Are hand-held Doppler (Doppler ultrasound) studies necessary prior to ordering vascular studies if pedal pulses are non-palpable?

From the Guidelines

Yes, a hand-held Doppler is recommended prior to ordering vascular studies when pedal pulses are non-palpable. When pedal pulses cannot be felt during physical examination, using a Doppler ultrasound device provides a more sensitive assessment of arterial blood flow in the feet, as noted in the 2016 guidelines by the IWGDF 1. This simple, non-invasive tool can detect blood flow even when pulses are too weak to palpate manually. The presence or absence of Doppler signals helps clinicians determine the severity of potential peripheral arterial disease and guides the decision to proceed with more comprehensive vascular studies.

Key Points to Consider

• A positive Doppler signal (audible blood flow) in the absence of palpable pulses suggests mild to moderate vascular compromise.
• Absence of both palpable pulses and Doppler signals indicates severe arterial insufficiency requiring urgent vascular studies and intervention.
• The use of a hand-held Doppler is supported by guidelines for the diagnosis and treatment of peripheral arterial disease in patients with diabetes and foot ulcers, as seen in the 2012 guidelines for the diagnosis and treatment of diabetic foot infections 1 and specific guidelines for the diagnosis and treatment of peripheral arterial disease in a patient with diabetes and ulceration of the foot 1.
• The IWGDF guidance from 2016 1 emphasizes the importance of a more objective evaluation of PAD in patients with foot ulcers, considering the limitations of medical history and clinical examination alone.

Clinical Application

In clinical practice, the stepwise approach of using a hand-held Doppler before proceeding to more advanced vascular studies is not only efficient but also cost-effective. It allows for the prioritization of patients who truly need more extensive vascular evaluation, thus optimizing resource allocation and potentially improving patient outcomes by ensuring timely intervention for those with severe arterial insufficiency. This approach is in line with the principles of evidence-based medicine, focusing on the use of the best available evidence to guide clinical decisions, as highlighted by the most recent and highest quality study available 1.

From the Research

Assessment of Pedal Pulses

• Palpation of pedal pulses alone is known to be an unreliable indicator for the presence of arterial disease 2.
• The use of portable Doppler ultrasound to measure the resting ankle brachial pressure index is superior to palpation of peripheral pulses as an assessment of the adequacy of the arterial supply in the lower limb 2.

Hand-Held Doppler Prior to Vascular Studies

• If pedal pulses are non-palpable, a hand-held Doppler may be necessary to assess the arterial supply in the lower limb 2, 3.
• Pedal pulse palpation is a reliable initial screening tool for peripheral arterial disease (PAD) in population-based programs, but only when four pedal pulses are present 4.
• If fewer than four pedal pulses are palpable, ankle-brachial index (ABI) measurement should be performed to confirm the presence of PAD 4.

Limitations of Palpation

• Palpation of foot pulses is subject to substantial observer error, particularly for the posterior tibial pulse 5.
• Doppler pressure measurement is preferable to palpation unless pulses are bounding 5.
• The absence of Doppler signals in both ankle arteries is a strong risk factor for predicting death and loss of limb 3.