Device for emptying the contents of a transfusion / infusion bag, which comprises a pumping sphere (11), a pressure gauge (3), a quick-acting ventilation valve (5； 15), a non-return valve (16 ) and a pressure chamber (12), where the transfusion / infusion bag is wound, where these components can be connected to each other by flexible tubes, characterized by a pressure gauge unit - valves (1) comprising the pressure gauge ( 3) and the quick-acting ventilation valve (5； 15) integrated into a common housing (2) and connected to each other through a tubular duct (6), whose internal diameter (6a) has a cross-sectional flow of a continuous uniform size such as the ends of the flexible tube (10, as well as 13) by a part of the pumping sphere (11), as well as by another part of the pressure chamber (12), where said ends of the tube are intended for the respective section connection it is of the connector (9a and 9b) at the two ends of the tubular conduit (6), where in the tubular conduit (6) between the connection section (9b) of the pumping sphere and the pressure gauge (3) a rotation cylinder (5) as a quick-acting multi-way ventilation valve (15), wherein said ventilation valve, in the positions of the valve (I and II) for pumping (I) or for venting (II), is it is incorporated with the same flow cross-section of a continuous uniform size or internal diameter (14, as well as 14b) as the tubular conductor (6) that connects the manometer and the quick-acting ventilation valve (5； 15), where the non-return valve (16) is provided in the connection section of the pumping sphere (9b； 10).Dispositivo para vaciar el contenido de una bolsa de transfusión / infusión, el cual comprende un esfera de bombeo (11), un manómetro (3), una válvula de ventilación de acción rápida (5； 15), una válvula de no retorno (16) y una cámara de presión (12), en donde se encuentra enrollada la bolsa de transfusión / infusión, donde estos componentes pueden conectarse unos a otros mediante tubos flexibl
