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

Adequate Oxygenation State Maintained during Electroconvulsive Therapy in Nonobese Patients Using the Oxygen Reserve Index: A Pilot Study

Some controversial reports have observed oxygen desaturation (defined as percutaneous oxygen saturation (SpO2) < 90%) during electroconvulsive therapy (ECT). The purpose of this pilot study was to examine oxygenation states in eight patients during ECT. In addition to the usual hemodynamic monitors and pulse oximeter, the oxygen reserve index (ORi) was monitored using a pulse oximeter. Patients received either no preoxygenation or preoxygenation with 100% oxygen via a tight-fitting mask for 1 or 3 min before induction of anesthesia. ORi increased after preoxygenation. ORi differed significantly between 3 min of preoxygenation and the other two methods before restarting mask ventilation. SpO2 was significantly increased with all methods before stopping manual mask ventilation or before restarting manual mask ventilation compared with that before preoxygenation. No oxygen desaturation was observed at any time with any treatment methods. In nonobese patients, the adequate oxygenation state as shown by SpO2 and ORi was maintained during ECT even without preoxygenation.

Microlaryngeal surgery in severely obese elite vocal performers

This study showed that microlaryngeal surgery under general anesthesia is feasible for patients with severe obese elite vocal performers if proper simulations are conducted beforehand and the position of the patient and anesthesia is considered.

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

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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.

[Ultrasound assessment of gastric insufflation in obese patients receiving transnasal humidified rapid-insufflation ventilatory exchange during general anesthesia induction]

OBJECTIVE

To assess the effect of transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) on gastric insufflation during general anesthesia induction in obese patients.

METHODS

Ninety obese patients (BMI 30-39.9 kg/m²) undergoing laparoscopic cholecystectomy under general anesthesia were randomized into 3 groups (n=30) to receive facemask pre- oxygenation followed by face mask ventilation (FMV) after administration of anesthetics (Group M), oxygenation with THRIVE (Group T), or pre-oxygenation with facemask combined with THRIVE followed continuous oxygenation with both FMV and THRIVE after administration of anesthetics (Group M+T). The patients in the latter two groups received continuous oxygen via THRIVE during tracheal intubation. All the patients received real-time ultrasound monitoring of the gastric antrum, and positive gastric insufflation (GI⁺) was defined by the presence of comet-tail artifacts. The cross-sectional area of the gastic antrum (CSA-GA) was measured by ultrasound before and after pre-oxygenation and after intubation. The patients' SpO₂, PaO₂, and PaCO₂ at admission (T₁), 5 min after pre-oxygenation (T₂), 5 min after medication (T₃), and immediately after intubation (T₄) were recorded, and the incidence of postoperative adverse events was assessed.

RESULTS

The incidence of gastric insufflation was significantly higher in Group M and Group M+T than in Group T (P < 0.05). The CSA-GA was significantly greater at T₄ than at T₁ in Group M and Group M+T and in their GI⁺s ubgroups. The GI⁺ subgroups in Group M and Group M+ T had significantly larger CSA-GA at T₄ than the GI^- subgroups (P < 0.05). CSA-GA did not vary significantly during anesthesia induction in Group T (P>0.05). The incidence of grade Ⅰ gastric distension was lower but grade Ⅱ gastric distention was higher in Group M and Group M+T than in Group T (P < 0.05). Group M showed significantly greater variations of PaO₂ at T₃ and T₄ than Group T and Group M+T (P < 0.05).

CONCLUSIONS

Ultrasound monitoring of the comet tail sign and the changes of CSA-GA in the gastric antrum is feasible and reliable for detecting gastrointestinal airflow, and in obese patients, the application of THRIVE for induction of anesthesia can ensure the oxygenation level without further increasing gastric insufflation.