What is the Wound, Ostomy, and Continence Nurses Society (WOCN)'s position on performing Ankle Brachial Index (ABI) measurements before applying compression?

WOCN Position on ABI Before Compression Therapy

The Wound, Ostomy, and Continence Nurses Society (WOCN) recommends performing an Ankle-Brachial Index (ABI) measurement before applying compression therapy to identify patients with peripheral arterial disease who may be at risk for complications from compression.

Importance of ABI Assessment

• ABI is a simple, noninvasive, and cost-effective screening tool for detecting peripheral arterial disease (PAD) before applying compression therapy 1
• ABI measurement helps identify patients with compromised arterial circulation who may experience adverse effects from compression therapy 1, 2
• Normal ABI values range from 0.91 to 1.40, with the optimal range being 1.11-1.40 3

ABI Interpretation Guidelines

• Normal ABI: 0.91-1.40 - Generally safe for compression therapy 3
• Abnormal ABI: ≤0.90 - Indicates PAD and requires caution with compression 4, 3
• Mild obstruction: 0.60-0.89 - Modified compression may be considered 4
• Moderate obstruction: 0.40-0.59 - Compression generally contraindicated 4
• Severe obstruction: <0.40 - Compression contraindicated; urgent vascular referral needed 4
• Non-compressible vessels: >1.40 - Suggests arterial calcification; requires alternative assessment methods 3, 5

Proper ABI Measurement Technique

• Position patient supine with head and heels fully supported for 5-10 minutes before measurement 1
• Use an 8-10 MHz Doppler ultrasound probe with appropriate gel 1
• Apply properly sized blood pressure cuffs (width should be at least 40% of limb circumference) 1
• Measure systolic pressures in both arms and use the highest reading as the denominator 1
• For diagnostic purposes, calculate ABI using the higher ankle pressure (posterior tibial or dorsalis pedis) divided by the higher brachial pressure 1
• Repeat measurements 2-3 times for accuracy 1

Special Considerations

• Patients with diabetes or end-stage renal disease may have falsely elevated ABIs due to arterial calcification 3
• When ABI is >1.40 but PAD is clinically suspected, alternative assessments such as toe-brachial index should be performed 3
• Post-exercise ABI may be necessary when resting ABI is normal but clinical suspicion of PAD remains 3
• Avoid placing compression over recent bypass grafts due to risk of thrombosis 1
• Serial ABI measurements provide more accurate assessment than a single measurement 1

Clinical Implications for Compression Therapy

• ABI <0.50 is an absolute contraindication for compression therapy due to high risk of tissue damage 4
• ABI 0.50-0.80 requires modified compression and careful monitoring 4
• ABI >0.80 generally indicates safe application of standard compression therapy 4
• Patients with non-compressible vessels (ABI >1.40) require careful clinical assessment before compression therapy, as they may have underlying PAD masked by arterial calcification 3, 5
• Patients with abnormal ABI should be referred for vascular assessment before initiating compression therapy 4, 2

Pitfalls to Avoid

• Failing to perform ABI before initiating compression therapy in patients with lower extremity wounds 4, 2
• Relying solely on palpable pulses to assess arterial circulation (pulses may be palpable despite significant PAD) 4
• Overlooking patients with borderline ABI values (0.91-1.00) who may still be at risk 3
• Not considering alternative diagnostic methods when ABI is elevated in high-risk populations 3
• Applying compression therapy in patients with severe PAD, which could lead to tissue necrosis and limb loss 4, 2