Verònica Gálvez1, Dusan Hadzi-Pavlovic2, Harry Wark3, Simon Harper4, John Leyden5, Colleen K Loo6. 1. School of Psychiatry, University of New South Wales (UNSW), Hospital Road, Randwick, NSW 2031, Australia; Black Dog Institute, Hospital Road, Randwick, NSW 2031, Australia; The Wesley Hospital, 7 Blake St, Kogarah, NSW 2217, Australia. 2. School of Psychiatry, University of New South Wales (UNSW), Hospital Road, Randwick, NSW 2031, Australia; Black Dog Institute, Hospital Road, Randwick, NSW 2031, Australia. 3. School of Psychiatry, University of New South Wales (UNSW), Hospital Road, Randwick, NSW 2031, Australia; The Wesley Hospital, 7 Blake St, Kogarah, NSW 2217, Australia; The Sydney Clinic, 22-24 Murray St, Bronte, NSW 2024, Australia; Children's Hospital Westmead, Hawkesbury Road & Hainsworth Street, Westmead, NSW 2145, Australia. 4. The Wesley Hospital, 7 Blake St, Kogarah, NSW 2217, Australia; Faculty of Medicine, University of New South Wales, Samuels Ave, Kensington, NSW 2052, Australia. 5. The Wesley Hospital, 7 Blake St, Kogarah, NSW 2217, Australia; Department of Anaesthesia and Pain Management, Royal North Shore Hospital, Reserve Rd, St Leonards, NSW 2065, Australia. 6. School of Psychiatry, University of New South Wales (UNSW), Hospital Road, Randwick, NSW 2031, Australia; Black Dog Institute, Hospital Road, Randwick, NSW 2031, Australia; The Wesley Hospital, 7 Blake St, Kogarah, NSW 2217, Australia; St. George Hospital, Gray St, Kogarah, NSW 2217, Australia. Electronic address: colleen.loo@unsw.edu.au.
Abstract
BACKGROUND: Because most common intravenous anaesthetics used in ECT have anticonvulsant properties, their plasma-brain concentration at the time of seizure induction might affect seizure expression. The quality of ECT seizure expression has been repeatedly associated with efficacy outcomes. The time interval between the anaesthetic bolus injection and the ECT stimulus (anaesthetic-ECT time interval) will determine the anaesthetic plasma-brain concentration when the ECT stimulus is administered. OBJECTIVE: The aim of this study was to examine the effect of the anaesthetic-ECT time interval on ECT seizure quality and duration. METHODS: The anaesthetic-ECT time interval was recorded in 771 ECT sessions (84 patients). Right unilateral brief pulse ECT was applied. Anaesthesia given was propofol (1-2 mg/kg) and succinylcholine (0.5-1.0 mg/kg). Seizure quality indices (slow wave onset, amplitude, regularity, stereotypy and post-ictal suppression) and duration were rated through a structured rating scale by a single blinded trained rater. Linear Mixed Effects Models analysed the effect of the anaesthetic-ECT time interval on seizure quality indices, controlling for propofol dose (mg), ECT charge (mC), ECT session number, days between ECT, age (years), initial seizure threshold (mC) and concurrent medication. RESULTS: Longer anaesthetic-ECT time intervals lead to significantly higher quality seizures (p < 0.001 for amplitude, regularity, stereotypy and post-ictal suppression). CONCLUSIONS: These results suggest that the anaesthetic-ECT time interval is an important factor to consider in ECT practice. This time interval should be extended to as long as practically possible to facilitate the production of better quality seizures. Close collaboration between the anaesthetist and the psychiatrist is essential.
BACKGROUND: Because most common intravenous anaesthetics used in ECT have anticonvulsant properties, their plasma-brain concentration at the time of seizure induction might affect seizure expression. The quality of ECTseizure expression has been repeatedly associated with efficacy outcomes. The time interval between the anaesthetic bolus injection and the ECT stimulus (anaesthetic-ECT time interval) will determine the anaesthetic plasma-brain concentration when the ECT stimulus is administered. OBJECTIVE: The aim of this study was to examine the effect of the anaesthetic-ECT time interval on ECTseizure quality and duration. METHODS: The anaesthetic-ECT time interval was recorded in 771 ECT sessions (84 patients). Right unilateral brief pulse ECT was applied. Anaesthesia given was propofol (1-2 mg/kg) and succinylcholine (0.5-1.0 mg/kg). Seizure quality indices (slow wave onset, amplitude, regularity, stereotypy and post-ictal suppression) and duration were rated through a structured rating scale by a single blinded trained rater. Linear Mixed Effects Models analysed the effect of the anaesthetic-ECT time interval on seizure quality indices, controlling for propofol dose (mg), ECT charge (mC), ECT session number, days between ECT, age (years), initial seizure threshold (mC) and concurrent medication. RESULTS: Longer anaesthetic-ECT time intervals lead to significantly higher quality seizures (p < 0.001 for amplitude, regularity, stereotypy and post-ictal suppression). CONCLUSIONS: These results suggest that the anaesthetic-ECT time interval is an important factor to consider in ECT practice. This time interval should be extended to as long as practically possible to facilitate the production of better quality seizures. Close collaboration between the anaesthetist and the psychiatrist is essential.