Pulmonary Function Testing: Flow Volume Loop Patterns • Variable extra-thoracic obstruction - truncated or flattened inspiratory flow & reduced FEF50/FIF50 • Variable intra-thoracic obstruction - truncation or flattening of the expiratory flow • Fixed obstruction - truncation or flattening of both the inspiratory and expiratory flows and an increase in FEF50/FIF50 ratio • Early airflow obstruction - concave upward or “scooped out” expiratory flow with decreased FEF25-75% and persevered FEV1 • Airflow obstruction - concave upward or “scooped out” expiratory flow with reduced FEV1 • Restriction - Nick Mark MD @nickmmark #FlowVolume #Loops #pulmonary #PFTs #patterns #diagnosis
