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NCT Number: NCT04627220

Effect of Intraoperative Arterial Oxygen Targets on Thiol-Disulfide Homeostasis and Ischemia-Modified Albumin

This single-center randomized trial compared two intraoperative arterial oxygen tension (PaO2) target strategies in adults undergoing elective isolated coronary artery bypass graft surgery. Sixty-four participants were assigned 1:1 to a higher target (PaO2 200 mmHg or greater) or a lower target (PaO2 80 to less than 200 mmHg). The study evaluated perioperative changes in thiol-disulfide homeostasis and ischemia-modified albumin.

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Key information

Conditions

Coronary Artery Disease Arterial Occlusive Diseases Arteriosclerosis Cardiovascular Diseases Coronary Disease Heart Diseases Myocardial Ischemia Vascular Diseases

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Health Sciences Bursa Yüksek İhtisas Training and Research Hospital

Bursa, 16310, Turkey (Türkiye)

About this study

Hyperoxemia is frequently used during cardiac surgery to reduce the risk of hypoxemia, but excessive oxygen exposure may increase oxidative stress and ischemia-reperfusion injury. In this prospective, randomized, parallel-group study, inspired oxygen concentration was adjusted intraoperatively to achieve the assigned PaO2 target. Allocation was generated by computer and concealed with sealed envelopes. The clinical team was aware of group assignment because oxygen administration had to be titrated, whereas laboratory personnel were blinded. Biomarker samples were collected before anesthesia induction, 30 minutes after aortic cross-clamp removal, at the end of surgery, and 6 hours postoperatively. Sixty-four participants were randomized (32 per group), and 59 participants were included in the final analysis.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18 to 75 years
  • Scheduled for elective isolated coronary artery bypass graft surgery
  • American Society of Anesthesiologists physical status III or higher
  • Left ventricular ejection fraction of 40% or greater

Exclusion criteria

  • Valvular heart disease requiring concomitant valve surgery
  • Left ventricular ejection fraction below 40%
  • Hemodynamically significant arrhythmia
  • Previous stroke or transient ischemic attack
  • End-stage organ failure

Treatment and study plan

Intraoperative Oxygenation Strategy: PaO2 200 mmHg or Greater

Other

The fraction of inspired oxygen was actively titrated during anesthesia and cardiopulmonary bypass to achieve an arterial oxygen tension (PaO2) of 200 mmHg or greater. The assigned strategy was maintained intraoperatively, subject to predefined cerebral oxygen saturation safety management.

Intraoperative Oxygenation Strategy: PaO2 80 to Less Than 200 mmHg

Other

The fraction of inspired oxygen was actively titrated during anesthesia and cardiopulmonary bypass to achieve an arterial oxygen tension (PaO2) from 80 to less than 200 mmHg. The assigned strategy was maintained intraoperatively, subject to predefined cerebral oxygen saturation safety management.

Primary outcomes

  1. Native Thiol Concentration

    Time frame: Before anesthesia induction; 30 minutes after aortic cross-clamp removal; at the end of surgery; and 6 hours postoperatively

    Serum native thiol concentration measured by the automated spectrophotometric thiol-disulfide homeostasis method and reported in micromoles per liter (micromol/L).

  2. Total Thiol Concentration

    Time frame: Before anesthesia induction; 30 minutes after aortic cross-clamp removal; at the end of surgery; and 6 hours postoperatively

    Serum total thiol concentration measured by the automated spectrophotometric thiol-disulfide homeostasis method and reported in micromoles per liter (micromol/L).

  3. Disulfide Concentration

    Time frame: Before anesthesia induction; 30 minutes after aortic cross-clamp removal; at the end of surgery; and 6 hours postoperatively

    Serum disulfide concentration calculated as one half of the difference between total thiol and native thiol concentrations and reported in micromoles per liter (micromol/L).

  4. Disulfide-to-Native Thiol Ratio

    Time frame: Before anesthesia induction; 30 minutes after aortic cross-clamp removal; at the end of surgery; and 6 hours postoperatively

    The ratio of serum disulfide concentration to native thiol concentration, calculated and reported as a percentage.

  5. Disulfide-to-Total Thiol Ratio

    Time frame: Before anesthesia induction; 30 minutes after aortic cross-clamp removal; at the end of surgery; and 6 hours postoperatively

    The ratio of serum disulfide concentration to total thiol concentration, calculated and reported as a percentage.

  6. Native Thiol-to-Total Thiol Ratio

    Time frame: Before anesthesia induction; 30 minutes after aortic cross-clamp removal; at the end of surgery; and 6 hours postoperatively

    The ratio of serum native thiol concentration to total thiol concentration, calculated and reported as a percentage.

Secondary outcomes

  1. Ischemia-Modified Albumin Level

    Time frame: Before anesthesia induction; 30 minutes after aortic cross-clamp removal; at the end of surgery; and 6 hours postoperatively

    Serum ischemia-modified albumin measured using the albumin cobalt-binding assay and reported in absorbance units (ABSU).

Sponsors and collaborators

Lead sponsor

Bursa Yuksek Ihtisas Training and Research Hospital

Other Gov

Registry information

Official study title

Effects of Two Intraoperative Arterial Oxygen Targets on Thiol-Disulfide Homeostasis and Ischemia-Modified Albumin in Coronary Artery Bypass Graft Surgery

Important dates

Study start
2020
Primary completion
2020
Study completion
2020
First posted
Nov 13, 2020
Registry last updated
Sep 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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