Anesthesiologic regimen and intraoperative delirium in deep brain stimulation surgery for Parkinson's disease

Background: In many centers the standard anesthesiological care for deep brain stimulation (DBS) surgery in Parkinson's disease patients is an asleep-awake-asleep procedure. However, sedative drugs and anesthetics can compromise ventilation and hemodynamic stability during the operation and some patients develop a delirious mental state after the initial asleep phase. Further, these drugs interfere with the patient's alertness and cooperativeness, the quality of microelectrode recordings, and the recognition of undesired stimulation effects. In this study, we correlated the incidence of intraoperative delirium with the amount of anesthetics used intraoperatively.

Methods: The anesthesiologic approach is based on continuous presence and care, avoidance of negative suggestions, use of positive suggestions, and utilization of the patient's own resources. Clinical data from the operations were analyzed retrospectively, the occurrence of intraoperative delirium was extracted from patients' charts. The last 16 patients undergoing the standard conscious sedation procedure (group I) were compared to the first 22 (group II) psychologically-guided patients.

Results: The median amount of propofol decreased from 146 mg (group I) to 0mg (group II), remifentanyl from 0.70 mg to 0.00 mg, respectively (P<0.001 for propofol and remifentanyl). Using the new procedure, 12 of 22 patients (55%) in group II required no anesthetics. Intraoperative delirium was significantly less frequent in group II (P=0.03).

Conclusions: The occurrence of intraoperative delirium correlates with the amount of intraoperative sedative and anesthetic drugs. Sedation and powerful analgesia are not prerequisites for patients' comfort during awake-DBS-surgery.