Within-Day and Between-Day Variability of Blood Pressure Measurement in Healthy Conscious Dogs
Diagnosis and management of systemic arterial hypertension in dogs is based on repeated blood pressure measurement (BPM). The objective was here to assess the within- and between-day variability of BPM using a new device (petMAP, Ramsey Medical, Inc., Tampa, FL).
The study was blinded and randomized. Five healthy conscious adult Beagles were used. They were not familiar with BPM procedure and the three investigators. Each investigator performed two testing on each dog on Day 1. The cuff was placed on the forelimb. For each testing (ie 8 consecutive BPM), the investigator could discard up to 3 outlier BPM and then averaged the values. Similarly, BPM was performed again on Day 2. Coefficients of variation (CV) and standard deviations (SD) for within- and between-day variability were calculated for each investigator using a general linear model.
Four hundred and eighty BPM were made on the two consecutive days. Average systolic (SAP) and diastolic (DAP) blood pressure ranges were [134-209 mmHg] and [66-126 mmHg], respectively. The CVs ranges were [9.0-10.1%] and [12.8-16.4%] for within-day and between-day variability of SAP, respectively. The corresponding SD values were [14.7-16.6 mmHg] and [21.0-27.1 mmHg], respectively. The within-day and between-day variability CVs for DAP were [10.3-14.4%] and [14.2-24.9%].
In conclusion, the within-day and between-day variability need to be documented for validation and relevant clinical interpretation of BPM.