Peripheral Pulse Palpation vs. Doppler SAP in Dogs What’s The Relationship?

The physical detection of peripheral pulses, and the characterization of those pulses – as strong, moderate or weak, has long been used in triage assessment protocols in both humans and animals – with the assumption that strong pulses correlate with higher blood pressure, whereas weak pulses correlate with lower blood pressure.

However, in humans, study of the association between peripheral pulse and arterial blood pressure has revealed that systolic arterial pressure measurements were lower than those expected based on traditional correlations, and this has raised concerns about the reliability of pulse pressure in patient assessment.

In this article, we review a veterinary study looking at the validity of this assumption. Prior to this study, there were no clinical studies evaluating the relationship of peripheral pulse to systolic arterial blood pressure in dogs – something the study under discussion aimed to rectify.

Pulse quality is determined by the difference between systolic blood pressure and diastolic blood pressure, and is influenced by several factors, including:

1. Systolic blood pressure
2. Diastolic blood pressure
3. Stroke volume
4. Arterial wall compliance, and
5. Intra-thoracic pressure

This study ^[1] was a prospective observational study of 93 dogs that presented to an emergency service where a physical examination and a systolic arterial blood pressure evaluation were performed prior to any intervention or therapy.

The results of the study were interesting, and revealed the following:

• Absent metatarsal pulses reliably predicted hypotension (systolic arterial blood pressure <90 mm Hg)
• The presence of metatarsal pulses did NOT correlate with normal blood pressure measurement – meaning that a patient with palpable metatarsal pulses could still be hypotensive