Mask adaptor—a novel method of positive pressure ventilation during propofol deep sedation for upper GI endoscopy

BackgroundPropofol dosages required for upper GI endoscopy are often high enough to pose serious risks of respiratory depression. Stopping the procedure and bag ventilating a patient until the propofol wears off may be a safer management because traditional mask ventilation is not available.ObjectiveWe introduce the mask adaptor for upper GI endoscopy (MAUGE), a new method of positive pressure ventilation during upper GI endoscopy, and assessed its feasibility and safety.DesignSubjects received propofol 1.5 to 2.5 mg/kg injection followed by repeated doses of 20 to 30 mg if necessary.SettingTertiary hospital.PatientsThirty patients, American Society of Anesthesiologists class I to III, undergoing upper GI endoscopy and requesting sedation.InterventionsAfter connecting the MAUGE to the anesthetic ventilation circuit and mask, the endoscope was inserted into the patient's digestive tract through the channel for endoscopes in the MAUGE and through the mask. Oxygen was supplied to the respiratory tract through the channel for gas in the MAUGE and through the mask by using positive pressure ventilation by bag-valve-mask ventilation.Main Outcome MeasurementsHeart rate, noninvasive blood pressure, end-tidal carbon dioxide tension, oxygen saturation, respiratory waveform.ResultsOxygen saturation was more than 95% throughout the endoscopy in all patients. Positive ventilation was achieved in all patients and consistent with thoracic wall movement and respiratory waveforms shown by capnography.LimitationsThe MAUGE cannot seal the respiratory tract. Patients in high risk for aspiration should not be considered candidates for using the MAUGE.ConclusionsBy use of the MAUGE, positive pressure ventilation was efficaciously achieved, and desaturation and carbon dioxide retention were effectively avoided during the upper GI endoscopy procedure.