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©2013 UpToDate ® Print Email Common patterns on flow-volume loops The flow-volume loops are plotted again absolute lung volume to show the influence of changes in lung volume. Upper left panel: Patient with airflow limitation (solid lines) compared to predicted (dashed lines). Upper middle panel: Patient with mixed disease with reduced airflow and reduced lung volumes. It is important to note that if one only measures airflow, this mixed picture would have been missed. Upper right panel: The flow volume loop observed in a patient with restrictive disease where the increased recoil causes increased airflow. Bottom left panel: Consistent truncation of the inspiratory phase of the loop, characteristic of a variable extrathoracic obstruction, eg, tracheal collapse as might be due to intubation trauma. Bottom middle panel: Another extrathoracic process of a more transient nature characteristic of vocal cord dysfunction. Bottom right panel: Consistent truncation of both inspiration and expiration, characteristic of a fixed obstruction, eg, tracheal stenosis.