Positive end-expiratory pressure attenuates hemodynamic effects induced by an overload of inspiratory muscles in patients with COPD

Analysis of the positive expiratory pressure valves of coupled oronasal mask

Positive expiratory pressure (PEP) is a technique used in respiratory physiotherapy to treat diseases related to the respiratory system through spontaneous breathing. This equipment consists of an oronasal mask coupled to a T connector with a unidirectional valve. Studies that evaluate whether the pressure level in the one-way valve corresponds to the actual pressure level provided are scarce in the scientific literature. In order to investigate the failures, bench tests were carried out on the spring-loaded valves, using a U-tube manometer. This pressure was exerted on the valve using a syringe that generated air flow inside the U-tube, allowing analysis numerical value of the measured pressure and the specified values of the valve, thus verifying the disparity of these measured values in relation to the PEP values operated by valves (0 to 20 cmH2O) from the three manufacturers under study. PEPs generated by spring-loaded valves from all three manufacturers were higher than pressures in the range of 2.5 to 20 cmH2O, with significant differences between manufacturers. This bench study showed inaccurate operation of all spring-loaded PEP valves of the three manufactures. The results obtained and the performance of the valves require a reevaluation of manufacturing procedures to preserve product quality and efficacy in clinical application.

Mapping the global research landscape and hotspot of exercise therapy and chronic obstructive pulmonary disease: A bibliometric study based on the web of science database from 2011 to 2020

Background: The application of exercise therapy (ET) in chronic obstructive pulmonary disease (COPD) is generating increasing clinical efficacy and social-economic value. In this study, research trends, evolutionary processes and hot topics in this field are detailed, as well as predictions of future development directions.

Methods: Search for literature in the field of COPD and ET and analyze data to generate knowledge graphs using VOSiewer and CiteSpace software. The time frame for the search was from 2011 to January 2021. Then we extracted full-text key information (such as title, journal category, publication date, author, country and institution, abstract, and keyword) and obtained the co-citation analysis. Use hierarchal clustering analysis software developed by VOSviewer to map common citations, and use Citespace software to plot trend networks.

Results: The United States topped the list with 27.91% of the number of articles posted, followed by the UK at 25.44%. Imperial College London was the highest number of article publications in institutions, followed by Maastricht University and the University of Toronto. The Royal Brompton Harefield NHS Foundation Trust was one of many research institutions and currently holds the highest average citations per item (ACI) value, followed by Imperial College London and the University of Leuven. Judging from the number of publications related to ET and COPD, it is mainly published in cell biology, respiratory pulmonary diseases, and rehabilitation experiments study medicine. The European Respiration Journal is the most widely published in this field, followed by the International Journal of Chronic Obstructive Pulmonary Disease and Respiratory Medicine.

Conclusion: COPD combined with ET is widely used in clinical practice and is on the rise. A distinctive feature of the field is multidisciplinary integration. Rehabilitation research for COPD involves multidisciplinary collaboration, tissue engineering, and molecular biology mechanism studies to help patients remodel healthy breathing. Multidisciplinary rehabilitation measures provide a solid foundation for advancing clinical efficacy in the field of COPD.

Tolerable Maximum Positive End Expiratory Pressure in Mechanically Ventilated Patients and Its Impact on Blood Flow across Cardiac Valves: Index Case Report of a Physiology Study

<b><i>Introduction:</i></b> Positive end expiratory pressure (PEEP) exerts variable effects on preload, pulmonary vascular flow, and afterload. Lung recruitment with gradual increase in PEEP improves oxygenation, but it may have variable cardiovascular effects. <b><i>Method:</i></b> A patient with respiratory failure from tetanus was recruited after informed consent. The sedated and paralyzed patient was subjected to sequential increase in PEEP with measurement of hemodynamics, ventilator parameters, and echocardiographic parameters (Doppler flow across tricuspid, pulmonic, and mitral valves at end inspiration and end expiration, in addition to blood volume flowing across RVOT and mitral valve). <b><i>Results:</i></b> We observed an initial rise in pulmonic and mitral blood flows, followed by a decline back to baseline around PEEP of 20, with an eventual decline associated with a drop in mean MAP &#x3c;60 torr above PEEP of 29. Similar effects were also observed on blood volume flowing across RVOT and mitral valve. PEEP of 5 was associated with best blood flow parameters. <b><i>Conclusion:</i></b> Although systemic pressure was maintained at PEEP of 29, pulmonary blood flow started to be compromised at PEEP of 20. Best pulmonary perfusion parameters were achieved at PEEP of 5.