Circulation - Arterial line insertion (radial)
Indications
Blood pressure monitoring
Haemodynamic instability
Failed non-invasive monitoring
Titrating drug therapies
or
Frequent arterial blood sampling
Contraindications (absolute in bold)
Proximal traumatic injury (absolute)
Deficient collateral circulation
Site infection
Coagulopathy
Alternatives
Non-invasive blood pressure monitoring
Informed consent
Medical emergency
Consent is not required if the patient lacks capacity or is unable to consent
Brief verbal discussion is recommended if the situation allows
or
Verbal consent
Less complex non-emergency procedure with low risk of complications
Potential complications
Pain
Failure or sampling error (air in sample, venous blood, improper mixing, transportation delay)
Arterial injury (haematoma, haemorrhage, pseudoaneurysm, arterial dissection)
Nerve injury
Thrombosis and distal ischaemia
Infection
Procedural hygiene
Standard precautions
Surgical aseptic non-touch technique
PPE: sterile gloves, surgical mask, eye protection, sterile ultrasound probe cover, gown (provider-dependent)
Area
Resuscitation bay or monitored acute bed
Staff
Procedural clinician and assistant
Equipment
Ultrasound (recommended)
Rolled towel and tape (for arm positioning)
Drawing up needle for lignocaine, 25g needle and 5ml syringes
Arterial cannula (long 20g), integral guidewire cannula set or arterial line set
Non-absorbable suture or transparent adhesive dressing
Fluid giving set primed with 500ml of sterile 0.9% sodium chloride in pressure bag at 300mmHg
Transducer set
Arm board
Pre-heparinised 3ml blood gas syringe and non-injectable red bung
Positioning
Supine with arm and wrist extension (radial artery)
Hand and wrist immobilised in mild dorsiflexion (rolled towel under wrist)
Medication
1-2ml lignocaine 1%
Sequence (insertion)
Palpate pulse or locate with ultrasound
Local anaesthetic infiltration
Insert finding needle 30-45 degrees to skin
Obtain arterial flashback
Perform Seldinger technique or cannulate vessel
Pulsatile flow of blood confirms position in vessel
Sequence (set up)
Connect transducer set to giving set under pressure and prime with flush device to remove all air bubbles
Position transducer at phlebostatic axis (height of atria, fourth intercostal space mid-axillary line)
Connect transducer cable to monitor
Calibrate: set off to patient and open to air then press ‘Zero’ on monitor
Calibrate: when ‘0’ on screen, set open to patient and transducer, off to air
Secure line and dress insertion site (suture if difficulty access or difficult to secure)
Arm board to hold wrist in extension (radial site only)
Sequence (collection from arterial line)
Remove bung from sampling port and attach a 5ml syringe
Turn three-way tap so the arterial line is open from the patient to the sampling port
Attach 5ml syringe to the sampling port and aspirate 2-5ml to ensure the line is clear of saline
Turn the three-way tap so the arterial line is closed from the patient to the sampling port
Remove the 5ml syringe and discard into yellow bin
Attach blood gas syringe to the sampling port
Turn three-way tap so the arterial line is open from the patient to the sampling port and allow syringe to fill
Gentle aspirate if passive filling is slow
Turn three-way tap so the arterial line is closed from the patient to the sampling port
Remove the blood gas syringe from the sampling port
Turn the three-way tap so the arterial line is open from the patient to the flush device
Press the flush device together or pull the toggle to flush the line
Turn the three-way tap so the arterial line is open from the flush device to the sampling port
Flush again into sterile gauze swab to ensure all air is expelled from the system
Turn the three-way tap so it is open to the patient and the transducer
Check there is an arterial waveform on the monitor
Place a new red non-injectable bung on the sampling port
Post-procedure care
Limb neurovascular observations (pulse, colour, temperature, sensation and cap refill)
Document insertion site, attempts, guidewire removal (if used) and any immediate complications
Tips
The radial artery is the preferred site due to accessibility and collateral circulation
The second option is a femoral arterial line, with brachial as a third option
Lignocaine relieves pain and reduces vasospasm at time of puncture aiding placement
If a catheter fails to thread it has not entered the lumen and should not be forced to advance
Ultrasound can significantly improve first attempt success rate
Discussion
We do not recommend Allen’s test or a modified version of Allen’s test prior to placing an arterial line. The evidence for this test is weak with case reports of ischaemic complications after normal test results, and case reports of no ischaemic complications after catheterising of patients with abnormal results.
Peer review
This guideline has been reviewed and approved by the following expert groups:
Emergency Care Institute
Please direct feedback for this procedure to ACI-ECIs@health.nsw.gov.au.
References
NSW Agency for Clinical Innovation. Arterial lines monitoring and management. Sydney: ACI; 2014. 13pp. ICU guide (2014). Report LH_ICU2014. Available from: https://www.aci.health.nsw.gov.au/__data/assets/pdf_file/0007/380185/Arterial_lines_monitoring_and_management.pdf
Roberts JR, Custalow CB, Thomsen TW. Roberts and Hedges’ clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia, PA: Elsevier; 2019.
Dunn RJ, Borland M, O’Brien D (eds.). The emergency medicine manual. Online ed. Tennyson, SA: Venom Publishing; 2019.
Theordore AC, Clermost G, Dalton A. Indications, interpretation, and techniques for arterial catheterization for invasive monitoring. In UpToDate. Waltham (MA): UpToDate; 2019. Available from: https://www.uptodate.com/contents/indications-interpretation-and-techniques-for-arterial-catheterization-for-invasive-monitoring
Melhuish TM, White LD. Optimal wrist positioning for radial arterial cannulation in adults: A systematic review and meta-analysis. Am J Emerg Med. 2016;34(12):2372-2378. doi:10.1016/j.ajem.2016.08.059
White L, Halpin A, Turner M, Wallace L. Ultrasound-guided radial artery cannulation in adult and paediatric populations: a systematic review and meta-analysis. Br J Anaesth. 2016;116(5):610-617. doi:10.1093/bja/aew097