Intraoperative Oxygen Concentration and Neurocognition After Cardiac Surgery

Not Applicable

• Conditions: Hyperoxia; Normoxic; Delirium
• Interventions: Other: Normoxic oxygenation; Other: Hyperoxic oxygenation

• Registration Number: NCT02591589
• Lead Sponsor: Beth Israel Deaconess Medical Center

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2015-02-13
• Study Start: 2015-07
• Study First Submitted QC: 2015-10-28
• Study First Posted: 2015-10-29
• Primary Completion: 2018-01-17
• Status Verified: 2020-09
• Last Update Submitted: 2020-09-21
• Last Update Posted: 2020-09-23
• Study Completion: 2021-03-01

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 100

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Normoxic group	Normoxic oxygenation	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.
Hyperoxic group	Hyperoxic oxygenation	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.

Primary Outcome Measures

Name	Time	Method
Telephonic-MoCA (t-MoCA)	Change from baseline tMoCA score through 6 months	t-MoCA will be performed baseline, daily starting POD#1 as well as at 1, 3 and 6 months post-operatively. In previous studies, testing through month 6, has been shown to accurately reflect more longitudinal follow-up. t-MoCA results are on a 22 point scale and will be used as a marker for cognitive function and has been validated. Blinded study staff trained in administering the assessments will collect the data.

Secondary Outcome Measures

Name	Time	Method
Days of mechanical ventilation	Post-operative day 1 through discharge from hospital (3-5 days on average)
Confusion Assessment Method for the ICU	Post-operative day 1 through discharge from hospital (3-5 days on average)	CAM and CAM-ICU as a marker of delirium post-operatively will be administered and measured at the same time as the t-MoCA. This is a validated test to measure delirium. There is much data to support an increased reduction in cognitive ability in patients exhibiting post-operative delirium.
Length of stay in hospital	Post-operative day 1 through discharge from hospital (3-5 days on average)
Patient mortality	30 days and 6 months post-operatively
Time to extubation	Post-operative day 1 through discharge from hospital
Biomarkers of oxidative stress, IL-6, IL-8 and others	Intraoperatively at cardiopulmonary bypass (CPB)

Trial Locations

Locations (1)

Beth Israel Deaconess Medical Center; 🇺🇸 Boston, Massachusetts, United States