Introduction: Oesophagectomy is a major surgical procedure, associated with high rates of postoperative cardiopulmonary morbidity, that is in part due to the frequent requirement for periods of intraoperative one-lung ventilation (OLV). The current pilot study aims to investigate variation in exhaled NO levels during oesophagectomy with emphasis on the response to OLV and correlation to physiological variables and clinical outcomes.
Methods: Breath-to-breath concentrations of NO were analysed in patients undergoing oesophagectomy at various stages of two-lung ventilation. Furthermore, we also analysed the effects of OLV both in the selectively ventilated and collapsed lungs.
Results: Twenty-four patients were recruited to the study (17 male, 60.2 ± 12.8 years). Regarding two-lung ventilation, the baseline levels of NO (2.9 ppb), tended to increase after re-inflation of the collapsed lung (3.5 ppb, P = 0. 888) and decreased at 2 h (2.1 ppb, P = 0.022) and 12 h (2.2 ppb, P = 0.733) postoperatively. Compared to baseline, selective measurements of NO at the end of OLV demonstrated a significant reduction of NO levels in the ventilated lung (1.6 versus 3.1 ppb, P = 0.028), whereas re-inflation of the collapsed lung revealed higher levels of NO (3.4 versus 2.7 ppb, P = 0.657). Exhaled NO correlated significantly with systolic blood pressure and lactate (P < 0.007). Exhaled NO levels tended to be higher at all perioperative time points in patients who developed postoperative respiratory complications (P > 0.05).
Conclusion: This study highlights effects of oesophagectomy and OLV on exhaled concentrations of NO. The observed variations may be related to differential ventilation during OLV altering the complex balance between synthesis and consumption of NO as well as local and generalised tissue injury associated with this surgery. Findings should prompt further larger studies to establish the relationship between exhaled NO and lung injury both during and after oesophagectomy and one-lung ventilation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1088/1752-7163/aa9387 | DOI Listing |
PLoS One
January 2025
Transfers, Interfaces and Processes, Université libre de Bruxelles, Brussels, Belgium.
In this paper, we present a new computational framework for the simulation of airway resistance, the fraction of exhaled nitric oxide, and the diffusion capacity for nitric oxide in healthy and unhealthy lungs. Our approach is firstly based on a realistic representation of the geometry of healthy lungs as a function of body mass, which compares well with data from the literature, particularly in terms of lung volume and alveolar surface area. The original way in which this geometry is created, including an individual definition of the airways in the first seven generations of the lungs, makes it possible to consider the heterogeneous nature of the lungs in terms of perfusion and ventilation.
View Article and Find Full Text PDFAnesthesiology
January 2025
Department of Critical Care, Melbourne Medicine School, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria, Australia.
Background: Multi-compartment computer models of heterogeneity in alveolar ventilation-perfusion ratios (VA/Q scatter) across the lung explain the significant alveolar-arterial (A-a) partial pressure gradients and associated alveolar dead-space fractions (VDA/VA) seen in anesthetized patients for both carbon dioxide and for anesthetic gases of different blood solubilities. However, the accuracy of a simpler two-compartment model of VA/Q scatter to do this has not been tested or compared to calculations from the traditional Riley model with "ideal", unventilated (shunt) and unperfused (deadspace) compartments.
Methods: Measurements of gas partial pressures in inspired and expired gas and arterial and mixed venous blood from 29 patients undergoing inhalational general anesthesia for cardiac surgery was used to compare the accuracy of two simple models of VA/Q scatter and lung gas exchange in predicting measured alveolar and arterial partial pressure differences, and associated alveolar dead-space calculations for the modern anesthetic gases isoflurane, sevoflurane and desflurane.
Br J Anaesth
February 2025
CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; Intensive Care Unit, Hospital Universitario La Princesa, Madrid, Spain.
Despite the maturity and sophistication of anaesthesia workstations, improvements in our understanding of intraoperative mechanical ventilation, and use of less invasive surgical techniques, postoperative pulmonary complications (PPCs) are still a common problem in surgical patients of all ages. PPCs are associated with a higher incidence of perioperative morbidity and mortality, longer hospital stays, and higher healthcare costs. PPCs are strongly associated with anaesthesia-induced atelectasis, which predisposes to lung damage when partially collapsed lungs are subjected to mechanical ventilation.
View Article and Find Full Text PDFPediatr Pulmonol
January 2025
Department of Clinical Research, Faculty of Health sciences, University of Southern Denmark, Odense, Denmark.
Introduction: A main feature of CDH is lung hypoplasia and the related presentation of pulmonary hypertension and cardiac dysfunction. Multiple factors influence pulmonary status after CDH: degree of hypoplasia, ventilator-induced injury, altered growth and development of pulmonary structures, reduced diaphragm function and chest wall abnormalities. The evolution of pulmonary sequela in this population is still unclear.
View Article and Find Full Text PDFEur J Med Res
January 2025
Department of Thoracic Medicine, Chang Gung Memorial Hospital, Linkou Branch, No. 5, Fu-Shing St., GuiShan, Taoyuan, Taiwan.
Background: This study compared the ventilatory variables and computed tomography (CT) features of patients with coronavirus disease 2019 (COVID-19) versus those of patients with pulmonary non-COVID-19-related acute respiratory distress syndrome (ARDS) during the early phase of ARDS.
Methods: This prospective, observational cohort study of ARDS patients in Taiwan was performed between February 2017 and June 2018 as well as between October 2020 and January 2024. Analysis was performed on clinical characteristics, including consecutive ventilatory variables during the first week after ARDS diagnosis.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!