An anti-blood-loss valve based on a valve body (6) of flexible, soft material, divided into two parts by an open/close valve (3) on each side of which two valves are seen, one for extracting blood for analysis (4) and the other for blood for reinfusion (5). The valve body (6) also has an input with a connector to the catheter (1) and, opposite, another connector to the serum and/or reinfusion system (2).
