Clinicians may continue to use their Avance, Aisys and Avance CS2anesthesia delivery system, but should be aware that a unique sequence of inputs and a collapsed bellows could result in delivery of higher-than-expected tidal volume when using the Pressure Control Ventilation – Volume Guarantee (PCV-VG) mode. All safety over-pressure controls and alarms will continue to function properly. However, over delivery of tidal volume may result in alterations to blood flow within the thorax that, under extreme circumstances, may result in gradual reductions in blood pressure. The unique sequence of inputs includes transitioning from mechanical PCV-VG mode to manual ventilation, changing the set tidal volume (while in manual mode), and then returning to mechanical PCV-VG mode. To avoid this situation, when using PCV-VG mode, do not adjust the ventilator tidal volume while in a manual ventilation mode. At any time during the use of the device should an over delivery of tidal volume occur while in PCV-VG mode, transitioning to a different ventilation mode will resolve the issue.