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Leeds H, Muralidaran A, Johnson AJ, Schilling D, Parkhotyuk K, Shen I, McEvoy CT. Presurgical pulmonary function tests in the first few days of life in neonates with congenital heart disease, a pilot study. J Perinatol 2024:10.1038/s41372-024-01979-3. [PMID: 38750194 DOI: 10.1038/s41372-024-01979-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 05/28/2024]
Abstract
OBJECTIVE To compare early pulmonary function tests (PFTs) in neonates with critical congenital heart disease (CHD) compared to a historical reference group. DESIGN Infants ≥ 37 weeks gestation with critical CHD were studied within the first few days of life, prior to cardiac surgery, and compared to data from a published reference group of healthy term neonates without CHD, studied at the same institution. Passive respiratory resistance (Rrs) and compliance (Crs) were measured with the single breath occlusion technique following specific acceptance criteria. The study was powered for a 30% difference in Rrs. RESULTS PFTs in 24 infants with CHD were compared to 31 historical reference infants. There was no difference in the Rrs between the groups. The infants with CHD had a significantly decreased Crs (1.02 ± 0.26 mL/cmH2O/kg versus 1.32 ± 0.36; (p < 0.05; mean ± SD)). CONCLUSIONS Further prospective studies are required to quantify early PFTs in infants with CHD of different phenotypes.
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Affiliation(s)
- Hayden Leeds
- Department of Pediatrics, Oregon Health and Science University, Portland, OR, USA.
| | - Ashok Muralidaran
- Department of Surgery, Section of Pediatric and Congenital Heart Surgery, Oregon Health and Science University, Portland, OR, USA
| | - Alicia J Johnson
- Department of Surgery, Oregon Health and Science University, Portland, OR, USA
| | - Diane Schilling
- Department of Pediatrics, Division of Neonatology, Oregon Health and Science University, Portland, OR, USA
| | - Kseniya Parkhotyuk
- Department of Pediatrics, Division of Neonatology, Oregon Health and Science University, Portland, OR, USA
| | - Irving Shen
- Department of Surgery, Section of Pediatric and Congenital Heart Surgery, Oregon Health and Science University, Portland, OR, USA
| | - Cindy T McEvoy
- Department of Pediatrics, Division of Neonatology, Oregon Health and Science University, Portland, OR, USA
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McEvoy C, Leeds H, Muralidaran A, Johnson A, Schilling D, Parkhotyuk K, Shen I. Presurgical Pulmonary Function Tests in the First Few Days of Life in Neonates with Congenital Heart Disease, A Pilot Study. RESEARCH SQUARE 2024:rs.3.rs-3938413. [PMID: 38410443 PMCID: PMC10896390 DOI: 10.21203/rs.3.rs-3938413/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Objective To compare early pulmonary function tests (PFTs) in neonates with critical congenital heart disease (CHD) compared to a historical reference group. Design Infants > 37 weeks gestation with critical CHD were studied within the first few days of life and prior to cardiac surgery and compared to data from a published reference group. Passive respiratory resistance (Rrs) and compliance (Crs) were measured with the single breath occlusion technique following specific acceptance criteria. The study was powered for a 30% difference in Rrs. Results PFTs in 24 infants with CHD were compared to 31 historical reference infants. There was no difference in the Rrs between the groups. The infants with CHD had a significantly decreased Crs (1.02 ± 0.26 mL/cmH2O/kg versus 1.32 ± 0.36; (p < 0.05; mean ± SD)). Conclusions Further prospective studies are required to quantify early PFTs in infants with CHD of different phenotypes.
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3
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Ren CL, Slaven JE, Haas DM, Haneline LS, Tiller C, Hogg G, Bjerregaard J, Tepper RS. Forced expiratory flows and diffusion capacity in infants born from mothers with pre-eclampsia. Pediatr Pulmonol 2022; 57:2481-2490. [PMID: 35796049 PMCID: PMC9489632 DOI: 10.1002/ppul.26064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 01/01/2023]
Abstract
RATIONALE Animal models suggest pre-eclampsia (Pre-E) affects alveolar development, but data from humans are lacking. OBJECTIVE Assess the impact of Pre-E on airway function, diffusion capacity, and respiratory morbidity in preterm and term infants born from mothers with Pre-E. METHODS Infants born from mothers with and without Pre-E were recruited for this study; term and preterm infants were included in both cohorts. Respiratory morbidity in the first 12 months of life was assessed through monthly phone surveys. Raised volume rapid thoracoabdominal compression and measurement of diffusion capacity of the lung to carbon monoxide (DLCO) were performed at 6 months corrected age. MEASUREMENTS AND MAIN RESULTS There were 146 infants in the Pre-E cohort and 143 in the control cohort. The Pre-E cohort was further divided into nonsevere (N = 41) and severe (N = 105) groups. There was no significant difference in DLCO and DLCO/alveolar volume among the three groups. Forced vital capacity was similar among the three groups, but the nonsevere Pre-E group had significantly higher forced expiratory flows than the other two groups. After adjusting for multiple covariates including prematurity, the severe Pre-E group had a lower risk for wheezing in the first year of life compared to the other two groups. CONCLUSIONS Pre-E is not associated with reduced DLCO, lower forced expiratory flows, or increased wheezing in the first year of life. These results differ from animal models and highlight the complex relationships between Pre-E and lung function and respiratory morbidity in human infants.
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Affiliation(s)
- Clement L. Ren
- Division of Pulmonary and Sleep MedicineChildren's Hospital of PhiladephiaPhiladelphiaPennsylvaniaUSA
- Department of Pediatrics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - James E. Slaven
- Department of Biostatistics and Health Data ScienceIndiana University School of MedicineIndianapolisIndianaUSA
| | - David M. Haas
- Department of Obstetrics and GynecologyIndiana University School of MedicineIndianapolisIndianaUSA
| | - Laura S. Haneline
- Department of Pediatrics, Division of Neonatal‐Perinatal MedicineIndiana University School of MedicineIndianapolisIndianaUSA
| | - Christina Tiller
- Department of Pediatrics, Division of Pulmonary, Allergy, and Sleep MedicineIndiana University School of MedicineIndianapolisIndianaUSA
| | - Graham Hogg
- Department of Obstetrics and GynecologyIndiana University School of MedicineIndianapolisIndianaUSA
| | - Jeffrey Bjerregaard
- Department of Pediatrics, Division of Pulmonary, Allergy, and Sleep MedicineIndiana University School of MedicineIndianapolisIndianaUSA
| | - Robert S. Tepper
- Department of Pediatrics, Division of Pulmonary, Allergy, and Sleep MedicineIndiana University School of MedicineIndianapolisIndianaUSA
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Functional, transcriptional, and microbial shifts associated with healthy pulmonary aging in rhesus macaques. Cell Rep 2022; 39:110725. [PMID: 35443183 PMCID: PMC9096119 DOI: 10.1016/j.celrep.2022.110725] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 02/09/2022] [Accepted: 03/30/2022] [Indexed: 01/04/2023] Open
Abstract
Older individuals are at increased risk of developing severe respiratory infections. However, our understanding of the impact of aging on the respiratory tract remains limited as samples from healthy humans are challenging to obtain and results can be confounded by variables such as smoking and diet. Here, we carry out a comprehensive cross-sectional study (n = 34 adult, n = 49 aged) to define the consequences of aging on the lung using the rhesus macaque model. Pulmonary function testing establishes similar age and sex differences as humans. Additionally, we report increased abundance of alveolar and infiltrating macrophages and a concomitant decrease in T cells were in aged animals. scRNAseq reveals shifts from GRZMB to IFN expressing CD8+ T cells in the lungs. These data provide insight into age-related changes in the lungs’ functional, microbial, and immunological landscape that explain increased prevalence and severity of respiratory diseases in the elderly. Rhoades et al. describe age-associated functional, microbial, and immunological changes in the lung using the rhesus macaque model. These data will support further studies aimed at designing and testing interventions to mitigate the impact of age-associated shifts in the lung environment to reduce age-related pulmonary disease in the elderly.
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Balinotti JE, Maffey A, Colom A, Roldán O, Díaz W, Medín M, Racimo M, Teper A. Clinical, functional, and computed tomography findings in a cohort of patients with neuroendocrine cell hyperplasia of infancy. Pediatr Pulmonol 2021; 56:1681-1686. [PMID: 33580744 DOI: 10.1002/ppul.25319] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/16/2021] [Accepted: 02/09/2021] [Indexed: 11/12/2022]
Abstract
INTRODUCTION Neuroendocrine cell hyperplasia of infancy (NEHI) is one of the most common interstitial lung diseases in children. Both the etiology and pathophysiological mechanisms of the disease are still unknown. Prognosis is usually favorable; however, there are significant morbidities during the early years of life. OBJECTIVE To describe the clinical course, infant pulmonary function tests and computed tomography (CT) findings in a cohort of patients with NEHI in Argentina. METHODS This is a observational multicenter cohort study of children diagnosed with NEHI between 2011 and 2020. RESULTS Twenty patients participated in this study. The median age of onset of symptoms was 3 months and the median age at diagnosis was 6 months. The most common clinical presentation was tachypnea, retractions and hypoxemia. The chest CT findings showed central ground glass opacities and air trapping. Infant pulmonary function tests revealed an obstructive pattern in 75% of the cases (10/12). Most patients (75%) required home oxygen therapy for 17 months (interquartile range 12-25). In 85% of them, tachypnea and hypoxemia spontaneously resolved between the second and third years of life. CONCLUSION In this cohort, the first symptoms appeared during the early months of life. The typical clinical, CT, and functional findings allowed the diagnosis without the need of a lung biopsy. Although most patients required home oxygen therapy, they showed a favorable evolution.
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Affiliation(s)
- Juan E Balinotti
- Department of Medicine, Respiratory Center, Ricardo Gutierrez Children's Hospital, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Alberto Maffey
- Department of Medicine, Respiratory Center, Ricardo Gutierrez Children's Hospital, Buenos Aires, Argentina
| | - Alejandro Colom
- Department of Medicine, Respiratory Center, Ricardo Gutierrez Children's Hospital, Buenos Aires, Argentina
| | - Oscar Roldán
- Division of Pediatric, Sanatorio del Salvador, Córdoba, Argentina
| | - Walter Díaz
- Division of Pediatric, Alexander Fleming Hospital, Mendoza, Argentina
| | - Martín Medín
- Department of Pathology, Ricardo Gutierrez Children's Hospital, Buenos Aires, Argentina
| | - Mariano Racimo
- Department of Medicine, Respiratory Center, Ricardo Gutierrez Children's Hospital, Buenos Aires, Argentina
| | - Alejandro Teper
- Department of Medicine, Respiratory Center, Ricardo Gutierrez Children's Hospital, Buenos Aires, Argentina
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Choi YJ, Stoecklin B, Hemy NR, Hall GL, Doherty DA, Simpson SJ, Pillow JJ. Pulmonary Gas Exchange Improves over the First Year in Preterm Infants with and without Bronchopulmonary Dysplasia. Neonatology 2021; 118:98-105. [PMID: 33592606 DOI: 10.1159/000513357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 11/25/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Right shift of the peripheral oxyhaemoglobin saturation (SpO2) versus inspired oxygen pressure (PIO2) curve is a sensitive marker of pulmonary gas exchange. OBJECTIVES The aim of this study was to assess the impact of prematurity and bronchopulmonary dysplasia (BPD) on gas exchange and right-to-left shunt in the neonatal period, and its evolution over the first year of life. METHOD We assessed shift and shunt in extremely preterm (EP) and very preterm (VP) infants at 36 and 44 weeks' postmenstrual age (PMA), and at 1-year corrected postnatal age (cPNA). PIO2 was decreased stepwise to achieve SpO2 between 85 and 98%. Shift and shunt were calculated from paired SpO2/PIO2 measurements using customized software. Results were examined cross-sectionally at each time point, and longitudinally using generalized linear regression. Term infants were assessed at 44 wk PMA as a comparative reference. RESULTS Longitudinal modelling showed continuous decline in shift in EP and VP infants during the first year of life. There was no difference in shift compared to term infants at 44 wk PMA (p = 0.094). EP infants with BPD had higher shift than infants without BPD at 36 wk PMA (p < 0.001) and 44 wk PMA (p = 0.005) but not at 1-year cPNA. CONCLUSIONS In the absence of lung disease, prematurity per se did not result in reduced gas exchange at 1-year cPNA. We report ongoing, significant improvements in pulmonary gas exchange in all preterm infants during the first year of life, despite evidence of early deficits in gas exchange in EP infants with BPD.
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Affiliation(s)
- Y Jane Choi
- Telethon Kids Institute, Perth, Washington, Australia.,School of Human Sciences, University of Western Australia, Perth, Washington, Australia
| | - Benjamin Stoecklin
- School of Human Sciences, University of Western Australia, Perth, Washington, Australia.,Department of Neonatology, University Children's Hospital Basel, Basel, Switzerland
| | - Naomi R Hemy
- Telethon Kids Institute, Perth, Washington, Australia
| | - Graham L Hall
- Telethon Kids Institute, Perth, Washington, Australia.,School of Physiotherapy and Exercise Science, Curtin University, Perth, Washington, Australia
| | - Dorota A Doherty
- Division of Obstetrics and Gynaecology, Medical School, University of Western Australia, Perth, Washington, Australia
| | - Shannon J Simpson
- Telethon Kids Institute, Perth, Washington, Australia.,School of Physiotherapy and Exercise Science, Curtin University, Perth, Washington, Australia
| | - J Jane Pillow
- Telethon Kids Institute, Perth, Washington, Australia, .,School of Human Sciences, University of Western Australia, Perth, Washington, Australia,
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Bandyopadhyay A, Slaven J, Evrard C, Tiller C, Haas D, Tepper RS. Antenatal corticosteriods decrease forced vital capacity in infants born fullterm. Pediatr Pulmonol 2020; 55:2630-2634. [PMID: 32618132 PMCID: PMC7722163 DOI: 10.1002/ppul.24941] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/09/2020] [Accepted: 06/24/2020] [Indexed: 11/10/2022]
Abstract
Antenatal corticosteroids (ACS) administration to pregnant women for threatened preterm labor is standard obstetric care to reduce neonatal respiratory distress syndrome and the associated respiratory morbidity. While ACS stimulates surfactant production in the fetal lung, the effects of ACS upon the subsequent growth and development of the lung are unclear. Follow-up studies outside of the neonatal period have been primarily limited to spirometry, and most subjects evaluated were born prematurely. To our knowledge, no study has assessed both airway and parenchymal function in infants or adults following ACS exposure. We hypothesized that ACS impairs lung growth and performed infant pulmonary function testing, which included spirometry, alveolar volume (VA ) and lung diffusion (DL ). As a pilot study, we limited our assessment to infants whose mothers received ACS for threatened preterm labor, but then proceeded to full term delivery. This approach evaluated a more homogenous population and eliminated the confounding effects of preterm birth. We evaluated 36 full-term infants between 4 to 12 months of age; 17 infants had ACS exposure and 19 infants had no ACS exposure. Infants exposed to ACS had a significantly lower forced vital capacity compared with non-ACS exposed infants (250 vs 313 mL; P = .0075). FEV0.5 tended to be lower for the ACS exposed group (205 vs 237 mL; P = .075). VA and DL did not differ between the two groups. These findings suggest that ACS may impair subsequent growth of the lung parenchyma.
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Affiliation(s)
- Anuja Bandyopadhyay
- Department of Pediatrics–Division of Pulmonology; Indiana University School of Medicine, Indianapolis, Indiana
| | - James.E. Slaven
- Department of Biostatistics; Indiana University School of Medicine, Indianapolis, Indiana
| | - Cindy Evrard
- Departments of Obstetrics and Gynecology; Indiana University School of Medicine, Indianapolis, Indiana
| | - Christina Tiller
- Department of Pediatrics–Division of Pulmonology; Indiana University School of Medicine, Indianapolis, Indiana
| | - David.M. Haas
- Departments of Obstetrics and Gynecology; Indiana University School of Medicine, Indianapolis, Indiana
| | - Robert S. Tepper
- Department of Pediatrics–Division of Pulmonology; Indiana University School of Medicine, Indianapolis, Indiana
- Herman Wells Center for Pediatric Research; Indiana University School of Medicine, Indianapolis, Indiana
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Ring AM, Carlens J, Bush A, Castillo-Corullón S, Fasola S, Gaboli MP, Griese M, Koucky V, La Grutta S, Lombardi E, Proesmans M, Schwerk N, Snijders D, Nielsen KG, Buchvald F. Pulmonary function testing in children's interstitial lung disease. Eur Respir Rev 2020; 29:29/157/200019. [PMID: 32699025 DOI: 10.1183/16000617.0019-2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 04/11/2020] [Indexed: 12/17/2022] Open
Abstract
The use of pulmonary function tests (PFTs) has been widely described in airway diseases like asthma and cystic fibrosis, but for children's interstitial lung disease (chILD), which encompasses a broad spectrum of pathologies, the usefulness of PFTs is still undetermined, despite widespread use in adult interstitial lung disease. A literature review was initiated by the COST/Enter chILD working group aiming to describe published studies, to identify gaps in knowledge and to propose future research goals in regard to spirometry, whole-body plethysmography, infant and pre-school PFTs, measurement of diffusing capacity, multiple breath washout and cardiopulmonary exercise tests in chILD. The search revealed a limited number of papers published in the past three decades, of which the majority were descriptive and did not report pulmonary function as the main outcome.PFTs may be useful in different stages of management of children with suspected or confirmed chILD, but the chILD spectrum is diverse and includes a heterogeneous patient group in all ages. Research studies in well-defined patient cohorts are needed to establish which PFT and outcomes are most relevant for diagnosis, evaluation of disease severity and course, and monitoring individual conditions both for improvement in clinical care and as end-points in future randomised controlled trials.
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Affiliation(s)
- Astrid Madsen Ring
- Paediatric Pulmonary Service, Dept of Paediatrics and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Danish PCD & chILD Centre, CF Centre Copenhagen, Copenhagen, Denmark.,Joint first authors
| | - Julia Carlens
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Medizinische Hochschule Hannover Zentrum fur Kinderheilkunde und Jugendmedizin, Hannover, Germany.,Joint first authors
| | - Andy Bush
- Paediatrics and Paediatric Respiratory Medicine, Imperial College London, London, UK.,Paediatric Respiratory Medicine, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Silvia Castillo-Corullón
- Unidad de Neumología infantil y Fibrosis quística, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | - Salvatore Fasola
- Institute of Biomedical Research and Innovation, National Research Council of Italy, Palermo, Italy
| | - Mirella Piera Gaboli
- Neumologia Infantil y Unidad de Cuidados Intensivos Pediatricos, Hospital Universitario Salamanca, Salamanca, Spain
| | - Matthias Griese
- University Hospital of Munich, Dr. von Hauner Children's Hospital, German Center for Lung Research (DZL), Munich, Germany
| | - Vaclav Koucky
- Dept of Paediatrics, Univerzita Karlova v Praze 2 lekarska fakulta, Prague, Czech Republic
| | - Stefania La Grutta
- Institute of Biomedical Research and Innovation, National Research Council of Italy, Palermo, Italy
| | - Enrico Lombardi
- Pediatric Pulmonary Unit, Anna Meyer Pediatric University-Hospital, Florence, Italy
| | | | - Nicolaus Schwerk
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Medizinische Hochschule Hannover Zentrum fur Kinderheilkunde und Jugendmedizin, Hannover, Germany
| | | | - Kim Gjerum Nielsen
- Paediatric Pulmonary Service, Dept of Paediatrics and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Danish PCD & chILD Centre, CF Centre Copenhagen, Copenhagen, Denmark.,Joint last authors
| | - Frederik Buchvald
- Paediatric Pulmonary Service, Dept of Paediatrics and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Danish PCD & chILD Centre, CF Centre Copenhagen, Copenhagen, Denmark .,Joint last authors
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Diffusing Capacity of the Lung for Carbon Monoxide in Mexican/Latino Children. Quality Control and Reference Values. Ann Am Thorac Soc 2020; 16:240-247. [PMID: 30517026 DOI: 10.1513/annalsats.201712-922oc] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
RATIONALE Single-breath diffusing capacity of the lung for carbon monoxide (DlCOsb) values are used to evaluate gas exchange; however, the quality of maneuvers performed by children has not been evaluated, and reference values for young people living at moderate altitudes are not well established. OBJECTIVES Our objectives were 1) to determine whether DlCOsb maneuvers performed by a pediatric population would meet 2017 European Respiratory Society/American Thoracic Society (ERS/ATS) quality control standards; and 2) to report normal DlCOsb values for Mexican/Latino children and adolescents living at moderate altitudes. METHODS This study involved healthy young people 4-20 years of age from the metropolitan area of Mexico City (2,240 m above sea level) who were recruited in schools from July 2014 to August 2017. DlCOsb testing was performed according to the 2005 ATS/ERS standards, and the quality control of each maneuver was analyzed according to the 2017 ERS/ATS standards. We constructed models for DlCOsb with linear and quadratic terms for weight, height, and age as independent variables using shrinkage statistics, variance inflation factors, the Akaike information criterion, and R2 to compare the results of different models. RESULTS Results were obtained for 420 individuals (53% boys) with a mean age of 11.7 ± 4.5 standard deviation (SD) years; 47% of maneuvers from children age 4-6 years were grade A (13% grade B), and 90% of those in children older than 13 years were grade A or B. Forty-six percent of the subjects had a DlCOsb repeatability of <1 ml/min/mm Hg. The mean DlCOsb was higher for boys than for girls (32.4 ± 13.6 [SD] vs. 24.1 ± 7.5 ml/min/mm Hg, respectively). The reference equation for boys was DlCOsb = exp(1.63469 + [0.03251 × age] + [0.00846 × height] + [0.00304 × weight]), R2 = 0.87; for girls, the best equation was DlCOsb = exp(1.56516 + [0.0193 × age] + [0.00893 × height] + [0.00273 × weight]), R2 = 0.75. The single-breath transfer coefficient of the lung for carbon monoxide remained constant with age and height, with a lower limit of normal of 6.5 ml/min/mm Hg/L in boys and 5.4 ml/min/mm Hg/L in girls. Measured DlCOsb was higher than predicted by other authors (P < 0.001 by paired t test). CONCLUSIONS Individuals 4-20 years of age can complete high-quality DlCOsb tests. Children and adolescents living at 2,240 m have higher DlCOsb values than those living at sea level. Reference equations for DlCOsb obtained at sea level are poor predictors of the values measured at moderate altitude.
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Praca ELL, Tiller CJ, Kisling JA, Tepper RS. An alternative method to measure the diffusing capacity of the lung for carbon monoxide in infants. Pediatr Pulmonol 2018; 53:332-336. [PMID: 29265767 DOI: 10.1002/ppul.23926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/16/2017] [Indexed: 11/09/2022]
Abstract
BACKGROUND Lung diffusion assessed by the uptake of carbon monoxide (DLCO ) and alveolar volume (VA ) by inert gas dilution are readily assessed in cooperative older subjects; however, obtaining these measurements in infants has been much more difficult. Our laboratory has measured DLCO and VA in sleeping infants using a mass spectrometer, which continuously measures gas concentrations, and demonstrated that infants with bronchopulmonary dysplasia (BPD) have lower DLCO , but no difference in VA compared to full-term controls. The mass spectrometer is expensive and lacks portability; therefore, we evaluated whether measurement of end-expiratory alveolar gas concentrations using a gas chromatograph would provide an alternative approach. METHODS (1) Using our previously digitized data for infants with BPD and full-term controls, DLCO and VA were calculated at end-expiration rather than between 60 and 80% of expired volume, as previously reported. (2) In a new group of infants, DLCO and VA were measured using gas concentrations obtained at end-expiration with a mass spectrometer and a gas chromatograph. RESULTS (1) Using end-expiratory concentrations, infants with BPD (n = 49) had significantly lower DLCO , but similar VA compared to healthy controls (n = 34) (DLCO : 4.2 vs 4.6 mL/min/mmHg, P = 0.047; VA : 614 vs 608 mL, P = 0.772). (2) Among newly evaluated infants (n = 28), DLCO and VA obtained with a mass spectrometer and a gas chromatograph were highly correlated (R2 = 0.94 and 0.99, respectively), and were not significantly different for the two analyzers. CONCLUSION Measuring DLCO and VA at end-expiration using a gas chromatograph can provide an effective assessment of gas exchange in sleeping infants.
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Affiliation(s)
- Eduardo L L Praca
- Department of Pediatric Pulmonology and Respiratory Care, James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana
| | - Christina J Tiller
- Department of Pediatric Pulmonology and Respiratory Care, James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jeffrey A Kisling
- Department of Pediatric Pulmonology and Respiratory Care, James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana
| | - Robert S Tepper
- Department of Pediatric Pulmonology and Respiratory Care, James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana
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11
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Chang DV, Assaf SJ, Tiller CJ, Kisling JA, Tepper RS. Membrane and Capillary Components of Lung Diffusion in Infants with Bronchopulmonary Dysplasia. Am J Respir Crit Care Med 2016; 193:767-71. [PMID: 26566056 DOI: 10.1164/rccm.201506-1219oc] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Autopsied lungs of infants with bronchopulmonary dysplasia (BPD) demonstrate impaired alveolar development with larger and fewer alveoli, which is consistent with our previous physiologic findings of lower pulmonary diffusing capacity of the lung for carbon monoxide (DL(CO)) in infants and toddlers with BPD compared with healthy controls born at full term (FT). However, it is not known whether the decreased DL(CO) in infants with BPD results from a reduction in both components of DL(CO): pulmonary membrane diffusing capacity (D(M)) and Vc. OBJECTIVES We hypothesized that impairment of alveolar development in BPD results in a decrease in both D(M) and Vc components of DlCO but that the D(M)/Vc ratio would not differ between the BPD and FT groups. METHODS DL(CO) was measured under conditions of room air and high inspired oxygen (90%), which enabled D(M) and Vc to be calculated. MEASUREMENTS AND MAIN RESULTS D(M) and Vc increased with increasing body length; however, infants with BPD had significantly lower D(M) and Vc than FT subjects after adjustment for race, sex, body length, and corrected age. In contrast to D(M) and Vc, the D(M)/Vc ratio remained constant with increasing body length and did not differ for infants with BPD and FT subjects. CONCLUSIONS Our findings are consistent with infants with BPD having impaired alveolar development with fewer but larger alveoli, as well as a reduced Vc.
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Affiliation(s)
- Daniel V Chang
- Department of Pediatric Pulmonology, James Whitcomb Riley Hospital for Children at Indiana University, Indianapolis, Indiana
| | - Santiago J Assaf
- Department of Pediatric Pulmonology, James Whitcomb Riley Hospital for Children at Indiana University, Indianapolis, Indiana
| | - Christina J Tiller
- Department of Pediatric Pulmonology, James Whitcomb Riley Hospital for Children at Indiana University, Indianapolis, Indiana
| | - Jeffrey A Kisling
- Department of Pediatric Pulmonology, James Whitcomb Riley Hospital for Children at Indiana University, Indianapolis, Indiana
| | - Robert S Tepper
- Department of Pediatric Pulmonology, James Whitcomb Riley Hospital for Children at Indiana University, Indianapolis, Indiana
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Assaf SJ, Chang DV, Tiller CJ, Kisling JA, Case J, Mund JA, Slaven JE, Yu Z, Ahlfeld SK, Poindexter B, Haneline LS, Ingram DA, Tepper RS. Lung parenchymal development in premature infants without bronchopulmonary dysplasia. Pediatr Pulmonol 2015; 50:1313-9. [PMID: 25462113 PMCID: PMC4452454 DOI: 10.1002/ppul.23134] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 07/10/2014] [Accepted: 08/17/2014] [Indexed: 12/20/2022]
Abstract
RATIONALE While infants who are born extremely premature and develop bronchopulmonary dysplasia (BPD) have impaired alveolar development and decreased pulmonary diffusion (DLCO), it remains unclear whether infants born less premature and do not develop BPD, healthy premature (HP), have impaired parenchymal development. In addition, there is increasing evidence that pro-angiogenic cells are important for vascular development; however, there is little information on the relationship of pro-angiogenic cells to lung growth and development in infants. OBJECTIVE and Methods Determine among healthy premature (HP) and fullterm (FT) infants, whether DLCO and alveolar volume (VA) are related to gestational age at birth (GA), respiratory support during the neonatal period (mechanical ventilation [MV], supplemental oxygen [O2], continuous positive airway pressure [CPAP]), and pro-angiogenic circulating hematopoietic stem/progenitor cells (CHSPCs). We measured DLCO, VA, and CHSPCs in infants between 3-33 months corrected-ages; HP (mean GA = 31.7 wks; N = 48,) and FT (mean GA = 39.3 wks; N =88). RESULT DLCO was significantly higher in HP than FT subjects, while there was no difference in VA , after adjusting for body length, gender, and race. DLCO and VA were not associated with GA, MV and O2; however, higher values were associated with higher CHSPCs, as well as treatment with CPAP. CONCLUSION Our findings suggest that in the absence of extreme premature birth, as well as BPD, prematurity per se, does not impair lung parenchymal development.
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Affiliation(s)
- Santiago J Assaf
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Sections of Pulmonology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Daniel V Chang
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Sections of Pulmonology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Christina J Tiller
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Sections of Pulmonology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jeffrey A Kisling
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Sections of Pulmonology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jamie Case
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Section of Neonatology, Indiana University School of Medicine, Indianapolis, Indiana.,James Whitcomb Riley Hospital for Children Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.,Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Julie A Mund
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Section of Neonatology, Indiana University School of Medicine, Indianapolis, Indiana.,James Whitcomb Riley Hospital for Children Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.,Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - James E Slaven
- Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Zhangsheng Yu
- Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Shawn K Ahlfeld
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Section of Neonatology, Indiana University School of Medicine, Indianapolis, Indiana.,Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Brenda Poindexter
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Section of Neonatology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Laura S Haneline
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Section of Neonatology, Indiana University School of Medicine, Indianapolis, Indiana.,James Whitcomb Riley Hospital for Children Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.,Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.,Departments of Microbiology and Immunology and Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - David A Ingram
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Section of Neonatology, Indiana University School of Medicine, Indianapolis, Indiana.,Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Robert S Tepper
- James Whitcomb Riley Hospital for Children Department of Pediatrics, Sections of Pulmonology, Indiana University School of Medicine, Indianapolis, Indiana.,Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
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Simpson SJ, Hall GL, Wilson AC. Lung function following very preterm birth in the era of ‘new’ bronchopulmonary dysplasia. Respirology 2015; 20:535-40. [DOI: 10.1111/resp.12503] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/07/2014] [Accepted: 12/29/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Shannon J. Simpson
- Telethon Kids Institute; The University of Western Australia; Perth Western Australia Australia
| | - Graham L. Hall
- Telethon Kids Institute; The University of Western Australia; Perth Western Australia Australia
| | - Andrew C. Wilson
- Department of Respiratory Medicine; Princess Margaret Hospital for Children; Perth Western Australia Australia
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Schwartz CL, Hobbie WL, Constine LS, Ruccione KS. Pulmonary Effects of Antineoplastic Therapy. PEDIATRIC ONCOLOGY 2015. [PMCID: PMC7124061 DOI: 10.1007/978-3-319-16435-9_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Pulmonary toxicity is common after cancer therapy and can result from all therapeutic modalities. The consequential decrease in lung function ranges in severity from subclinical to life-threatening or even fatal and can manifest in the acute setting or many years after completion of therapy. Radiation effects are due to direct insult to the pulmonary parenchyma and, for younger children, impaired thoracic musculoskeletal development. Radiation pneumonitis can occur in the acute/subacute setting, as well as fibrosis with comprised gas exchange as a late effect of direct lung irradiation; thoracic wall malformation can cause restriction of function as a chronic sequela. The pulmonary effects of cytotoxic drugs usually present as acute effects, but there is the potential for significant late morbidity and mortality. Of course, surgical interventions can also cause both acute and/or late pulmonary effects as well, depending on the specific procedure. Although treatment approaches for the management of pediatric cancers are continually adapted to provide optimal therapy while minimizing toxicities, to a varying degree all therapies have the potential for both acute and late pulmonary toxicity. Of note, the cumulative incidence of pulmonary complications rises with increasing time since diagnosis, which suggests that adult survivors of childhood cancer require lifelong monitoring and management of potential new-onset pulmonary morbidity as they age. Knowledge of cytotoxic therapies and an understanding of lung physiology and how it may be altered by therapy facilitate appropriate clinical care and monitoring of long-term survivors.
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Affiliation(s)
- Cindy L. Schwartz
- Department of Pediatrics, MD Anderson Cancer Center, Houston, Texas USA
| | - Wendy L. Hobbie
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania USA
| | - Louis S. Constine
- Departments of Radiation Oncology and Pediatrics, University of Rochester Medical Center, James P. Wilmot Cancer Ctr, Rochester, New York USA
| | - Kathleen S. Ruccione
- Center for Cancer And Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California USA
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Ehsan Z, Montgomery GS, Tiller C, Kisling J, Chang DV, Tepper RS. An infant with pulmonary interstitial glycogenosis: clinical improvement is associated with improvement in the pulmonary diffusion capacity. Pediatr Pulmonol 2014; 49:E17-20. [PMID: 23401236 DOI: 10.1002/ppul.22738] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 09/05/2012] [Indexed: 11/10/2022]
Abstract
Pulmonary interstitial glycogenosis (PIG) is an idiopathic interstitial lung disease of infants. The underlying pulmonary pathophysiology of PIG has not been well characterized. Herein we report a term-gestation infant who presented with persistent tachypnea and hypoxia. A chest CT scan demonstrated a diffuse ground glass appearance and lung biopsy demonstrated increased alveolar septae cellularity with glycogen-containing cells, consistent with a diagnosis of PIG. At 3 months of age, pulmonary function testing included: pre- and post-bronchodilator forced expiratory flows using the raised-volume technique and the ratio of pulmonary diffusing capacity for carbon monoxide to alveolar volume (DLCO /VA ). He was prescribed 5 days of oral prednisolone (2mg/kg/day) and pulmonary function testing (PFT) was repeated at 5, 13, and 20 months of age. Initial PFTs demonstrated reduced forced vital capacity (FVC: Z-score = -2.36) and an increased ratio of forced expiratory volume in 0.5 sec to FVC (FEV0.5/FVC: Z-score = 1.15) with no significant change following an inhaled bronchodilator. There was also a marked reduction in DLCO /VA (Z-score = -4.74) compared to age-matched controls. Follow-up demonstrated progressive clinical improvement as well as an increase in Z-FVC and normalization of DLCO /VA . Our in vivo physiological findings are consistent with previous reports that symptom resolution correlated with histological thinning of the alveolar septae upon repeat lung biopsy. The restrictive lung disease we observed is consistent with expected reduced compliance of an alveolar interstitial lung process like PIG, whereas the absence of a reduction in FEV0.5/FVC confirms the absence of obstructive airway disease.
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Affiliation(s)
- Zarmina Ehsan
- Department of Pediatrics, Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana
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Chakr VC, Llapur CJ, Sarria EE, Mattiello R, Kisling J, Tiller C, Kimmel R, Poindexter B, Tepper RS. Ventilation homogeneity improves with growth early in life. Pediatr Pulmonol 2012; 47:373-80. [PMID: 21901860 PMCID: PMC3243777 DOI: 10.1002/ppul.21553] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 07/30/2011] [Indexed: 11/11/2022]
Abstract
Some studies have suggested that lung clearance index (LCI) is age-independent among healthy subjects early in life, which implies that ventilation distribution does not vary with growth. However, other studies of older children and adolescents suggest that ventilation becomes more homogenous with somatic growth. We describe a new technique to obtain multiple breath washout (MBWO) in sedated infants and toddlers using slow augmented inflation breaths that yields an assessment of LCI and the slope of phase III, which is another index of ventilation inhomogeneity. We evaluated whether ventilation becomes more homogenous with increasing age early in life, and whether infants with chronic lung disease of infancy (CLDI) have increased ventilation inhomogeneity relative to full-term controls (FT). FT (N = 28) and CLDI (N = 22) subjects between 3 and 28 months corrected-age were evaluated. LCI decreased with increasing age; however, there was no significant difference between the two groups (9.3 vs. 9.5; P = 0.56). Phase III slopes adjusted for expired volume (S(ND)) increased with increasing breath number during the washout and decreased with increasing age. There was no significant difference in S(ND) between full-term and CLDI subjects (211 vs. 218; P = 0.77). Our findings indicate that ventilation becomes more homogenous with lung growth and maturation early in life; however, there is no evidence that ventilation inhomogeneity is a significant component of the pulmonary pathophysiology of CLDI.
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Affiliation(s)
- Valentina C Chakr
- Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
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Balinotti JE, Chakr VC, Tiller C, Kimmel R, Coates C, Kisling J, Yu Z, Nguyen J, Tepper RS. Growth of lung parenchyma in infants and toddlers with chronic lung disease of infancy. Am J Respir Crit Care Med 2010; 181:1093-7. [PMID: 20133928 PMCID: PMC2874450 DOI: 10.1164/rccm.200908-1190oc] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Accepted: 01/29/2010] [Indexed: 11/16/2022] Open
Abstract
RATIONALE The clinical pathology describing infants with chronic lung disease of infancy (CLDI) has been limited and obtained primarily from infants with severe lung disease, who either died or required lung biopsy. As lung tissue from clinically stable outpatients is not available, physiological measurements offer the potential to increase our understanding of the pulmonary pathophysiology of this disease. OBJECTIVES We hypothesized that if premature birth and the development of CLDI result in disruption of alveolar development, then infants and toddlers with CLDI would have a lower pulmonary diffusing capacity relative to their alveolar volume compared with full-term control subjects. METHODS We measured pulmonary diffusing capacity and alveolar volume, using a single breath-hold maneuver at elevated lung volume. Subjects with chronic lung disease of infancy (23-29 wk of gestation; n = 39) were compared with full-term control subjects (n = 61) at corrected ages of 11.6 (4.8-17.0) and 13.6 (3.2-33) months, respectively. MEASUREMENTS AND MAIN RESULTS Alveolar volume and pulmonary diffusing capacity increased with increasing body length for both groups. After adjusting for body length, subjects with CLDI had significantly lower pulmonary diffusing capacity (2.88 vs. 3.23 ml/min/mm Hg; P = 0.0004), but no difference in volume (545 vs. 555 ml; P = 0.58). CONCLUSIONS Infants and toddlers with CLDI have decreased pulmonary diffusing capacity, but normal alveolar volume. These physiological findings are consistent with the morphometric data obtained from subjects with severe lung disease, which suggests an impairment of alveolar development after very premature birth.
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Affiliation(s)
- Juan E Balinotti
- Department of Pediatrics, Indiana University Medical Center, James Whitcomb Riley Hospital for Children, 702 Barnhill Drive, Indianapolis, IN 46202-5225, USA
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Balinotti JE, Tiller CJ, Llapur CJ, Jones MH, Kimmel RN, Coates CE, Katz BP, Nguyen JT, Tepper RS. Growth of the lung parenchyma early in life. Am J Respir Crit Care Med 2008; 179:134-7. [PMID: 18996997 DOI: 10.1164/rccm.200808-1224oc] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Early in life, lung growth can occur by alveolarization, an increase in the number of alveoli, as well as expansion. We hypothesized that if lung growth early in life occurred primarily by alveolarization, then the ratio of pulmonary diffusion capacity of carbon monoxide (Dl(CO)) to alveolar volume (V(A)) would remain constant; however, if lung growth occurred primarily by alveolar expansion, then Dl(CO)/V(A) would decline with increasing age, as observed in older children and adolescents. OBJECTIVES To evaluate the relationship between alveolar volume and pulmonary diffusion capacity early in life. METHODS In 50 sleeping infants and toddlers, with equal number of males and females between the ages of 3 and 23 months, we measured Dl(CO) and V(A) using single breath-hold maneuvers at elevated lung volumes. MEASUREMENTS AND MAIN RESULTS Dl(CO) and V(A) increased with increasing age and body length. Males had higher Dl(CO) and V(A) when adjusted for age, but not when adjusted for length. Dl(CO) increased with V(A); there was no gender difference when Dl(CO) was adjusted for V(A). The ratio of Dl(CO)/V(A) remained constant with age and body length. CONCLUSIONS Our results suggest that surface area for diffusion increases proportionally with alveolar volume in the first 2 years of life. Larger Dl(CO) and V(A) for males than females when adjusted for age, but not when adjusted for length, is primarily related to greater body length in boys. The constant ratio for Dl(CO)/V(A) in infants and toddlers is consistent with lung growth in this age occurring primarily by the addition of alveoli rather than the expansion of alveoli.
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Affiliation(s)
- Juan E Balinotti
- Department of Pediatrics, Indiana University Medical Center, James Whitcomb Riley Hospital for Children, Herman B. Wells Center for Pediatric Research, Indianapolis, Indiana 46202-5225, USA
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Bolle I, Eder G, Takenaka S, Ganguly K, Karrasch S, Zeller C, Neuner M, Kreyling WG, Tsuda A, Schulz H. Postnatal lung function in the developing rat. J Appl Physiol (1985) 2008; 104:1167-76. [DOI: 10.1152/japplphysiol.00587.2007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Little is known about lung function during early stages of postnatal maturation, although the complex structural changes associated with developing rat lung are well studied. We therefore analyzed corresponding functional (lung volume, respiratory mechanics, intrapulmonary gas mixing, and gas exchange) and structural (alveolar surface area, mean linear intercept length, and alveolar septal thickness) changes of the developing rat lung at 7–90 days. Total lung capacity (TLC) increased from 1.54 ± 0.07 to 16.7 ± 2.46 (SD) ml in proportion to body weight, but an increase in body weight exceeded an increase in lung volume by almost twofold. Series dead space volume increased from 0.21 ± 0.03 to 1.38 ± 0.08 ml but decreased relative to TLC from 14% to 8%, indicating that parenchymal growth exceeded growth of conducting airways. Diffusing capacity of CO (Dco) increased from 8.1 ± 0.8 to 214.1 ± 23.5 μmol·min−1·hPa−1, corresponding to a substantial increase in surface area from 744 ± 20 to 6,536 ± 488 cm2. Dco per unit of lung volume is considerably lower in the immature lung, inasmuch as Dco/TLC in 7-day-old rats was only 42% of that in adult (90 day-old) rats. In humans, however, infants and adults show comparable specific Dco. Our functional and structural analysis shows that gas exchange is limited in the immature rat lung. The pivotal step for improvement of gas exchange occurs with the transition from bulk alveolarization to the phase of expansion of air spaces with septal reconstruction and microvascular maturation.
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