Assessment of functional residual capacity using nitrogen washout and plethysmographic techniques in infants with and without bronchopulmonary dysplasia

Wauer, Roland R.; Maurer, Tatjana; Nowotny, T.; Schmalisch, Gerd

doi:10.1007/s001340050598

Cited by 36 publications

(22 citation statements)

References 22 publications

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“…46 Likewise, diuretics (chlorothiazide and spironolactone) had a short-term effect on pulmonary mechanics, without altering FRC. 48 The authors interpreted a significant discrepancy between FRC pleth and FRC N2 in this study as attributable to gastrapping and ''underestimation'' of FRC by the washout method, but may have grossly overestimated FRC pleth in infants <5-6 kg, 14 as they used an early model commercial baby plethysmograph. In recurrently wheezing infants following preterm birth (with and without CLDI), FRC He , airway resistance (R) aw , and the FRC He :FRC pleth ratio decreased significantly postsalbutamol, whereas no significant change was observed in FRC pleth .…”

Section: The Extent To Which Functional Findings Can Be Related To Pamentioning

confidence: 67%

“…Table 3 for details). In contrast, FRC pleth from studies using the older ''Hammersmith Hospital Infant Whole Body Plethysmograph'' (Department of Medical Engineering, Hammersmith Hospital, London, UK), 8,65 or the previous model of the Jaeger Baby body plethysmograph, 14 are in agreement with the reference equation of Stocks and Quanjer. 1 The reasons for this seemingly secular change with ''declining'' FRC pleth when using contemporary equipment were discussed in detail recently, 29 and can be attributed primarily to minimizing and adequately accounting for equipment and other residual dead space.…”

Section: Gas Dilutionmentioning

confidence: 76%

“…The method would substantially profit from concomitant assessments of airway resistance 101 and the assessment of gas-trapping by combining plethysmographic and gas dilution measurements of FRC. 14,15 Gas dilution techniques have been used in the neonatal population for some time. Research results have substantially broadened our understanding of RDS and the course of CLDI during infancy and early childhood.…”

Section: Discussionmentioning

confidence: 99%

“…Assessment of FRC using plethysmographic and gas dilution techniques within the same test occasion may provide a clinically relevant indicator of trapped gas in the presence of airway disease. [14][15][16] The assessment of FRC He involves an end-expiratory switch of the infant's normal breathing circuit to a closed circuit of known volume and known initial He concentration. The infant (who initially has no helium in the lungs) breathes from the closed circuit until the He concentration has equilibrated throughout the spirometer-lung system.…”

Section: Gas Dilution Techniquesmentioning

confidence: 99%

“…45 This is in contrast to the gross overestimation (by up to 60%) of small lung volumes (50-100 ml) by the earlier generation of a commercially available plethysmograph, as demonstrated in vitro. 14 Consequently, values of FRC pleth as determined in small infants using this equipment [46][47][48][49] should be interpreted with skepticism. Additional factors contributing to overestimation of FRC pleth were reviewed recently.…”

Section: What Are the Limitations And Strengths Of The Individual Tecmentioning

confidence: 99%

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Lung Function Tests in Neonates and Infants with Chronic Lung Disease of Infancy: Functional Residual Capacity

Hülskamp¹,

Pillow²,

Dinger³

et al. 2005

Pediatric Pulmonology

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Summary. This is the second paper in a review series that will summarize available data and discuss the potential role of lung function testing in infants and young children with acute neonatal respiratory disorders and chronic lung disease of infancy. The current paper addresses the expansive subject of measurements of lung volume using plethysmography and gas dilution/ washout techniques. Following orientation of the reader to the subject area, we focus our comments on areas of inquiry proposed in the introductory paper to this series. The quality of the published literature is reviewed critically, and recommendations are provided to guide future investigation in this field. Measurements of lung volume are important both for assessing growth and development of lungs in health and disease, and for interpreting volume-dependent lung function parameters such as respiratory compliance, resistance, forced expiratory flows, and indices of gas-mixing efficiency. Acute neonatal lung disease is characterized by severely reduced functional residual capacity (FRC), with treatments aimed at securing optimal lung recruitment. While FRC may remain reduced in established chronic lung disease of infancy, more commonly it becomes normalized or even elevated due to hyperinflation, with or without gas-trapping, secondary to airway obstruction. Ideally, accurate and reliable bedside measurements of FRC would be feasible from birth, throughout all phases of postnatal care (including assisted ventilation), and during subsequent long-term follow-up. Although lung volume measurements in extremely preterm infants were described in a research environment, resolution of several issues is required before such investigations can be translated into routine clinical monitoring. Pediatr

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Section: The Extent To Which Functional Findings Can Be Related To Pamentioning

confidence: 67%

Section: Gas Dilutionmentioning

confidence: 76%

Section: Discussionmentioning

confidence: 99%

Section: Gas Dilution Techniquesmentioning

confidence: 99%

Section: What Are the Limitations And Strengths Of The Individual Tecmentioning

confidence: 99%

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Lung Function Tests in Neonates and Infants with Chronic Lung Disease of Infancy: Functional Residual Capacity

Hülskamp¹,

Pillow²,

Dinger³

et al. 2005

Pediatric Pulmonology

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Physical effects of heliox versus oxygen on measurements of functional residual capacity by the nitrogen washout technique in small lung volumes: A model study

Hentschel

Suska

Volbracht

et al. 2001

Pediatric Pulmonology

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Measurements of functional residual capacity (FRC) by the nitrogen (N(2)) washout technique yield low N(2) signals in neonates and preterm infants, especially when they are on high fractions of inspired oxygen (FiO(2)). Thus, recorded values often lie in the low range of detectability. We hypothesized that using heliox instead of oxygen as a washout gas would affect the electric discharge conditions of N(2) molecules in a standard UV analyzer and thus yield higher N(2) signals. We performed three laboratory experiments using conditions similar to those in neonates with pulmonary disease, reproducing different initial FiO(2) values and very small lung volumes. Standard calibration procedures with physical models between 13.5-87 mL using a calibration syringe and purpose-built small calibration cylinders were carried out, and washout gas was either pure oxygen (as is general practice) or heliox at different ratios. We observed that the calibration line with heliox was shifted upwards and the slope was increased, depending on helium concentration and initial FiO(2). Since this effect was dose-dependent with respect to the proportion of helium in the washout gas, this strongly suggests a physical process elicited by the noble gas helium. We conclude that the heliox wash-out modification may help to increase the accuracy of FRC measurements and thus may enable studies of smaller patients or patients on high inspired FiO(2).

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Lung function testing: Chronic lung disease of infancy

Allen¹,

Panitch²

2001

Pediatr. Pulmonol.

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Now that infants with chronic lung disease are reaching adulthood, it is possible to discern patterns of long-term abnormalities in lung function. These patterns indicate that the airway dysfunction in infancy has implications for airway dysfunction in later life. Most studies in later childhood and adolescence report changes in lung volumes, flow rates and prevalence of airway hyper-reactivity in children born prematurely with respiratory distress syndrome (RDS) requiring ventilatory support for more than thirty days, i.e., with classic bronchopulmonary dysplasia (BPD). Comparing the numerous studies of these children enables us to draw certain conclusions regarding the pathogenesis of these abnormalities. The longitudinal evaluation of lung function in infants born prematurely, with or without RDS or BPD, from infancy to early adulthood, may allow us to answer some important fundamental questions about lung and airway growth following premature birth and early lung injury. Some of these questions are: 1) Does prematurity per se lead to abnormal lung and airway function? 2) Does the severity of the neonatal insult correlate with later abnormalities in lung function? 3) What role does airway hyper-reactivity play in the airway dysfunction of later life? 4) Is airway function affected more severely than lung volumes? STUDIES IN INFANTS AND TODDLERSThe recent advances in our ability to assess lung function in infants show great promise in enhancing our understanding of the early abnormalities of infants with chronic lung disease of infancy. Airway function has been assessed by measurements of lung resistance by esophageal manometry and forced expiratory flows by the rapid thoracic compression technique. Low Vmax functional residual capacity (FRC) has been demonstrated in the first year of life in infants with BPD compared to full term infants,' and compared to full term and preterm controk2 Baraldi3 showed similar results in children to age 2 years, and Farstad4 demonstrated infants with BPD had lower flows at 1 and 2 years than did children with RDS alone. Airway conductance through the third year of life is lower in infants with BPD compared to full term and preterm control^,^ and forced expiratory flows by the rapid deflation technique are lower in BPD infants in this age group than in age matched controls.6 0 2001 Wiley-Liss, Inc.Lung volumes, specifically FRC, have also been measured. Gerhardt has shown, using nitrogen washout, that in the first year of life, lung volumes in infants with BPD are lower than in normal controls, whereas in the second and third years, they are higher than in control^.^ The switch from low to high lung volumes can be interpreted as evidence of increasing air trapping due to worsening airway disease during the first year of life. Alternatively, since nitrogen washout can underestimate lung volumes in patients with airway disease, it could indicate improving airway function. A recent study compared measurements of FRC by both nitrogen washout and body plethysmography in the first yea...

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Assessment of functional residual capacity using nitrogen washout and plethysmographic techniques in infants with and without bronchopulmonary dysplasia

Abstract: The FRC(pleth-N2) is a reliable indicator for pulmonary inhomogeneities in infants with respiratory diseases.

Cited by 36 publications

References 22 publications

Lung Function Tests in Neonates and Infants with Chronic Lung Disease of Infancy: Functional Residual Capacity

Lung Function Tests in Neonates and Infants with Chronic Lung Disease of Infancy: Functional Residual Capacity

Physical effects of heliox versus oxygen on measurements of functional residual capacity by the nitrogen washout technique in small lung volumes: A model study

Lung function testing: Chronic lung disease of infancy

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