Intraoperative Oxygen Concentration and Neurocognition After Cardiac Surgery

The Relationship Between Administered Oxygen Levels and Arterial Partial Oxygen Pressure to Neurocognition in Post-operative Mechanically Ventilated Cardiac Surgical Patients

This is a randomized, prospective controlled trial in patients undergoing cardiac surgery, specifically on-pump coronary artery bypass grafting, comparing level of administered oxygen and partial pressure of arterial oxygen in the operating room and its impact on a widely-used and validated neurocognitive score, the telephonic Montreal Cognitive Assessment (t-MoCA), throughout the hospital stay and at 1 month, 3 months, and 6 postoperatively. It is hypothesized that cardiac surgical patients who undergo normoxic conditions throughout the intraoperative period will have better neurocognitive function than those with maintenance of hyperoxia.

Inclusion Criteria:

• Males and females aged 65 years and older
• Undergoing elective or urgent on-pump Coronary Artery Bypass Graft (CABG) only

Exclusion Criteria:

• Off-pump or any other procedure in addition to CABG
• Emergent procedure
• One-lung ventilation
• Non-English speaking
• Baseline tMoCA score <10
• Preoperative inotrope use
• Preoperative vasopressor use
• Intra-aortic balloon counterpulsation
• Mechanical circulatory support (Intra-aortic balloon pump (IABP)/ Ventricular assisted devices (VAD)/Extracorporeal membrane oxygenation (ECMO))
• Active cardiac ischemia
• Acute decompensated arrhythmia
• O2 sat < 90% on supplemental oxygen
• Use of continuous vasopressor or inotrope infusion medications
• Significant physician or nurse concern

Cessation Criteria

• Development of significant intraoperative hemodynamic compromise as a result of cardiac surgery
• Oxygen desaturation <90% for > 3 min
• Significant physician or nurse concern