Background: Standard spirometry cannot identify the predominant mechanism underlying airflow obstruction in COPD, namely emphysema or airway disease. We aimed at validating a previously developed methodology to detect emphysema by mathematical analysis of the maximal expiratory flow-volume (MEFV) curve in standard spirometry.
Methods: From the COPDGene population we selected those 5930 subjects with MEFV curve and inspiratory-expiratory CT obtained on the same day. The MEFV curve descending limb was fit real-time using forced vital capacity (FVC), peak expiratory flow, and forced expiratory flows at 25, 50 and 75% of FVC to derive an emphysema severity index (ESI), expressed as a continuous positive numeric parameter ranging from 0 to 10. According to inspiratory CT percent lung attenuation area below - 950 HU we defined three emphysema severity subgroups (%LAA < 6, 6-14, ≥14). By co-registration of inspiratory-expiratory CT we quantified persistent (%pLDA) and functional (%fLDA) low-density areas as CT metrics of emphysema and airway disease, respectively.
Results: ESI differentiated CT emphysema severity subgroups increasing in parallel with GOLD stages (p < .001), but with high variability within each stage. ESI had significantly higher correlations (p < .001) with emphysema than with airway disease CT metrics, explaining 67% of %pLDA variability. Conversely, standard spirometric variables (FEV, FEV/FVC) had significantly lower correlations than ESI with emphysema CT metrics and did not differentiate between emphysema and airways CT metrics.
Conclusions: ESI adds to standard spirometry the power to discriminate whether emphysema is the predominant mechanism of airway obstruction. ESI methodology has been validated in the large multiethnic population of smokers of the COPDGene study and therefore it could be applied for clinical and research purposes in the general population of smokers, using a readily available online website.
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http://dx.doi.org/10.1186/s12931-020-01366-4 | DOI Listing |
Chest
January 2025
Division of Respirology, Critical Care and Sleep Medicine, Department of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
Alpha-1-Antitrypsin (A1AT) deficiency is a common hereditary disorder associated with increased risk of developing chronic obstructive pulmonary disease (COPD). Many individuals with severe A1AT deficiency go undiagnosed, or are diagnosed late, and fail to benefit from disease-specific counseling and modifying care. Since the 2012 Canadian Thoracic Society (CTS) A1AT deficiency clinical practice guideline, new approaches to optimal diagnosis using modern genetic testing and studies of A1AT augmentation therapy have been published.
View Article and Find Full Text PDFPLoS Genet
January 2025
Mater Research Institute-University of Queensland, Translational Research Institute, Woolloongabba, Brisbane, Australia.
Adaptation to existence outside the womb is a key event in the life of a mammal. The absence of macrophages in rats with a homozygous mutation in the colony-stimulating factor 1 receptor (Csf1r) gene (Csf1rko) severely compromises pre-weaning somatic growth and maturation of organ function. Transfer of wild-type bone marrow cells (BMT) at weaning rescues tissue macrophage populations permitting normal development and long-term survival.
View Article and Find Full Text PDFCureus
December 2024
Pediatric Anesthesiology, University of Arkansas for Medical Sciences, Little Rock, USA.
Subcutaneous emphysema results from air or gas being forced into the fascial spaces of subcutaneous tissue. Once the air or gas has entered the fascial spaces, it travels along connective tissue causing a mass effect and swelling. This rare complication usually presents with mild severity during the immediate postoperative period following surgical procedures of the head or neck regions and self-resolves with conservative treatment.
View Article and Find Full Text PDFJ Thorac Dis
December 2024
Guangdong Lung Cancer Institute, Guangdong Provincial Key Laboratory of Translational Medicine in Lung Cancer, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China.
Background: Postoperative air leak is the most common complication after pulmonary resection. "Provocative clamping" was first described in 1992 in the context of guiding chest tube removal despite persistent air leak. However, early provocative clamping after pulmonary resection has not been evaluated.
View Article and Find Full Text PDFCureus
December 2024
Division of Respiratory Medicine, Universiti Malaya Medical Centre, Kuala Lumpur, MYS.
Subcutaneous emphysema is a well-known complication of chest tube insertion that can become life-threatening. Severe cases often progress rapidly, necessitating prompt intervention to prevent complications such as airway obstruction and respiratory failure. We report the case of a 57-year-old man who developed extensive subcutaneous emphysema following chest tube insertion.
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