A vascular access device, the device includes a hollow needle (180) having a sharpened distal tip and defining a side hole (182) proximal to the distal tip； a guidewire (204) preloaded in the needle； a dilator (184) coaxially mounted on the needle； and a sheath (196) coaxially mounted on the dilator (184). A space is defined between the needle and the sheath in communication with the needle bore through the side hole, and a passage communicates with the space independent of the side hole, the passage is of a sufficiently small size such that air escapes from the space through the passage but body fluid within the space does not flow through the passage. At least one of the dilator (184) and sheath (196) is clear, semi-opaque, or translucent, so that body fluid in the space may be visualized through the dilator and/or sheath to confirm proper placement of the needle in a body location.
