Can an arterial sample be obtained from the same arm where an arteriovenous fistula (AVF) for dialysis is located?

Arterial Sampling in Patients with Arteriovenous Fistulas

Arterial blood samples should not be drawn from the same arm where an arteriovenous fistula (AVF) is located. 1

Rationale for Avoiding Arterial Sampling from Fistula Arm

Risk to the Fistula

Arteriovenous fistulas are critical lifelines for patients requiring hemodialysis. Guidelines explicitly state that any procedures involving the arm with an AVF should be avoided due to several serious risks:

• Risk of infection: Puncturing near the fistula increases infection risk that could compromise the access 1
• Risk of thrombosis: Arterial sampling could damage the vessel wall, potentially leading to clot formation 1
• Risk of damage: The fistula is considered the "lifeline" for individuals on dialysis 1

Clinical Practice Guidelines

The 2024 Diabetologia guidelines clearly state:

• "Any blood draws, infusions and/or blood pressure measurements are contraindicated in the AVF/AVG arm because of the risk of infection, clotting and/or damage to arteriovenous access" 1

The American College of Radiology's 2023 guidelines reinforce this, describing the fistula as the "lifeline" for individuals requiring dialysis and emphasizing protection of this critical access 1

Alternative Sampling Sites

When arterial blood sampling is required in a patient with an AVF, the following alternatives should be used:

1. Contralateral arm: Use the arm without the fistula as the primary alternative site
2. Femoral artery: When both arms have fistulas or other contraindications
3. Radial artery in non-fistula arm: Preferred peripheral site due to dual blood supply to the hand

Blood Gas Accuracy Considerations

It's worth noting that samples taken from an AVF are not accurate for blood gas analysis. Research has shown that:

• Blood samples from either the arterial or venous line within an AVF cannot be used for accurate determination of arterial blood gas and pH values 2
• Direct arterial puncture from a site other than the fistula arm is necessary for accurate clinical results 2

Protecting the Arteriovenous Fistula

The preservation of vascular access is paramount for hemodialysis patients. Additional precautions include:

• No blood pressure measurements on the fistula arm
• No intravenous lines in the fistula arm
• Patient education about protecting the access site
• Regular monitoring of the fistula for signs of dysfunction

Conclusion

The importance of preserving the arteriovenous fistula cannot be overstated. Arterial sampling from the arm with an AVF poses significant risks to this vital access and is contraindicated according to current guidelines. Always use alternative sites for obtaining arterial samples in these patients.