title: Pre-ictal bispectral index has a positive correlation with seizure duration during electroconvulsive therapy.
abstract: Propofol anesthesia increases the seizure threshold of patients receiving electroconvulsive therapy. Excessive neuronal suppression could result in an unacceptably short seizure. We sought to identify the correlation between the pre-ictal bispectral index (BIS) score and seizure duration in patients receiving electroconvulsive therapy under propofol anesthesia. BIS was monitored in 38 psychotically depressed patients. Anesthesia was induced by a bolus injection of 1 mg/kg of propofol. The duration of muscular and electroencephalographic seizure was measured during the therapy. The BIS immediately before the electrical shock was 54 +/- 13. Both muscular and electroencephalographic seizure durations had a positive correlation with pre-ictal BIS (r = 0.68 and 0.73, respectively; P < 0.01). After the electrically induced seizure, BIS decreased to 30 +/- 8, reflecting post-ictal suppression. BIS scores when the patients had awakened after the seizure had a wide variation (range, 29-81; mean, 45; SD, 13). In conclusion, seizure duration has a positive correlation with BIS immediately before electrical shock; however, BIS may not be an accurate predictor of awakening after electrical shock.
  
  
  CONCLUSIONS
  Pre-ictal bispectral index had a positive correlation with seizure duration and could be useful to prevent an unacceptably short seizure in electroconvulsive therapy under propofol anesthesia.
authors.affiliation: Department of Anesthesiology & Reanimatology, Gunma University School of Medicine, Maebashi, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Nishihara
authors.forename: Shigeru
authors.initials: S
authors.lastname: Saito
mesh_terms: D000328:Adult; D000368:Aged; D004565:Electroconvulsive Therapy; D004569:Electroencephalography; D006801:Humans; D008875:Middle Aged; D015742:Propofol / Q000494:pharmacology; D012640:Seizures / Q000503:physiopathology*; D013997:Time Factors
chemical_list: D015742:Propofol