Low dose lignocaine added to propofol does not attenuate the response to electroconvulsive therapy

BackgroundThe addition of small amounts of lignocaine (50 mg) to propofol (200 mg) has been previously shown to reduce pain in injection, a common problem with this particular anaesthetic agent. The aim of this study was to investigate whether using the mixture of propofol plus lignocaine had any adverse effects on ECT seizure expression (duration, and ictal quality).MethodIctal EEG records were retrospectively examined in 29 patients who underwent 80 pairs of ECT treatments, one given with propofol alone and one with propofol plus lignocaine. Ictal quality was manually rated for the transition from the polyspike phase to the slow wave phase, amplitude of the mid-ictal spike-and-wave phase, regularity of morphology of the predominant pattern of the slow wave phase, stereotypy, variability of the morphology and amplitude of the slow wave phase and post-ictal suppression.ResultsThere was no significant difference in seizure duration between the two groups (33.4 ± 13.0 s (propofol) vs. 33.6 ± 11.2 s (propofol plus lignocaine). Furthermore although the addition of lignocaine delayed the onset of the slow wave phase by about 1 s, it resulted in an improvement in three of four of the other measures of ictal quality.ConclusionThe addition of a small dose of lignocaine to propofol during ECT treatment enhanced rather than reduced the quality of the seizures produced.