Concordance between linear deflection oscillometry and Doppler decreases as systolic arterial pressure increases in conscious dogs.

Abstract

OBJECTIVE: To evaluate the agreement between linear deflection oscillometry (LDO) and Doppler ultrasonography (DU) for measuring systolic arterial pressure (SAP) in nonsedated dogs. METHODS: Prospective, cross-sectional study, conducted at 2 veterinary teaching hospitals. The study included nonsedated, hospitalized dogs classified by DU SAP as normotensive (90 to 160 mm Hg), hypotensive (< 90 mm Hg), or hypertensive (> 160 mm Hg). The SAP was measured using both DU and LDO. RESULTS: 60 dogs were included (29 normotensive, 17 hypotensive, 14 hypertensive). Passing-Bablok regression demonstrated a significant systematic (intercept, 17.6; 95% CI, 7.4 to 29.7; P < .01) and proportional bias (slope, 0.81; 95% CI, 0.71 to 0.92; P < .01), indicating progressively larger differences between DU and LDO at higher SAP values. Bland-Altman analysis showed a bias of -3.0 &#xb1; 8.49 mm Hg (limits of agreement [LoA], -19.66 to 13.64) in hypotensive dogs, 1.66 &#xb1; 11.96 mm Hg (LoA, -21.8 to 25.1) in normotensive dogs, and 26.7 &#xb1; 26.17 mm Hg (LoA, -24.77 to 78.2) in hypertensive. Receiver operating characteristic analysis suggested LDO thresholds of 93 mm Hg for DU SAP < 90 mm Hg (AUC, 0.994; P < .0001) and 143 mm Hg for DU SAP > 160 mm Hg (AUC, 0.891; P < .0001). CONCLUSIONS: LDO and DU demonstrated acceptable agreement in normotensive and hypotensive dogs but weak concordance in hypertensive. CLINICAL RELEVANCE: LDO may be a practical alternative to DU in normotensive and hypotensive states, but caution is warranted in hypertensive patients.