14. Intra-arterial Injection Flashcards
Intro
Inadvertent intra-arterial injection is now a relatively rare occurrence, nevertheless it remains an anaesthetic
emergency requiring prompt and effective management. The consequences of intra-arterial injection depend on
the characteristics of the drug injected; sodium thiopentone, for example, precipitates into crystals, which cause
intense vasospasm and may lead to arterial thrombosis.
What are the risk factors for intra-arterial injection?
> Patient:
- Difficult intravenous access
- Unconscious or anaesthetised patients
- Positioning intravenous and intra-arterial access ports close to each other.
> Site of cannulation:
• Antecubital fossa –
unrecognised inadvertent cannulation of the
brachial artery or aberrant ulnar artery
• Dorsum of the hand
inadvertent cannulation of superficial branches
of the radial artery.
How would you recognise inadvertent intra-arterial
injection of thiopentone?
> Awake patients will complain of
pain on injection,
which should always be taken seriously.
Intra-arterial injection may be associated with
other signs such as skin blanching
leading to cyanosis secondary to arterial
spasm.
> Severe ischaemia from vasospasm and intra-arterial thrombosis may lead to digital necrosis.
How would you manage an inadvertent intra-arterial
injection?
State that this is an anaesthetic emergency and that you would call for senior anaesthetic assistance.
> Stop injecting the drug.
> Aim to dilute the drug,
dilate the artery,
prevent thrombosis and
provide analgesia.
> Leave the cannula in situ.
> Dilute the drug by flushing the cannula with 0.9% NaCl or heparinised saline.
> Vasodilate the artery by administering
papaverine 40–80 mg if available.
> Administer 1000 IU heparin to
minimise thrombosis risk.
> 10 mL of 1% lignocaine will provide
some analgesia and has vasodilator properties.
Other management / down the line
Sympathetic blockade of the upper limb will provide both analgesia and vasodilatation.
• Sympathectomy may be achieved via stellate ganglion block, interscalene block or axillary block.
• Guanethedine block is also an option if
expertise is available,
and has the advantage of
long-lasting therapeutic effect.
> Anticoagulation should be continued for 10–14 days.
> Consult with a vascular surgeon if necessary.
> Inform the patient, complete a critical incident report form and document in the medical notes the sequence of events and management.
