Methylene Blue Administration Mimics an Oxygenator Failure during Cardiopulmonary Bypass

An oxygenator failure during cardiopulmonary bypass is an emergency. The entire cardiac surgical team requires a comprehensive and methodical approach to troubleshoot the possible cause. We report that the bolus administration of methylene blue during cardiopulmonary bypass will induce a syndrome that mimics an oxygenator failure. Methylene blue has physical properties that cause venous saturation monitors to function inaccurately and the post oxygenator blood in the cardiopulmonary bypass circuit to appear deoxygenated. However, these events are temporary and do not require an emergent oxygenator change out. All members of the cardiac surgical team need to be aware of the effect of methylene blue administration during cardiopulmonary bypass and integrate this into their oxygenator failure troubleshooting algorithm.