title: Predictors of Seizure Threshold in Right Unilateral Ultrabrief Electroconvulsive Therapy: Role of Concomitant Medications and Anaesthesia Used.
abstract: BACKGROUND
  An individualized approach to maximize electroconvulsive therapy (ECT) efficacy and minimize cognitive side effects is to treat patients relative to their seizure threshold (ST). However, although Right Unilateral-Ultrabrief (0.3 ms) (RUL-UB) ECT is increasingly used in clinical settings as an effective form of ECT with minimal cognitive effects, there is sparse data regarding predictors of ST.
  
  
  OBJECTIVE
  To analyze the relationship between ST and clinical and demographic factors in a sample of patients treated with RUL-UB ECT.
  
  
  METHODS
  Clinical, demographic and ECT data from 179 patients in ECT research studies were examined. Seizure threshold was titrated at the first ECT session. ECT was performed with a Thymatron(®) or Mecta(®) device, with thiopentone (2.5-5 mg/kg) or propofol (1-2 mg/kg) anaesthesia. Medications taken at the time of ST titration were documented. The association between ST and candidate predictor variables was examined with regression analysis.
  
  
  RESULTS
  Multiple regression analyses showed that 34% of the variance in ST (P < 0.001) could be predicted. Older age (R(2) = 0.194, P < 0.001), propofol (vs thiopentone) (R(2) = 0.029, P ≤ 0.01) and higher anaesthetic dose (mg in propofol equivalents) (R(2) = 0.029, P < 0.05) were found to be predictors of higher initial ST. Treatment with lithium (R(2) = 0.043, P < 0.01) and study site (R(2) = 0.019, P < 0.05) significantly predicted lower initial ST.
  
  
  CONCLUSIONS
  Empirical titration is recommended for accurate determination of ST in patients receiving RUL-UB ECT. Novel findings of this study are that propofol anaesthesia resulted in higher ST than thiopentone and concomitant treatment with lithium treatment lowered ST.
authors: School of Psychiatry, University of New South Wales (UNSW), Hospital Road, 2031, Randwick, Sydney, NSW, Australia; Black Dog Institute, Hospital Road, 2031, Randwick, Sydney, NSW Australia.
authors: Verònica
authors: V
authors: Gálvez
authors: School of Psychiatry, University of New South Wales (UNSW), Hospital Road, 2031, Randwick, Sydney, NSW, Australia; Black Dog Institute, Hospital Road, 2031, Randwick, Sydney, NSW Australia.
authors: Dusan
authors: D
authors: Hadzi-Pavlovic
authors: The Melbourne Clinic & Department of Psychiatry, University of Melbourne, Grattan St Parkville 3010, Melbourne, VIC, Australia.
authors: Deidre
authors: D
authors: Smith
authors: School of Psychiatry, University of New South Wales (UNSW), Hospital Road, 2031, Randwick, Sydney, NSW, Australia; Black Dog Institute, Hospital Road, 2031, Randwick, Sydney, NSW Australia; Department of Psychiatry, St George Hospital, Level 2, James Laws House, Gray St, Kogarah 2217, Sydney, NSW, Australia. Electronic address: colleen.loo@unsw.edu.au.
authors: Colleen K
authors: CK
authors: Loo
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology; D000758:Anesthesia; D000777:Anesthetics / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology; D001714:Bipolar Disorder / Q000523:psychology / Q000628:therapy; D003866:Depressive Disorder / Q000523:psychology / Q000628:therapy; D004305:Dose-Response Relationship, Drug; D004565:Electroconvulsive Therapy / Q000295:instrumentation / Q000379:methods*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D016651:Lithium Carbonate / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015742:Propofol / Q000494:pharmacology; D012640:Seizures / Q000503:physiopathology*; D013874:Thiopental / Q000494:pharmacology; D016896:Treatment Outcome
chemical_list: D000777:Anesthetics; D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D016651:Lithium Carbonate; D013874:Thiopental; D015742:Propofol
keywords: Electroconvulsive therapy; Lithium; Propofol; Right-unilateral; Seizure threshold; Ultrabrief