Agreement between an oscillometric monitor positioned outside the magnetic resonance imaging (MRI) room and invasive blood pressure using an MRI-compatible monitor in dogs

• Grant number: 24/07464-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2024
• End date: June 30, 2025
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Francisco José Teixeira Neto
• Grantee: Leonardo Siqueira Antunes
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

In veterinary medicine, arterial blood pressure measurement must be accurate and reliable, especially during prolonged anesthetic procedures such as magnetic resonance imaging (MRI) examinations, where continuous monitoring of blood pressure is crucial for anesthesia safety. The use of oscillometric blood pressure monitors has proven to be a viable alternative for measuring blood pressure in dogs and cats in various situations, considering that direct (invasive) blood pressure measurement may not be feasible. The environment of the MRI room (Faraday cage) poses a challenge for anesthetic monitoring, as the magnet of the MRI equipment prevents the use of conventional multiparametric monitors inside the MRI environment. Additionally, specific anesthesia/monitoring equipment designed for use within the MRI room is costly. A cost-effective alternative involves using conventional multiparametric monitors outside the MRI room, connected to the patient/animal via long cables. In the specific case of oscillometric pressure monitoring, a cable longer than three times the length of a conventional cable is used (9.3 versus 3 meters, respectively). Although this practice has become routine in many MRI rooms, the effect of the length of the oscillometric pressure cable on the accuracy and precision of arterial blood pressure values is unknown. Based on the aforementioned rationale, the objective is to retrospectively determine the agreement between indirect blood pressure, obtained through an oscillometric monitor positioned outside the Faraday cage, and invasive blood pressure using an MRI-compatible monitor in dogs undergoing magnetic resonance imaging. Anesthetic records of client-owned dogs undergoing MRI at the Veterinary Hospital FMVZ-UNESP, where both invasive blood pressure (obtained through an arterial catheter connected to an MRI-compatible monitor) and non-invasive blood pressure (obtained through an oscillometric monitor positioned outside the Faraday cage, connected to the cuff via a 9.3-meter cable), will be retrospectively collected from February 2023. The agreement between the two methods will be determined using the Bland-Altman method for repeated samples.