1
|
Pisi R, Aiello M, Calzetta L, Frizzelli A, Alfieri V, Bertorelli G, Pisi G, Chetta A. Ventilation Heterogeneity in Asthma and COPD: The Value of the Poorly Communicating Fraction as the Ratio of Total Lung Capacity to Alveolar Volume. Respiration 2021; 100:404-410. [PMID: 33784705 DOI: 10.1159/000513954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/18/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The ventilation heterogeneity (VH) is reliably assessed by the multiple-breath nitrogen washout (MBNW), which provides indices of conductive (Scond) and acinar (Sacin) VH as well as the lung clearance index (LCI), an index of global VH. VH can be alternatively measured by the poorly communicating fraction (PCF), that is, the ratio of total lung capacity by body plethysmography to alveolar volume from the single-breath lung diffusing capacity measurement. OBJECTIVES Our objective was to assess VH by PCF and MBNW in patients with asthma and with COPD and to compare PCF and MBNW parameters in both patient groups. METHOD We studied 35 asthmatic patients and 45 patients with COPD. Each patient performed spirometry, body plethysmography, diffusing capacity, and MBNW test. RESULTS Compared to COPD patients, asthmatics showed a significantly lesser degree of airflow obstruction and lung hyperinflation. In asthmatic patients, both PCF and LCI and Sacin values were significantly lower than the corresponding ones of COPD patients. In addition, in both patient groups, PCF showed a positive correlation with LCI (p < 0.05) and Sacin (p < 0.05), but not with Scond. Lastly, COPD patients with PCF >30% were highly likely to have a value ≥2 of the mMRC dyspnea scale. CONCLUSIONS These results showed that PCF, a readily measure derived from routine pulmonary function testing, can provide a comprehensive measure of both global and acinar VH in asthma and in COPD patients and can be considered as a comparable tool to the well-established MBNW technique.
Collapse
Affiliation(s)
- Roberta Pisi
- Respiratory Disease and Lung Function Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Marina Aiello
- Respiratory Disease and Lung Function Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Luigino Calzetta
- Respiratory Disease and Lung Function Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Annalisa Frizzelli
- Respiratory Disease and Lung Function Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Veronica Alfieri
- Respiratory Disease and Lung Function Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Giuseppina Bertorelli
- Respiratory Disease and Lung Function Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Giovanna Pisi
- Cystic Fibrosis Unit, Department of Pediatrics, University Hospital of Parma, Parma, Italy
| | - Alfredo Chetta
- Respiratory Disease and Lung Function Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| |
Collapse
|
2
|
Davis C, Sheikh K, Pike D, Svenningsen S, McCormack DG, O'Donnell D, Neder JA, Parraga G. Ventilation Heterogeneity in Never-smokers and COPD:: Comparison of Pulmonary Functional Magnetic Resonance Imaging with the Poorly Communicating Fraction Derived From Plethysmography. Acad Radiol 2016; 23:398-405. [PMID: 26774739 DOI: 10.1016/j.acra.2015.10.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/22/2015] [Accepted: 10/04/2015] [Indexed: 11/29/2022]
Abstract
RATIONALE AND OBJECTIVES Pulmonary functional magnetic resonance imaging provides a way to quantify ventilation and its heterogeneity-a hallmark finding in chronic obstructive pulmonary disease (COPD). Unfortunately, the etiology and physiological meaning of ventilation defects and their relationship to pulmonary function and symptoms in COPD are not well understood. Another biomarker of ventilation heterogeneity is provided by the "poorly communicating fraction" (PCF), and is calculated as the ratio of total lung capacity to alveolar volume made using whole-body plethysmography. Our objective was to compare ventilation heterogeneity using hyperpolarized (3)He magnetic resonance imaging (MRI) and PCF measurements in elderly never-smokers and in ex-smokers with COPD. MATERIALS AND METHODS One hundred forty-six participants (71 ± 8 years, range = 48-87 years) provided written informed consent including 45 elderly never-smokers (71 ± 6 years, range = 61-84 years) and 101 ex-smokers with COPD (71 ± 8 years, range = 48-87 years). During a single 2-hour visit, spirometry, plethysmography, and hyperpolarized (3)He MRI were acquired. The MRI-derived ventilation defect percent (VDP) and plethysmography measurements were acquired and PCF values were calculated. Linear regression, Pearson correlations, and Bland-Altman analysis were used to evaluate the relationships for PCF and MRI VDP. RESULTS PCF (P < 0.001) and VDP (P < 0.001) were significantly increased with increasing COPD severity. There was a significant relationship for VDP and PCF (r = 0.68, P < 0.001) in all subjects and COPD subjects alone (r = 0.61, P < 0.001). Bland-Altman analysis showed that PCF and VDP were significantly different (mean bias = 9.7, upper limit = 32, lower limit = -13, P < 0.001), and in severe-grade COPD, PCF overestimates of VDP were significantly greater. CONCLUSIONS In elderly never-smokers and in ex-smokers with COPD, PCF and VDP are moderately correlated estimates of COPD ventilation heterogeneity that may be reflecting similar pathophysiology.
Collapse
Affiliation(s)
- Christopher Davis
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada
| | - Khadija Sheikh
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, N6A 5B7, Canada
| | - Damien Pike
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, N6A 5B7, Canada
| | - Sarah Svenningsen
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, N6A 5B7, Canada
| | - David G McCormack
- Division of Respirology, Department of Medicine, The University of Western Ontario, London, Canada
| | - Denis O'Donnell
- Division of Respirology, Department of Medicine, Queens University, 99 University Ave, Kingston, K7L 3N6, Canada
| | - J Alberto Neder
- Division of Respirology, Department of Medicine, Queens University, 99 University Ave, Kingston, K7L 3N6, Canada
| | - Grace Parraga
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, N6A 5B7, Canada.
| |
Collapse
|