Heart rate variability in anaesthesiology - narrative review.

Heart rate variability (HRV) is a measure that shows the variation in time between consecutive heartbeats - a physiological phenomenon controlled by the autonomic nervous system. Over the years the analysis of this parameter has been used in many fields of medicine, including anaesthesiology, for scientific and research purposes. We carried out a review of the available literature on the applicability of HRV assessment in anaesthesiology. Several potential applications of HRV in clinical anaesthesia have been identified and proven feasible. As a non-invasive and relatively easy method to gauge the autonomic nervous system, HRV analysis can provide the anaesthesiologist with additional datapoints, potentially useful in assessing efficacy of a blockade and adequacy of analgesia, and in predicting adverse events. However, interpretation of HRV and generalizability of research findings can be problematic due to the multiplicity of factors that influence this parameter and bias in methods introduced by the researchers.