Seminars in Respiratory and Critical Care Medicine Seminars in Respiratory and Critical Care Medicine RSS feedThis is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Updated Hemodynamic Definition and Classification of Pulmonary Hypertension
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770115Pulmonary hypertension (PH) is a pathophysiological manifestation of a heterogeneous group of diseases characterized by abnormally elevated pulmonary arterial pressures diagnosed on right heart catheterization. The 2022 European Society of Cardiology (ESC) and European Respiratory Society (ERS) Guidelines for the diagnosis and treatment of PH provides a new hemodynamic definition to define PH by lowering the threshold of the mean pulmonary artery pressure (mPAP) to 20 mm Hg. Precapillary PH is thus now defined as a mPAP >20 mm Hg together with a normal pulmonary ...
Source: Seminars in Respiratory and Critical Care Medicine - August 18, 2023 Category: Respiratory Medicine Authors: Lechartier, Benoit Kularatne, Mithum Ja ïs, Xavier Humbert, Marc Montani, David Tags: Review Article Source Type: research

Blood Gas Transport: Implications for O2 and CO2 Exchange in Lungs and Tissues
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1771161The well-known ways in which O2 and CO2 (and other gases) are carried in the blood were presented in the preceding chapter. However, what the many available texts about O2 and CO2 transport do not emphasize is why knowing how gases are carried in blood matters, and this second, companion, article specifically addresses that critical aspect of gas exchange physiology. During gas exchange, both at the lungs and in the peripheral tissues, it is the shapes and the slopes of the O2 and CO2 binding curves that explain almost all of the behaviors of each gas and the quantitati...
Source: Seminars in Respiratory and Critical Care Medicine - August 11, 2023 Category: Respiratory Medicine Authors: Wagner, Peter D. Tags: Review Article Source Type: research

Blood Gas Transport: Carriage of Oxygen and Carbon Dioxide in Blood
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1771160The ways in which oxygen (O2) and carbon dioxide (CO2) are carried in the blood are well known and well understood, with a plethora of textbooks, both general and lung specific, all presenting the topic in a very similar manner. This first of two companion chapters similarly summarizes this information. First, carriage of gases by physical solution is described, followed by discussion of O2, carbon monoxide, and CO2 transport in that order. However, what available texts have not emphasized is why knowing how gases are carried in blood matters, and the second, companion,...
Source: Seminars in Respiratory and Critical Care Medicine - August 11, 2023 Category: Respiratory Medicine Authors: Wagner, Peter D. Tags: Review Article Source Type: research

Monographic Issue on Pulmonary Hypertension: Medical and Interventional Treatment for Chronic Thromboembolic Pulmonary Hypertension
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770122Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. The reasons why clots do not resorb are incompletely understood, but the result is partial or complete fibrothrombotic obstruction of pulmonary arteries. A secondary microvasculopathy aggravates the pulmonary hypertension (PH) as a consequence of high flow and shear stress in the nonoccluded arteries. The treatment of CTEPH has long been purely surgical, but many patients were inoperable because of inaccessible lesions or severe comorbidities. Alternatives were deve...
Source: Seminars in Respiratory and Critical Care Medicine - August 11, 2023 Category: Respiratory Medicine Authors: Delcroix, Marion Belge, Catharina Maleux, Geert Godinas, Laurent Tags: Review Article Source Type: research

Tissue Perfusion and Diffusion and Cellular Respiration: Transport and Utilization of Oxygen
This article provides an overview of the journey of inspired oxygen after its uptake across the alveolar–capillary interface, and the interplay among tissue perfusion, diffusion, and cellular respiration in the transport and utilization of oxygen. The critical interactions between oxygen and its facilitative carriers (hemoglobin in red blood cells and myoglobin in muscle cells), and with other respiratory and vasoactive molecules (carbon dioxide, nitric oxide, and carbon monoxide), are emphasized to illustrate how this versatile system dynamically optimizes regional convective transport and diffusive gas exchange. The ra...
Source: Seminars in Respiratory and Critical Care Medicine - August 4, 2023 Category: Respiratory Medicine Authors: Hsia, Connie C. W. Tags: Review Article Source Type: research

Heart –Lung Interactions
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770062The pulmonary and cardiovascular systems have profound effects on each other. Overall cardiac function is determined by heart rate, preload, contractility, and afterload. Changes in lung volume, intrathoracic pressure (ITP), and hypoxemia can simultaneously change all of these four hemodynamic determinants for both ventricles and can even lead to cardiovascular collapse. Intubation using sedation depresses vasomotor tone. Also, the interdependence between right and left ventricles can be affected by lung volume-induced changes in pulmonary vascular resistance and the ri...
Source: Seminars in Respiratory and Critical Care Medicine - August 4, 2023 Category: Respiratory Medicine Authors: Hamahata, Natsumi Pinsky, Michael R. Tags: Review Article Source Type: research

The Right Ventricle in Pulmonary Hypertension
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770117The right ventricle plays a pivotal role in patients with pulmonary hypertension (PH). Its adaptation to pressure overload determines a patient's functional status as well as survival. In a healthy situation, the right ventricle is part of a low pressure, high compliance system. It is built to accommodate changes in preload, but not very well suited for dealing with pressure overload. In PH, right ventricular (RV) contractility must increase to maintain cardiac output. In other words, the balance between the degree of RV contractility and afterload determines stroke vol...
Source: Seminars in Respiratory and Critical Care Medicine - July 24, 2023 Category: Respiratory Medicine Authors: Wessels, Jeroen N. Celant, Lucas R. de Man, Frances S. Noordegraaf, Anton Vonk Tags: Review Article Source Type: research

The Diagnostic Approach to Pulmonary Hypertension
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770116The clinical presentation of pulmonary hypertension (PH) is nonspecific, resulting in significant delays in its detection. In the majority of cases, PH is a marker of the severity of other cardiopulmonary diseases. Differential diagnosis aimed at the early identification of patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) who do require specific and complex therapies is as important as PH detection itself. Despite all efforts aimed at the noninvasive assessment of pulmonary arterial pressure, the formal confir...
Source: Seminars in Respiratory and Critical Care Medicine - July 24, 2023 Category: Respiratory Medicine Authors: Torbicki, Adam Kurzyna, Marcin Tags: Review Article Source Type: research

Perioperative Management in Pulmonary Endarterectomy
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770123Pulmonary endarterectomy (PEA) is the treatment of choice for patients with chronic thromboembolic pulmonary hypertension (PH), provided lesions are proximal enough in the pulmonary vasculature to be surgically accessible and the patient is well enough to benefit from the operation in the longer term. It is a major cardiothoracic operation, requiring specialized techniques and instruments developed over several decades to access and dissect out the intra-arterial fibrotic material. While in-hospital operative mortality is low (<5%), particularly in high-volume center...
Source: Seminars in Respiratory and Critical Care Medicine - July 24, 2023 Category: Respiratory Medicine Authors: Jenkins, David P. Martinez, Guillermo Salaunkey, Kiran Reddy, S. Ashwin Pepke-Zaba, Joanna Tags: Review Article Source Type: research

Management of Pulmonary Hypertension Associated with Chronic Lung Disease
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770121Pulmonary hypertension (PH) is a common complication of chronic lung diseases, particularly in chronic obstructive pulmonary disease (COPD) and interstitial lung diseases (ILD) and especially in advanced disease. It is associated with greater mortality and worse clinical course. Given the high prevalence of some respiratory disorders and because lung parenchymal abnormalities might be present in other PH groups, the appropriate diagnosis of PH associated with respiratory disease represents a clinical challenge. Patients with chronic lung disease presenting symptoms that...
Source: Seminars in Respiratory and Critical Care Medicine - July 24, 2023 Category: Respiratory Medicine Authors: Blanco, Isabel Hern ández-González, Fernanda Garc ía, Agustín Torres-Castro, Rodrigo Barber à, Joan A. Tags: Review Article Source Type: research

Ventilation Mechanics
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770340A 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 O2 and CO2 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 (R aw), and the compliance of the lung tissue (C L) and chest wall (C CW). Both ai...
Source: Seminars in Respiratory and Critical Care Medicine - July 19, 2023 Category: Respiratory Medicine Authors: Farr é, Ramon Navajas, Daniel Tags: Review Article Source Type: research

Pulmonary Function in Human Spaceflight
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770064Human spaceflight is entering a time of markedly increased activity fueled by collaboration between governmental and private industry entities. This has resulted in successful mission planning for destinations in low Earth orbit, lunar destinations (Artemis program, Gateway station) as well as exploration to Mars. The planned construction of additional commercial space stations will ensure continued low Earth orbit presence and destinations for science but also commercial spaceflight participants. The human in the journey to space is exposed to numerous environmental ch...
Source: Seminars in Respiratory and Critical Care Medicine - July 17, 2023 Category: Respiratory Medicine Authors: Stepanek, Jan Blue, Rebecca S. Connolly, Desmond Tags: Review Article Source Type: research

End-of-Life and Palliative Care Issues for Patients Living with Pulmonary Arterial Hypertension: Barriers and Opportunities
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770124Pulmonary arterial hypertension (PAH) is a progressive, incurable disease that results in significant symptom burden, health care utilization, and eventually premature death. Despite the advancements made in treatment and management strategies, survival has remained poor. End-of-life care is a challenging issue in management of PAH, especially when patients are in younger age group. End-of-life care revolves around symptom palliation and reducing psychosocial disease burden for a dying patient and entails advanced care planning that are often challenging. Thus, support ...
Source: Seminars in Respiratory and Critical Care Medicine - July 17, 2023 Category: Respiratory Medicine Authors: Ali, Hyeon-Ju Sahay, Sandeep Tags: Review Article Source Type: research

Control of Breathing
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770342Substantial advances have been made recently into the discovery of fundamental mechanisms underlying the neural control of breathing and even some inroads into translating these findings to treating breathing disorders. Here, we review several of these advances, starting with an appreciation of the importance of V̇A:V̇CO2:PaCO2 relationships, then summarizing our current understanding of the mechanisms and neural pathways for central rhythm generation, chemoreception, exercise hyperpnea, plasticity, and sleep-state effects on ventilatory control. We apply these fundam...
Source: Seminars in Respiratory and Critical Care Medicine - July 11, 2023 Category: Respiratory Medicine Authors: Dempsey, Jerome A. Welch, Joseph F. Tags: Review Article Source Type: research

Exercise Physiology and Cardiopulmonary Exercise Testing
Semin Respir Crit Care Med DOI: 10.1055/s-0043-1770362Aerobic, or endurance, exercise is an energy requiring process supported primarily by energy from oxidative adenosine triphosphate synthesis. The consumption of oxygen and production of carbon dioxide in muscle cells are dynamically linked to oxygen uptake (V̇O2) and carbon dioxide output (V̇CO2) at the lung by integrated functions of cardiovascular, pulmonary, hematologic, and neurohumoral systems. Maximum oxygen uptake (V̇O2max) is the standard expression of aerobic capacity and a predictor of outcomes in diverse populations. While commonly limited in young fit ind...
Source: Seminars in Respiratory and Critical Care Medicine - July 10, 2023 Category: Respiratory Medicine Authors: Sietsema, Kathy E. Rossiter, Harry B. Tags: Review Article Source Type: research