Prospective clinical study to evaluate an oscillometric blood pressure monitor in pet rabbits

Abstract

BackgroundRabbits are particularly sensitive to develop hypotension during sedation or anaesthesia. Values of systolic or mean non-invasive arterial blood pressure below 80 or 60 mmHg respectively are common under anaesthesia despite an ongoing surgery. A reliable method of monitoring arterial blood pressure is extremely important, although invasive technique is not always possible due to the anatomy and dimension of the artery. The aim of this study was to evaluate the agreement between a new oscillometric device for non-invasive arterial blood pressure measurement and the invasive method. Moreover the trending ability of the device, ability to identify changes in the same direction with the invasive methods, was evaluated as well as the sensibility of the device in identifying hypotension arbitrarily defined as invasive arterial blood pressure below 80 or 60 mmHg.ResultsBland-Altman analysis for repeated measurements showed a poor agreement between the two methods; the oscillometric device overestimated the invasive arterial blood pressure, particularly at high arterial pressure values. The same analysis repeated considering oscillometric measurement that match invasive mean pressure lower or equal to 60 mmHg showed a decrease in biases and limits of agreement between methods. The trending ability of the device, evaluated with both the 4-quadrant plot and the polar plot was poor. Concordance rate of mean arterial blood pressure was higher than systolic and diastolic pressure although inferior to 90%. The sensibility of the device in detecting hypotension defined as systolic or mean invasive arterial blood pressure lower than 80 or 60 mmHg was superior for mean oscillometric pressure rather than systolic. A sensitivity of 92% was achieved with an oscillometric measurement for mean pressure below 65 mmHg instead of 60 mmHg. Non-invasive systolic blood pressure is less sensitive as indicator of hypotension regardless of the cutoff limit considered.ConclusionsAlthough mean invasive arterial blood pressure is overestimated by the device, the sensitivity of this non-invasive oscillometric monitor in detecting invasive mean pressure below 60 mmHg is acceptable but a cutoff value of 65 mmHg needs to be used.

Retrospective comparison of the effects of laryngeal mask and endotracheal tube on some cardio-respiratory variables in pet rabbits undergoing anaesthesia for elective gonadectomy

“…Mean and diastolic systemic arterial blood pressure showed a reduction over time mainly during surgery and at the end of the procedure although no statistical differences were observed between groups. An increase in the concentration of volatile anaesthetic in that period may explain the results and confirms the high sensitivity of this species regarding the isoflurane-induced vasodilation [ 4 , 15 ]. Regardless of the device used to secure the airways, values recorded for mean and systolic arterial blood pressures remained above 60 and 85 mmHg, respectively, in most rabbits.…”

“…The anaesthetic records of 21 adult (15 females and 6 males) mixed breed pet rabbits classified as American Society of Anesthesiologists (ASA) physical status 1, collected by the authors for two previous studies [ 15 , 20 ], were retrospectively assessed. The animals were considered healthy based on clinical history and physical examination, and all rabbits did not show abnormal respiratory sounds or nasal and ocular discharge.…”

“…The intraoperative impact of those devices in spontaneously ventilating rabbits has received limited investigation. Moreover, rabbits are particularly sensitive to the cardiovascular depressant effects of general anaesthetics, particularly volatile anaesthetics, and their associated hypotension [ 15 , 16 ]. In dogs, the insertion of the LMA required a lower dose of propofol compared to an endotracheal tube [ 17 ] and in young adult patients undergoing surgery, the LMA was tolerated at lower isoflurane concentration than those required with endotracheal intubation [ 18 ].…”

Agreement between invasive and oscillometric arterial blood pressure measurement using a high-definition oscillometric device in normotensive New Zealand White rabbits using two different anaesthetic protocols

“…A non-HDO oscillometric device (PetTrust Blood Pressure Monitor, Aster Electrical, Taiwan) was tested in anaesthetized rabbits by Bellini et al (2018). As in our study, the device met the ACVIM recommendations for MAP and DAP but not for SAP, but the recommendations of the AAMI were only met for MAP, while the HDO device evaluated in our study met the AAMI requirements for both MAP and DAP.…”

Variation of intraocular pressure comparing rebound (TONOVET Plus®) and applanation (TONO-PEN VET®) tonometry in New Zealand rabbits treated with Amlodipine®

“…At the ophthalmology level, they have also made it possible to understand the pathophysiology of such dire diseases as glaucoma (8,16,32) . Systemic blood pressure can affect the structure and function of the eye as has been reported in different studies indicating that it has an influence on intraocular pressure, becoming a risk factor for the development and progression of glaucoma (2,6,17) . In these studies it has been indicated that not only hypertension, but also hypotension are risk factors for the development of glaucoma, since it can generate a reduction in the perfusion pressure of the central retinal artery and the posterior portion of the optic nerve (produced by cardiovascular changes that increase resistance to blood flow and / or reduce perfusion) (5,17) .…”