and airways hyperresponsiveness.
Topics: Humans; Lung; Bronchodilator Agents
PubMed: 37429331
DOI: 10.1055/s-0043-1770058 -
Presse Medicale (Paris, France : 1983) Sep 2023Bronchiectasis is a final common pathway of a wide variety of underlying conditions including infectious, autoimmune, allergic, genetic and inflammatory conditions.... (Review)
Review
Bronchiectasis is a final common pathway of a wide variety of underlying conditions including infectious, autoimmune, allergic, genetic and inflammatory conditions. Patients experience a chronic disease with variable clinical symptoms and course, but most experience cough, sputum production and recurrent exacerbations. Symptoms of bronchiectasis lead to poor quality of life and exacerbations are the major driver of morbidity and mortality. Patients are often chronically infected with bacteria with the most common being Pseudomonas aeruginosa and Haemophilus influenzae. Treatment of bronchiectasis includes standardised testing to identify the underlying cause with targeted treatment if immune deficiency, allergic bronchopulmonary aspergillosis or non-tuberculous mycobacterial infection, for example, are identified. Airway clearance is the mainstay of therapy for patients with symptoms of cough and sputum production. Frequently exacerbating patients may benefit from long term antibiotic or mucoactive therapies. Bronchiectasis is a heterogeneous disease and increasingly precision medicine approaches are advocated to target treatments most appropriately and to limit the emergence of antimicrobial resistance.
Topics: Bronchiectasis; Humans; Anti-Bacterial Agents; Quality of Life
PubMed: 37778637
DOI: 10.1016/j.lpm.2023.104174 -
Cureus Nov 2023Nasal congestion is a common issue stemming from various factors such as allergies and anatomical variations. Allergic rhinitis frequently leads to nasal congestion. The... (Review)
Review
Nasal congestion is a common issue stemming from various factors such as allergies and anatomical variations. Allergic rhinitis frequently leads to nasal congestion. The pathophysiology involves inflammation, swelling, and mucus production in the nasal mucosa. Multiple treatments are available, including oral phenylephrine, an over-the-counter or prescription option. However, the effectiveness and safety of phenylephrine have been subjects of debate. This systematic review aims to provide an updated perspective on the efficacy of oral phenylephrine versus placebo in addressing nasal congestion in adults. We conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, a systematic review involving searches on PubMed, Cochrane, and Scopus databases. Inclusion/exclusion criteria were defined to identify high-quality studies. The focus was on randomized controlled trials (RCTs) and case-control studies published in English between 1998 and 2023, involving adult populations. The interventions compared oral phenylephrine with placebo or standard care, with outcomes centering on changes in nasal congestion symptoms and nasal airway resistance. We identified four articles that met the criteria. These studies exhibited varied designs and populations. The findings consistently indicated that phenylephrine was not more effective than a placebo in relieving nasal congestion. This systematic review demonstrates that oral phenylephrine did not offer substantial relief from nasal congestion compared to a placebo in adults. The studies featured diverse designs, yet the prevailing conclusion was that phenylephrine's efficacy was limited. Safety assessments showed no life-threatening adverse events, with common side effects including headaches and mild discomfort. In summary, this systematic review indicates that oral phenylephrine is not significantly more effective than a placebo in alleviating nasal congestion in adults. Clinicians should explore alternative treatment options, considering the review's limitations. Additional research may be needed to clarify the role of oral phenylephrine in managing nasal congestion.
PubMed: 38125218
DOI: 10.7759/cureus.49074 -
Seminars in Respiratory and Critical... Oct 2023A fundamental task of the respiratory system is to operate as a mechanical gas pump ensuring that fresh air gets in close contact with the blood circulating through the...
A fundamental task of the respiratory system is to operate as a mechanical gas pump ensuring that fresh air gets in close contact with the blood circulating through the lung capillaries to achieve O and CO exchange. To ventilate the lungs, the respiratory muscles provide the pressure required to overcome the viscoelastic mechanical load of the respiratory system. From a mechanical viewpoint, the most relevant respiratory system properties are the resistance of the airways ( ), and the compliance of the lung tissue ( ) and chest wall ( ). Both airflow and lung volume changes in spontaneous breathing and mechanical ventilation are determined by applying the fundamental mechanical laws to the relationships between the pressures inside the respiratory system (at the airway opening, alveolar, pleural, and muscular) and , , and . These relationships also are the basis of the different methods available to measure respiratory mechanics during spontaneous and artificial ventilation. Whereas a simple mechanical model ( , , and ) describes the basic understanding of ventilation mechanics, more complex concepts (nonlinearity, inhomogeneous ventilation, or viscoelasticity) should be employed to better describe and measure ventilation mechanics in patients.
PubMed: 37467769
DOI: 10.1055/s-0043-1770340