BACKGROUND The anaesthetic approach adopted in ECT practice has the potential to influence patient outcomes. However, the impact of the time interval between anaesthetic induction and ECT stimulus administration has not been studied prospectively to date. This variable may represent an indirect measure of anaesthetic concentration at the time of stimulation, and therefore may influence the quality of seizures induced. OBJECTIVE To examine the impact of the anaesthetic to ECT stimulus time interval, and ventilation rate pre-treatment, on ictal seizure quality. METHODS In a prospective, crossover trial, 54 depressed participants were randomised to variations in anaesthetic technique at four sequential ECT treatment sessions, in a 2 x 2 design: randomisation to a short or long anaesthetic-ECT time interval, and randomisation to normal ventilation or hyperventilation during anaesthetic induction with thiopentone. Ictal EEG data were collected at each study session and assessed by a blinded rater for ictal quality (seizure amplitude, regularity, post-ictal suppression and general seizure quality), using a quantitative-qualitative structured rating scale. Linear mixed effects models were used to analyse the effect of the anaesthetic-ECT time interval, and that of ventilation rate, on seizure quality indices. RESULTS The anaesthetic-ECT time interval had a significant impact on ictal EEG quality indices (p < 0.01), with longer time intervals producing higher quality seizures. Ventilation rate did not significantly influence quality measures. CONCLUSION The time between anaesthetic induction and ECT stimulus administration has a significant impact on ictal EEG seizure quality. Conversely, manipulations of ventilation rate did not significantly affect seizure quality. These results suggest the anaesthetic-ECT time interval should be routinely monitored clinically and potentially optimised for maximising seizure quality with ECT.

中文翻译：

---

麻醉-ECT 时间间隔和通气率对电惊厥治疗癫痫发作质量的影响：一项前瞻性随机试验

背景 ECT 实践中采用的麻醉方法有可能影响患者的预后。然而，迄今为止尚未前瞻性地研究麻醉诱导和 ECT 刺激给药之间的时间间隔的影响。该变量可能代表刺激时麻醉剂浓度的间接测量，因此可能影响诱发癫痫发作的质量。目的检查麻醉剂对 ECT 刺激时间间隔和通气率预处理对发作性癫痫发作质量的影响。方法 在一项前瞻性交叉试验中，54 名抑郁参与者在 4 次连续 ECT 治疗期间随机接受不同麻醉技术，采用 2 x 2 设计：随机分配到短或长的麻醉-ECT 时间间隔，在用硫喷酮进行麻醉诱导期间随机化为正常通气或过度通气。在每个研究阶段收集发作期脑电图数据，并由不知情的评估者使用定量-定性结构化评定量表评估发作质量（发作幅度、规律性、发作后抑制和一般发作质量）。线性混合效应模型用于分析麻醉-ECT 时间间隔和通气率对癫痫发作质量指标的影响。结果 麻醉 ECT 时间间隔对发作期 EEG 质量指数有显着影响 (p < 0.01)，时间间隔越长，癫痫发作质量越高。通风率对质量测量没有显着影响。结论 麻醉诱导和 ECT 刺激给药之间的时间对发作期 EEG 癫痫发作质量有显着影响。相反，通气率的操作对癫痫发作质量没有显着影响。这些结果表明，麻醉-ECT 的时间间隔应该在临床上进行常规监测，并可能优化以最大限度地提高 ECT 的癫痫发作质量。