Intra-operative Fraction of Inspired Oxygen and Lung Injury in Coronary Artery Bypass Grafting Surgery

Study Overview
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Brief Summary
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This study is a prospective observer blinded, central randomization controlled, multi-center clinical trial to assess the relationship between intraoperative FiO2 and postoperative pulmonary complications with lung injury.

Detailed Description
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Hyperoxia is common in cardiac surgery and is easy to prevent by adjusting FiO2. Since there is no prospective study on different FiO2 and postoperative pulmonary complications (PPCs) during cardiac surgery. We hypothesized that hyperoxia during cardiac surgery could lead to higher incidence of lung injury and PPCs than normoxia. The objective of this trial is to compare postoperative PPCs and other outcomes between hyperoxia and normoxia strategy by PaO2/FiO2 in CABG patients.

Official Title
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Intraoperative Fraction of Inspired Oxygen and Lung Injury in Coronary Artery Bypass Grafting Surgery

Conditions
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Lung Injury, Pulmonary Complication

Intervention / Treatment
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* Other: Fraction of Inspired Oxygen


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age from 18 to 75 BMI from 20 to 39.9 ASA II/III Undergoing isolated selective on-pump CABG through median sternotomy Subsequent admission to an intensive care unit (ICU). Exclusion Criteria: with severe chronic obstructive pulmonary disease (COPD) Pregnant woman. With current acute coronary syndrome (<1 week) Severe anemia (hemoglobin <10g/L) Preoperative supplemental oxygen requirement to maintain arterial O2 of 92%, Right to left shunt in heart Carotid stenosis defined as >50% stenosis of either carotid artery, Cardiac surgery that requires intraoperative circulatory arrest, Current use of dialysis, One-lung ventilation during surgery, Recent smoking (within 1 month), Non-respiratory reason to reintubate or delayed extubation such as bleeding or heart failure, Perioperative allogenic transfusion with red blood cell, plasma or platelet

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Restrictive Oxygen<br>The restrictive oxygen patients' Fraction of Inspired Oxygen (FiO2) will be set at a minimum of 0.3 to maintain their oxygen saturations (SpO2) greater than or equal to 95% intraoperatively. During CPB a blended air/oxygen mixture will be titrated to arterial blood gas analysis with aim of maintenance of PaO2 between 100 and 150 mmHg. After transfer to ICU, all patients' FiO2 will be set to 50% initially, and titrate to minimal FiO2 (not less than 21%) for maintain SPO2≥95% until extubation. | Other: Fraction of Inspired Oxygen<br>* Fraction of Inspired Oxygen during cardiac surgery, including cardiopulmonary bypass<br>|
| No Intervention: Liberal Oxygen<br>The liberal oxygen group will consist of subjects exposed to a Fraction of Inspired Oxygen (FiO2) set at 1.0 throughout the intraoperative period, including during cardiopulmonary bypass. After transfer to ICU, all patients' FiO2 will be set to 50% initially, and titrate to minimal FiO2 (not less than 21%) for maintain SPO2≥95% until extubation. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| arterial PO2/FiO2 Ratio | minimal postoperative arterial PO2/FiO2 Ratio | 48hr post operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulmonary complications | ARDS, noncardiogenic pulmonary edema, pulmonary infection, pneumonia, pleural effusion, atelectasis, and respiratory failure are secondary endpoints | up to one week while in the hospital | 
| length of mechanical ventilation | time from skin closure to extubation | up to one week while in the hospital | 
| length of postoperative ICU stay | time from ICU entry to discharge from ICU | up to one week while in the hospital | 
| length of hospital stay | time from surgery day to discharge from ICU | up to one week while in the hospital |