Resuscitation assembly (101) comprising a patient mask (107), a ventilation bag (105), an inflation valve (113), an exhalation valve (111), and an expiration indicator (119). The expiration indicator (119) is a positive end expiratory pressure valve in the form of a slit valve that exhibits a slit (131) in a flexible sheet part (125). Also disclosed is a resuscitation assembly (101) comprising a patient mask (107), a ventilation bag (105), an inflation valve (113), an exhalation valve (111), a positive end expiratory pressure valve (119), and a pressure sensor (133) adapted to measure pressure on the patient side (127) of the positive end expiratory pressure valve (119).
