HyperoxiaNCT07525661
Perioperative Hyperoxia vs Normoxia Biomarker Trial
A study testing Perioperative Oxygen Strategy - Normoxia and Perioperative Oxygen Strategy-Hyperoxia in people with Hyperoxia and Perioperative Care, run by Istanbul University at 1 site in Turkey (Türkiye).
Trial summary
This single-center randomized interventional study evaluated the biological effects of two perioperative oxygen strategies in adults undergoing elective laparoscopic lower abdominal surgery under standardized general anesthesia. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Hyperoxia, Perioperative Care, Oxidative Stress
- What is being tested?
- Perioperative Oxygen Strategy - Normoxia and Perioperative Oxygen Strategy-Hyperoxia
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 76 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jul 2017to 1 Feb 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18 to 70 years
- Scheduled for elective laparoscopic lower abdominal surgery
- Expected surgery duration of at least 90 minutes
- ASA physical status I to III
- Body mass index 18.5 to 35 kg/m2
- Planned management under standardized general anesthesia with volume-controlled ventilation
Who cannot join
- Known chronic pulmonary disease, including chronic obstructive pulmonary disease or asthma requiring regular medication
- Baseline peripheral oxygen saturation below 92% on room air
- Significant cardiovascular instability
- Severe hepatic or renal dysfunction
- Active infection or systemic inflammatory disease
- Use of systemic corticosteroids or immunosuppressive therapy
Show all 10Show fewer
- Pregnancy
- Inability to provide informed consent
- Anticipated difficult airway
- Expected need for postoperative mechanical ventilation
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Istanbul University, Istanbul Faculty of Medicine
Istanbul
About this study
Official title: Effects of Perioperative Hyperoxia Versus Normoxia on Pulmonary, Endothelial, and Inflammatory Biomarkers in Elective Laparoscopic Lower Abdominal Surgery
This single-center randomized interventional study evaluated the biological effects of two perioperative oxygen strategies in adults undergoing elective laparoscopic lower abdominal surgery under standardized general anesthesia. Participants were assigned to receive either normoxia (FiO2 0.35) or hyperoxia (FiO2 0.80) after intubation and throughout the intraoperative period. The study assessed perioperative changes in circulating biomarkers related to pulmonary epithelial stress, endothelial glycocalyx injury, oxidative stress, and inflammation, together with blood gas and hemodynamic parameters. The study was completed before registration and is being registered retrospectively.
Read the detailed description
Perioperative oxygen administration is widely used during general anesthesia, but the biological effects of liberal oxygen exposure remain uncertain. This randomized parallel-group study compared a normoxic strategy (FiO2 0.35) with a hyperoxic strategy (FiO2 0.80) in adult patients undergoing elective laparoscopic lower abdominal surgery. The assigned inspired oxygen fraction was initiated immediately after tracheal intubation and maintained intraoperatively under volume-controlled ventilation with otherwise standardized anesthetic management.
The primary objective was to compare perioperative changes in circulating biomarkers reflecting endothelial glycocalyx injury and inflammatory activation. Biomarkers assessed included syndecan-1, sialic acid, surfactant protein-A, ischemia-modified albumin, tumor necrosis factor-alpha, and total protein. Secondary assessments included arterial and venous blood gas variables, lactate, mean arterial pressure, and heart rate.
This study was completed before registry submission and is being entered retrospectively for transparency.
- Being tested
- Perioperative Oxygen Strategy - Normoxia, Perioperative Oxygen Strategy-Hyperoxia
- Keywords
- Hyperoxia, Normoxia, Perioperative Oxygen Therapy, Syndecan-1, Sialic Acid, Surfactant Protein-A, TNF-alpha, Randomized Trial
- Medical subject headings
- Hyperoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Perioperative Oxygen Strategy - NormoxiaOther
Normoxia arm: FiO2 0.35 Intervention started immediately after intubation and maintained intraoperatively
Perioperative Oxygen Strategy-HyperoxiaOther
Hyperoxia arm: FiO2 0.80 Intervention started immediately after intubation and maintained intraoperatively
| Study group | Role | What they receive |
|---|---|---|
| Normoxia | Experimental | Intraoperative inspired oxygen fraction (FiO2) of 0.35 under standardized general anesthesia and volume-controlled ventilation. Receives: Other: Perioperative Oxygen Strategy - Normoxia |
| Hyperoxia | Experimental | Intraoperative inspired oxygen fraction (FiO2) of 0.80 under standardized general anesthesia and volume-controlled ventilation. Receives: Other: Perioperative Oxygen Strategy-Hyperoxia |
What is being measured
The primary outcome is the main question the study is designed to answer.
Concentration of syndecan-1
Serum syndecan-1 concentration measured in duplicate.
Measured: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Concentration of sialic acid
Serum sialic acid concentration measured in duplicate.
Measured: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Concentration of surfactant protein-A
Serum surfactant protein-A concentration measured in duplicate.
Measured: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Concentration of ischemia-modified albumin
Serum ischemia-modified albumin concentration measured in duplicate.
Measured: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Concentration of TNF-alpha
Serum TNF-alpha concentration measured in duplicate.
Measured: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Concentration of total protein
Serum total protein concentration measured in duplicate.
Measured: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Secondary outcomes (12)
Arterial oxygen tension (PaO2)
Measured: 10 minutes after establishment of assigned oxygen fraction
Intraoperative mean arterial pressure
Measured: Immediately after intubation and every 15 minutes up to 90 minutes
Intraoperative heart rate
Measured: Immediately after intubation and every 15 minutes up to 90 minutes
Arterial oxygen tension (PaO2)
Arterial partial pressure of oxygen.
Measured: 10 minutes after establishment of assigned oxygen fraction
Arterial pH
Arterial pH measured on blood gas analysis.
Measured: 10 minutes after establishment of assigned oxygen fraction
Arterial carbon dioxide tension (PaCO2)
Arterial partial pressure of carbon dioxide.
Measured: 10 minutes after establishment of assigned oxygen fraction
Venous oxygen tension (PvO2)
Venous partial pressure of oxygen.
Measured: 10 minutes after establishment of assigned oxygen fraction
Venous carbon dioxide tension (PvCO2)
Venous partial pressure of carbon dioxide.
Measured: 10 minutes after establishment of assigned oxygen fraction
Arterial oxygen saturation (SaO2)
Arterial oxygen saturation measured on blood gas analysis.
Measured: 10 minutes after establishment of assigned oxygen fraction
Venous oxygen saturation (SvO2)
Venous oxygen saturation measured on blood gas analysis.
Measured: 10 minutes after establishment of assigned oxygen fraction
Arteriovenous oxygen difference
Difference between arterial and venous oxygen saturation.
Measured: 10 minutes after establishment of assigned oxygen fraction
Lactate concentration
Blood lactate concentration measured on blood gas analysis.
Measured: 10 minutes after establishment of assigned oxygen fraction
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Apr 2026
- Study start1 Jul 2017
- Primary completion1 Jan 2019
- Study completion1 Feb 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for HyperoxiaStudies of the same condition, open and under way.
- More trials run by Istanbul UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 76 participants (actual)
Sponsor and investigators
- Lead sponsor
- Istanbul University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Nuzhet Mert Senturk, MD, Prof, Istanbul University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07525661
- Sponsor's protocol ID
- 2017/771
- Status last verified
- Apr 2026
- First submitted
- 30 Mar 2026
- Last updated
- 13 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Lopez MG, Pandey AK, Hennessy C, Hughes CG, Absi TS, Shah AS, Shotwell MS, Harrison DG, Billings FT 4th; ROCS Trial Investigators. Effects of Oxygen on Perioperative Vascular Function: A Randomized Clinical Trial. J Am Heart Assoc. 2025 Aug 5;14(15):e041778. doi: 10.1161/JAHA.125.041778. Epub 2025 Jul 17.
PubMed 40673571Farag E, Esa Y, Chehade NEH, Sleiman VB, Seif J. Endothelial glycocalyx in perioperative medicine current understanding and future direction. J Clin Anesth. 2026 Mar;110:112154. doi: 10.1016/j.jclinane.2026.112154. Epub 2026 Feb 16.
PubMed 41702329Larvin J, Edwards M, Martin DS, Feelisch M, Grocott MPW, Cumpstey AF. Perioperative oxygenation-what's the stress? BJA Open. 2024 Mar 20;10:100277. doi: 10.1016/j.bjao.2024.100277. eCollection 2024 Jun.
PubMed 38545565Meyhoff CS, Wetterslev J, Jorgensen LN, Henneberg SW, Hogdall C, Lundvall L, Svendsen PE, Mollerup H, Lunn TH, Simonsen I, Martinsen KR, Pulawska T, Bundgaard L, Bugge L, Hansen EG, Riber C, Gocht-Jensen P, Walker LR, Bendtsen A, Johansson G, Skovgaard N, Helto K, Poukinski A, Korshin A, Walli A, Bulut M, Carlsson PS, Rodt SA, Lundbech LB, Rask H, Buch N, Perdawid SK, Reza J, Jensen KV, Carlsen CG, Jensen FS, Rasmussen LS; PROXI Trial Group. Effect of high perioperative oxygen fraction on surgical site infection and pulmonary complications after abdominal surgery: the PROXI randomized clinical trial. JAMA. 2009 Oct 14;302(14):1543-50. doi: 10.1001/jama.2009.1452.
PubMed 19826023Elfeky A, Chen YF, Grove A, Couper K, Court R, Tomassini S, Wilson A, Hooper A, Buckle A, Vadeyar S, Thompson M, Uthman O, Yeung J. Perioperative oxygen therapy: an overview of systematic reviews and meta-analyses. Br J Anaesth. 2025 Nov;135(5):1456-1476. doi: 10.1016/j.bja.2025.04.020. Epub 2025 Jun 6.
PubMed 40483181
Study at a glance
From the registry record, last updated by the sponsor on 13 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Perioperative Hyperoxia Versus Normoxia on Pulmonary, Endothelial, and Inflammatory Biomarkers in Elective Laparoscopic Lower Abdominal Surgery
- ClinicalTrials.gov ID
- NCT07525661
- Acronym / sponsor ID
- 2017/771
- Keywords
- Hyperoxia, Normoxia, Perioperative Oxygen Therapy, Syndecan-1, Sialic Acid, Surfactant Protein-A, TNF-alpha, Randomized Trial
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 76 participants (actual)
- Lead sponsor
- Istanbul UniversityUniversity, hospital or other
- Study start
- 1 Jul 2017 (actual)
- Primary completion
- 1 Jan 2019 (actual)
- Study completion
- 1 Feb 2019 (actual)
- First posted
- 13 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This single-center randomized interventional study evaluated the biological effects of two perioperative oxygen strategies in adults undergoing elective laparoscopic lower abdominal surgery under standardized general anesthesia. Participants were assigned to receive either normoxia (FiO2 0.35) or hyperoxia (FiO2 0.80) after intubation and throughout the intraoperative period. The study assessed perioperative changes in circulating biomarkers related to pulmonary epithelial stress, endothelial glycocalyx injury, oxidative stress, and inflammation, together with blood gas and hemodynamic parameters. The study was completed before registration and is being registered retrospectively.
Detailed description
Perioperative oxygen administration is widely used during general anesthesia, but the biological effects of liberal oxygen exposure remain uncertain. This randomized parallel-group study compared a normoxic strategy (FiO2 0.35) with a hyperoxic strategy (FiO2 0.80) in adult patients undergoing elective laparoscopic lower abdominal surgery. The assigned inspired oxygen fraction was initiated immediately after tracheal intubation and maintained intraoperatively under volume-controlled ventilation with otherwise standardized anesthetic management.
The primary objective was to compare perioperative changes in circulating biomarkers reflecting endothelial glycocalyx injury and inflammatory activation. Biomarkers assessed included syndecan-1, sialic acid, surfactant protein-A, ischemia-modified albumin, tumor necrosis factor-alpha, and total protein. Secondary assessments included arterial and venous blood gas variables, lactate, mean arterial pressure, and heart rate.
This study was completed before registry submission and is being entered retrospectively for transparency.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Normoxia | Experimental | Other: Perioperative Oxygen Strategy - NormoxiaIntraoperative inspired oxygen fraction (FiO2) of 0.35 under standardized general anesthesia and volume-controlled ventilation. |
| Hyperoxia | Experimental | Other: Perioperative Oxygen Strategy-HyperoxiaIntraoperative inspired oxygen fraction (FiO2) of 0.80 under standardized general anesthesia and volume-controlled ventilation. |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Adults aged 18 to 70 years
- Scheduled for elective laparoscopic lower abdominal surgery
- Expected surgery duration of at least 90 minutes
- ASA physical status I to III
- Body mass index 18.5 to 35 kg/m2
Key exclusion criteria (10 listed)
- Known chronic pulmonary disease, including chronic obstructive pulmonary disease or asthma requiring regular medication
- Baseline peripheral oxygen saturation below 92% on room air
- Significant cardiovascular instability
- Severe hepatic or renal dysfunction
- Active infection or systemic inflammatory disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Perioperative Oxygen Strategy - NormoxiaNormoxia arm: FiO2 0.35 Intervention started immediately after intubation and maintained intraoperatively | Other | Normoxia |
| Perioperative Oxygen Strategy-HyperoxiaHyperoxia arm: FiO2 0.80 Intervention started immediately after intubation and maintained intraoperatively | Other | Hyperoxia |
Primary outcome
Concentration of syndecan-1
Time frame: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Serum syndecan-1 concentration measured in duplicate.
Concentration of sialic acid
Time frame: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Serum sialic acid concentration measured in duplicate.
Concentration of surfactant protein-A
Time frame: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Serum surfactant protein-A concentration measured in duplicate.
Concentration of ischemia-modified albumin
Time frame: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Serum ischemia-modified albumin concentration measured in duplicate.
Concentration of TNF-alpha
Time frame: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Serum TNF-alpha concentration measured in duplicate.
Concentration of total protein
Time frame: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation
Serum total protein concentration measured in duplicate.
12 secondary outcomes
Arterial oxygen tension (PaO2)
Time frame: 10 minutes after establishment of assigned oxygen fraction
Intraoperative mean arterial pressure
Time frame: Immediately after intubation and every 15 minutes up to 90 minutes
Intraoperative heart rate
Time frame: Immediately after intubation and every 15 minutes up to 90 minutes
Arterial oxygen tension (PaO2)
Time frame: 10 minutes after establishment of assigned oxygen fraction
Arterial pH
Time frame: 10 minutes after establishment of assigned oxygen fraction
Arterial carbon dioxide tension (PaCO2)
Time frame: 10 minutes after establishment of assigned oxygen fraction
Venous oxygen tension (PvO2)
Time frame: 10 minutes after establishment of assigned oxygen fraction
Venous carbon dioxide tension (PvCO2)
Time frame: 10 minutes after establishment of assigned oxygen fraction
Arterial oxygen saturation (SaO2)
Time frame: 10 minutes after establishment of assigned oxygen fraction
Venous oxygen saturation (SvO2)
Time frame: 10 minutes after establishment of assigned oxygen fraction
Arteriovenous oxygen difference
Time frame: 10 minutes after establishment of assigned oxygen fraction
Lactate concentration
Time frame: 10 minutes after establishment of assigned oxygen fraction
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Apr 2026.
- Background: PubMed 40673571Lopez MG, Pandey AK, Hennessy C, Hughes CG, Absi TS, Shah AS, Shotwell MS, Harrison DG, Billings FT 4th; ROCS Trial Investigators. Effects of Oxygen on Perioperative Vascular Function: A Randomized Clinical Trial. J Am Heart Assoc. 2025 Aug 5;14(15):e041778. doi: 10.1161/JAHA.125.041778. Epub 2025 Jul 17.
- Background: PubMed 41702329Farag E, Esa Y, Chehade NEH, Sleiman VB, Seif J. Endothelial glycocalyx in perioperative medicine current understanding and future direction. J Clin Anesth. 2026 Mar;110:112154. doi: 10.1016/j.jclinane.2026.112154. Epub 2026 Feb 16.
- Background: PubMed 38545565Larvin J, Edwards M, Martin DS, Feelisch M, Grocott MPW, Cumpstey AF. Perioperative oxygenation-what's the stress? BJA Open. 2024 Mar 20;10:100277. doi: 10.1016/j.bjao.2024.100277. eCollection 2024 Jun.
- Background: PubMed 19826023Meyhoff CS, Wetterslev J, Jorgensen LN, Henneberg SW, Hogdall C, Lundvall L, Svendsen PE, Mollerup H, Lunn TH, Simonsen I, Martinsen KR, Pulawska T, Bundgaard L, Bugge L, Hansen EG, Riber C, Gocht-Jensen P, Walker LR, Bendtsen A, Johansson G, Skovgaard N, Helto K, Poukinski A, Korshin A, Walli A, Bulut M, Carlsson PS, Rodt SA, Lundbech LB, Rask H, Buch N, Perdawid SK, Reza J, Jensen KV, Carlsen CG, Jensen FS, Rasmussen LS; PROXI Trial Group. Effect of high perioperative oxygen fraction on surgical site infection and pulmonary complications after abdominal surgery: the PROXI randomized clinical trial. JAMA. 2009 Oct 14;302(14):1543-50. doi: 10.1001/jama.2009.1452.
- Background: PubMed 40483181Elfeky A, Chen YF, Grove A, Couper K, Court R, Tomassini S, Wilson A, Hooper A, Buckle A, Vadeyar S, Thompson M, Uthman O, Yeung J. Perioperative oxygen therapy: an overview of systematic reviews and meta-analyses. Br J Anaesth. 2025 Nov;135(5):1456-1476. doi: 10.1016/j.bja.2025.04.020. Epub 2025 Jun 6.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Perioperative Oxygen Strategy - Normoxia and Perioperative Oxygen Strategy-Hyperoxia in people with Hyperoxia and Perioperative Care, run by Istanbul University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Concentration of syndecan-1 (time frame: 10 minutes after establishment of assigned oxygen fraction and immediately after surgery/post-extubation). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07525661, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Apr 2026.