In this study participants who are due to undergo elective major surgery and have an arterial line as part of their standard care will be invited to have the additional monitoring device (HDA) included as part of their care. Agreeing participants will have demographic, contact and medical history information necessary to conduct the study recorded, including a record of their intraoperative arterial line measurements.~After completing the consent process participants will receive intraoperative monitoring with Hypotension Decision Assist in addition to their standard care. The HDA monitor will be attached to the patient vital signs monitor, which will in turn be attached to the blood pressure transducer. All sampled arterial line data collected by the patient vital signs monitored will be automatically transmitted in real time to the HDA device via a serial cable attached to a digital export port of the vital signs monitor. HDA will process this input data to display, in graphical and numeric format, vital signs data and physiological parameters derived from the arterial wave form data including: Mean Arterial Pressure (MAP), systolic and diastolic blood pressure, heart rate and changes in heart rate, cardiac output and systemic vascular resistance.~The output from the study will be compared to the primary and secondary outcomes to evaluate the performance and safety of the device and to evaluate whether HDA improves control of the cardiovascular system from the anaesthetists' perspective.
This clinical investigation will investigate whether Hypotension Decision Assist (HDA) is a feasible, safe and effective patient clinical decision support system to enhance an anaesthetist's ability to manage a patient's cardiovascular system when undergoing surgery. If successful, this study will provide evidence that the use of HDA facilitates beneficial outcomes for patients who have this device used.