Determination of loss of consciousness: a comparison of clinical assessment, bispectral index and electroencephalogram: An observational study.

Background: Computer-processed algorithms of encephalographic signals are widely used to assess the depth of anaesthesia. However, data indicate that the bispectral index (BIS), a processed electroencephalography monitoring system, may not be reliable for assessing the depth of anaesthesia.

Objective: The aim of this study was to evaluate the ability of the BIS monitoring system to assess changes in the level of unconsciousness, specifically during the transition from consciousness to unconsciousness, in patients undergoing total intravenous anaesthesia with propofol.

Pharmacogenetics, plasma concentrations, clinical signs and EEG during propofol treatment.

A variety of techniques have been developed to monitor the depth of anaesthesia. Propofol's pharmacokinetics and response vary greatly, which might be explained by genetic polymorphisms. We investigated the impact of genetic variations on dosage, anaesthetic depth and recovery after total intravenous anaesthesia with propofol.

Cumulated time with low bispectral index values is not related to the risk of new cancer or death within 5 years after surgery in patients with previous or prevailing malignancy.

Background: Preclinical data indicate that anesthesia and surgery may promote cancer growth. We previously found no increased risk of malignant disease within 5 years regarding duration of general anesthesia (TANESTH) and time with Bispectral Index (BIS) under 45 (TBIS < 45) in patients without any diagnosis or history of malignancy before or within 1 month after surgery. Because immunocompetence may be different in patients with previous malignant disease, we investigated the corresponding risk in patients with earlier or existing malignant disease at the time of surgery.

Malignant disease within 5 years after surgery in relation to duration of sevoflurane anesthesia and time with bispectral index under 45.

Background: Surgery, general anesthesia, and related events have been implicated to promote cancer proliferation. We investigated the incidence of cancer within 5 years after surgery in relation to duration of anesthesia (T(ANESTH)) and also by time with bispectral index (BIS) under 45 (T(BIS<45)) serving as a proxy for more profound anesthesia exposure.

Methods: New malignant diagnoses after surgery under sevoflurane anesthesia were obtained in a prospective cohort of 2972 BIS-monitored patients without any clinically diagnosed malignant disease at the time of index surgery.

Mortality within 2 years after surgery in relation to low intraoperative bispectral index values and preexisting malignant disease.

Background: A correlation between deep anesthesia (defined as time with Bispectral Index (BIS) <45; T(BIS <45)) and death within 1 yr after surgery has previously been reported. In order to confirm or refute these findings, we evaluated T(BIS <45) as an independent risk factor for death within 1 and 2 yr after surgery and also the impact of malignancy, the predominant cause of death in the previous report.

Methods: Mortality within 2 yr after surgery, causes of death and the occurrence of malignant disease at the time of surgery were identified in a cohort of 4087 BIS-monitored patients.