Intra-arterial drug injection

Question 1

What patient factors can predispose to patient harm following inadvertent intra-arterial injection

Answer 1

Unconscious and hence unable to indicate there is pain on injection

Hypotension or hypoxia (or both), which leads to a failure to recognise that the cannula is arterial

An anatomically anomalous artery that is accidentally cannulated

Thoracic outlet syndrome with loss of the radial pulse on abduction or rotation of the arm

Question 2

What organisational factors may predispose to inadvertent intra-arterial drug injection

Answer 2

Failure to label the line as arterial

Failure to check which line is being accessed due to the proximity between venous and arterial sampling ports

Poor training resulting in failure to differentiate between an artery and vein prior to cannulation

Question 3

What drug features increase the likelihood of severe extremity injury if injected intra-arterially

Answer 3

Vasoactive Drugs

Hyperosmolar Drugs

Alkaline Drugs that crystallise at physiological pH

Question 4

Describe the mechanisms of injury following inadvertent intra-arterial injection

Answer 4

Arterial Spasm resulting in distal ichaemia: which can be secondary to the drug itself or due to mediators released in response to the drug.

Chemical Arteritis: i.e. direct tissue damage, causing endothelial damage

Initiation of release of harmful endogenous substances, such as thromboxane, which cause endothelial damage and activation of platelets, resulting in thrombosis

Drug precipitation and crystal formation: in the distal microcirculation, causing ischaemia and thrombosis

Question 5

List the acute clinical features of intra-arterial injection

Answer 5

Failure of the drug to have its intended effect (as it should have been administered IV)

Pain at, and distal to, the injection site

Pallor, cyanosis and coolness of limb OR redness and warmth

Paraesthesia

Loss of Distal Pulse

Question 6

What are the steps in managing inadvertent intra arterial injection

Answer 6

Stop the injection

ABC assessment of the patient, to include IV access and administration of the drug by it’s intended route (especially if administration of this drug is urgent)

Keep the original cannula (which is intra-arterial) in situ for treatment of the intra-arterial treatment but ensure it is not used for anything else.

Intra-arterial iloprost (a synthetic analog of prostacyclin (PGI2), a substance that naturally relaxes blood vessels and inhibits platelet aggregation).

Intra-arterial local anaesthetic treatment

Elevation of the extremity to improve venous and lymphatic drainage

Anticoagulation or thrombolysis

Pain control

Involvement of vascular surgeons, radiology, or plastics

Consideration of stellate ganglion or lower limb sympathetic block, depending on the site of the error

Duty of Candour explanation and letter to patient and family

Incident reporting