Blood vessel access instrument with vessel entry indicator

A surgical instrument for administering fluids and having a vessel entry indicator to confirm proper placement of the surgical instrument within the vessel includes a vessel access member (100) adapted for accessing a blood vessel and having insertion and trailing ends (110). The access member defines a primary lumen (118) for administering fluids to the blood vessel and a secondary lumen. A pressure detector is in fluid communication with the secondary lumen (120). The pressure detector (124) is adapted to detect pressure associated with a disposition of the insertion end of the access member in the blood vessel. The access member (100) may define a port adjacent the leading end and in fluid communication with the secondary lumen. In one embodiment, the secondary lumen is independent of the primary lumen. The pressure detector (124) may include a float valve responsive to pressure of blood entering from the blood vessel through the port and into the secondary lumen (120). In the alternative, the pressure detector includes a pressure gauge. The pressure gauge is adapted to register pressure associated with a presence of blood entering from the blood vessel through the port and into the secondary lumen.