Hyperoxia vs Normoxia During Cardiopulmonary Bypass (IPEROXIA)

Hyperoxia During Cardiopulmonary Bypass in Adult Cardiac Surgery: A Randomized Controlled Pilot Study

This single-center randomized controlled pilot trial evaluates the effects of intraoperative hyperoxia compared with normoxia during cardiopulmonary bypass (CPB) in adult patients undergoing elective cardiac surgery. The primary aim is to assess the impact on postoperative renal function. Secondary outcomes include inflammatory markers, cardiovascular and pulmonary complications, resource utilization, and short-term mortality.

Study Overview

• Status: Completed
• Conditions: Mortality; Tracheostomy; AKI; Cardiac Surgery; Renal Replacement Therapy; Mechanical Ventilation; Surgical Complication; Arrythmia; Hospital Length of Stay; Mechanical Circulatory Support; NGAL; ICU Length of Stay
• Intervention / Treatment: Other: Normoxia group (control); Other: Hyperoxia group

Detailed Description

This monocentric randomized controlled pilot trial enrolled adult patients undergoing elective cardiac surgery requiring CPB. Participants were randomized (1:1) to receive either normoxic (PaO₂ 70-150 mmHg) or hyperoxic (PaO₂ >300 mmHg) oxygenation strategies intraoperatively.

The study evaluates postoperative renal function using eGFR, NGAL, renal replacement therapy, and KDIGO classification. Secondary outcomes include IL-6 levels, arrhythmias, mechanical circulatory support, surgical complications, ventilation duration, ICU/hospital stay, and 28-day mortality.

• Study Type: Interventional
• Enrollment (Actual): 104
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Italy
  • PD
    • Padova, PD, Italy, 35121
      • Padova University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• adult patients (>18 years old)
• need for elective cardiac surgery requiring CPB (i.e., isolated valve repair/replacement, coronary artery bypass grafting, or ascending aorta surgery)
• Time frame from July 1st to September 15th 2025

Exclusion Criteria:

• refusal of consent,
• pregnancy,
• previous Intensive Care Unit (ICU) admission,
• history of cardiac surgery requiring CPB,
• signs of preoperative cardiogenic shock (defined as requiring inotropic support, intra-aortic balloon pump, or other mechanical circulatory assistance),
• intraoperative need for circulatory arrest.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Normoxia group; Normoxia group (control): After endotracheal intubation, FiO₂ was initially set to 0.3 and subsequently adjusted to maintain PaO₂ between 70 and 150 mmHg. During CPB, air and oxygen flows through the oxygenator were titrated to maintain a target PaO₂ between 70 and 150 mmHg.	Other: Normoxia group (control); After endotracheal intubation, FiO₂ was initially set to 0.3 and subsequently adjusted to maintain PaO₂ between 70 and 150 mmHg. During CPB, air and oxygen flows through the oxygenator were titrated to maintain a target PaO₂ between 70 and 150 mmHg.
Experimental: Hyperoxia group; Hyperoxia group (intervention): After endotracheal intubation, FiO₂ was maintained at 0.8 and subsequently adjusted to achieve PaO₂ above 300 mmHg. During CPB, air and oxygen flows through the oxygenator were titrated to maintain a target PaO₂ greater than 300 mmHg.	Other: Hyperoxia group; After endotracheal intubation, FiO₂ was maintained at 0.8 and subsequently adjusted to achieve PaO₂ above 300 mmHg. During CPB, air and oxygen flows through the oxygenator were titrated to maintain a target PaO₂ greater than 300 mmHg.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of of kidney failure in adult patients undergoing to elective cardiac surgery required CPB	The renal outcomes were evaluated 24 hours after surgery, on the first postoperative day. The failure was defined according to KDIGO criteria and included estimated glomerular filtration rate (eGFR), serum Neutrophil Gelatinase-Associated Lipocalin (NGAL), and the need for postoperative renal replacement therapy.	At 24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of patients with NGAL > 50ng/ml (index of acute kidney injury)	Serum NGAL was measured on blood sample and if NGAL: < 50 ng/mL → normal renal function 50-150 ng/mL → possible early injury 150-200 ng/mL → suggestive of AKI 400-500 ng/mL → likely AKI / moderate to severe AKI	At 24 hours after surgery
Number of renal replacement therapy after surgey	Requirement for CRRT	Within 24 hours postoperatively
Number of patients affected by postoperative arrhythmias	Postoperative arrhythmias were defined according to AHA criteria	within 28 days after randomization
Number of patients needing extracorporeal membrane support	Mechanical circulatory support requirement was defined as veno-venous support, veno-arterial support	within 28 days after randomization
Number of patients experienced surgical complications	Surgical complications were defined according to Clavien-Dindo scale	within 28 days after randomization
Number of patients needing tracheostomy	Tracheostomy	within 28 days after randomization

Collaborators and Investigators

• Sponsor: University of Padova

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2025
• Primary Completion (Actual): September 15, 2025
• Study Completion (Actual): October 15, 2025

Study Registration Dates

• First Submitted: March 17, 2026
• First Submitted That Met QC Criteria: April 1, 2026
• First Posted (Actual): April 3, 2026

Study Record Updates

• Last Update Posted (Actual): April 3, 2026
• Last Update Submitted That Met QC Criteria: April 1, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: hyperoxia; oxygen therapy; The Hyperoxia trial
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Arrhythmias, Cardiac; Hyperoxia
• Other Study ID Numbers: HOT-CPB-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No