Background

Oxygenator failure during cardiopulmonary bypass (CPB) is a rare but potentially catastrophic intraoperative event that can result in sudden hypoxemia and neurological injury if not promptly recognized and managed.

Case presentation

We report the case of a 72-year-old man undergoing urgent on-pump coronary artery bypass grafting who developed early oxygenator failure within minutes of CPB initiation. The event was identified by progressive darkening of the arterial blood and a decline in pulse oximetry values. Immediate corrective measures included resuming lung ventilation with 100% oxygen, brief hypothermic circulatory arrest, and rapid oxygenator replacement. The duration of impaired oxygenation was brief, and the oxygenation parameters improved promptly following the intervention. The patient was extubated early in the intensive care unit and did not exhibit neurological deficits during recovery.

Conclusion

This case highlights the importance of continuous clinical vigilance, early recognition of unexpected hypoxemia, and decisive team-based management to prevent adverse neurological outcomes during rare perfusion emergencies.