Asthma and lower airway disease
Impulse oscillometry versus spirometry in a long-term study of controller therapy for pediatric asthma

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Background

Determination of the benefits and limitations of specific physiologic tests has not been well studied in long-term clinical pediatric trials.

Objective

We sought to determine the utility of impulse oscillometry in a long-term comparison of 3 controller regimens in children with persistent asthma.

Methods

Children 6 to 14 years of age with mild-to-moderate persistent asthma were characterized with oscillometry and spirometry before entry into a clinical trial and then serially during 48 weeks of therapy with either an inhaled corticosteroid, a combination inhaled corticosteroid with a long-acting β-agonist, or a leukotriene receptor antagonist.

Results

The FEV1/forced vital capacity ratio, as well as the forced expiratory flow from 25% to 75% of forced vital capacity in terms of spirometric parameters and the reactance area (XA) from impulse oscillometry, appeared to complement information provided by FEV1 when comparing the tests and factors that appeared to predict a response to treatment. XA was unique in that it, as distinct from spirometric variables, reflected ongoing improvement during the latter part of the trial. In general, improvements in XA during the latter part of the study occurred independently of indices of atopy and the level of airway responsiveness.

Conclusion

Assessment of respiratory mechanics over time with oscillometry might offer additional insights into the response of asthmatic patients to therapy. In particular, the pattern of improvement seen in XA over the course of therapy suggests this test might detect alterations in airway mechanics not reflected by spirometry. The possibility that changes in XA reflect ongoing improvement in small airway function deserves additional study.

Section snippets

Study population

The study population for the PACT has been described.12 Briefly, children with asthma 6 to less than 14 years of age were screened, characterized, and randomized at 5 clinical centers of the Childhood Asthma Research and Education (CARE) Network funded by the National Heart, Lung, and Blood Institute (NHLBI). The PACT was designed to compare the effectiveness of 3 treatment regimens in achieving asthma control in school-aged children with mild-to-moderate persistent asthma. Inclusion criteria

Demographics/clinical characteristics of study participants

Demographic characteristics were presented by Sorkness et al.12 Of the 285 randomized subjects, 252 completed the study. The 3 treatment groups were well matched, with characteristics at baseline of mild-to-moderate asthma. Of the scheduled visits, 97% were completed. Adherence to study medications was high, as presented in the main outcome article.12 In terms of the primary outcome (asthma control days), fluticasone monotherapy and PACT combination therapy were comparable and superior to

Discussion

Assessment of lung function with IOS was easily accomplished in children with persistent asthma who were 6 to 14 years of age. This study found one IOS parameter (XA) demonstrated continued improvement over a prolonged period of time compared with spirometric variables. As such, IOS might offer a valuable adjunct to spirometry in following the course of subjects enrolled in clinical studies. In terms of biomarkers, a higher level of circulating eosinophils identified subjects more likely to

References (37)

  • G.L. Larsen et al.

    Assessing respiratory function in young children: developmental considerations

    J Allergy Clin Immunol

    (2005)
  • G.L. Larsen et al.

    Functional assessment of asthma

  • E. Oostveen et al.

    The forced oscillation technique in clinical practice: methodology, recommendations and future developments

    Eur Respir J

    (2003)
  • K.N. Desager et al.

    Forced oscillation technique

  • E.J. Duiverman et al.

    Comparison of forced oscillometry and forced expirations for measuring dose-related responses to inhaled methacholine in asthmatic children

    Bull Eur Physiopathol Respir

    (1986)
  • B. Klug et al.

    Measurement of lung function in awake 2-4-year-old asthmatic children during methacholine challenge and acute asthma: a comparison of the impulse oscillation technique, the interrupter technique, and transcutaneous measurement of oxygen versus whole-body plethysmography

    Pediatr Pulmonol

    (1996)
  • E.J. Duiverman et al.

    Bronchial responsiveness in asthmatic children aged 3 to 8 years measured by forced pseudo-random noise oscillometry

    Bull Eur Physiopathol Respir

    (1986)
  • G.R. Vink et al.

    Impulse oscillometry: a measure for airway obstruction

    Pediatr Pulmonol

    (2003)
  • Cited by (0)

    Supported by grants U10HL064287, 5U10HL064288, 5U10HL064295, 5U10HL064305, and 5U10HL064307 from the National Heart, Lung, and Blood Institute. This study was carried out in part in the General Clinical Research Centers at National Jewish Medical and Research Center (M01 RR00051), Washington University School of Medicine (M01 RR00036), and the University of Wisconsin (MO1 RR03186).

    Disclosure of potential conflict of interest: G. L. Larsen is on the Asthma Advisory Board for Genentech and receives grant support from the National Institutes of Health. V. M. Chinchilli receives grant support from the National Heart, Lung, and Blood Institute. R. F. Lemanske is on the speakers' bureau for Merck, is a consultant for GlaxoSmithKline, and receives grant support from the National Heart, Lung, and Blood Institute. F. Martinez is on the Advisory Boards for Merck and MedImmune, receives lecture fees from Merck and Pfizer, and is a consultant for GlaxoSmithKline and Pfizer. S. J. Szefler is a consultant for AstraZeneca, GlaxoSmithKline, Aventis, Genentech, and Merck and receives grant support from the National Institutes of Health; the National Heart, Lung, and Blood Institute; and Ross Pharmaceuticals. R. S. Zeiger is a consultant for Aerocrine, AstraZeneca, Dynavax, Genentech, Merck, Novartis, and GlaxoSmithKline and receives grant support from Sanofi-Aventis, Teva Pharmaceuticals, Merck, AstraZeneca, GlaxoSmithKline, and Genentech. L. B. Bacharier receives honoraria from AstraZeneca, Genentech, GlaxoSmithKline, Merck, and Aerocrine and is on the Advisory Board for Schering-Plough. T. W. Guilbert receives honoraria from GlaxoSmithKline, AstraZeneca, the Peerpoint Medical Education Institute, Merck, Schering-Plough, Genentech/Novartis, and Antidote; receives grant support from Altus Pharmaceuticals, Inspire Pharmaceuticals, the National Institutes of Health, and the National Heart, Lung, and Blood Institute; and is a member of the American Lung Association, American Thoracic Society, and American Academy of Pediatrics. C. A. Sorkness is a consultant and on the speakers' bureau for GlaxoSmithKline and receives grant support from Pharmaxis. The rest of the authors have declared that they have no conflict of interest.

    Deceased.

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