Intravascular devices and catheters can be inserted in the intensive
care unit (ICU) for a variety of purposes, including fluid and drug
administration, pressure monitoring, pacemaking, or cardiac augmentation.
Several techniques can be used to obtain access to and cannulate
the vessel. Parenthetically, these same techniques can be used for
other procedures such as thoracentesis or paracentesis.
- ▪ Needle through catheter: Large bore needle inserted
into vessel and smaller bore catheter threaded through needle into
- ▪ Catheter over needle: smaller bore needle inserted into
vessel and large bore catheter threaded over needle into vessel
- ▪ Seldinger technique: Small bore needle inserted into vessel,
wire passed through needle into vessel, needle removed, catheter
threaded over wire into vessel, wire removed
- ▪ Modified Seldinger technique: Small bore needle inserted
into vessel, wire passed through needle into vessel, needle removed,
dilator/sheath passed over wire into vessel, wire and dilator removed,
catheter threaded through sheath into vessel, sheath removed
- ▪ Vessel identification
- —Anatomy: Some vessels are identified primarily
through anatomic landmarks.
- • Internal jugular: Typically cannulated at
the apex of the triangle formed by the sternal and clavicular portions
of the sternocleidomastoid muscle and the clavicle, wherein the
needle is inserted at this location and aimed toward the ipsilateral
- • Subclavian vein: Typically passes under the clavicle
in the midclavicular line, and the needle is inserted so as to pass
under the clavicle at this point aiming toward the sterna notch
- —Pulses: Vessel location may be indicated by
- —The internal jugular vein is typically adjacent
and lateral to the internal carotid artery.
- —The femoral vein is medial to the femoral artery
in the groin.
- —Ultrasound: Increasingly portable, high fidelity
ultrasound devices are available at the bedside to guide vascular
- ▪ Vessel cannulation
- —Direct cannulation: The needle is inserted
into the vessel and a catheter is threaded directly over it into
the vessel (Figure 34-1).
- —Transfixion: The needle is passed through both
the front and back walls of the vessel and withdrawn until there
is free blood flow, at which point the cannula is threaded off of
the needle into the vessel (Figure 34-2).
- —Seldinger variants: The vessel is cannulated with
a needle or catheter as above, and a wire is passed into the vessel
over which dilators or catheters can readily be exchanged while
access to the vessel is maintained with the wire (Figure 34-3).
Figure 34-1. Figure 34-2.