Central Line Placement: The Steel Needle vs Angiocatheter Debates

Central line placement is as standardized of a procedure as you can find in healthcare. No matter the city or hospital, the steps are exactly the same without much debate except for the great divide; using a steel needle vs angiocatheter to access the vein.

If you are getting into a debate, it is important to know what you are really debating. The steel needle vs angiocatheter debate is really a debate about the Seldinger Technique versus the Modified Seldinger Technique for central venous access.

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Steel needle vs angiocatheters
Choose your needle

The Steel Needle Club:

The steel needle club generally includes most EM and ICU docs as well as the surgical specialties. This also includes any provider for whom speed is of the essence.

For a crash resuscitation central line, there is nothing faster than the Rapid Introducer Three Step:

  1. Blind stick with steel needle – gain access
  2. Thread the wire – nick
  3. 9fr sheath – over the wire and start resuscitation.

From a patient safety perspective, the challenge with this technique is that the same habits learned in a speed is of the essence Introducer 3 Step are used for every other non-emergent line that is placed.

This can lead to unintended arterial cannulation, hematoma or other central line complications.

Making the Steel Needle, Seldinger Technique Safer:

There are techniques that we can use to make the steel needle, Seldinger technique safer.

The first technique, also the most common, is using ultrasound to guide needle placement.

While there are multiple benefits to ultrasound guidance, simple use of ultrasound does not prevent arterial cannulation.

In fact, use of ultrasound for IJ placement can lead to sloppy technique and result in more arterial injuries due to improper needle direction towards the carotid artery as inexperienced staff start far away from the artery as possible.

Proper needle direction away from the carotid artery as the needle passes deeper in the neck is fundamental to the landmark approach to IJ central line placement that is rarely taught anymore.

The second technique is to use manometry to confirm venous placement of your needle.

With the steel needle Seldinger Technique, this is harder than it sounds. The most common way of performing manometry with a short piece of IV extension tubing requires holding the needle absolutely still to prevent migrating out of the vein and into adjacent structures. The staff or resident who can do this consistently are highly skilled and its not a beginners technique.

Some sites use a t-piece with an pressure waveform monitor to confirm venous placement of the needle tip before passing the wire.

There is also a device on the market that measures the pressure a the needle tip to let you know if your are venous or arterial.

The third technique is to convert the Seldinger technique into a modified-Seldinger technique.

This is done in a series of steps:

  • Pass a wire through your steel needle that is in an unknown vessel.
  • Remove the needle over the wire, while leaving the wire in the unknown vessel.
  • Pass the angiocather over the wire into the unknown vessel
  • Remove the wire from the angiocatheter and unknown vessel
  • Perform manometry using the angiocatheter to confirm venous placement.

As you can see, If you are trying to be safe, this adds a lot of steps to what was a simple three step technique. The solution is to used the modified Seldinger technique from the start.

Steel Needle, Seldinger Technique Summary:

Pro

  • Fast, single pass access
  • Some needles are designed to be more echogenic for ultrasound.
  • Large bore needle makes it easy to pass wire
  • Good for collapsable veins where cannulation can be difficult.

Con

  • Large needle, large holes along the needle path.
  • Difficult to perform manometry and not change position.
  • Adding manometry adds steps
  • Long needle encourages beginners to pass to deep for IJ technique

As you can see, there are a lot of things to like about the steel needle and I will turn to it in very difficult situations. The caveat is that I like to use a micro puncture needle that is 21 gauge instead of the 18 gauge needle that comes in the kit.

The Angiocatheter Club:

This is normally a smaller group at the hospital. It tends to be comprised of mostly comprised of Anesthesiologists and a few ICU and ED physicians who saw the light.

The angiocatheter, modified Seldinger technique is a little more complicated to learn at first, it is a more consistently safe technique than the steel needle, Seldinger technique

The most difficult part of the modified Seldinger technique is threading the angiocatheter off the needle once you have accessed a vessel. Without an understanding of how the angiocatheter is different than the steel needle this can cause lots of challenges for beginners.

Angiocatheter, Modified Seldinger Technique Summary

Pro

  • Single needle pass
  • Smaller needle, smaller hole

Con

  • threading the catheter
  • more difficult the deeper the target vessel

Steel Needle vs Angiocatheter Summary:

Either technique works well and can be used safely. Like most procedures, you are safest when you know what you are doing and why you are doing it.

My general preference is to use the angiocather, modified Seldinger technique as my standard approach. If the patient is severely hypovolemic and the veins are completely collapsed, I will use the steel needle and cannulate the vein as I pull the needle back out, tenting the vein open.

Whats your preferred technique?

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