Benefits of the laryngeal mask for airway management during electroconvulsive therapy

Comparison of laryngeal mask airway and endotracheal tube in general anesthesia in children

At present, there is no relevant expert consensus indicating which ventilation device is more efficient for general anesthesia. The present literature review and meta-analysis compared the effects of the laryngeal mask airway and endotracheal intubation on airway complications during general anesthesia. The keywords 'laryngeal mask airway', 'endotracheal tube', 'tracheal tube', 'children', 'pediatric', 'anesthesia', 'randomized controlled trials' (RCTs) and 'randomized' were used to perform the literature search in PubMed. Quality assessment was performed by two reviewers according to domains defined by the Cochrane Collaboration tool. Data extraction, risk of bias assessment and quality of evidence assessment were performed with the Cochrane tool. A total of 16 RCTs were included. The results indicated that the effects of the laryngeal mask airway group on heart rate variability [mean difference=-13.76; 95% CI, -18.19-(-9.33); P<0.00001], the incidence of hypoxemia [odds ratio (OR)=0.52; 95% CI, 0.28-0.97; P=0.04] and the incidence of postoperative cough (OR=0.22; 95% CI, 0.12-0.40; P<0.0001) were significantly lower than those of the endotracheal intubation group. The success rate of one-time implantation in the laryngeal mask airway group was significantly higher than that noted in the endotracheal intubation group (OR=0.20; 95% CI, 0.07-0.59; P=0.003). However, no significant differences were noted between the two groups in bronchospasm, sore throat, mucosal injury, nausea and vomiting and reflux aspiration. In conclusion, the results indicated that laryngeal mask airway application can reduce complications during general anesthesia compared with endotracheal intubation.

Prevention of Oxygen Desaturation in Morbidly Obese Patients During Electroconvulsive Therapy: A Narrative Review

In general, preoxygenation is performed using a face mask with oxygen in a supine position, and oxygenation is maintained with manual mask ventilation during electroconvulsive therapy (ECT). However, hypoxic episodes during ECT are not uncommon with this conventional method, especially in morbidly obese patients. The most important property of ventilatory mechanics in patients with obesity is reduced functional residual capacity (FRC). Thus, increasing FRC and oxygen reserves is an important step to improve oxygenation and prevent oxygen desaturation in these individuals. Head-up position, use of apneic oxygenation, noninvasive positive pressure ventilation, and high-flow nasal cannula help increase FRC and oxygen reserves, resulting in improved oxygenation and prolonged safe apnea period. Furthermore, significantly higher incidence of difficult mask ventilation is common in morbidly obese individuals. Supraglottic airway devices establish effective ventilation in patients with difficult airways. Thus, the use of supraglottic airway devices is strongly recommended in these patients. Conversely, because muscle fasciculation induced by depolarizing neuromuscular blocking agents markedly increases oxygen consumption, especially in individuals with obesity, the use of nondepolarizing neuromuscular blocking agents may contribute to better oxygenation in morbidly obese patients during ECT.

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 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.

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.

Electroconvulsive therapy can benefit from controlled hyperventilation using a laryngeal mask

Hypocapnia through hyperventilation is a well-known procedure in electroconvulsive therapy (ECT) to enhance seizure activity. However, it has mostly been applied in an uncontrolled manner. Originally intended for a better management of the supraglottic airway, laryngeal masks are more suited to monitor levels of CO(2) during hyperventilation than face masks and thereby provide for the possibility of controlled hyperventilation (CHV). The impact of CHV was retrospectively studied in 114 consecutive patients; 65 of them had received ECT with CHV and 49 had received ECT with uncontrolled hyperventilation (UHV) directly prior to the time period when the laryneal mask was introduced to the ECT treatment procedure. The CO(2) level in the CHV group was aimed at 30 mmHg or below. CHV considerably enhanced the seizure activity leading to changes in clinically determined parameters of the treatment course: the necessity for increasing the electric charge, for re-stimulations (trend) and for bilateral stimulations was lower in the CHV group as compared to the UHV group. The improvement in the Global Assessment of Functioning Scores was not different in both groups. CHV was associated with a higher amount of prolonged seizures, with a reduced number of delirious symptoms after treatments and an attenuating effect on heart rate. Concluding, CHV can help to maintain the applied electric charge low without worsening the clinical outcome. Therefore, it is a helpful technical improvement. However, it should be used carefully with regard to prolonged seizures.

Carbon dioxide exhalation temporarily increases during electroconvulsive therapy

Electroconvulsive therapy induces hypermetabolism and elevates oxygen and energy demands, while more carbon dioxide is produced than usual. The purpose of the present study was to determine the elevated carbon dioxide exhalation and the adequate ventilation volume during electroconvulsive therapy. Carbon dioxide exhalation during an electrically induced seizure was continuously monitored by capnography and spirography in 15 patients with endogenous depression. A laryngeal mask airway was used to measure the airway gas flow. Data were collected during a total of 80 electroconvulsive therapy trials. The carbon dioxide exhalation at 1 min after electrical stimulation was higher than the control value (2.8 +/- 0.4 versus 2.3 +/- 0.3 ml.min(-1).kg(-1), mean +/- SD; P < 0.05). The ventilation volume was increased for 3 min after the electrical stimulation to maintain the end-tidal carbon dioxide partial pressure at 35-40 mmHg. The results showed that increasing the ventilation volume by approximately 20% may be necessary to compensate for the increased carbon dioxide exhalation during electroconvulsive therapy.

Anaesthesia for patients with mood disorders

PURPOSE OF REVIEW

Treatment of patients with mood disorders has changed over the past few years. It is not always clear how the anaesthesiologist has to incorporate these antidepressants and mood stabilizers in premedication or even how to anticipate any interaction with anaesthetic technique.

RECENT FINDINGS

The older generation of antidepressants (tricyclic antidepressants, monoamine oxidase inhibitors) is seldom used nowadays. Actually, treatment with selective serotonin-reuptake inhibitors, serotonin noradrenaline-reuptake inhibitors, noradrenaline-reuptake inhibitor, noradrenergic and specific serotonin antidepressants, or noradrenaline- and dopamine-reuptake inhibitors is common practice. Combination with atypical antipsychotics and newer antiepileptics is suggested as an add-on therapy or as monotherapy, while lithium and valproate therapy is still the first choice in bipolar mood stabilization. Electroconvulsive therapy is still used in therapy-resistant forms of depression; however, the anaesthesia technique herein has been increasingly well described in the last years. Electroencephalogram-derived monitoring such as bispectral index (BIS) can be used as a tool to predict seizure duration. Intoxications with these newer agents are not infrequent and deserve specific attention. In particular, serotonin syndrome is a life-threatening condition that requires great care by the anaesthesiologist. The chronic use of antidepressants does affect the anaesthetized patient: hypotension, arrhythmias, changed thermoregulation, altered postoperative pain, differences in surgical stress response and postoperative confusion. However, it is advised to continue these drugs in the perioperative period.

SUMMARY

Discontinuation of treatment with the new antidepressants in the perioperative period is not advised. Intoxication with the newer drugs appears to be safer. The anaesthesiologist must pay attention to serotonin syndrome. Electroconculsive therapy has gained renewed attention.