Catheter insertion unit with separate flashback indication for the cannula

摘要

An intravenous assembly includes a needle extending through a hub and a catheter or cannula secured at its proximal end to the hub. The cannula includes a side port near the distal end thereof in fluid communication with an annular flashback chamber formed between the cannula and needle to provide visual indication of venous entry of the cannula. In another embodiment, a longitudinal slot in the internal wall of the cannula defines the cannula flashback chamber. In accordance with the preferred construction, the needle is hollow, and a plug is secured thereto defining another flashback chamber to provide a separate indication of venous entry of the needle.