Potential misinterpretation of infant lung function unless prospective healthy controls are studied

Lum, Sooky; Hoo, Ah‐Fong; Hülskamp, Georg; Wade, Angie; Stocks, Janet

doi:10.1002/ppul.21255

Cited by 47 publications

(71 citation statements)

References 29 publications

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“…[37][38][39] We have recently demonstrated marked equipment differences in predicted values for parameters of forced expired volumes and flows derived from the rapid thoraco-abdominal compression technique and provided an interim solution for investigators using the Jaeger BabyBody device. 13 In contrast to the outcomes investigated in the current study, forced flows and volumes are known to be influenced by the sex of the infant, 11,12 thereby requiring larger numbers of individuals before reliable reference equations can be developed independently for the Jaeger equipment. Similarly, although equations were formulated for C rs and R rs , these were based on only 105 sets of results, which may be insufficient to create reliable reference equations.…”

Section: Methodsmentioning

confidence: 87%

“…Two investigators (AFH, SL) worked at both sites in London to provide training and on-site supervision throughout the 12 year period of data collection, with random inspection and audit of quality control by an independent investigator (JS). Although raised volume forced expiratory maneuvers were undertaken as part of the research protocols, 13 (see below) these were performed at the end in order to avoid the effect of passive lung inflation used during the raised volume technique on measurements of tidal breathing, plethysmographic FRC and passive respiratory mechanics. With the exception of R rs , within-subject, within-occasion measurements were generally highly repeatable.…”

Section: Methodsmentioning

confidence: 99%

“…This has rarely been done due to the specialized and time-consuming nature of IPF tests and the need for sedation beyond the first few weeks of life. While some reference values have been published previously, [7][8][9][10][11][12] these were frequently derived using custom-built equipment (which may no longer be appropriate when interpreting results collected using current, commercially available equipment 13,14 ) or only encompass a narrow age range. 15 With increasing use of modern IPF devices, there is an urgent need for appropriate equipment-specific normative data that encompass the entire age range over which such measurements are made (generally 0-2 years).…”

Section: Introductionmentioning

confidence: 99%

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New reference equations to improve interpretation of infant lung function

Nguyen¹,

Hoo²,

Lum³

et al. 2012

Pediatric Pulmonology

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Summary. Rationale: With increasing use of infant pulmonary function tests (IPFTs) in both clinical and research studies, appropriate interpretation of results is essential. Objectives: To investigate the potential bias associated with ''normalising'' IPF by expressing results as a ratio of body size and to develop reference ranges for tidal breathing parameters, passive respiratory mechanics (compliance [C rs ] and resistance [R rs ]) and plethysmographic functional residual capacity (FRC p ) for white infants during the first 2 years of life. Methods: IPFTs were measured using the Jaeger BabyBody system and standardized protocols. Reference equations, adjusted for body size, age, and sex where appropriate, were created using multilevel modeling. Results: The ratio of lung function to body length changes markedly with growth, thereby precluding its use for any outcome. While the ratio of tidal volume and C rs to body weight remained relatively constant with growth, this was not the case for FRC p . Even in healthy infants, a strong inverse relationship was observed between lung function/body weight and weight z-score which could distort interpretation of results in growth-restricted infants with lung disease, such as cystic fibrosis. Reference equations were derived from 153 healthy white infants on 232 test occasions (median age 35.5 weeks [range: 2.6-104.7]). Crown-heel length was the strongest predictor of IPF. Conclusions: When reporting IPF, use of size-corrected ratios should be discouraged, with interpretation instead based on appropriate reference equations. The current equations are applicable to white infants and young children up to 2 years of age, studied using the same commercially available equipment. The extent to which these equations are applicable to infants and young children of other ethnic backgrounds or who are tested with different equipment needs to be established.

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Section: Methodsmentioning

confidence: 87%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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New reference equations to improve interpretation of infant lung function

Nguyen¹,

Hoo²,

Lum³

et al. 2012

Pediatric Pulmonology

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“…Early lung function changes may affect longterm respiratory morbidity and even mortality [5][6][7], necessitating longitudinal studies. Although lung function in infants is frequently measured in various ongoing cohort studies, there is still a lack of contemporary and equipment-specific normative data to identify reduced lung function, define disease states and assess lung growth [8].…”

mentioning

confidence: 99%

Normative data for lung function and exhaled nitric oxide in unsedated healthy infants

Fuchs¹,

Latzin²,

Thamrin³

et al. 2010

European Respiratory Journal

123

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Despite association with lung growth and long-term respiratory morbidity, there is a lack of normative lung function data for unsedated infants conforming to latest European Respiratory Society/American Thoracic Society standards.Lung function was measured using an ultrasonic flow meter in 342 unsedated, healthy, termborn infants at a mean¡SD age of 5.1¡0.8 weeks during natural sleep according to the latest standards. Tidal breathing flow-volume loops (TBFVL) and exhaled nitric oxide (eNO) measurements were obtained from 100 regular breaths. We aimed for three acceptable measurements for multiple-breath washout and 5-10 acceptable interruption resistance (Rint) measurements.Acceptable ) for Rint. In males, TBFVL outcomes were associated with anthropometric parameters and in females, with maternal smoking during pregnancy, maternal asthma and Caesarean section.This large normative data set in unsedated infants offers reference values for future research and particularly for studies where sedation may put infants at risk. Furthermore, it highlights the impact of maternal and environmental risk factors on neonatal lung function.

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“…Interpretation of the changes in these parameters (including MEF25-75%) is very difficult due to their low diagnostic specificity and variability in the healthy population [18]. Furthermore, it is advisable to interpret MEF25-75% together with other spirometric parameters, e.g., FVC, FEV1, and PEF [19].…”

Section: Discussionmentioning

confidence: 99%