Maximal Expiratory Flow Rate

**Definition:** The airflow rate measured during the first liter expired after the first 200 ml have been exhausted during a FORCED VITAL CAPACITY determination. Common abbreviations are MEFR, FEF 200-1200, and FEF 0.2-1.2.

**Tree numbers:** - E01.370.386.700.660.225.500 - G09.772.650.300.590

**Synonyms:** - Forced Expiratory Flow 0.2-1.2 - Forced Expiratory Flow 200-1200 - Flow Rate, Maximal Expiratory - MEFR