Arterial line

Indications

  • Hemodynamic instability
  • Unreliable non-invasive BP monitoring
  • Titration of vasopressors or other cardioactive drugs
  • Need for recurrent or serial ABG analysis

Contraindications

  • Infection overlying insertion site
  • Known arterial insufficiency or occlusion distal to placement site
  • Traumatic or vascular injury proximal to placement site
  • Dialysis fistula at site

Equipment Needed

Arterial catheter (Seldinger technique)
Arterial catheter (Punktion technique)
  • Sterile gloves, gown, cap, mask
  • Sterile drape
  • Iodine or chlorhexidine prep
  • Local anesthetic
  • 27-30ga needle and syringe for local anesthetic administration
  • Appropriately sized needle and catheter for chosen site
  • Guidewire (may be integrated into needle/catheter)
  • Nonabsorbable suture
  • Armboard to hold wrist in extension (radial site only)
  • 500cc IV NS with pressure bag
  • Transducer kit with tubing
  • Transducer cable
  • Bioderm patch
  • Tegaderm dressing
  • Ultrasound (if using ultrasound-guided technique)

Procedure[1]

General Setup

  1. Identify landmarks and palpate pulse
    • Radial - 1-2 cm proximal to wrist
      • Supinate hand and hold wrist in extension
      • Check for collateral circulation by performing the Allen test
    • Femoral - anteromedial thigh distal to inguinal ligament
  2. Cleanse skin with iodine or chlorhexidine
  3. Anesthetize skin and subcutaneous tissue over site with local anesthetic

"Over-the-needle" technique

  • Gently palpate pulse with nondominant hand to guide needle placement
  • Insert needle at 30-45 degrees to the skin
  • Advance until pulsatile blood is seen in flash chamber or catheter
  • Lower angle of catheter to 10-15 degrees to the skin
  • Advance catheter over needle into artery

"Over-the-wire" technique (Seldinger or modified Seldinger)

  • Gently palpate pulse with nondominant hand to guide needle placement
  • Insert needle at 30-45 degrees to the skin
  • Advance until pulsatile blood is seen in flash chamber or catheter
  • Insert wire through needle into artery
  • Remove needle, leaving wire in place, and advance catheter over wire into artery, then remove wire
    • Some arterial line needles have the wire integrated into flash chamber, allowing the wire to be advanced into artery and the catheter over the needle/wire system without removing the needle

Ultrasound guidance

  • Ultrasound guidance of arterial line placement has been shown to significantly increase first attempt success and decrease time to placement[2][3][4], and should be considered in all arterial line placements

Complications[5]

  • Bleeding
  • Hematoma at puncture site
  • Infection
  • Temporary occlusion of artery (permanent occlusion reported, but rare)
  • Pseudoaneurysm formation

Miscellaneous

  • While you are trying to get an arterial line to get a crude estimate of the systolic pressure (especially if automatic cuff BP machine is not working due to BP too low) you can try one of the following:[6]
    • POCUS blood pressure: inflate cuff and watch when you stop getting flow stops on ultrasound of brachial artery.
    • SpO2 blood pressure: inflate cuff and watch when you stop getting SpO2 on the finger.
  • Arterial line still preferred over the above methods since these are just rough estimates.

References

  1. Tegtmeyer K, Brady G, Lai S, Hodo R, Braner D. Videos in Clinical Medicine. Placement of an arterial line. N Engl J Med. 2006 Apr 13;354(15):e13.
  2. Shiver S, Blaivas M, Lyon M. A prospective comparison of ultrasound-guided and blindly placed radial arterial catheters. Acad Emerg Med. 2006 Dec;13(12):1275-9.
  3. Gu W-J, Tie H-T, Liu J-C, Zeng X-T. Efficacy of ultrasound-guided radial artery catheterization: a systematic review and meta-analysis of randomized controlled trials. Critical Care. 2014;18(3):R93. doi:10.1186/cc13862.
  4. Tang L, Wang F, Li Y, et al. Ultrasound Guidance for Radial Artery Catheterization: An Updated Meta-Analysis of Randomized Controlled Trials. Lazzeri C, ed. PLoS ONE. 2014;9(11):e111527. doi:10.1371/journal.pone.0111527.
  5. Scheer BV, Perel A, Pfeiffer UJ. Clinical review: Complications and risk factors of peripheral arterial catheters used for haemodynamic monitoring in anaesthesia and intensive care medicine. Critical Care. 2002;6(3):199-204.
  6. Scott Weingart. EMCrit 267 – They are not All Right!! An interview on Hemodynamic Assessment with Mike Patterson. EMCrit Blog. Published on March 6, 2020. Accessed on March 8th 2020. Available at https://emcrit.org/emcrit/hemodynamic-lows/