Relationship between plasma concentrations of Lignocaine, Bupivacaine and heart rate variability in patients undergoing transarterial axillary plexus blockade
Principal Investigator: Prof P A Kyriacou
Co-Investigators: Dr S K Pal (St Andrew's Centre for Plastic Surgery & Burns Broomfield Hospital)
Researcher: Dr K Shafqat
Funding: CMERT (charity)
Information about the autonomic neural regulation of the heart and the circulatory system can be obtained by analysing the variability in the cardiovascular signals. Neural regulation due to the sympathetic and parasympathetic divisions of the autonomic nervous system involves responses to respiration, blood pressure regulation and thermoregulation. The degree of neural regulation could be altered by many cardiovascular diseases, medications and physical and mental stress. Several factors can have an indirect effect on cardiovascular signals. Artefacts and other types of noises are also present with the useful information. Heart rate variability (HRV), the beat to beat fluctuation in the heart rate, is a non-invasive technique used with an aim in gaining information about the cardiovascular function. Although there are generally accepted standards for the calculation of HRV metrics and some agreement concerning the clinical application of these metrics, the field of HRV analysis contains many contradictory studies and there exists no clear consensus on the clinical value of HRV metrics. The aim of this study is to utilise the technique of HRV for the first time in a group of locally anaesthetised patients. The focus of the study is to investigate the effect of the local anaesthetics drugs on the parameters estimated during HRV analysis. This study will provide better control on the parameters that might affect HRV analysis. Using advance signal analysis techniques it will be possible to examine the nonlinear complex behaviour of HRV signals. This might reveal further information about the effect of different physical factors affecting HRV. The knowledge gained from this study will allow more precise application of HRV analysis in the field of anaesthesia. For instance, for the detection of toxicity and for the measurement of anaesthetic depth.