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Sonneveld N, Rayment JH, Usemann J, Nielsen KG, Robinson PD. Multiple breath washout and oscillometry after allogenic HSCT: a scoping review. Eur Respir Rev 2023; 32:220251. [PMID: 37495248 PMCID: PMC10369167 DOI: 10.1183/16000617.0251-2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 05/04/2023] [Indexed: 07/28/2023] Open
Abstract
Pulmonary chronic graft-versus-host disease (cGVHD) is a substantial cause of pulmonary morbidity and mortality post-haematopoietic stem cell transplantation (HSCT). Current spirometry-based monitoring strategies have significant limitations. Understanding the utility of novel peripheral airway function tests - multiple breath washout (MBW) and oscillometry - is critical in efforts to improve detection, facilitate earlier intervention and improve outcomes. In this scoping review, we identified 17 studies investigating MBW or oscillometry, or both, after allogenic HSCT. Despite small study numbers limiting the ability to draw firm conclusions, several themes were evident. Detectable peripheral airway abnormality in MBW occurred in a substantial proportion prior to HSCT. MBW indices post-HSCT were more frequently abnormal than spirometry when reporting group data and among those with extrapulmonary cGVHD and pulmonary cGVHD. Changes in MBW indices over time may be more indicative of pulmonary complications than absolute values at any given time point. Oscillometry indices were often normal at baseline, but more frequently abnormal in those who developed pulmonary cGVHD. Pooling currently available individual participant data across these studies may improve our ability to formally compare their respective sensitivity and specificity at specific time points and assess the trajectory of MBW and oscillometry indices over time.
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Affiliation(s)
- Nicole Sonneveld
- Department of Respiratory Medicine, Children's Hospital at Westmead, Sydney Children's Hospitals Network, Sydney, Australia
- Discipline of Paediatrics and Child Health, University of Sydney, Sydney, Australia
| | - Jonathan H Rayment
- Division of Respiratory Medicine, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
- BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Jakob Usemann
- University Children's Hospital Basel (UKBB), Basel, Switzerland
- Division of Respiratory Medicine and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Kim G Nielsen
- Paediatric Pulmonary Service, Copenhagen University Hospital, Department of Paediatric and Adolescent Medicine, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Paul D Robinson
- Department of Respiratory Medicine, Children's Hospital at Westmead, Sydney Children's Hospitals Network, Sydney, Australia
- Discipline of Paediatrics and Child Health, University of Sydney, Sydney, Australia
- Airway Physiology and Imaging Group, The Woolcock Institute of Medical Research, Sydney, Australia
- Children's Health and Environment Program, Child Health Research Centre, University of Queensland, Brisbane, Australia
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2
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Zafar A, Hall M. In children with primary ciliary dyskinesia, which type of lung function test is the earliest determinant of decline in lung health: A systematic review. Pediatr Pulmonol 2023; 58:475-483. [PMID: 36268989 DOI: 10.1002/ppul.26213] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/12/2022] [Accepted: 10/15/2022] [Indexed: 01/28/2023]
Abstract
BACKGROUND Primary ciliary dyskinesia is a rare genetic disorder characterized by recurrent sinopulmonary infections and worsening obstructive lung disease. Kidney and brain involvement is less common and is associated with overlapping ciliopathies/syndromes. The lungs are impacted early in the course of the disease, so it is vital to monitor lung function and recognize any decline by doing appropriate lung function tests. This systematic review compares different lung function tests and analyzes which one becomes abnormal earlier in the disease. METHODS A systematic review was conducted following the methodology in the "Cochrane Handbook on Systematic Reviews for diagnostic tests." The Preferred Reporting Items for Systematic Review and Meta-Analyses were used to report the results. The risk of bias assessment was done using "The Cochrane Handbook for Systematic Reviews tool for interventional studies." A meta-analysis was not performed due to the small sample size. All studies were analyzed by using Joanna Briggs Institute's critical appraisal tool. RESULTS After screening for the duplication of results and applying inclusion and exclusion criteria, 14 studies were assessed by reading the full texts. Out of these, eight were finally included in this systematic review. The total sample size from all studies was 165, including 80 males. All the studies used spirometry as a lung function test, whereas multiple breath washout was used in five studies. Other tests used for comparison were computed tomography (CT), magnetic resonance imaging (MRI), cardiopulmonary exercise testing, 6-min walk test, DLCO, maximal inspiratory pressure, maximal expiratory pressure, and PaO2 . Lung clearance index (LCI) by multiple breath washout had a stronger association with the structural changes on CT/MRI than spirometry indices like forced expiratory volume in 1 s (FEV1) and forced expiratory flow at 25% to 75% of lung volume (FEF 25-75). CONCLUSIONS Based on the evidence from this systematic review, LCI becomes abnormal earlier than FEV1 or FEF 25-75 and positively correlates with the findings on high-resolution CT. It has limitations like the lack of reference values and a complex technique to perform the test.
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Affiliation(s)
- Adnan Zafar
- John Hopkins Aramco Healthcare, Dhahran, Saudi Arabia
| | - Michael Hall
- University of Southampton, Southampton, United Kingdom
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3
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Dassios T. Critical functional lung volumes in neonatal intensive care: evidence and clinical applications. Pediatr Res 2023:10.1038/s41390-022-02450-9. [PMID: 36624281 DOI: 10.1038/s41390-022-02450-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/08/2022] [Accepted: 12/14/2022] [Indexed: 01/11/2023]
Abstract
Respiratory disease is common in premature and sick newborn infants and can often necessitate the initiation of intensive care. Newborn infants often suffer from conditions that are associated with decreased lung volumes that occur as a result of abnormal or incomplete lung development. Such conditions are prematurity and respiratory distress syndrome, preterm premature rupture of membranes and the ensuing pulmonary hypoplasia and congenital lung anomalies such as congenital diaphragmatic hernia. These diseases have a structural component manifesting with lower lung volumes and a functional component that can present with increased oxygen and ventilatory requirements. The corresponding decreased functional lung volume is possibly responsible for some unfavourable pulmonary outcomes. Some infants are unable to wean off invasive respiratory support and, in extreme cases, unable to sustain independent breathing that can lead to long-term invasive ventilation or subsequent death. The aim of this review is to summarise the available evidence behind the concept of a critical functional lung volume in neonatal intensive care and describe the clinical implications that arise from decreased functional lung volumes in the main high-risk populations of newborn infants. IMPACT: Newborn infants suffer from diseases such as respiratory distress syndrome, pulmonary hypoplasia and congenital diaphragmatic hernia that are associated with a decrease in the total lung volume and impaired lung function. Critically decreased functional lung volumes during neonatal care are associated with failure to wean off invasive respiratory support, increased mortality and possibly longer-term respiratory complications.
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Affiliation(s)
- Theodore Dassios
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK. .,Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
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Kentgens AC, Latzin P, Anagnostopoulou P, Jensen R, Stahl M, Harper A, Yammine S, Foong RE, Hall GL, Singer F, Stanojevic S, Mall MA, Ratjen F, Ramsey KA. Normative multiple breath washout data in school-aged children corrected for sensor error. Eur Respir J 2022; 60:13993003.02398-2021. [PMID: 35710262 DOI: 10.1183/13993003.02398-2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 06/07/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Anne-Christianne Kentgens
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Philipp Latzin
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Pinelopi Anagnostopoulou
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland.,Insitute of Anatomy, University of Bern, Bern, Switzerland.,Medical School, University of Cyprus, Nicosia, Cyprus
| | - Renee Jensen
- Division of Respiratory Medicine, The Hospital for Sick Children and Translational Medicine, SickKids Research Institute, University of Toronto, Toronto, ON, Canada
| | - Mirjam Stahl
- Dept of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany.,Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Dept of Pediatrics, University of Heidelberg, Heidelberg, Germany.,Department of Pediatric Respiratory Medicine, Immunology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Berlin, Germany.,German Center for Lung Research (DZL), associated partner, Berlin, Germany
| | - Alana Harper
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, Australia
| | - Sophie Yammine
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Rachel E Foong
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, Australia.,School of Allied Health, Curtin University, Perth, Australia
| | - Graham L Hall
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, Australia.,School of Allied Health, Curtin University, Perth, Australia
| | - Florian Singer
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Sanja Stanojevic
- Division of Respiratory Medicine, The Hospital for Sick Children and Translational Medicine, SickKids Research Institute, University of Toronto, Toronto, ON, Canada
| | - Marcus A Mall
- Department of Pediatric Respiratory Medicine, Immunology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Berlin, Germany.,German Center for Lung Research (DZL), associated partner, Berlin, Germany
| | - Felix Ratjen
- Division of Respiratory Medicine, The Hospital for Sick Children and Translational Medicine, SickKids Research Institute, University of Toronto, Toronto, ON, Canada
| | - Kathryn A Ramsey
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland .,Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, Australia.,School of Child Health Research, University of Western Australia, Perth, Australia
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Steindor M, Pichler A, Heitschmidt L, Pitsikoulis E, Kavvalou A, Orhan E, Olivier M, Stehling F. Multiple breath washout lung function reveals ventilation inhomogeneity unresponsive to mechanical assisted cough in patients with neuromuscular disease. BMC Pulm Med 2022; 22:217. [PMID: 35659287 PMCID: PMC9166427 DOI: 10.1186/s12890-022-02012-z] [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] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Respiratory involvement defines the clinical outcome of neuromuscular diseases (NMD). The lung clearance index (LCI) is a marker of lung ventilation inhomogeneity and indicates small airway disease. It is determined by mulitple breath washout lung function (MBW). The merit of LCI is undisputed for primary lung diseases like cystic fibrosis, but its role in NMD is unclear. METHODS We investigated the role of MBW in patients with NMD and the effect of two different tracer gases and cough assist devices on the LCI. Patients and controls performed MBW with nitrogen (N2) and sulfur hexafluoride (SF6), whereas the latter analysis was repeated after the use of a cough assist device in the NMD group. LCI was compared to forced vital capacity (FVC) and peak cough flow (PCF). RESULTS 24 NMD patients (12 Duchenne Muscular Dystrophy, 8 Spinal Muscular Atrophy, 4 other NMDs) and 15 healthy controls were enrolled. In the NMD group, overall LCI N2 was higher than LCI SF6 (9.67 ± 1.56 vs. 8.71 ± 1.47; mean ± SD; p < 0.033). In controls, LCI N2 did not differ significantly from LCI SF6 (7.03 ± 0.37 vs. 7.05 ± 0.67; p = 0.882). Both LCI N2 and LCI SF6 were significantly higher in NMD patients as in controls (9.67 ± 1.56 vs. 7.03 ± 0.37, p < 0.001, and 8.71 ± 1.478.65 vs. 7.05 ± 0.67, p < 0.001). In the NMD group, both LCI N2 and LCI SF6 showed a negative correlation to FVC (r = - 0.525; p = 0.008 and r = - 0.526; p = 0.008, respectively) and PCF (r = - 0.590; p = 0.002 and r = - 0.641; p = 0.001, respectively). LCI N2 and LCI SF6 correlated well in the NMD group. LCI SF6 did not change significantly after the use of the cough assist in NMD patients (n = 22; 8.65 ± 1.52 pre vs. 8.79 ± 2.03 post, p = 0.667). CONCLUSION Lung involvement of patients with neuromuscular diseases goes beyond weakness of respiratory muscles. MBW with both N2 and SF6 is suitable to detect ventilation inhomogeneity in NMD patients with respiratory impairment. Cough assist devices with low to moderate pressure levels do not immediately improve the LCI.
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Affiliation(s)
- Mathis Steindor
- Pediatric Pulmonology and Sleep Medicine, Department of Paediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany.
| | - Anna Pichler
- Pediatric Pulmonology and Sleep Medicine, Department of Paediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
| | - Laura Heitschmidt
- Pediatric Pulmonology and Sleep Medicine, Department of Paediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
| | - Eva Pitsikoulis
- Pediatric Pulmonology and Sleep Medicine, Department of Paediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
| | - Alexandra Kavvalou
- Pediatric Pulmonology and Sleep Medicine, Department of Paediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
| | - Eser Orhan
- Pediatric Research Network Essen, Essen, Germany
| | - Margerete Olivier
- Pediatric Pulmonology and Sleep Medicine, Department of Paediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
| | - Florian Stehling
- Pediatric Pulmonology and Sleep Medicine, Department of Paediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
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6
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Darquenne C, Theilmann RJ, Fine JM, Verbanck SAB. Nitrogen-based lung clearance index: a valid physiological biomarker for the clinic. J Appl Physiol (1985) 2022; 132:1290-1296. [PMID: 35446597 PMCID: PMC9126222 DOI: 10.1152/japplphysiol.00511.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Multiple breath washout (MBW) testing is increasingly used as a physiological measurement in the clinic, due in part to the availability of commercial equipment and reference values for MBW indices. Commercial N2 washout devices are usually based on indirect measurement of N2 concentration (CN2), by directly measuring either molar mass and O2 and CO2, or molar mass and CO2. We aim to elucidate the role of two potential pitfalls associated with N2-MBW testing that could override its physiological content: indirect N2 measurement and blood-solubility of N2. We performed MBW in 12 healthy adult subjects using a commercial device (MBWindirect) with simultaneous direct gas concentration measurements by mass spectrometry (MBWdirect) and compared CN2 between MBWdirect and MBWindirect. We also measured argon concentration during the same washouts to verify the maximal effect gas solubility can have on N2-based functional residual capacity (FRC) and lung clearance index (LCI). Continuous N2 concentration traces were very similar for MBWindirect and MBWdirect, resulting in comparable breath-by-breath washout plots of expired concentration and in no significant differences in FRCN2, LCIN2, Scond, and Sacin between the two methods. Argon washouts were slightly slower than N2 washouts, as expected for a less diffusive and more soluble gas. Finally, comparison between LCIN2 and LCIAr indicates that the maximum impact from blood-tissue represents less than half a LCI unit in normal subjects. In conclusion, we have demonstrated by direct measurement of N2 and twice as soluble argon, that indirect N2 measurement can be safely used as a meaningful physiological measurement.NEW & NOTEWORTHY The physiological content of N2 multibreath washout testing has been questioned due to N2 indirect measurement accuracy and N2 blood solubility. With direct measurement of N2 and twice as soluble argon, we show that these effects are largely outweighed by ease of use.
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Affiliation(s)
- Chantal Darquenne
- Department of Medicine, University of California, San Diego, California
| | | | - Janelle M Fine
- Department of Medicine, University of California, San Diego, California
| | - Sylvia A B Verbanck
- Respiratory Division, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
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7
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Sandvik RM, Gustafsson PM, Lindblad A, Buchvald F, Olesen HV, Olsen JH, Skov M, Schmidt MN, Thellefsen MR, Robinson PD, Rubak S, Pressler T, Nielsen KG. Contemporary N 2 and SF 6 multiple breath washout in infants and toddlers with cystic fibrosis. Pediatr Pulmonol 2022; 57:945-955. [PMID: 35029068 DOI: 10.1002/ppul.25830] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/20/2021] [Accepted: 01/12/2022] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Multiple breath washout (MBW) is used for early detection of cystic fibrosis (CF) lung disease, with SF6 MBW commonly viewed as the reference method. The use of N2 MBW in infants and toddlers has been questioned for technical and physiological reasons, but a new correction of the N2 signal has minimized the technical part. The present study aimed to assess the remaining differences and the contributing mechanisms for the differences between SF6 and N2 MBW,corrected-such as tidal volume reduction during N2 washout with pure O2 . METHOD This was a longitudinal multicenter cohort study. SF6 MBW and N2 MBW were performed prospectively at three CF centers in the same visits on 154 test occasions across 62 children with CF (mean age: 22.7 months). Offline analysis using identical algorithms to the commercially available program provided outcomes of N2,original and N2,corrected for comparison with SF6 MBW. RESULTS Mean functional residual capacity, FRCN2,corrected was 14.3% lower than FRCN2, original , and 1.0% different from FRCSF6 . Lung clearance index, LCIN2,corrected was 25.2% lower than LCIN2,original , and 7.3% higher than LCISF6 . Mean (SD) tidal volume decreased significantly during N2 MBWcorrected , compared to SF6 MBW (-13.1 ml [-30.7; 4.6], p < 0.0001, equal to -12.0% [-25.7; 1.73]), but this tidal volume reduction did not correlate to the differences between LCIN2,corrected and LCISF6 . The absolute differences in LCI increased significantly with higher LCISF6 (0.63/LCISF6 ) and (0.23/LCISF6 ), respectively, for N2,original and N2,corrected , but the relative differences were stable across disease severity for N2,corrected , but not for N2,original . CONCLUSION Only minor residual differences between FRCN2,corrected and FRCSF6 remained to show that the two methods measure gas volumes very similar in this age range. Small differences in LCI were found. Tidal volume reduction during N2 MBW did not affect differences. The corrected N2 MBW can now be used with confidence in young children with CF, although not interchangeably with SF6 .
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Affiliation(s)
- Rikke M Sandvik
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Per M Gustafsson
- Department of Paediatrics, Central Hospital, Skövde, Sweden.,Institute of Clinical Science, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Lindblad
- Institute of Clinical Science, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Pediatrics, CF Center, Queen Silvia Children's Hospital, Gothenburg, Sweden
| | - Frederik Buchvald
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Hanne V Olesen
- Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Jørgen H Olsen
- Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Marianne Skov
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Marika N Schmidt
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Mette R Thellefsen
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Paul D Robinson
- Department of Respiratory Medicine, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - Sune Rubak
- Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Tacjana Pressler
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Kim G Nielsen
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Rayment JH, Sandoval RA, Roden JP, Schultz KR. Multiple breath washout testing to identify pulmonary chronic graft versus host disease in children after haematopoietic stem cell transplantation. Transplant Cell Ther 2022; 28:328.e1-328.e7. [DOI: 10.1016/j.jtct.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 10/19/2022]
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Stanojevic S, Bowerman C, Robinson P. Multiple breath washout: measuring early manifestations of lung pathology. Breathe (Sheff) 2022; 17:210016. [PMID: 35035543 PMCID: PMC8753656 DOI: 10.1183/20734735.0016-2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 07/13/2021] [Indexed: 11/05/2022] Open
Abstract
The multiple breath washout (MBW) test measures the efficiency of gas mixing in the lungs and has gained significant interest over the past 20 years. MBW outcomes detect early lung function impairment and peripheral airway pathology, through its main outcome measure lung clearance index (LCI). LCI measures the number of lung turnovers required to washout an inert tracer gas. MBW is performed during normal (tidal) breathing, making it particularly suitable for young children or those who have trouble performing forced manoeuvres. Additionally, research in chronic respiratory disease populations has shown that MBW can detect acute clinically relevant changes before conventional lung function tests, such as spirometry, thus enabling early intervention. The development of technical standards for MBW and commercial devices have allowed MBW to be implemented in clinical research and potentially routine clinical practice. Although studies have summarised clinimetric properties of MBW indices, additional research is required to establish the clinical utility of MBW and, if possible, shorten testing time. Sensitive, feasible measures of early lung function decline will play an important role in early intervention for people living with respiratory diseases. Educational aim To describe the multiple breath washout test, its applications to lung pathology and respiratory disease, as well as directions for future research.
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Affiliation(s)
- Sanja Stanojevic
- Dept of Community Health and Epidemiology, Dalhousie University, Halifax, NS, Canada
| | - Cole Bowerman
- Dept of Community Health and Epidemiology, Dalhousie University, Halifax, NS, Canada
| | - Paul Robinson
- Dept of Respiratory Medicine, Children's Hospital at Westmead, Sydney, Australia.,The Children's Hospital at Westmead Clinical School, The University of Sydney, Sydney, Australia
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Wyler F, Oestreich MAH, Frauchiger BS, Ramsey KA, Latzin PT. Correction of sensor crosstalk error in Exhalyzer D multiple-breath washout device significantly impacts outcomes in children with cystic fibrosis. J Appl Physiol (1985) 2021; 131:1148-1156. [PMID: 34351818 DOI: 10.1152/japplphysiol.00338.2021] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
RATIONALE Nitrogen multiple-breath washout is an established technique to assess functional residual capacity and ventilation inhomogeneity in the lung. Accurate measurement of gas concentrations is essential for the appropriate calculation of clinical outcomes. OBJECTIVES We investigated the accuracy of oxygen and carbon dioxide gas sensor measurements used for the indirect calculation of nitrogen concentration in a commercial multiple-breath washout device (Exhalyzer D, Eco Medics AG, Duernten, Switzerland) and its impact on functional residual capacity and lung clearance index. METHODS High precision calibration gas mixtures and mass spectrometry were used to evaluate sensor output. We assessed the impact of corrected signal processing on multiple-breath washout outcomes in a dataset of healthy children and children with cystic fibrosis using custom analysis software. RESULTS We found inadequate correction for the cross sensitivity of the oxygen and carbon dioxide sensors in the Exhalyzer D device. This results in an overestimation of expired nitrogen concentration, and consequently multiple-breath washout outcomes. Breath-by-breath correction of this error reduced the mean (SD) cumulative expired volume by 19.6 (5.0)%, functional residual capacity by 8.9 (2.2)%, and lung clearance index by 11.9 (4.0)%. It also substantially reduced the level of the tissue nitrogen signal at the end of measurements. CONCLUSIONS Inadequate correction for cross sensitivity in the oxygen and carbon dioxide gas sensors of the Exhalyzer D device leads to an overestimation of functional residual capacity and lung clearance index. Correction of this error is possible and could be applied by re-analyzing the measurements in an updated software version.
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Affiliation(s)
- Florian Wyler
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Marc-Alexander H Oestreich
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland.,Graduate School for Health Sciences, University of Bern, Switzerland
| | - Bettina Sarah Frauchiger
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland.,Graduate School of Cellular and Biomedical Sciences, University of Bern, Switzerland
| | - Kathryn A Ramsey
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Philipp T Latzin
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
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11
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Koucký V. Multiple breath washout test in infants-still in search for technical ideal. Pediatr Pulmonol 2021; 56:2397-2398. [PMID: 34126000 DOI: 10.1002/ppul.25531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/03/2021] [Indexed: 11/07/2022]
Affiliation(s)
- Václav Koucký
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University and University Hospital Motol, Prague, Czech Republic
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12
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Horsley AR, Belcher J, Bayfield K, Bianco B, Cunningham S, Fullwood C, Jones A, Shawcross A, Smith JA, Maitra A, Gilchrist FJ. Longitudinal assessment of lung clearance index to monitor disease progression in children and adults with cystic fibrosis. Thorax 2021; 77:357-363. [PMID: 34301741 PMCID: PMC8938654 DOI: 10.1136/thoraxjnl-2021-216928] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/05/2021] [Indexed: 12/02/2022]
Abstract
Background Lung clearance index (LCI) is a valuable research tool in cystic fibrosis (CF) but clinical application has been limited by technical challenges and uncertainty about how to interpret longitudinal change. In order to help inform clinical practice, this study aimed to assess feasibility, repeatability and longitudinal LCI change in children and adults with CF with predominantly mild baseline disease. Methods Prospective, 3-year, multicentre, observational study of repeated LCI measurement at time of clinical review in patients with CF >5 years, delivered using a rapid wash-in system. Results 112 patients completed at least one LCI assessment and 98 (90%) were still under follow-up at study end. The median (IQR) age was 14.7 (8.6–22.2) years and the mean (SD) FEV1 z-score was −1.2 (1.3). Of 81 subjects with normal FEV1 (>−2 z-scores), 63% had raised LCI (indicating worse lung function). For repeat stable measurements within 6 months, the mean (limits of agreement) change in LCI was 0.9% (−18.8% to 20.7%). A latent class growth model analysis identified four discrete clusters with high accuracy, differentiated by baseline LCI and FEV1. Baseline LCI was the strongest factor associated with longitudinal change. The median total test time was under 19 min. Conclusions Most patients with CF with well-preserved lung function show stable LCI over time. Cluster behaviours can be identified and baseline LCI is a risk factor for future progression. These results support the use of LCI in clinical practice in identifying patients at risk of lung function decline.
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Affiliation(s)
- Alex R Horsley
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester Faculty of Biology, Medicine and Health, Manchester, UK .,Manchester Adult Cystic Fibrosis Centre, Manchester University NHS Foundation Trust, Manchester, UK
| | | | - Katie Bayfield
- Respiratory Medicine, Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Brooke Bianco
- Manchester Adult Cystic Fibrosis Centre, Manchester University NHS Foundation Trust, Manchester, UK
| | - Steve Cunningham
- MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, UK
| | - Catherine Fullwood
- Statistics, Research and Innovation, Manchester University NHS Foundation Trust, Manchester, UK.,MAHSC Centre for Biostatistics, University of Manchester, Manchester, UK
| | - Andrew Jones
- Manchester Adult Cystic Fibrosis Centre, Manchester University NHS Foundation Trust, Manchester, UK
| | - Anna Shawcross
- Royal Manchester Children's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Jaclyn A Smith
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester Faculty of Biology, Medicine and Health, Manchester, UK
| | - Anirban Maitra
- Royal Manchester Children's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Francis J Gilchrist
- Academic Department of Child Health, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, UK.,Institute of Applied Clinical Sciences, Keele University, Keele, UK
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13
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Sandvik R, Gustafsson PM, Lindblad A, Robinson PD, Nielsen K. Improved agreement between N 2 and SF 6 multiple-breath washout in healthy infants and toddlers with improved EXHALYZER D sensor performance. J Appl Physiol (1985) 2021; 131:107-118. [PMID: 34043468 DOI: 10.1152/japplphysiol.00129.2021] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Recent studies indicate limited utility of nitrogen multiple-breath washout (N2MBW) in infancy and advocate for using sulfur hexafluoride (SF6) MBW in this age-group. Modern N2MBW systems, such as EXHALYZER D (ECO MEDICS AG, Duernten, Switzerland), use O2 and CO2 sensors to calculate N2 concentrations (in principle, N2% = 100 - CO2% - O2%). High O2 and CO2 concentrations have now been shown to significantly suppress signal output from the other sensor, raising apparent N2 concentrations. We examined whether improved EXHALYZER D N2 signal, accomplished after thorough examination of this CO2 and O2 interaction on gas sensors and its correction, leads to better agreement between N2MBW and SF6MBW in healthy infants and toddlers. Within the same session, 52 healthy children aged 1-36 mo [mean = 1.30 (SD = 0.72) yr] completed SF6MBW and N2MBW recordings (EXHALYZER D, SPIROWARE version 3.2.1) during supine quiet sleep. SF6 and N2 SPIROWARE files were reanalyzed offline with in-house software using identical algorithms as in SPIROWARE with or without application of the new correction factors for N2MBW provided by ECO MEDICS AG. Applying the improved N2 signal significantly reduced mean [95% confidence interval (CI)] differences between N2MBW and SF6MBW recorded functional residual capacity (FRC) and lung clearance index (LCI): for FRC, from 26.1 (21.0, 31.2) mL, P < 0.0001, to 1.18 (-2.3, 4.5) mL, P = 0.5, and for LCI, from 1.86 (1.68, 2.02), P < 0.001, to 0.44 (0.33, 0.55), P < 0.001. Correction of N2 signal for CO2 and O2 interactions on gas sensors resulted in markedly closer agreement between N2MBW and SF6MBW outcomes in healthy infants and toddlers.NEW & NOTEWORTHY Modern nitrogen multiple-breath washout (N2MBW) systems such as EXHALYZER D use O2 and CO2 sensors to calculate N2 concentrations. New corrections for interactions between high O2 and CO2 concentrations on the gas sensors now provide accurate N2 signals. The correct N2 signal led to much improved agreement between N2MBW and sulfur hexafluoride (SF6) MBW functional residual capacity (FRC) and lung clearance index (LCI) in 52 sleeping healthy infants and toddlers, suggesting a role for N2MBW in this age-group.
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Affiliation(s)
- Rikke Sandvik
- Danish Paediatric Pulmonary Service, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Per M Gustafsson
- Department of Paediatrics, Central Hospital, Skövde, Sweden.,Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Lindblad
- Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Gothenburg CF Centre, Queen Silvia Children's Hospital, Gothenburg, Sweden
| | - Paul D Robinson
- Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, New South Wales, Australia.,The Discipline of Paediatrics and Child Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Kim Nielsen
- Danish Paediatric Pulmonary Service, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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14
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Sandhu D, Ritchie GAD, Robbins PA. The differing physiology of nitrogen and tracer gas multiple-breath washout techniques. ERJ Open Res 2021; 7:00858-2020. [PMID: 33898618 PMCID: PMC8053910 DOI: 10.1183/23120541.00858-2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 03/02/2021] [Indexed: 11/08/2022] Open
Abstract
Background Multiple-breath washout techniques are increasingly used to assess lung function. The principal statistic obtained is the lung clearance index (LCI), but values obtained for LCI using the nitrogen (N2)-washout technique are higher than those obtained using an exogenous tracer gas such as sulfur hexafluoride. This study explored whether the pure oxygen (O2) used for the N2 washout could underlie these higher values. Methods A model of a homogenous, reciprocally ventilated acinus was constructed. Perfusion was kept constant, and ventilation adjusted by varying the swept volume during the breathing cycle. The blood supplying the acinus had a standard mixed-venous composition. Carbon dioxide and O2 exchange between the blood and acinar gas proceeded to equilibrium. The model was initialised with either air or air plus tracer gas as the inspirate. Washouts were conducted with pure O2 for the N2 washout or with air for the tracer gas washout. Results At normal ventilation/perfusion (V′/Q′) ratios, the rate of washout of N2 and exogenous tracer gas was almost indistinguishable. At low V′/Q′, the N2 washout lagged the tracer gas washout. At very low V′/Q′, N2 became trapped in the acinus. Under low V′/Q′ conditions, breathing pure O2 introduced a marked asymmetry between the inspiratory and expiratory gas flow rates that was not present when breathing air. Discussion The use of pure O2 to washout N2 increases O2 uptake in low V′/Q′ units. This generates a background gas flow into the acinus that opposes flow out of the acinus during expiration, and so delays the washout of N2. Differences in lung clearance index between nitrogen and exogenous tracer gas multiple-breath washout tests can be explained by the oxygen used to wash out nitrogen generating convective flows of gas into low ventilation/perfusion unitshttps://bit.ly/3l0xq0G
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Affiliation(s)
- Dominic Sandhu
- Dept of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
| | - Grant A D Ritchie
- Dept of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
| | - Peter A Robbins
- Dept of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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15
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Short C, Saunders C, Davies J. Utility of lung clearance index in CF: What we know, what we don't know and musings on how to bridge the gap. J Cyst Fibros 2020; 19:852-855. [DOI: 10.1016/j.jcf.2020.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 11/26/2022]
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16
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17
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Bayfield KJ, Alton E, Irving S, Bush A, Davies JC. Nitrogen offset in N 2 multiple washout method. ERJ Open Res 2020; 6:00043-2020. [PMID: 32201685 PMCID: PMC7073412 DOI: 10.1183/23120541.00043-2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 02/17/2020] [Indexed: 11/05/2022] Open
Abstract
Thank you for the opportunity to respond to the correspondence by J.G. Nielsen from Innovision about our recent paper [1]. We would like to respond with a few points to address any concerns that may have arisen from his comments amongst colleagues at cystic fibrosis centres using the Exhalyzer D (Eco Medics, Dürnten, Switzerland). Addressing concerns with use of the Exhalyzer D multiple breath washout devicehttp://bit.ly/2ug0fAi
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Affiliation(s)
- Katie J Bayfield
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK.,European Cystic Fibrosis Society Clinical Trials Network, Lung Clearance Index Core Facility, London, UK.,The Children's Hospital at Westmead, Sydney, Australia
| | - Eric Alton
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Samantha Irving
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Andrew Bush
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Jane C Davies
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK.,European Cystic Fibrosis Society Clinical Trials Network, Lung Clearance Index Core Facility, London, UK
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18
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Horsley AR, Alrumuh A, Bianco B, Bayfield K, Tomlinson J, Jones A, Maitra A, Cunningham S, Smith J, Fullwood C, Pandyan A, Gilchrist FJ. Lung clearance index in healthy volunteers, measured using a novel portable system with a closed circuit wash-in. PLoS One 2020; 15:e0229300. [PMID: 32097445 PMCID: PMC7041809 DOI: 10.1371/journal.pone.0229300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 02/03/2020] [Indexed: 11/18/2022] Open
Abstract
Introduction Lung clearance index (LCI) is a sensitive measure of early lung disease, but adoption into clinical practice has been slow. Challenges include the time taken to perform each test. We recently described a closed-circuit inert gas wash-in method that reduces overall testing time by decreasing the time to equilibration. The aim of this study was to define a normative range of LCI in healthy adults and children derived using this method. We were also interested in the feasibility of using this system to measure LCI in a community setting. Methods LCI was assessed in healthy volunteers at three hospital sites and in two local primary schools. Volunteers completed three washout repeats at a single visit using the closed circuit wash-in method (0.2% SF6 wash-in tracer gas to equilibrium, room air washout). Results 160 adult and paediatric subjects successfully completed LCI assessment (95%) (100 in hospital, 60 in primary schools). Median coefficient of variation was 3.4% for LCI repeats and 4.3% for FRC. Mean (SD) LCI for the analysis cohort (n = 53, age 5–39 years) was 6.10 (0.42), making the upper limit of normal LCI 6.8. There was no relationship between LCI and multiple demographic variables. Median (interquartile range) total test time was 18.7 (16.0–22.5) minutes. Conclusion The closed circuit method of LCI measurement can be successfully and reproducibly measured in healthy volunteers, including in out-of-hospital settings. Normal range appears stable up to 39 years. With few subjects older than 40 years, further work is required to define the normal limits above this age.
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Affiliation(s)
- Alex R. Horsley
- Division of Infection, Immunity & Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Adult CF Centre, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- * E-mail:
| | - Amnah Alrumuh
- Institute of Applied Clinical Science, Keele University, Newcastle-under-Lyme, United Kingdom
- Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, United Kingdom
| | - Brooke Bianco
- Manchester Adult CF Centre, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- NIHR Manchester Clinical Research Facility, Manchester, United Kingdom
| | - Katie Bayfield
- NIHR Manchester Clinical Research Facility, Manchester, United Kingdom
| | - Joanne Tomlinson
- Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, United Kingdom
| | - Andrew Jones
- Division of Infection, Immunity & Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Adult CF Centre, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Anirban Maitra
- Royal Manchester Children’s Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Steve Cunningham
- Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Jaclyn Smith
- Division of Infection, Immunity & Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Catherine Fullwood
- Research and Innovation, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- Centre for Biostatistics, Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Anand Pandyan
- Institute of Applied Clinical Science, Keele University, Newcastle-under-Lyme, United Kingdom
| | - Francis J. Gilchrist
- Institute of Applied Clinical Science, Keele University, Newcastle-under-Lyme, United Kingdom
- Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, United Kingdom
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19
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Trinkmann F, Lenz SA, Schäfer J, Gawlitza J, Schroeter M, Gradinger T, Akin I, Borggrefe M, Ganslandt T, Saur J. Feasibility and clinical applications of multiple breath wash-out (MBW) testing using sulphur hexafluoride in adults with bronchial asthma. Sci Rep 2020; 10:1527. [PMID: 32001782 PMCID: PMC6992773 DOI: 10.1038/s41598-020-58538-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 01/15/2020] [Indexed: 11/17/2022] Open
Abstract
Ventilation heterogeneity is frequent in bronchial asthma and can be assessed using multiple breath wash-out testing (MBW). Most data is available in paediatric patients and using nitrogen as a tracer gas. We aimed to evaluate sulphur hexafluoride (SF6) MBW in adult asthmatics. Spirometry, whole-body plethysmography, impulse oscillometry and SF6-MBW were prospectively performed. MBW parameters reflecting global (lung clearance index, LCI), acinar (Sacin) and conductive (Scond) ventilation heterogeneity were derived from three consecutive wash-outs. LCI was calculated for the traditional 2.5% and an earlier 5% stopping point that has the potential to reduce wash-out times. 91 asthmatics (66%) and 47 non-asthmatic controls (34%) were included in final analysis. LCI2.5 and LCI5 were higher in asthmatics (p < 0.001). Likewise, Sacin and Scond were elevated (p < 0.001 and p < 0.01). Coefficient of variation was 3.4% for LCI2.5 and 3.5% for LCI5 in asthmatics. Forty-one asthmatic patients had normal spirometry. ROC analysis revealed an AUC of 0.906 for the differentiation from non-asthmatic controls exceeding diagnostic performance of individual and conventional parameters (AUC = 0.819, p < 0.05). SF6-MBW is feasible and reproducible in adult asthmatics. Ventilation heterogeneity is increased as compared to non-asthmatic controls persisting in asthmatic patients with normal spirometry. Diagnostic performance is not affected using an earlier LCI stopping point while reducing wash-out duration considerably.
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Affiliation(s)
- Frederik Trinkmann
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany. .,Department of Biomedical Informatics of the Heinrich-Lanz-Centre, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.
| | - Steffi A Lenz
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Julia Schäfer
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Joshua Gawlitza
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Michele Schroeter
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Tobias Gradinger
- Department of Biomedical Informatics of the Heinrich-Lanz-Centre, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Ibrahim Akin
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Mannheim, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Martin Borggrefe
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Mannheim, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Thomas Ganslandt
- Department of Biomedical Informatics of the Heinrich-Lanz-Centre, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Joachim Saur
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
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20
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Nielsen JG. Nitrogen offset in N 2 multiple washout method. ERJ Open Res 2020; 6:00335-2019. [PMID: 32201687 PMCID: PMC7073414 DOI: 10.1183/23120541.00335-2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 11/18/2022] Open
Abstract
In a recent study of the nitrogen multiple breath washout (MBW) method to measure lung clearance index (LCI) using the Exhalyzer device (Eco Medics AG, Dürnten, Switzerland), Bayfieldet al. [1] reported an N2 offset signal of ∼1.4%, slightly higher than reported in several previous studies. There was no similar offset using sulfur hexafluoride as the tracer gas measured with the Innocor device (Innovision ApS, Glamsbjerg, Denmark), a finding that is in line with previous reports. The results of this and other studies are extremely important as the Exhalyzer is the device that is currently used in ≥100 cystic fibrosis centres in the European Cystic Fibrosis Society Clinical Trial Network and the Cystic Fibrosis Foundation Therapeutics Development Network in various drug trials [2]. An offset in the nitrogen signal significantly affects LCI measured by the N2 MBW methodhttp://bit.ly/35hwOuH
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