Symbolic analysis of heart rate variability differentiates anesthesiological procedures

The present study exploited symbolic analysis of heart period (HP) variability during three different anesthetic strategies during neurosurgical procedures. We monitored HP variability in 93 patients during elective neurosurgical procedures. Patients were randomly assigned to three anesthetic strategies: sevoflurane+fentanyl (S-F), sevoflurane+remifentanil (S-R) and propofol+remifentanil (P-R). All anesthetic strategies were characterized by a reduction of HP variability. An increased presence of stable patterns was detected in the P-R group. Conversely, an increased presence of instable patterns was present in the second hour of surgery in S-F group. Despite an important reduction of HP variability, the symbolic analysis differentiates anesthetic strategies.