Shortness of breath
Especially when using the white membrane closure of the membrane is already initiated at a very low expiratory airflow. In some patients the membrane also closes on increased exhaliation during physical activity. This causes shortness of breath. Explain proper use of the walk and talk position and practice its use. Also let the patient experience the strength of exhalation that causes closure of the valve and teach patient how to control it to prevent closure of the valve.