Combined pulmonary fibrosis and emphysema syndrome

**Definition:** Combined pulmonary fibrosis and emphysema (CPFE) is a syndrome of combined emphysema of the upper lobes and fibrosis of the lower lobes defined on chest computed tomography, and characterised by subnormal spirometry, severe impairment of gas exchange, high prevalence of pulmonary hypertension, and poor survival. Characteristic functional profile of CPEF is strongly impaired carbon monoxide diffusing capacity of the lung, and hypoxaemia at exercise, with preserved lung volumes. Despite subnormal spirometry, which may be responsible for its under recognition, CPFE is a severe entity. The presence of pulmonary arterial hypertension at diagnosis is a critical determinant of prognosis.