Bispectral index values and propofol concentrations at loss and return of consciousness in patients with frontal brain tumours and control patients

Abstract

The presence of a frontal brain tumour did not affect ipsilateral BIS values, and so need not influence the placement of unilateral BIS electrodes if BIS monitoring is used to titrate propofol anaesthesia.

Pharmacokinetics and pharmacodynamics of propofol: changes in patients with frontal brain tumours

“…This is a secondary analysis of data collected during a previously published study 8 that was approved by the local ethics committee (University Medical Center Groningen Ethics Committee, number 2009058) and registered at ClinicalTrials.gov (NCT01060631). All subjects provided written informed consent and were included between August 2009 and April 2011.…”

“…None had neurological, cognitive, sensory, or cardiovascular deficits, which could have potentially interfered with the study protocol. Initially 56 subjects were enrolled; 16 were excluded from further analysis, in most cases because they showed equivocal responses to command at transitions of consciousness, and in a few cases because of technical problems (see consort diagram in the previous article 8 ). This yielded a dataset originating from 20 subjects with frontal brain tumours and 20 control (spinal surgery) subjects.…”

“…The clinical protocol has been described previously. 8 Before the operation, a 20G intravenous cannula was inserted and standard monitoring equipment was applied as recommended by the American Society of Anesthesiologists. 9 Bilateral BIS electrodes were applied to the patient's forehead and connected to a BIS VISTA monitor (Medtronic, Minneapolis, MN, USA) to record continuous bilateral BIS values during the study.…”

“…[5][6][7] However, we found no significant differences in propofol dose requirements for loss of consciousness, measured propofol plasma concentrations at loss and return of consciousness, and bispectral index (BIS) values at loss and return of consciousness between patients with frontal brain tumours and control patients. 8 The purpose of the current study was to conduct a more extensive, secondary analysis of pharmacokinetic (PK) and pharmacodynamic (PD) data collected during the course of our previous study. We performed additional analyses using all available data and non-linear mixed-effects modelling to answer the following clinical questions: (1) Is it necessary to adjust the induction and maintenance dose of propofol in patients with frontal brain tumour compared with control patients?…”

Bispectral Index in Evaluating Effects of Sedation Depth on Drug-Induced Sleep Endoscopy

“…10,11 Loss of consciousness has been reported to occur at BIS values between 60 and 80. 12,13 Lately, several DISE studies have also investigated BIS during propofol sedation to evaluate sedation levels.…”