Hyperventilation and electroconvulsive therapy: A literature review

Effectiveness and Safety of Flumazenil Augmentation During Electroconvulsive Therapy

INTRODUCTION

Benzodiazepines are considered to negatively affect seizure quality and duration during electroconvulsive therapy (ECT). Several researchers have advocated the use of flumazenil, a competitive benzodiazepine receptor antagonist, for patients treated with benzodiazepines during ECT. However, clinical evidence regarding flumazenil use in ECT remains sparse. The aim of this study is to investigate the effects of flumazenil on seizure duration and adverse effects.

METHODS

All patients with depressive disorders, treated with flumazenil during a course of ECT in 2019 in a tertiary hospital, were identified through a retrospective chart review. Seizure duration was recorded before and after flumazenil administration. Effectiveness of ECT was assessed using the Inventory of Depressive Symptomatology and the Bush-Francis Catatonia Rating Scale. Postictal agitation was ascertained by identifying patients who received additional sedatives immediately after ECT or who needed physical restraint.

RESULTS

Twenty-six patients were included, receiving a total of 363 treatments, of which 263 were augmented with flumazenil. Flumazenil administration increased electroencephalogram seizure duration on average with 10.5 seconds comparing ECT with or without flumazenil (P = 0.003). In 21.8% of the cases, no increase in seizure duration was observed. Postictal agitation occurred at least once in 34.6% of the patients receiving flumazenil during their course of ECT.

CONCLUSION

Our results show that flumazenil increases seizure duration, albeit with limited clinical implications. Noteworthy, the prevalence of postictal agitation is high. When confronted with short seizures, clinicians should therefore deploy other available techniques to lower seizure threshold before considering flumazenil.

Impact of COVID-19 on electroconvulsive therapy practice across Canadian provinces during the first wave of the pandemic

BACKGROUND

Electroconvulsive therapy (ECT) is a procedural treatment that is potentially life-saving for some patients with severe psychiatric illness. At the start of the global coronavirus disease 2019 (COVID-19) pandemic, ECT practice was remarkably disrupted, putting vulnerable individuals at increased risk of symptom exacerbation and death by suicide. This study aimed to capture the self-reported experiences of psychiatrists based at healthcare facilities across Canadian provinces who were delivering ECT treatments during the first phase of the COVID-19 pandemic (i.e., from mid-March 2020 to mid-May 2020).

METHODS

A multidisciplinary team of experts developed a survey focusing on five domains: ECT unit operations, decision-making, hospital resources, ECT procedure, and mitigating patient impact. Responses were collected from psychiatrists providing ECT at 67 ECT centres in Canada, grouped by four geographical regions (Ontario, Quebec, Atlantic Canada, and Western Canada).

RESULTS

Clinical operations of ECT programs were disrupted across all four regions - however, centres in Atlantic Canada were able to best preserve outpatient and maintenance care, while centres in Western Canada were able to best preserve inpatient and acute care. Similarly, Atlantic and Western Canada demonstrated the best decision-making practices of involving the ECT team and clinical ethicists in the development of pandemic-related guidelines. Across all four regions, ECT practice was affected by the redeployment of professionals, the shortage of personal protective equipment, and the need to enforce social distancing. Attempts to introduce modifications to the ECT delivery room and minimize bag-valve-mask ventilation were consistently reported. All four regions developed a new patient prioritization framework, and Western Canada, notably, aimed to provide ECT to only the most severe cases.

CONCLUSIONS

The results suggest that ECT provision was disproportionately affected across different parts of Canada. Possible factors that could explain these interregional differences include population, distribution of urban vs. rural areas, pre-pandemic barriers in access to ECT, number of cases, ability to control the spread of infection, and the general reduction in physicians' activities across different areas of health care. Studying these factors in the future will inform how medical centres should respond to public health emergencies and pandemic-related circumstances in the context of procedural treatments.

Rocuronium action can be affected by hyperventilation: a case report and computational simulation

The neuromuscular blocking potency of rocuronium varies with respiratory pH changes, increasing at lower pH and decreasing at higher pH; thus, hyperventilation-induced respiratory alkalosis is expected to decrease the potency of rocuronium. We report a case of anesthetic management of modified electroconvulsive therapy (m-ECT) for a patient monitored with electromyography-based neuromuscular monitoring during two patterns of ventilation to elucidate their relationship and propose the possible mechanisms underlying the effects by computational simulations. Case presentation: The patient was a 25-year-old man with schizophrenia. In m-ECT, hyperventilation may be used to produce longer seizures. We compared the neuromuscular monitoring data recorded during hyperventilation and during normal ventilation while receiving the same dose of rocuronium. Despite receiving the same dose of rocuronium, the time required for the first twitch to decrease to 80% of the control value was delayed in hyperventilation compared to normal ventilation. Conclusions: This case report and computational simulation suggest that respiratory alkalosis might delay the action of rocuronium. It is necessary to consider the delayed action of rocuronium when hyperventilation is performed.

Effects of Anesthesia Changes During Maintenance ECT: A Longitudinal Comparison of Seizure Quality Under Anesthesia Using Propofol/Esketamine Versus Methohexital

INTRODUCTION

The effectiveness of ECT relies on the induction of a generalized cerebral seizure. Among others, seizure quality (SQ) is potentially influenced by the anesthetic drug used. Commonly used anesthetics comprise barbiturates, etomidate, propofol, and esketamine, with different characteristics and impacts on seizure parameters. So far, no studies have compared the influence of methohexital vs. a combination of propofol/esketamine on established SQ parameters.

METHODS

This retrospective longitudinal study compared eight established SQ parameters (PSI, ASEI, MSC, midictal amplitude, motor and electroencephalography (EEG) seizure duration, concordance, PHR) before and after the change from propofol/esketamine to methohexital in 34 patients under maintenance ECT. Each patient contributed four measurements, two before and two after the anesthesia change. Anesthesia dose, stimulus dose, electrode placement, and concomitant medication remained unchanged throughout the analyzed treatments.

RESULTS

Under methohexital (M=88.97 mg), ASEI (p=0.039 to 0.013) and midictal amplitude (p=0.022 to<0.001) were significantly lower, whereas seizure duration (motor and EEG) was significantly longer when compared to propofol/esketamine (M=64.26 mg/51.18 mg; p=0.012 to<0.001). PSI, MSC, seizure concordance, and PHR were not affected by the anesthetic used.

DISCUSSION

Although to what extent these parameters correlate with the therapeutic effectiveness remains ambiguous, a decision for or against a particular anesthetic could be considered if a specific SQ parameter needs optimization. However, no general superiority for one specific substance or combination was found in this study. In the next step, anesthetic effects on treatment response and tolerability should be focused on.

Perianaesthetic challenges in patients undergoing vagus nerve stimulation (VNS) placement

Patients with medically refractory epilepsy (MRE) are indicated for vagus nerve stimulation (VNS) placement. Anaesthesia for VNS placement is extremely challenging and requires several considerations. We present a man in his 20s with MRE who successfully underwent VNS placement. We review the mechanism of action of VNS, anaesthetic challenges and measures to prevent seizures.

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.

Contemporary Anesthetic Evaluation and Management for Electroconvulsive Therapy

Electroconvulsive therapy (ECT) is a medical treatment most often used in patients with severe major depression that has not responded to other treatments. ECT is also indicated for patients with other severe psychiatric conditions, including bipolar disorder, schizophrenia, schizoaffective disorders, catatonia, and neuroleptic malignant syndrome. Contemporary "modified ECT" involves inducing general anesthesia with neuromuscular blockade before inducing the therapeutic seizure. The goal of this review is to combine an evidence-based update with the experience of the author's institution to provide a practical approach to anesthetic care for the patient undergoing ECT.

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.

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.

Changes in seizure duration during acute course electroconvulsive therapy

BACKGROUND

Seizure duration has long been measured as a potential marker of ECT treatment efficacy, with concern that short seizures may be clinically ineffective. Relatively small studies have documented a trend towards shorter seizures during acute course ECT, but data from large cohorts would help provide normative data on seizure duration changes during treatment.

OBJECTIVE

This study analyzes the effects of age, sex, ECT dose, and treatment number on the duration of electrographic seizures during acute course ECT in a large single-center cohort.

METHODS

A single-center retrospective chart review was conducted of adult patients receiving a first course of ECT from 2000 to 2017 at a large freestanding psychiatric hospital.

RESULTS

3648 patients met inclusion criteria, receiving 32,879 acute course ECT treatments. There was a shortening of mean ECT seizure duration over the acute course, with the greatest decrease in duration over the first 3 treatments but continuing decreases over the entire acute course. Older age, higher ECT dose, and increasing treatment number were all associated with shorter seizures, while sex was not significantly associated. Increasing treatment dose was associated with shorter seizures relative to no dose increase, with those patients receiving the highest cumulative doses also having the shortest cumulative seizure time.

CONCLUSIONS

Among patients undergoing acute-course ECT treatment, seizure duration decreased over the treatment course, and increases in applied electrical charge were associated with shorter seizures.

Effective Adaptation of Ventilation Maneuvers in Electroconvulsive Therapy Sessions During the Coronavirus Disease 2019 Pandemic

Supplemental digital content is available in the text.

Ventilation Adjustment in ECT During COVID-19: Voluntary Hyperventilation is an Effective Strategy

PURPOSE

Airway management is a key objective in adapted electroconvulsive therapy (ECT) protocols during the COVID-19 pandemic to prevent infection. The objective of this study was to describe the effectiveness of a modified ventilation procedure designed to reduce aerosol-generating bag-mask ventilation (BMV) and isolate possible droplets while maintaining adequate respiratory gas values in ECT sessions.

MATERIALS AND METHODS

This prospective study analyzed the results of the modified protocol applied over a month. Adaptations entailed preoxygenation and extension of the voluntary hyperventilation (VHV) time for two minutes before anesthesia induction, asking patients to hyperventilate with oxygen therapy via nasal cannula and while wearing a face mask. Thereafter, vigorous hyperventilation was avoided, and patients were only assisted with tightly sealed BMV until emergence from anesthesia, isolating the ventilation by using a single-use plastic device. Oxygen saturation (SpO2) and transcutaneous partial pressure of carbon dioxide (TcPCO2) were recorded throughout the session.

RESULTS

The study included 74 sessions of bilateral ECT with the modified ventilation protocol in 15 subjects. After VHV, the mean SpO2 increase was 2.12±2.14%, and the mean TcPCO2 decrease was 4.05±2.98 mmHg. TcPCO2 values at the moment of stimulus administration were 2.22±3.07 mmHg below pre-ECT values. The mean EEG seizure was 38.70±17.03 s, and postictal suppression was 68.31± 34.58% and 2.13±0.75 on a 0-3 scale. Brief desaturation (SpO2 <90) of 4-5 seconds duration was observed in 4 sessions.

CONCLUSION

This modified ventilation protocol was effective during COVID-19, and it did not elicit significant side effects. In addition to avoiding vigorous BMV, it induced moderate hypocapnia, which has been tied to seizure optimization and less hypercapnia during the apnea period.

Challenges and pitfalls in anesthesia for electroconvulsive therapy

Electroconvulsive therapy (ECT) refers to the application of electricity to the patients' scalp to treat psychiatric disorders, most notably, treatment-resistant depression. It is a safe, effective, and evidence-based therapy that is performed with general anesthesia. Muscle relaxation is used to prevent injuries related to the tonic-clonic seizure caused by ECT. Hypnotics are administered to induce amnesia and unconsciousness, so that, patients do not experience the period of muscle relaxation, while the generalized seizure is left unnoticed. For the anesthesiologist, ECT is associated with the challenges and pitfalls that are related to informed consent, social acceptance of ECT, airway management (especially in COVID-19 patients), and the interaction between ventilation and anesthetics from one viewpoint, and seizure induction and maintenance from another. The exact mode of action of the therapy is as unknown as the optimal choice or combination of anesthetics used.

Neuroanesthesia Practice During the COVID-19 Pandemic: Recommendations From Society for Neuroscience in Anesthesiology and Critical Care (SNACC)

The pandemic of coronavirus disease 2019 (COVID-19) has several implications relevant to neuroanesthesiologists, including neurological manifestations of the disease, impact of anesthesia provision for specific neurosurgical procedures and electroconvulsive therapy, and health care provider wellness. The Society for Neuroscience in Anesthesiology and Critical Care appointed a task force to provide timely, consensus-based expert guidance for neuroanesthesiologists during the COVID-19 pandemic. The aim of this document is to provide a focused overview of COVID-19 disease relevant to neuroanesthesia practice. This consensus statement provides information on the neurological manifestations of COVID-19, advice for neuroanesthesia clinical practice during emergent neurosurgery, interventional radiology (excluding endovascular treatment of acute ischemic stroke), transnasal neurosurgery, awake craniotomy and electroconvulsive therapy, as well as information about health care provider wellness. Institutions and health care providers are encouraged to adapt these recommendations to best suit local needs, considering existing practice standards and resource availability to ensure safety of patients and providers.

Modified Anesthesia Protocol for Electroconvulsive Therapy Permits Reduction in Aerosol-Generating Bag-Mask Ventilation during the COVID-19 Pandemic

INTRODUCTION

Electroconvulsive therapy (ECT) is a critical procedure in psychiatric treatment, but as typically delivered involves the use of bag-mask ventilation (BMV), which during the COVID-19 pandemic exposes patients and treatment staff to potentially infectious aerosols.

OBJECTIVE

To demonstrate the utility of a modified anesthesia protocol for ECT utilizing preoxygenation by facemask and withholding the use of BMV for only those patients who desaturate during the apneic period.

METHODS

This chart review study analyzes patients who were treated with ECT using both the traditional and modified anesthesia protocols.

RESULTS

A total of 106 patients were analyzed, of whom 51 (48.1%) required BMV using the new protocol. Of clinical factors, only patient BMI was significantly associated with the requirement for BMV. Mean seizure duration reduced from 52.0 ± 22.4 to 46.6 ± 17.1 s, but seizure duration was adequate in all cases. No acute physical, respiratory, or psychiatric complications occurred during treatment.

CONCLUSIONS

A modified anesthesia protocol reduces the use of BMV by more than 50%, while retaining adequate seizure duration.

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 3^rd minute of ventilation with an LMA (LMA₃), on the 1^st minute postictal (PI₁), on the 5^th (PI₅), and 10^th (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.

Use of ultrabrief pulse width electroconvulsive therapy to induce therapeutic seizures in an elderly patient with a high seizure threshold: a case report

OBJECTIVE

This case report describes a 73-year-old man suffering from unipolar major depression with melancholic features, in whom treatment with electroconvulsive therapy (ECT) proved difficult due to inadequate seizure generation.

METHODS

A number of augmentation strategies were trialled in an attempt to improve seizure quality. Pre-ECT and Post-ECT measurement of symptoms, quality of life and cognition were undertaken with a variety of validated scales.

RESULTS

The single most efficacious strategy to elicit therapeutic seizures was the use of right unilateral (RUL) electrode placement with an ultrabrief pulse width. The patient subsequently had a resolution of his depressive illness, with a concomitant improvement in cognitive functioning.

CONCLUSION

This case demonstrates that a number of ECT augmentation strategies can be used in routine clinical practice for patients with high seizure thresholds. It highlights that UB pulse width may be considered earlier in the treatment course for patients in whom conventional brief pulse ECT fails to generate effective seizures.

Overlooking the obvious? Influence of electrolyte concentrations on seizure quality parameters in electroconvulsive therapy

Clinical response to electroconvulsive therapy (ECT) depends on eliciting a generalized seizure. Though there are multiple ictal and other parameters to assess seizure quality, factors that influence these parameters have only been identified to a limited extend in antecedent studies (e.g., stimulus dosage, age). In the context of ECT, electrolyte concentrations have hardly been investigated so far-although hyponatremia is one well-known clinical factor to increase the risk of spontaneous seizures. In 31 patients with unipolar or bipolar depressive disorder, blood concentrations of sodium (Na), potassium (K), and calcium (Ca) were measured immediately prior to repeated sessions of maintenance ECT. Generalized linear mixed models were used to analyze the influence of Na, K, and Ca on seven seizure quality parameters: postictal suppression index (PSI), maximum sustained coherence (MSC), midictal amplitude, average seizure energy index, seizure duration (EEG/motor), and peak heart rate. Results show a statistically significant relationship between the serum sodium level and MSC: in the model, a reduction of 1 mmol/l led to an increase in interhemispheric coherence of 0.678%. The further markers remained unaffected by changes in electrolyte concentrations. This finding provides first evidence that a lower blood concentration of sodium could enhance the quality of ECT-induced seizures in terms of higher interhemispheric coherence.

Electro convulsive therapy: Modification of its effect on the autonomic nervous system using anti-cholinergic drugs

The antidepressant efficacy of electroconvulsive therapy (ECT) is correlated to the quality of the seizure as measured by EEG but has also been linked to the magnitude of changes in hemodynamic variables. Muscarinic receptor antagonists are frequently used in the treatment, and are known to affect the hemodynamic response. We hypothesized that atropine and glycopyrrolate alter the hemodynamic and autonomic hormonal response to ECT. In a randomized, cross-over study design 23 patients received either atropine, glycopyrrolate or placebo before ECT. Hemodynamic variable, EEG and EMG, and blood adrenaline, noradrenaline and pancreatic polypeptide was determined. No geriatric patients were included. Hemodynamic changes with ECT can be divided into three phases: Drop in blood pressure and pulse rate in 1st post-stimulus phase was less when using 1 mg atropine. In 2nd post-stimulus phase atropine gave a higher systolic blood pressure. No differences were seen in hormone levels after ECT in the three interventions. A significant longer tonic clonic seizure was seen in the glycopyrrolate group and a tendency of the same was seen with atropine. The study found that the changes in hemodynamic variables induced by ECT can be altered by concomitant administration of muscarinic receptor antagonist.