A cannula for the oxygenation of contaminated blood and for returning the blood to a patient, said cannula comprising; - at least one body having a plurality of openings in which, in use, the blood is collected and sprayed, the body having a double lumen structure with ends from which, in use, dirty blood leaves the body and the clean blood enters the body, - at least one anti-bacterial coating located on an upper part of the body that is configured to be in contact with the patient's skin, - more than one indicator, each indicator being a band made of radio opaque material that determines the level and one indicator being located on the upper part of the body in an arterial opening at which clean blood is to be ejected and a further indicator being located at a the lower part of the body, - at least one reinforced area that is resilient and resistant to breakage and that is located in the upper part of the body, - at least one upper venous opening located on the body and configured for the entry of venous blood, - at least one lower venous basket end located at a lower end of the body and having at least one basket end opening, - at least one lower end hole on the body for the withdrawal of blood, which is located such that it is on the upper side of the lower venous basket end, - at least one clamp configured for securing the body on the patient's skin, - the body being elliptical in shape in order to increase the amount of blood sucked, the body being formed by the non-concentric placement, within the elliptical body, of the lumen that is used to inject blood, the said lumen that is used to inject blood having a circular cross section. - at least one body having a plurality of openings in which, in use, the blood is collected and sprayed, the body having a double lumen structure with ends from which, in use, dirty blood leaves the body and the clean blood enters the body, - at least one anti-bacterial coating located on an upper part of the body that is configured to be in contact with the patient's skin, - more than one indicator, each indicator being a band made of radio opaque material that determines the level and one indicator being located on the upper part of the body in an arterial opening at which clean blood is to be ejected and a further indicator being located at a the lower part of the body, - at least one reinforced area that is resilient and resistant to breakage and that is located in the upper part of the body, - at least one upper venous opening located on the body and configured for the entry of venous blood, - at least one lower venous basket end located at a lower end of the body and having at least one basket end opening, - at least one lower end hole on the body for the withdrawal of blood, which is located such that it is on the upper side of the lower venous basket end, - at least one clamp configured for securing the body on the patient's skin, - the body being elliptical in shape in order to increase the amount of blood sucked, the body being formed by the non-concentric placement, within the elliptical body, of the lumen that is used to inject blood, the said lumen that is used to inject blood having a circular cross section.