Instantaneous Monitoring of Heart Rate Variability and Respiratory Sinus Arrhythmia during Dexmedetomidine Anesthesia

摘要: Background: In previous studies we have established a solid point process paradigm for analyzing heartbeat dynamics and have successfully applied these methods to protocols including induction and emergence from propofol anesthesia [1, 2]. Using a point process approach, these methods have provided accurate characterization of autonomic states at different stages of propofol anesthesia. These methods can assess vagal activity, the major contributor to the heart rate variability (HRV) high frequency component (ppHF), and respiratory sinus arrhythmia (RSA), the influence of respiration on HRV, both in the presence of non-stationary dynamics. Most importantly, these methods can track autonomic dynamics in real time. Our goal is to demonstrate that our framework is suitable for application to a broad range of anesthetic drugs. Specifically, here we aim to characterize the hemodynamic effects in patients undergoing dexmedetomidine anesthesia.Methods: We recorded pulse and respirations from five patients undergoing dexmedetomidine sedation during PET/MR imaging. Patients were fitted with a respiration belt and a piezo-electric pulse transducer for monitoring. We identified R waves with an automatic software program for heartbeat detection and correction [3]. We applied point process models with RR series and respiratory time series as in [2, 4].Results: We found that the mean RR and mean HR (Fig 1A-B) generally reflect a higher bradycardic effect during dexmedetomidine administration, confirmed by the increase of the instantaneous vagally mediated HF HRV power (Fig 1C) and RSA gain (Fig 1F). Our results show that generally …