Evaluation of the White-Coat Effect in Cats

Abstract

The diagnosis and management of systemic hypertension in cats requires a reliable method for measurement of systemic arterial blood pressure (BP) in clinical patients. Unfortunately, the setting of a clinical practice and the act of measuring BP might raise BP and heart rate (HR), an effect referred to as the white-coat effect in human patients. The purpose of the present study was to determine if a white-coat effect was experienced by cats. Radiotelemetric implants were used to measure BP and HR in 13 conscious cats in a research colony while undisturbed in their cages and while subjected to simulated visits to a veterinarian's office. The white-coat effect was taken to be the difference between the overall 24-hour average value for parameters of BP and HR and the corresponding value during the simulated office visit. A white-coat effect was observed in cats. In healthy cats, the systolic BP measured during the examination period of the simulated office visit exceeded the 24-hour average systolic BP by 17.6+/-1.5 mm Hg. However, marked heterogeneity occurred in the pattern and magnitude of the increase in systolic BP above the 24-hour baseline and the increase varied between 75.3 and -27.2 mm Hg for the healthy cats. Variation in response to the simulated office visit was observed among cats and among visits by the same cat. During an office visit, the magnitude of the white-coat effect tended to decrease, but not disappear, over time. The magnitude of the white-coat effect varied when cats were subjected to 5 repeat office visits, but did not diminish in the group as a whole. The mean increase in systolic BP during the examination (22.3+/-0.9 mm Hg) was greater (P < .05) in cats with renal insufficiency. Although the heterogeneity of response expected from companion animals might be greater than that observed in these colony cats, these results indicate that veterinarians should carefully consider the white-coat effect in evaluation of BP in cats. A quiet, undisturbed environment and adequate time for acclimation should be included in the standard protocol for measurements of BP. Because of day-to-day variation in the white-coat effect in individual cats, multiple serial measurements following a standard protocol should provide the best estimate of BP in cats.

Systemic hypertension in cats with acute kidney injury

“…Of particular concern in this study, is the "white coat effect," especially in those patients with fewer blood pressure readings in their clinical records. White-coat hypertension, an increase in blood pressure as a result of adrenergic stimulation during situations of stress, anxiety or excitement, has been documented in healthy cats during simulated visits to a veterinary clinic (Belew et al . 1999 ).…”

Blood Pressure Measurements in 780 Apparently Healthy Cats

“…8 Diseases associated with secondary systemic hypertension in the cat include chronic kidney disease, 9,10 hyperthyroidism, 9 primary hyperaldosteronism, 11 and pheochromocytoma. 12 If none of these diseases are present, and stress-related effects on blood pressure ("white-coat hypertension") 13 have been excluded, then cats with persistent hypertension are considered to have idiopathic hypertension. However, it can be difficult to definitively rule out subclinical renal disease or primary hyperaldosteronism, which can make an unconditional diagnosis of idiopathic hypertension difficult.…”

Blood Pressure, Heart Rate, and Urinary Catecholamines in Healthy Dogs Subjected to Different Clinical Settings

“…1,2 In a study on healthy cats, arrival to a waiting room and handling during clinical examination were associated with significant increases in BP. 3 Less is known about stress-induced effects on BP and heart rate (HR) in dogs in different clinical settings. Blood pressure has been shown to differ among breeds.…”