Impulse oscillometry system. Recommendations and procedure

Abstract

The Impulse Oscillometry System (IOS) is a lung function test that assesses the respiratory system impedance (Z) at different frequencies of oscillation. From the Z we can get the resistance Z (R) and reactance (X) that are the forces that must be overcome so that the air can be moved in and out of the respiratory system. By the results of the IOS is possible to know, indirectly, if the functional pattern is compatible with bronchial obstruction or restriction. The IOS is particularly useful in those patients with bronchial obstruction symptoms that have a normal spirometry, or, for uncooperative patients in testing effort dependent. Although there are international guidelines for carrying out the IOS, this document is intended to guide the clinician about the advantages and usefulness of the IOS and facilitate their implementation by describing the procedure that has been standardized in our laboratory. Finally, we propose a simple strategy on the clinical interpretation of the test.