The effects of hyperventilation on seizure length and cerebral oxygenation during electroconvulsive therapy

Narrative Review and Consensus Recommendations for the Use of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange in Modified Electroconvulsive Therapy

Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is a safe, effective, and novel technique that is currently being used in electroconvulsive therapy (ECT). This study aimed to summarize the clinical practices of THRIVE use in ECT to aid physicians and institutions in implementing the best practice guidelines for ECT. Thus, we reviewed the current literature and presented our consensus on the application of THRIVE in ECT in daily clinical practice. This consensus provides information regarding THRIVE use in ECT, including its safety, effectiveness, procedures, precautions, special case management, and application in special populations. Moreover, it guides the standardized use of THRIVE in ECT.

Two-handed facemask technique effectively causes hyperventilation in electroconvulsive therapy: an observational study

BACKGROUND

Electroconvulsive therapy (ECT) remains the mainstay treatment option for patients with psychiatric diseases, such as severe depression. Although various anesthetic techniques provide adequate therapeutic seizures, hyperventilation is a useful adjunct to augment seizure duration and improve seizure quality. We investigated how to efficiently use a facemask to accomplish protocolized hyperventilation and evaluate its effect on ECT seizure.

METHODS

We studied 60 patients aged ≥18 years who underwent ECT. The patients were divided into two groups according to the technique of facemask ventilation used: the one-handed (n = 30) and two-handed (n = 30) groups. Following anesthesia induction under preoxygenation conditions, hyperventilation induced hypocapnia in the one-handed facemask group with manual bag ventilation was compared to that in the two-handed facemask group with assisted pressure-controlled ventilation. Ictal and peri-ictal electroencephalogram parameters and cardiovascular responses were monitored and compared between the one-handed and two-handed groups.

RESULTS

The two-handed technique demonstrated better electroencephalogram regularity and minimized cardiovascular stress compared to the one-handed technique. These conclusions come from the fact that the one-handed technique induced a substantial volume of leaks around the facemask (201.7 ± 98.6 mL/breath), whereas minimal leaks (25.8 ± 44.6 mL/breath) with stabler and higher ventilation rate led to greater inhaled minute ventilation in the two-handed group (the one-handed group, 9.52 ± 3.94 L/min; the two-handed group, 11.95 ± 2.29 L/min; p <  0.005). At the end of ECT treatment, all parameters of blood pressure and heart rate increased significantly in both groups equally, with lower SpO₂ and more ST-segment depression on the electrocardiogram in the one-handed group. Comparing baseline values before anesthesia, ECT treatment significantly depressed ST-segment in both groups, while the degree of depression in ST-segment increased significantly in the one-handed group compared to that in the two-handed group.

CONCLUSIONS

End-tidal carbon dioxide monitoring for hyperventilation can reliably ensure hypocapnia only in the two-handed group. In ECT, the two-handed technique assisted by pressure-controlled ventilation is an effective and practical method for hyperventilation to induce adequate therapeutic seizures. While, the two-handed group with sufficient preoxygenation did not cause more cardiovascular stress than the one-handed group.

TRIAL REGISTRATION

UMIN Clinical Trials Registry 000046544, Date of registration 05/01/2022.

Evaluating Factors Affecting the Time Interval Between Propofol Injection and Induction of Electro-convulsion and Relationship Between These Factors and Duration of Convulsion

Background

Current evidence on the effect of anesthetic-ECT time interval (AETI) is controversial. This study aimed to investigate the factors affecting the time interval between propofol injection and electro-convulsion induction and the relationship between these factors and the duration of convulsion.

Methods

In this study, 102 patients (616 sessions of ECT) were studied. Demographic and clinical data (age, gender, receiving or not receiving medications that affected the seizure threshold, the total number of ECT sessions, clinical severity of admission scores, clinical diagnosis, propofol dose, seizure duration, and AETI) were collected in special forms and analyzed by appropriate statistical methods.

Results

Sessions with long-term AETI had longer seizure time than sessions with short-term AETI (33.47 ± 8.46 vs. 28.68 ± 9.74, P value < 0.05). The duration of seizures was significantly longer in the group with long AETI in sessions 1, 2, and 4 than in the other group (P value < 0.05). There was a significant relationship between the duration of seizures and propofol dose, AETI, and receiving drugs effective in the seizure threshold (P value < 0.05).

Conclusions

The results showed that increasing AETI and injecting a lower dose of propofol to induce anesthesia would increase the duration of seizures. Also, taking medications that would affect the seizure threshold reduces the duration of seizures.