Agreement between directly measured blood pressure and pressures obtained with three veterinary-specific oscillometric units in cats

OBJECTIVE: To determine whether veterinary-specific oscillometric blood pressure units yield measurements that are in good agreement with directly measured blood pressures in cats. DESIGN: Evaluation study. ANIMALS: 21 cats undergoing routine spaying or neutering. PROCEDURES: A 24-gauge catheter was inserted in a dorsal pedal artery, and systolic, diastolic, and mean arterial pressures were directly measured with a validated pressure measurement system. Values were compared with indirect blood pressure measurements obtained with 3 veterinary-specific oscillometric blood pressure units. RESULTS: There was poor agreement between indirectly and directly measured blood pressures. For unit 1, bias between indirectly and directly measured values was -14.9 mm Hg (95% limits of agreement [LOA], -52.2 to 22.4 mm Hg), 4.4 mm Hg (95% LOA, -26.0 to 34.8 mm Hg), and -1.3 mm Hg (95% LOA, -26.7 to 24.1 mm Hg) for systolic, diastolic, and mean arterial pressures, respectively. For unit 2, bias was -10.3 mm Hg (95% LOA, -52.9 to 32.2 mm Hg), 13.0 mm Hg (95% LOA, -32.1 to 58.0 mm Hg), and 9.1 mm Hg (95% LOA, -32.9 to 51.2 mm Hg) for systolic, diastolic, and mean arterial pressures, respectively. For unit 3, bias was -13.4 mm Hg (95% LOA, -51.8 to 25.1 mm Hg), 8.0 mm Hg (95% LOA, -25.5 to 41.6 mm Hg), and -3.6 mm Hg (95% LOA, -31.6 to 24.5 mm Hg) for systolic, diastolic, and mean arterial pressures, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that none of the 3 veterinary-specific oscillometric blood pressure units could be recommended for indirect measurement of blood pressure in cats.