A dräger technician evaluated the device in follow-up of the event, the logfile was provided for the investigation.The unit was tested and confirmed to be operating per manufacturer's specifications.Log file evaluation revealed that the automatic power-on self-test was passed in the morning without deviations.The concerned surgical procedure went widely stable until a significant circuit leak was present reflected in several apnea alarms given and resulting in a fresh gas deficiency.At this point the patient most likely was rolled their stomach to their back.One minute later a too fast and too high pressure increase was detected resulting in an emergency shutdown while autonomously changing mode to man/spont.The shutdown was accompanied by the corresponding ventilator fail alarm.The therapy was continued using manual ventilation until the unit was placed in standby.All in all, no indication for the potential presence of a device malfunction could be found.The safety shut-down was triggered by a transient pressure peak in the airway system.Since the user described that the patient coughed during the event, a reasonable explanation would be that the patient was coughing in a moment where the ventilator piston was moving upwards.To protect from potentially hazardous output, the device is designed to shut-down automatic ventilation when such fast and significant rise in airway pressure is detected.Dräger finally concluded that the device behaved according to specification.
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