DRE Vet Dispomed Veterinary Circuit AlarmDescription DRE Vet Dispomed Veterinary Circuit Alarm Assisted Ventilation It is challenging to gauge the airway pressure when assisted ventilation is required. Your anesthesia machine's circuit alarm can help lower the possibility of an elevated pressure. If the pressure reaches a dangerous level, the alarm will sound. Evacuation valve The circuit alarm will let you know when the level is about to become dangerous if you happen to forget to re open