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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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2
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Jansen D, Jonkman AH, Vries HJD, Wennen M, Elshof J, Hoofs MA, van den Berg M, Man AMED, Keijzer C, Scheffer GJ, van der Hoeven JG, Girbes A, Tuinman PR, Marcus JT, Ottenheijm CAC, Heunks L. Positive end-expiratory pressure affects geometry and function of the human diaphragm. J Appl Physiol (1985) 2021; 131:1328-1339. [PMID: 34473571 DOI: 10.1152/japplphysiol.00184.2021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Positive end-expiratory pressure (PEEP) is routinely applied in mechanically ventilated patients to improve gas exchange and respiratory mechanics by increasing end-expiratory lung volume (EELV). In a recent experimental study in rats, we demonstrated that prolonged application of PEEP causes diaphragm remodeling, especially longitudinal muscle fiber atrophy. This is of potential clinical importance, as the acute withdrawal of PEEP during ventilator weaning decreases EELV and thereby stretches the adapted, longitudinally atrophied diaphragm fibers to excessive sarcomere lengths, having a detrimental effect on force generation. Whether this series of events occurs in the human diaphragm is unknown. In the current study, we investigated if short-term application of PEEP affects diaphragm geometry and function, which are prerequisites for the development of longitudinal atrophy with prolonged PEEP application. Nineteen healthy volunteers were noninvasively ventilated with PEEP levels of 2, 5, 10, and 15 cmH2O. Magnetic resonance imaging was performed to investigate PEEP-induced changes in diaphragm geometry. Subjects were instrumented with nasogastric catheters to measure diaphragm neuromechanical efficiency (i.e., diaphragm pressure normalized to its electrical activity) during tidal breathing with different PEEP levels. We found that increasing PEEP from 2 to 15 cmH2O resulted in a caudal diaphragm displacement (19 [14-26] mm, P < 0.001), muscle shortening in the zones of apposition (20.6% anterior and 32.7% posterior, P < 0.001), increase in diaphragm thickness (36.4% [0.9%-44.1%], P < 0.001) and reduction in neuromechanical efficiency (48% [37.6%-56.6%], P < 0.001). These findings demonstrate that conditions required to develop longitudinal atrophy in the human diaphragm are present with the application of PEEP.NEW & NOTEWORTHY We demonstrate that PEEP causes changes in diaphragm geometry, especially muscle shortening, and decreases in vivo diaphragm contractile function. Thus, prerequisites for the development of diaphragm longitudinal muscle atrophy are present with the acute application of PEEP. Once confirmed in ventilated critically ill patients, this could provide a new mechanism for ventilator-induced diaphragm dysfunction and ventilator weaning failure in the intensive care unit (ICU).
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Affiliation(s)
- Diana Jansen
- Department of Anesthesiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Annemijn H Jonkman
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Heder J de Vries
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Myrte Wennen
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Judith Elshof
- Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands.,Department of Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Maud A Hoofs
- Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands.,Department of Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Marloes van den Berg
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Physiology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Angélique M E de Man
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Christiaan Keijzer
- Department of Anesthesiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gert-Jan Scheffer
- Department of Anesthesiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Armand Girbes
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Pieter Roel Tuinman
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - J Tim Marcus
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Coen A C Ottenheijm
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Physiology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Leo Heunks
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, The Netherlands.,Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
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3
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Mondéjar-López P, Horsley A, Ratjen F, Bertolo S, de Vicente H, Asensio de la Cruz Ò. A multimodal approach to detect and monitor early lung disease in cystic fibrosis. Expert Rev Respir Med 2021; 15:761-772. [PMID: 33843417 DOI: 10.1080/17476348.2021.1908131] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Introduction: In the early stages, lung involvement in cystic fibrosis (CF) can be silent, with disease progression occurring in the absence of clinical symptoms. Irreversible airway damage is present in the early stages of disease; however, reliable biomarkers of early damage due to inflammation and infection that are universally applicable in day-to-day patient management have yet to be identified.Areas covered: At present, the main methods of detecting and monitoring early lung disease in CF are the lung clearance index (LCI), computed tomography (CT), and magnetic resonance imaging (MRI). LCI can be used to detect patients who may require more intense monitoring, identify exacerbations, and monitor responses to new interventions. High-resolution CT detects structural alterations in the lungs of CF patients with the best resolution of current imaging techniques. MRI is a radiation-free imaging alternative that provides both morphological and functional information. The role of MRI for short-term follow-up and pulmonary exacerbations is currently being investigated.Expert opinion: The roles of LCI and MRI are expected to expand considerably over the next few years. Meanwhile, closer collaboration between pulmonology and radiology specialties is an important goal toward improving care and optimizing outcomes in young patients with CF.
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Affiliation(s)
- Pedro Mondéjar-López
- Pediatric Pulmonologist, Pediatric Pulmonology and Cystic Fibrosis Unit, University Hospital Virgen de la Arrixaca, Murcia, Spain
| | - Alexander Horsley
- Honorary Consultant, Respiratory Research Group, Division of Infection, Immunity & Respiratory Medicine, University of Manchester, Manchester, UK
| | - Felix Ratjen
- Head, Division of Respiratory Medicine, Department of Pediatrics, Translational Medicine, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Silvia Bertolo
- Radiologist, Department of Radiology, Ca'Foncello Regional Hospital, Treviso, Italy
| | | | - Òscar Asensio de la Cruz
- Pediatric Pulmonologist, Pediatric Unit, University Hospital Parc Taulí de Sabadell, Sabadell, Spain
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4
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Trinkmann F, Maros M, Roth K, Hermanns A, Schäfer J, Gawlitza J, Saur J, Akin I, Borggrefe M, Herth FJF, Ganslandt T. Multiple breath washout (MBW) testing using sulfur hexafluoride: reference values and influence of anthropometric parameters. Thorax 2021; 76:380-386. [PMID: 33593931 DOI: 10.1136/thoraxjnl-2020-214717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 01/07/2021] [Accepted: 01/20/2021] [Indexed: 11/04/2022]
Abstract
BACKGROUND Multiple breath washout (MBW) using sulfur hexafluoride (SF6) has the potential to reveal ventilation heterogeneity which is frequent in patients with obstructive lung disease and associated small airway dysfunction. However, reference data are scarce for this technique and mostly restricted to younger cohorts. We therefore set out to evaluate the influence of anthropometric parameters on SF6-MBW reference values in pulmonary healthy adults. METHODS We evaluated cross-sectional data from 100 pulmonary healthy never-smokers and smokers (mean 51 (SD 20), range 20-88 years). Lung clearance index (LCI), acinar (Sacin) and conductive (Scond) ventilation heterogeneity were derived from triplicate SF6-MBW measurements. Global ventilation heterogeneity was calculated for the 2.5% (LCI2.5) and 5% (LCI5) stopping points. Upper limit of normal (ULN) was defined as the 95th percentile. RESULTS Age was the only meaningful parameter influencing SF6-MBW parameters, explaining 47% (CI 33% to 59%) of the variance in LCI, 32% (CI 18% to 47%) in Sacin and 10% (CI 2% to 22%) in Scond. Mean LCI increases from 6.3 (ULN 7.4) to 8.8 (ULN 9.9) in subjects between 20 and 90 years. Smoking accounted for 2% (CI 0% to 8%) of the variability in LCI, 4% (CI 0% to 13%) in Sacin and 3% (CI 0% to 13%) in Scond. CONCLUSION SF6-MBW outcome parameters showed an age-dependent increase from early adulthood to old age. The effect was most pronounced for global and acinar ventilation heterogeneity and smaller for conductive ventilation heterogeneity. No influence of height, weight and sex was seen. Reference values can now be provided for all important SF6-MBW outcome parameters over the whole age range. TRIAL REGISTRATION NUMBER NCT04099225.
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Affiliation(s)
- Frederik Trinkmann
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany .,Department of Pneumology and Critical Care Medicine, Thoraxklinik at University Hospital Heidelberg, Translational Lung Research Centre Heidelberg (TLRC), Member of German Centre for Lung Research (DZL), Heidelberg, Baden-Württemberg, Germany.,Department of Biomedical Informatics, Centre for Preventive Medicine & Digital Health Baden-Württemberg, University Medical Centre Mannheim, Mannheim, Germany
| | - Máté Maros
- Department of Biomedical Informatics, Centre for Preventive Medicine & Digital Health Baden-Württemberg, University Medical Centre Mannheim, Mannheim, Germany.,Department of Neuroradiology, University Medical Centre Mannheim, Mannheim, Germany
| | - Katharina Roth
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany
| | - Arne Hermanns
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany
| | - Julia Schäfer
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany
| | - Joshua Gawlitza
- Institute for Clinical Radiology and Nuclear Medicine, University Medical Centre Mannheim, Mannheim, Germany
| | - Joachim Saur
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany
| | - Ibrahim Akin
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany.,DZHK (German Centre for Cardiovascular Research), Mannheim, Germany
| | - Martin Borggrefe
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany.,DZHK (German Centre for Cardiovascular Research), Mannheim, Germany
| | - Felix J F Herth
- Department of Pneumology and Critical Care Medicine, Thoraxklinik at University Hospital Heidelberg, Translational Lung Research Centre Heidelberg (TLRC), Member of German Centre for Lung Research (DZL), Heidelberg, Baden-Württemberg, Germany
| | - Thomas Ganslandt
- Department of Biomedical Informatics, Centre for Preventive Medicine & Digital Health Baden-Württemberg, University Medical Centre Mannheim, Mannheim, Germany
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Frauchiger BS, Carlens J, Herger A, Moeller A, Latzin P, Ramsey KA. Multiple breath washout quality control in the clinical setting. Pediatr Pulmonol 2021; 56:105-112. [PMID: 33058570 DOI: 10.1002/ppul.25119] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/08/2020] [Accepted: 10/10/2020] [Indexed: 01/21/2023]
Abstract
BACKGROUND Multiple breath washout (MBW) is increasingly used in the clinical assessment of patients with cystic fibrosis (CF). Guidelines for MBW quality control (QC) were developed primarily for retrospective assessment and central overreading. We assessed whether real-time QC of MBW data during the measurement improves test acceptability in the clinical setting. METHODS We implemented standardized real-time QC and reporting of MBW data at the time of the measurement in the clinical pediatric lung function laboratory in Bern, Switzerland, in children with CF aged 4-18 years. We assessed MBW test acceptability before (31 tests; 89 trials) and after (32 tests; 96 trials) implementation of real-time QC and compared agreement between reviewers. Further, we assessed the implementation of real-time QC at a secondary center in Zurich, Switzerland. RESULTS Before the implementation of real-time QC in Bern, only 58% of clinical MBW tests were deemed acceptable following retrospective QC by an experienced reviewer. After the implementation of real-time QC, MBW test acceptability improved to 75% in Bern. In Zurich, after the implementation of real-time QC, test acceptability improved from 38% to 70%. Further, the agreement between MBW operators and an experienced reviewer for test acceptability was 84% in Bern and 93% in Zurich. CONCLUSION Real-time QC of MBW data at the time of measurement is feasible in the clinical setting and results in improved test acceptability.
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Affiliation(s)
- Bettina S Frauchiger
- Pediatric Respiratory Medicine, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Julia Carlens
- Pediatric Respiratory Medicine, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Andreas Herger
- Division of Respiratory Medicine and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Alexander Moeller
- Division of Respiratory Medicine and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Philipp Latzin
- Pediatric Respiratory Medicine, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Kathryn A Ramsey
- Pediatric Respiratory Medicine, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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6
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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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Nielsen JG. Impact of leaks in sulfur hexafluoride and nitrogen multiple-breath washout systems. ERJ Open Res 2018; 4:00119-2018. [PMID: 30364376 PMCID: PMC6194202 DOI: 10.1183/23120541.00119-2018] [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: 07/23/2018] [Accepted: 08/30/2018] [Indexed: 12/01/2022] Open
Abstract
A recent study by Lenherret al. [1] helps quantify impacts of leaks on multiple-breath washout (MBW) systems for functional residual capacity (FRC) and lung clearance index (LCI) measurements. In my view, technical leaks (post-capillary and intra-capillary leaks) are avoidable by careful testing of the equipment before connecting to the patient. However, pre-capillary leaks (interface between the device and patient) will occur, even in carefully controlled tests. The study [1], based primarily on computer modelling, provides detailed data showing that LCI measurements are relatively insensitive to expiratory leaks, but quantitative data on errors due to inspiratory leaks are not reported. It is, however, important to note that inspiratory leaks have a much higher impact on nitrogen (N2) MBW LCI and FRC measurements than expiratory leaks. Sulfur hexafluoride multiple-breath washout is insensitive to inspiratory leakshttp://ow.ly/Y3o830lKOpY
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Whitfield CA, Jensen OE, Horsley A. Effect of intermittent inspiratory leaks on measurement of lung clearance index using nitrogen and sulfur hexafluoride. ERJ Open Res 2018; 4:00132-2018. [PMID: 30364344 PMCID: PMC6194200 DOI: 10.1183/23120541.00132-2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 08/30/2018] [Indexed: 11/25/2022] Open
Abstract
Even small air leaks can have a significant impact on LCI measured using N2. This is particularly the case for leaks that occur towards the end of washout. In contrast, leaks generally have a much smaller impact on LCI measured by SF6. http://ow.ly/az7b30lG5Ku.
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Affiliation(s)
- Carl A. Whitfield
- Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester, UK
- School of Mathematics, University of Manchester, Manchester, UK
| | | | - Alex Horsley
- Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester, UK
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Singer F, Ramsey K, Latzin P. Effect of intermittent inspiratory leaks on measurement of lung clearance index using nitrogen and sulfur hexafluoride. ERJ Open Res 2018; 4:00140-2018. [PMID: 30364358 PMCID: PMC6194201 DOI: 10.1183/23120541.00140-2018] [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: 08/28/2018] [Accepted: 08/28/2018] [Indexed: 11/15/2022] Open
Abstract
Nitrogen MBW is susceptible to leaks; effects of leaks on sulfur hexafluoride MBW require further study http://ow.ly/iY6o30lGchV.
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Affiliation(s)
- Florian Singer
- Division of Respiratory Medicine, Dept of Paediatrics, University Hospital of Bern, University of Bern, Bern, Switzerland
| | - Kathryn Ramsey
- Division of Respiratory Medicine, Dept of Paediatrics, University Hospital of Bern, University of Bern, Bern, Switzerland
| | - Philipp Latzin
- Division of Respiratory Medicine, Dept of Paediatrics, University Hospital of Bern, University of Bern, Bern, Switzerland
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