The Refinement and Assessment of a Technique for General Anaesthesia Maintenance by Feedback Control

Humphreys, Karen J (1989) The Refinement and Assessment of a Technique for General Anaesthesia Maintenance by Feedback Control. MSc(R) thesis, University of Glasgow.

Abstract

The objectives are to improve the quality of control obtained in a previous work which developed a system to maintain anaesthesia by feedback control of systolic arterial pressure (SAP). The study also aims to further validate the anaesthetic state produced by this system. The relationship of arterial pressure (AP) on admission to hospital and in the anaesthetic room to resting values is examined in a preliminary study, bearing in mind the recognition of the phenomenon of "white coat hypertension". Resting SAP, measured by an automatic monitor (Dinamap 1846), is then used to determine target SAP, which is the controlled variable in the feedback control system. Also, fentanyl analgesia is substituted for morphine in 20 of the 64 patients undergoing anaesthesia in this way. This narcotic has a more rapid onset of action than morphine, and it was thought that this would smooth anaesthesia and improve the SAP control. There has been no conscious awareness in patients undergoing anaesthesia by this method, and in this work we aim to further investigate the level of cognitive function during anaesthesia. We use a sensitive technique based on homophone priming in 24 patients. The anaesthetic state is assessed by the quality of SAP control, the absence of conscious awareness, the safety of the recovery period, and by the value of physiological variables during anaesthesia.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: Medicine
• Date of Award: 1989
• Depositing User: Enlighten Team
• Unique ID: glathesis:1989-78035
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:42
• Last Modified: 30 Jan 2020 15:42
• URI: https://theses.gla.ac.uk/id/eprint/78035