Rationale: There are several approaches to select the optimal positive end-expiratory pressure (PEEP), resulting in different PEEP levels. The impact of different PEEP settings may extend beyond respiratory mechanics, affecting pulmonary hemodynamics.
Objectives: To compare PEEP levels obtained with three titration strategies-(i) highest respiratory system compliance (C), (ii) electrical impedance tomography (EIT) crossing point; (iii) positive end-expiratory transpulmonary pressure (P)-in terms of regional respiratory mechanics and pulmonary hemodynamics.
Methods: Experimental studies in two porcine models of acute lung injury: (I) bilateral injury induced in both lungs, generating a highly recruitable model (n = 37); (II) asymmetrical injury, generating a poorly recruitable model (n = 13). In all experiments, a decremental PEEP titration was performed monitoring P, EIT (collapse, overdistention, and regional ventilation), respiratory mechanics, and pulmonary and systemic hemodynamics.
Measurements And Main Results: PEEP titration methods resulted in different levels of median optimal PEEP in bilateral lung injury: 14(12-14) cmHO for C, 11(10-12) cmHO for EIT, and 8(8-10) cmHO for P, p < 0.001. Differences were less pronounced in asymmetrical lung injury. PEEP had a quadratic U-shape relationship with pulmonary artery pressure (R = 0.94, p < 0.001), right-ventricular systolic transmural pressure, and pulmonary vascular resistance. Minimum values of pulmonary vascular resistance were found around individualized PEEP, when ventilation distribution and pulmonary circulation were simultaneously optimized.
Conclusions: In porcine models of acute lung injury with variable lung recruitability, both low and high levels of PEEP can impair pulmonary hemodynamics. Optimized ventilation and hemodynamics can be obtained simultaneously at PEEP levels individualized based on respiratory mechanics, especially by EIT and esophageal pressure.
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http://dx.doi.org/10.1186/s13054-025-05325-7 | DOI Listing |
Acta Anaesthesiol Scand
April 2025
Department of Anesthesiology and Intensive Care Medicine, Institute of Clinical Sciences at the Sahlgrenska Academy, University of Gothenburg and Section for Cardiothoracic Anesthesia and Intensive Care, Sahlgrenska University Hospital, Gothenburg, Sweden.
Background: Acute kidney injury (AKI) is a serious complication after lung transplantation, but the reported incidence varies in the literature. No data on AKI have been published from the Swedish lung transplantation program.
Methods: The aim of our study was to investigate the incidence, perioperative risk factors, and effects of early postoperative acute kidney injury (Kidney Disease Improving Global Outcomes [KDIGO] criteria) after lung transplantation.
Front Immunol
March 2025
Department of Laboratory Medicine, Jiangsu Province Engineering Research Center for Precise Diagnosis and Treatment of Inflammatory Diseases, The Affiliated Hospital of Jiangsu University, Zhenjiang, China.
Macrophage metabolic reprogramming refers to the process by which macrophages adjust their physiological pathways to meet survival and functional demands in different immune microenvironments. This involves a range of metabolic pathways, including glycolysis, the tricarboxylic acid cycle, oxidative phosphorylation, fatty acid oxidation, and cholesterol transport. By modulating the expression and activity of key enzymes and molecules within these pathways, macrophages can make the transition between pro- and anti-inflammatory phenotypes, thereby linking metabolic reprogramming to inflammatory responses and the progression of several diseases, such as atherosclerosis, inflammatory bowel disease (IBD), and acute lung injury (ALI).
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March 2025
Duke Ex Vivo Organ Laboratory, Department of Surgery, Duke University Medical Center, Durham, NC, United States.
Ex-vivo lung perfusion (EVLP) has emerged as a transformative technique in lung transplantation, offering a solution for evaluating and rehabilitating donor lungs that would otherwise be deemed unsuitable. This review article examines the significant advancements in EVLP technology and its application in clinical practice. We discuss the criteria for selection and rehabilitation of donor lungs, emphasizing the use of EVLP for lungs with compromised function due to factors like prolonged ischemic time and donor smoking history.
View Article and Find Full Text PDFFront Med (Lausanne)
February 2025
Integrated Medical Center, Tianjin University, Tianjin, China.
Respiratory diseases rank among the foremost causes of mortality and disability globally, with long-term exposure to environmental pollutants playing a critical role in their onset and progression. Despite this, the underlying mechanisms and effective targeted treatments for these disorders remain poorly understood, highlighting an urgent need for focused research. Cell death, a programmed cellular response to external harmful stimuli, including ferroptosis-a recently identified form of iron-dependent programmed cell death-emerges as a pivotal process.
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