Blood Pressure Measurement on Arm with Failed AV Fistula
Yes, you can and should measure blood pressure on the arm with a failed (non-functioning) brachiocephalic arteriovenous fistula if it is the only arm available. A failed fistula that is no longer patent or functional does not pose the same hemodynamic concerns as a functioning access.
Key Distinction: Failed vs. Functioning Fistula
The critical factor here is that your fistula has failed - meaning it is no longer patent or carrying high flow. This fundamentally changes the clinical scenario:
Functioning AV fistula: Creates high-flow, low-resistance shunt that significantly alters hemodynamics. Blood flow can exceed 700-1000 mL/min in mature fistulae 1, 2. This causes substantial changes in arterial pressure distal to the access and can lead to falsely low BP readings.
Failed AV fistula: No longer has the high-flow shunt. The hemodynamic alterations that would affect BP measurement accuracy are absent. The arm essentially returns to normal vascular physiology.
Standard BP Measurement Guidelines
The Canadian and American guidelines consistently recommend measuring BP in both arms initially, then using the arm with consistently higher pressure for subsequent measurements 3, 4, 5. Nowhere do these guidelines specifically contraindicate BP measurement on an arm with a failed (non-functioning) vascular access.
The guidelines state to avoid BP measurement on arms with:
- Active, functioning vascular access (due to hemodynamic alterations)
- Lymphedema (post-mastectomy)
- Arterial obstruction
Practical Approach
Measure BP on the arm with the failed fistula using standard technique 3:
- Position patient seated, back supported, feet flat, arm at heart level
- Use appropriately sized cuff (bladder width 40% of arm circumference, length 80-100%)
- Place cuff 3 cm above antecubital fossa, centered over brachial artery
- Rest 5 minutes before measurement
- Take at least 3 measurements, discard first, average latter 2
Important Caveats
- Document clearly that BP is being measured on the arm with the failed fistula
- If there is any residual flow or the fistula status is uncertain, consider alternative sites (lower extremity) or use the contralateral arm if it becomes available
- Be aware that if the failed fistula caused previous arterial steal syndrome, there may be residual arterial insufficiency affecting readings 1
- The presence of scar tissue or previous surgical manipulation should not prevent measurement if the fistula is truly non-functional
When Only One Arm Available
The guidelines prioritize obtaining BP measurements for cardiovascular risk assessment and treatment monitoring 3. When only one arm is available and it contains a failed fistula, the benefit of obtaining BP measurements outweighs theoretical concerns, as the hemodynamic alterations that would compromise accuracy are no longer present.
If you had a functioning fistula and only one arm available, you would need to consider alternative sites (lower extremity with appropriate technique) 6, 5, but this is not your situation.