ABSTRACT
This study was conducted to validate the use of high definition oscillometry (HDO) for non-invasive blood pressure (NIBP) measurements in ferrets and to establish reference ranges for NIBP in minimally sedated, healthy, young adult ferrets (<4years of age). The bias, limits of agreement and correlation for HDO compared to direct arterial blood pressure (DABP) measurement were established in 14 anaesthetised ferrets. Measurements were performed at the forelimb, hind limb and tail under hypo- (<110mmHg), normo- (110-170mmHg) and hypertensive (>170mmHg) conditions. Although HDO correlated well with DABP (r>0.90), it showed significant proportional bias, whereby HDO generally underestimated DABP with hyper- and normotensive conditions, and overestimated DABP with hypotensive conditions. Measurements obtained from the hind limb showed higher bias than those obtained from the tail or forelimb (P<0.001). Based on the above, and for practical reasons, the tail was selected as the preferred site of cuff placement in ferrets. Subsequently, a cross-over study was performed in 10 ferrets to establish the minimum dose of butorphanol and midazolam needed to successfully obtain NIBP in 100% of cases. Using this dose (0.2mg/kg IM, each), reference intervals for NIBP from 63 healthy, young adult ferrets were established at 95-155mmHg (systolic), 69-109mmHg (mean) and 51-87mmHg (diastolic) arterial pressures.
Subject(s)
Blood Pressure Determination/veterinary , Blood Pressure/physiology , Ferrets/physiology , Animals , Male , Oscillometry/veterinary , Reference ValuesABSTRACT
BACKGROUND: Current approaches for accurate blood pressure determination rely predominantly on invasive techniques. High Definition Oscillometry (HDO) was evaluated as a potential non-invasive approach for accurate blood pressure recordings in cynomolgus monkeys. METHODS: In conscious animals, systolic, diastolic, mean arterial blood pressure (MAP) and pulse/minute were determined 15 times within approx. 9 minutes per individual. This session was performed during 3 consecutive days. Anaesthesia induced hypotension was controlled simultaneously with HDO and telemetry as reference. RESULTS: Repeated measurements were highly reproducible. After procedural habituation, mean MAP was 96.2 +/- 13.7 mmHg in males and 86.9 +/- 4.3 mmHg in females. Mean intraindividual coefficients of variation ranged between 10.8% and 2.4% depending on the session and parameter. Values determined by HDO corresponded to those reported for invasive techniques. CONCLUSION: Our results demonstrate, using telemetry as reference, the accuracy of HDO-based non-invasive blood pressure measurements in macaques to detect drug-related cardiovascular changes.
Subject(s)
Blood Pressure , Oscillometry/methods , Telemetry/methods , Anesthetics, Dissociative , Animals , Blood Pressure/drug effects , Blood Pressure Determination , Female , Ketamine , Macaca fascicularis , MaleSubject(s)
Cat Diseases/diagnosis , Dog Diseases/diagnosis , Hypertension/veterinary , Practice Guidelines as Topic , Aging , Animals , Antihypertensive Agents/therapeutic use , Blood Pressure/physiology , Cat Diseases/drug therapy , Cat Diseases/therapy , Cats , Dog Diseases/drug therapy , Dog Diseases/therapy , Dogs , Hypertension/diagnosis , Hypertension/drug therapy , Hypertension/therapy , Risk FactorsABSTRACT
Two arm and two leg nerves in each of a group of healthy subjects were stimulated electrically and the muscle action potentials were taken from the corresponding regions by surface electrodes. Volumetrically conducted potentials appeared in almost all cases, and other nerves were stimulated at the same time in many cases. The resultant errors in the calculation of the speed of pulse transmission are considerable. The use of a concentric needle electrode is recommended for recording evoked muscle action potentials.
