Effects of Hyperoxia on Open Heart Surgery

Study Overview
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Brief Summary
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Patients undergoing Open Cardiac Surgery will be randomized into two groups. Group I will be ventilated with 40% Fio2 during induction, surgery and in Postoperative care unit. Group II will be ventilated with 100% Fio2 during induction and with 60-70% ( determined according to the arterial blood gas sample results) during surgery and in Postoperative care unit. Hemodynamic parameters ( systolic arterial pressure, diastolic arterial pressure, heart rate ), Arterial blood gas samples ( PaO2, PaCO2, pH, Oxygen saturation, Lactate), and pre and post cardiopulmonary bypass Superoxide dismutase and malonyl aldehyde levels.

Official Title
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Effects of Hyperoxia on Oxidative Stress in Patients Undergoing Open Heart Surgery

Conditions
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Heart Valve Disease, Coronary (Artery) Disease

Intervention / Treatment
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* Other: Fraction of inspired oxygen 40%
* Other: Fraction of inspired oxygen 100%


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA II-III Patients with EF higher than 50%. patients undergoing elective open heart surgery on pump ( CABG, Valve Replacement) Exclusion Criteria: patients with Diabetes Mellitus patients with COPD Patients with Cerebral Vascular Disease Patients with hypoxia in Arterial blood gas samples ( PaO2 lower than 80 mmHg) and hypercarbia (PaCO2 higher than 45 mmHg)

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 65 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: Screening
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Active Comparator: 40% oxygen<br>Patients in this group will be ventilated with fraction of inspired oxygen 40% during the induction, surgery and in Postoperative care unit. | Other: Fraction of inspired oxygen 40%<br> <br> |
| Active Comparator: Active Comparator: 100% oxygen<br>Patients in this group will be ventilated with fraction of inspired oxygen during 100% induction and with 60-70% ( determined according to the arterial blood gas sample results) during surgery and in Postoperative care unit. | Other: Fraction of inspired oxygen 100%<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in Malondialdehyde (MDA) (nmol/mg pr) levels (as a biomarker for oxidative stress ) and Superoxide dismutase (SOD) (nmol/mg pr) levels as a biomarker for antioxidant response in the plasma between before and after cardiopulmonary bypass | As primary outcome, the effects of different inspired oxygen fractions on oxidative stress and anti-oxidant response in before and after cardiopulmonary bypass will be evaluated | 72 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Partial pressure of oxygen(mmHg), | Partial pressure of oxygen(mmHg) in arterial-blood-gas samples before induction, following induction, before and after cardiopulmonary bypass, before extubation and following extubation, postoperative 24 and 72th hours. | 72 hours | 
| Partial pressure of carbondioxide(mm Hg) | ,Partial pressure of carbondioxide(mm Hg) in arterial-blood-gas samples before induction, following induction, before and after cardiopulmonary bypass, before extubation and following extubation, postoperative 24 and 72th hours. | 72 hours | 
| lactate (mmol/l) | lactate (mmol/l) levels in arterial blood gas samples before induction, following induction, before and after cardiopulmonary bypass, before extubation and following extubation, postoperative 24 and 72th hours. | 72 hours | 
| ph values | ph values in arterial blood gas samples before induction, following induction, before and after cardiopulmonary bypass, before extubation and following extubation, postoperative 24 and 72th hours. | 72 hours | 
| systolic arterial pressure (mmHg), | systolic arterial pressure (mmHg), levels before induction, following induction, before and after cardiopulmonary bypass, before extubation and following extubation, postoperative 24 and 72th hours. | 72 hours | 
| diastolic arterial pressure (mmHg) | diastolic arterial pressure (mmHg) levels before induction, following induction, before and after cardiopulmonary bypass, before extubation and following extubation, postoperative 24 and 72th hours. | 72 hours | 
| Oxygen saturation (%) | Oxygen saturation (%) levels in arterial blood gas samples before induction, following induction, before and after cardiopulmonary bypass, before extubation and following extubation, postoperative 24 and 72th hours. | 72 hours | 
| heart rate (beat/min) | heart rate (beat/min) levels before induction, following induction, before and after cardiopulmonary bypass, before extubation and following extubation, postoperative 24 and 72th hours. | 72 hours |