Comparison of high-definition oscillometry — a non-invasive technology for arterial blood pressure measurement — with a direct invasive method using radio-telemetry in awake healthy cats

Abstract

This study compared indirect blood pressure measurements using a non-invasive method, high-definition oscillometry (HDO), with direct measurements using a radio-telemetry device in awake cats. Paired measurements partitioned to five sub-ranges were collected in six cats using both methods. The results were analysed for assessment of correlation and agreement between the two methods, taking into account all pressure ranges, and with data separated in three sub-groups, low, normal and high ranges of systolic (SBP) and diastolic (DBP) blood pressure. SBP data displayed a mean correlation coefficient of 0.92 ± 0.02 that was reduced for low SBP. The agreement level evaluated from the whole data set was high and slightly reduced for low SBP values. The mean correlation coefficient of DBP was lower than for SBP (ie, 0.81 ± 0.02). The bias for DBP between the two methods was 22.3 ± 1.6 mmHg, suggesting that HDO produced lower values than telemetry. These results suggest that HDO met the validation criteria defined by the American College of Veterinary Internal Medicine consensus panel and provided a faithful measurement of SBP in conscious cats. For DBP, results suggest that HDO tended to underestimate DBP. This finding is clearly inconsistent with the good agreement reported in dogs, but is similar to outcomes achieved in marmosets and cynomolgus monkeys, suggesting that this is not related to HDO but is species related. The data support that the HDO is the first and only validated non-invasive blood pressure device and, as such, it is the only non-invasive reference technique that should be used in future validation studies.

Non-invasive blood pressure measurement in ferrets ( Mustela putorius furo ) using high definition oscillometry

“…These findings are similar to those found in dogs, cats and horses (Wernick et al, 2010;Martel et al, 2013;Rysnik et al, 2013;Seliškar et al, 2013;Tünsmeyer et al, 2015). This discrepancy between DABP and NIBP measurement might be explained in part by the inaccuracy of the device (Wernick et al, 2010), but might also be the result of the technique used to measure NIBP.…”

“…At higher BP and/ or heart rates, amplifications and distortions of the arterial wall will be smaller (Warner, 1957), resulting in lower resonance and thus underestimation of DABP. This phenomenon could explain the shift from a negative to a positive bias seen in the ferrets in our study, as well as in dogs, cats and rabbits (Ypsilantis et al, 2005;Martel et al, 2013;Rysnik et al, 2013).…”

“…These threshold values for hypo-, normo-and hypertensive conditions were based on threshold values used in cats (Martel et al, 2013) and previously published normotensive ranges for ferrets (Lichtenberger and Ko, 2007), where SAP ranged from 80 to 120 mmHg when Fig. 1.…”

“…HDO has been evaluated previously in dogs, cats, horses, cheetahs and monkeys (Schmelting et al, 2009;Meyer et al, 2010;Petri9 c et al, 2010;Wernick et al, 2010;Martel et al, 2013;Rysnik et al, 2013;Seliškar et al, 2013;Mietsch and Einspanier, 2015;Sant Cassia et al, 2015;Tünsmeyer et al, 2015), but not ferrets.…”

Practical guide to monitoring anaesthetised small animal patients

“…To overcome these difficulties, a high-definition oscillometric technique has been developed. This method shows limited agreement with measurements obtained by invasive methods in anaesthetised dogs (Seliškar and others 2013) and awake cats (Martel and others 2013), or when using the Doppler technique in anaesthetised cats (Petric and others 2010); however, it is being increasingly used in small animal clinics.…”