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.

Podcast version:

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.

Conclusion

The authors conclude that their study highlights the importance of performing blood pressure measurement, as well as taking into consideration other physical indicators such as mucous membrane colour, capillary refill time, mental status and temperature when evaluating dogs for hypotension.

Additionally, they conclude that, as hypotension is a late marker of shock, if blood pressure is normal, but other clinical signs support a diagnosis of shock, that aggressive resuscitation efforts should not be delayed.

Reference:

1. Ateca, Laura B., Erica L. Reineke, and Kenneth J. Drobatz. “Evaluation of the relationship between peripheral pulse palpation and Doppler systolic blood pressure in dogs presenting to an emergency service.” Journal of veterinary emergency and critical care3 (2018): 226-231.

Disclaimer: Every effort has been made to ensure that the information contained in this article is current and correct. No responsibility is assumed by the publisher for loss or injury resulting from any use or operation of methods described herein. Because of rapid advances in medical sciences, independent verification of drug doses and recommendations should be made.

About the Author

Dr. Philip Judge

BVSc MVS PG Cert Vet Stud MACVSc (VECC; Medicine of Dogs)

Director: Vet Education Pty Ltd
Consultant in Veterinary Emergency and Critical Care
Internationally renowned lecturer and published author
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