Electroconvulsive therapy can benefit from controlled hyperventilation using a laryngeal mask

Anesthetic Influence on Electroconvulsive Therapy: A Comprehensive Review

The prevalence of severe mental disorders has been rising annually. Electroconvulsive therapy (ECT) is considered a valuable treatment option in psychiatry for conditions such as schizophrenia and medication-resistant depression, especially when other treatments have proven insufficient. ECT rapidly improves patients' mood, alleviates symptoms, and demonstrates significant therapeutic effects. Currently, the form of ECT used in clinical practice is modified electroconvulsive therapy (mECT), which is administered under general anesthesia. Accumulative evidence has confirmed that different anesthetic drugs, anesthetic-ECT time interval, anesthetic depth, and airway management can impact the outcomes of ECT. Therefore, this review aims to summarize the current impact of anesthesia factors on ECT, providing reference for clinical anesthesia during ECT procedures.

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.

Cerebral oxygen saturation in the prefrontal cortex during electroconvulsive therapy and its relation with the postictal reorientation time

The therapeutic effect of Electroconvulsive Therapy (ECT) has been attributed to generalised seizure. Although patients are well oxygenated prior to and during treatment, critics have associated ECT with brain tissue hypoxemia. In this study, the regional oxygen saturation (rSO₂) was measured continuously during ECT in the prefrontal cortex (PFC) of both hemispheres using 2-channel Near Infrared Spectroscopy (NIRS). Additionally, the postictal reorientation time (PRT) was determined and related to the rSO₂ course. We evaluated 72 ECT treatments in 22 adult patients who were treated for a therapy-resistant depressive syndrome. The therapy was performed according to our standard clinical procedures deploying right unilateral (RUL) and left anterior versus right temporal (LART) electrode placements. According to our results, the rSO₂ courses showed an increase during hyperventilation, a sharp drop immediately after the stimulus, and a long recovery period with values far exceeding the baseline. In 55,6% of treatments the rSO₂ course stayed above the baseline. In the others, the drop fell below it for an average of 12.6 s. According to a cardio surgical standard no signs of hypoxemia occurred during ECT treatments. The rSO₂ drop at seizure onset was the only parameter of the oxygen course related to the PRT in the multivariate analysis and might therefore be a characteristic feature of the seizure. It could reflect its physiological intensity and thereby be involved in the mechanism of action of ECT. NIRS seems to be an interesting non-invasive tool for monitoring and studying ECT.

Factors Predicting Ictal Quality in Bilateral Electroconvulsive Therapy Sessions

In electroconvulsive therapy (ECT), ictal characteristics predict treatment response and can be modified by changes in seizure threshold and in the ECT technique. We aimed to study the impact of ECT procedure-related variables that interact during each session and might influence the seizure results. Two hundred and fifty sessions of bilateral ECT in forty-seven subjects were included. Seizure results were evaluated by two different scales of combined ictal EEG parameters (seizure quality index (SQI) and seizure adequacy markers sum (SAMS) scores) and postictal suppression rating. Repeated measurement regression analyses were performed to identify predictors of each session’s three outcome variables. Univariate models identified age, physical status, hyperventilation, basal oxygen saturation, days between sessions, benzodiazepines, lithium, and tricyclic antidepressants as predictors of seizure quality. Days elapsed between sessions, higher oxygen saturation and protocolized hyperventilation application were significant predictors of better seizure quality in both scales used in multivariate models. Additionally, lower ASA classification influenced SQI scores as well as benzodiazepine use and lithium daily doses were predictors of SAMS scores. Higher muscle relaxant doses and lower applied stimulus intensities significantly influenced the postictal suppression rating. The study found several modifiable procedural factors that impacted the obtained seizure characteristics; they could be adjusted to optimize ECT session results.

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

OBJECTIVE

Previous studies have reported that hyperventilation prolongs seizure length. However, there is no clear consensus in clinical guidelines on how to perform hyperventilation during Electroconvulsive Therapy (ECT). The present study aims to investigate the effects of hyperventilation on seizure length and cerebral oxygenation.

METHODS

Forty patients aged 18-65 and classified as ASA I-II, who would have their first ECT course were included in the study. Ethics committee approval was obtained and all patients' consent was taken. The consecutive patients were randomized into two groups as follows: group H (20 patients; target etCO2: 25-30 mmHg) and group N (20 patients; target etCO2 35-40 mmHg). All patients were ventilated with a facial mask for two minutes and later were ventilated by a laryngeal mask (LMA) for one minute. Vital signs, peripheric oxygen saturation (SpO2), and regional oxygen saturation (rSO2) were measured before general anesthesia induction, on the 3rd minute of ventilation with an LMA (LMA3), on the 1st minute postictal (PI1), on the 5th (PI5), and 10th (PI10) minutes. The motor seizure duration, Richmond sedation-agitation scale, and the time needed to reach Aldrete Score 9 were also recorded.

RESULTS

There was a significant difference between the groups when they were compared concerning seizure length and recovery time. However, when we compared the rSO2 values that were measured at different times in group H, the difference between the measurements was statistically significant. When rSO2 values in group H were compared in doubles, there were significant differences between measurements between the basal and LMA3, basal and PI1, and the basal and PI5. When Richmond agitation scores in both groups are compared, there were no significant differences between the groups.

CONCLUSION

This study found that seizure length was longer, and the recovery time was shorter in group H. There was a contribution of hyperventilation on cerebral oxygenation that was measured on the same person at different times, but cerebral oxygenation was not statistically different from patients that were normoventilated. More studies are required to form a consensus regarding how hyperventilation applies to ECT.

Royal Australian and New Zealand College of Psychiatrists professional practice guidelines for the administration of electroconvulsive therapy

OBJECTIVES

To provide guidance for the optimal administration of electroconvulsive therapy, in particular maintaining the high efficacy of electroconvulsive therapy while minimising cognitive side-effects, based on scientific evidence and supplemented by expert clinical consensus.

METHODS

Articles and information were sourced from existing guidelines and the published literature. Information was revised and discussed by members of the working group of the Royal Australian and New Zealand College of Psychiatrists' Section for Electroconvulsive Therapy and Neurostimulation, and findings were then formulated into consensus-based recommendations and guidance. The guidelines were subjected to rigorous successive consultation and external review within the Royal Australian and New Zealand College of Psychiatrists, involving the full Section for Electroconvulsive Therapy and Neurostimulation membership, and expert and clinical advisors and professional bodies with an interest in electroconvulsive therapy administration.

RESULTS

The Royal Australian and New Zealand College of Psychiatrists' professional practice guidelines for the administration of electroconvulsive therapy provide up-to-date advice regarding the use of electroconvulsive therapy in clinical practice and are informed by evidence and clinical experience. The guidelines are intended for use by psychiatrists and also others with an interest in the administration of electroconvulsive therapy. The guidelines are not intended as a directive about clinical practice or instructions as to what must be done for a given patient, but provide guidance to facilitate best practice to help optimise outcomes for patients. The outcome is guidelines that strive to find the appropriate balance between promoting best evidence-based practice and acknowledging that electroconvulsive therapy is a continually evolving practice.

CONCLUSION

The guidelines provide up-to-date advice for psychiatrists to promote optimal standards of electroconvulsive therapy practice.

The anaesthetic-ECT time interval with thiopentone-Impact on seizure quality

BACKGROUND

The time between anaesthetic induction and ECT stimulus administration has been hypothesised to significantly impact ictal EEG quality. In this study, our aim was to examine the effect of the time interval between anaesthetic induction and the ECT stimulus for ictal seizure quality in ECT sessions utilising thiopentone anaesthesia.

METHODS

413 EEG traces from 42 patients, collected retrospectively, were manually rated using a quantitative-qualitative structured rating scale (indices including seizure amplitude, regularity, post-ictal suppression and general seizure quality). Linear Mixed Effects Models were used to analyse the effect of the anaesthetic-ECT time interval on seizure quality indices, seizure duration and orientation scores after ECT, controlling for patient and ECT treatment factors.

RESULTS

The anaesthetic-ECT time interval had a significant impact on ictal EEG quality indices (p < 0.05), with longer times producing higher quality seizures. Seizure duration and orientation scores after ECT were not significantly influenced by the anaesthetic-ECT time interval. Age, anaesthetic dose, ECT type and ECT treatment number also had a significant impact on measures of seizure quality (p < 0.05).

LIMITATIONS

The effect of ventilation technique was not explicitly measured. Only manual ratings of ictal quality were analysed.

CONCLUSIONS

The time between anaesthetic induction and ECT stimulus administration has a significant impact on the ictal EEG seizure quality observed, with thiopentone anaesthetic. These results are consistent with prior findings with propofol anaesthesia, and suggest a need for routine clinical monitoring of this time interval. This variable warrants consideration when interpreting ictal EEGs, which often informs subsequent dosing decisions.

Brief vs. ultrabrief pulse ECT: focus on seizure quality

The effect of electroconvulsive therapy (ECT) performed with ultrabrief pulse (UBP) stimulation has been found inferior to brief pulse (BP) ECT in various studies. We reinvestigated this issue using a new dosing strategy that is based on seizure quality instead of seizure threshold. There is a long history of studies associating ictal characteristics of ECT with the clinical outcome. Accordingly, we used the clinical status of the patient and the quality of the prior seizure to determine the dosage for the upcoming treatment-referred to as Clinical and Seizure Based Stimulation (CASBAS). This approach aims at continuously providing high-quality seizures to optimize the outcome. While this dosing strategy was applied in our department, the pulse width was changed for a period of time from BP to UBP. It was hypothesized that the procedure would: (1) maintain seizure quality and clinical outcome under both conditions and would; and (2) compensate the lesser clinical efficacy of UBP by an increase in stimulus intensity. 245 patients received an ECT course according to the dosing strategy described, 162 with brief pulse (BP) and 83 with ultrabrief pulse ECT (UBP). In a retrospective evaluation, seizure quality and clinical outcome (available in a 20% subgroup of patients) did not differ between both groups in most of the examined parameters, while stimulus intensity was found to be significantly higher in the UBP group. As hypothesized, UBP was less efficient than BP in providing comparable ictal quality and clinical outcome. In a first test of concept the dosing strategy CASBAS seemed suitable to continuously adjust the stimulus intensity in ECT and maintain the seizure quality.

Changes in cardiac autonomic nervous system activity during a course of electroconvulsive therapy

AIM

Although electroencephalogram (EEG) seizure duration and seizure threshold change during a course of electroconvulsive therapy, the mechanisms by which these factors influence heart rate during subsequent electroconvulsive therapy sessions are currently unclear. In the current study, we investigated changes in heart rate during electroconvulsive therapy.

METHODS

We recorded electroencephalography and electrocardiography during electroconvulsive therapy in 12 patients with major depressive disorder. Baseline heart rate was defined as the mean heart rate in the 30 seconds prior to stimulus onset. The Time_Max peak refers to the maximum heart rate after stimulus onset. Time_1/2 points represent the time points at which the heart rate had decreased to a value midway between the baseline heart rate and the Time_Max peak. We examined the relationships between EEG seizure duration, Time_Max , and Time_1/2 throughout the course of electroconvulsive therapy.

RESULTS

Time_1/2 decreased as the number of electroconvulsive sessions increased. Time_1/2 was positively correlated with EEG seizure duration.

CONCLUSION

The duration in which electroconvulsive therapy-induced sympathetic nervous system activation returned halfway to baseline levels gradually shortened during the course of electroconvulsive therapy.

Anaesthesia for electroconvulsive therapy - new tricks for old drugs: a systematic review

OBJECTIVE

The objective of this review is to investigate existing literature in order to delineate whether the use of anaesthesia and timing of seizure induction in a new and optimised way may improve the efficacy of electroconvulsive therapy (ECT).

METHODS

PubMed/MEDLINE was searched for existing literature, last search on 24 June 2015. Relevant clinical studies on human subjects involving choice of anaesthetic, ventilation and bispectral index (BIS) monitoring in the ECT setting were considered. The references of relevant studies were likewise considered.

RESULTS

Propofol yields the shortest seizures, etomidate and ketamine the longest. Etomidate and ketamine+propofol 1 : 1 seems to yield the seizures with best quality. Seizure quality is improved when induction of ECT is delayed until the effect of the anaesthetic has waned - possibly monitored with BIS values. Manual hyperventilation with 100% O2 may increase the pO2/pCO2-ratio, which may be correlated with better seizure quality.

CONCLUSION

Etomidate or a 1 : 1 ketamine and propofol combination may be the best method to achieve general anaesthesia in the ECT setting. There is a need for large randomised prospective studies comparing the effect of methohexital, thiopental, propofol, ketamine, propofol+ketamine 1 : 1 and etomidate in the ECT treatment of major depressed patients. These studies should investigate safety and side effects, and most importantly have antidepressant efficacy and cognitive side effects as outcome measures instead of seizure quality.

Hyperventilation and electroconvulsive therapy: A literature review

BACKGROUND

Hyperventilation has been proposed as an augmentation strategy in electroconvulsive therapy (ECT) in accordance with its proconvulsant effect.

OBJECTIVE

This study reviews the existing literature on the application of hyperventilation in ECT, its efficacy, and tolerance.

METHODS

A systematic search was performed in PubMed and EMBASE databases. Search terms ('electroconvulsive therapy' and 'hyperventilation', 'ventilation', 'hyperoxygenation', 'hyperoxia', 'hypocapnia') were used to retrieve works from 1966 to June 2016. Works that described hyperventilation manoeuvres in ECT settings and their clinical repercussion were included in the review.

RESULTS

A total of 17 observational and experimental studies were selected. An important heterogeneity in study designs, samples and ECT conditions, was detected. Findings support a positive influence of hyperventilation on seizure duration, which is the main study variable across different works. Effects of hyperventilation on seizure threshold and quality parameters have been less thoroughly studied. Systematic recording of clinical outcomes and adverse effects of hyperventilation is uncommon.

CONCLUSIONS

The literature suggests that hyperventilation may be an effective and safe technique to enhance ECT, but many aspects remain to be studied. Further investigations, especially controlled clinical trials, are necessary and should result in a specific and reliable hyperventilation protocol for ECT settings.

Protocolized hyperventilation enhances electroconvulsive therapy

BACKGROUND

Hyperventilation is recommended in electroconvulsive therapy (ECT) to enhance seizures and to increase patients' safety. However, more evidence is needed regarding its effects and the optimum method of application.

METHODS

This prospective study involving 21 subjects compared two procedures, protocolized hyperventilation (PHV) and hyperventilation as usual (HVau), applied to the same patient in two consecutive sessions. Transcutaneous partial pressure of carbon dioxide (TcPCO₂) was measured throughout all sessions. Ventilation parameters, hemodynamic measures, seizure characteristics, and side effects were also explored.

RESULTS

PHV resulted in lower TcPCO₂ after hyperventilation (p=.008) and over the whole session (p=.035). The lowest TcPCO₂ was achieved after voluntary hyperventilation. Changes in TcPCO₂ from baseline showed differences between HVau and PHV at each session time-point (all p<.05). Between- and within-subjects factors were statistically significant in a general linear model. Seizure duration was greater in PHV sessions (p=.028), without differences in other seizure quality parameters or adverse effects. Correlations were found between hypocapnia induction and seizure quality indexes.

LIMITATIONS

Secondary outcomes could be underpowered.

CONCLUSIONS

PHV produces hypocapnia before the stimulus, modifies patients' TcPCO₂ values throughout the ECT session and lengthens seizure duration. Voluntary hyperventilation is the most important part of the PHV procedure with respect to achieving hypocapnia. A specific ventilation approach, CO₂ quantification and monitoring may be advisable in ECT. PHV is easy to apply in daily clinical practice and does not imply added costs. Ventilation management has promising effects in terms of optimizing ECT technique.

Hypocapnia and hyperoxia induction using a hyperventilation protocol in electroconvulsive therapy

INTRODUCTION

Hyperventilation in electroconvulsive therapy sessions has been associated with seizure threshold, seizure characteristics, and cognitive effects. There is no consensus on the optimal procedure of applying hyperventilation manoeuvres during electroconvulsive therapy.

MATERIAL AND METHODS

Prospective evaluation of the effects of systematic use of hyperventilation manoeuvres with facial mask and capnography (protocolized hyperventilation [pHV]), on ventilation parameters and on seizures. The study included a sample of 130 sessions (65 performed according to hyperventilation standard practice and 65 successive sessions, with pHV) of 35 patients over a period of 10 weeks.

RESULTS

The pHV manoeuvres reduced exhaled CO₂ and increased O₂ saturation significantly (P<.001). The average CO₂ reduction achieved was 6.52±4.75mmHg (95% CI -7.7 to -5.3). The CO₂ values after pHV correlated significantly with seizure duration and O₂ values, with other electroencephalographic quality indices. In pHV sessions, compared with sessions performed according to hyperventilation standard practice, the average lengthening of the motor and electroencephalographic seizure was 3.86±14.62 and 4.73±13.95s, respectively. No differences were identified in other ictal quality parameters.

CONCLUSIONS

The proposed pHV manoeuvres significantly modify ventilation parameters. The hypocapnia and hyperoxia obtained by applying these manoeuvres lengthen the duration of seizures without worsening the quality of the electroencephalographic trace. The use of pHV is generalisable and might improve electroconvulsive therapy procedure without adding costs.

The integrative role of the sigh in psychology, physiology, pathology, and neurobiology

"Sighs, tears, grief, distress" expresses Johann Sebastian Bach in a musical example for the relationship between sighs and deep emotions. This review explores the neurobiological basis of the sigh and its relationship with psychology, physiology, and pathology. Sighs monitor changes in brain states, induce arousal, and reset breathing variability. These behavioral roles homeostatically regulate breathing stability under physiological and pathological conditions. Sighs evoked in hypoxia evoke arousal and thereby become critical for survival. Hypoarousal and failure to sigh have been associated with sudden infant death syndrome. Increased breathing irregularity may provoke excessive sighing and hyperarousal, a behavioral sequence that may play a role in panic disorders. Essential for generating sighs and breathing is the pre-Bötzinger complex. Modulatory and synaptic interactions within this local network and between networks located in the brainstem, cerebellum, cortex, hypothalamus, amygdala, and the periaqueductal gray may govern the relationships between physiology, psychology, and pathology. Unraveling these circuits will lead to a better understanding of how we balance emotions and how emotions become pathological.