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

The forced oscillation technique in clinical practice: methodology, recommendations and future developments. E. Oostveen, D. MacLeod, H. Lorino, R. Farré, Z. Hantos, K. Desager, F. Marchal, on behalf of the ERS Task Force on Respiratory Impedance Measurements. #ERS Journals Ltd 2003. ABSTRACT: The forced oscillation technique (FOT) is a noninvasive method with which to measure respiratory mechanics. FOT employs small-amplitude pressure oscillations superimposed on the normal breathing and therefore has the advantage over conventional lung function techniques that it does not require the performance of respiratory manoeuvres. The present European Respiratory Society Task Force Report describes the basic principle of the technique and gives guidelines for the application and interpretation of FOT as a routine lung function test in the clinical setting, for both adult and paediatric populations. FOT data, especially those measured at the lower frequencies, are sensitive to airway obstruction, but do not discriminate between obstructive and restrictive lung disorders. There is no consensus regarding the sensitivity of FOT for bronchodilation testing in adults. Values of respiratory resistance have proved sensitive to bronchodilation in children, although the reported cutoff levels remain to be confirmed in future studies. Forced oscillation technique is a reliable method in the assessment of bronchial hyperresponsiveness in adults and children. Moreover, in contrast with spirometry where a deep inspiration is needed, forced oscillation technique does not modify the airway smooth muscle tone. Forced oscillation technique has been shown to be as sensitive as spirometry in detecting impairments of lung function due to smoking or exposure to occupational hazards. Together with the minimal requirement for the subject9s cooperation, this makes forced oscillation technique an ideal lung function test for epidemiological and field studies. Novel applications of forced oscillation technique in the clinical setting include the monitoring of respiratory mechanics during mechanical ventilation and sleep. Eur Respir J 2003; 22: 1026–1041. *Dept of Pulmonary Medicine, University Hospital Antwerp, Belgium. Scottish Intercollegiate Research Training Network, NHS Education for Scotland, UK. }Service de Physiologie, Hôpital Henri Mondor, CréteilParis, France. z Unitat de Biof ı́sica i Bioenginyeria, Facultat de Medicina, Barcelona, Spain. § Dept of Medical Informatics, University of Szeged, Hungary. Dept of paediatrics, University Hospital Antwerp, Belgium. **Laboratoire d9Explorations Fonctionnelles Pediatriques, Hopital d9Enfants, CHU de Nancy, Vandoeuvre, France.