Preoperative Ultra Short-Term Entropy Predicts Arterial Blood Pressure Fluctuation During the Induction of Anesthesia

In Brief BACKGROUND: In this study, we sought to determine whether the preoperative nonlinear index of heart rate variability, ultra short-term entropy (UsEn), could predict cardiovascular responses to the induction of general anesthesia. METHODS: UsEn was estimated by a linearized version of the nonlinear least squares method combined with the maximum entropy spectral analysis method (MemCalc method). Preoperative UsEn of 46 patients (ASA PS 1 or 2, aged 40–60 yr) without a history of hypertension was evaluated using the MemCalc method. Patients were assigned to two groups according to preoperative UsEn (Group LOW; UsEn <45, Group HIGH; UsEn ≥45). Anesthesia was induced with propofol, fentanyl and vecuronium bromide and endotracheal intubation was performed. Hemodynamic fluctuations during the induction of anesthesia were recorded and compared between the two groups. RESULTS: It was found that arterial blood pressure fluctuations during the induction of anesthesia were significantly greater in patients with a low UsEn. CONCLUSION: UsEn could predict arterial blood pressure fluctuations during the induction of anesthesia. IMPLICATIONS: We investigated whether preoperative heart rate variability can predict hemodynamic fluctuations during the induction of general anesthesia. We found that ultra short-term entropy can independently predict arterial blood pressure fluctuations.