Intraoperative Oxygen Concentration and Neurocognition After Cardiac Surgery

Beth Israel Lahey Health

Status: Unknown

Conditions: Delirium; Hyperoxia; Normoxic

Treatments: Other: Normoxic oxygenation; Other: Hyperoxic oxygenation

Study type: Interventional

Funder types: Other

Identifiers

NCT02591589

2014P000398

Details and patient eligibility

About

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.

Enrollment: 100 estimated patients

Sex: All

Ages: 65+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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100 participants in 2 patient groups

Normoxic group

Experimental group

Description:

To standardize key aspects of ventilator support, tidal volume will be set to 6-8ml/kg and PEEP levels will be set to 0-5cm H2O, allowing flexibility for provider preference. For normoxic oxygenation FiO2 will be set at 0.35 (35%) ideally to maintain PaO2 above 70mmHg (or saturations greater than or equal to 92%), and titrated up if need be to prevent potentially injurious hypoxemia (saturations below 92%). During cardiopulmonary bypass, blended air/ oxygen mixture will be titrated to arterial blood gas analysis with maintenance of PaO2 between 100mmHg and 150mmHg.

Treatment:

Other: Normoxic oxygenation

Hyperoxic group

Active Comparator group

Description:

To standardize key aspects of ventilator support, tidal volume will be set to 6-8ml/kg and PEEP levels will be set to 0-5cm H2O, allowing flexibility for provider preference. For hyperoxic oxygenation FiO2 will be set at 1.0 (100%) throughout the intraoperative period, including cardiopulmonary bypass.

Treatment:

Other: Hyperoxic oxygenation