Effect of Arterial Oxygen Partial Pressure on Mixed Venous Oxygen Saturation

Effect of Arterial Oxygen Partial Pressure on Mixed Venous Oxygen Saturation and Regional Cerebral Oxygen Saturation During Cardiopulmonary Bypass in Patients Undergoing Cardiac Surgery: a Pilot Study

Mixed venous oxygen saturation is known to reflect oxygen delivery and, thus, is frequently monitored in patients undergoing cardiac surgery. Factors that affect mixed venous oxygen saturation include hemoglobin level, arterial oxygen saturation and arterial oxygen partial pressure. Among them, arterial oxygen partial pressure is known to have minimal effect on oxygen delivery compared to hemoglobin and arterial oxygen saturation. However, some argues that in certain clinical setting, such as anemia which is very common in cardiac surgery patients, the contribution of plasma (arterial oxygen partial pressure in this case) to oxygen delivery becomes more significant. Therefore, we planned to perform a pilot clinical trial to observe the change of oxygen delivery, which would be reflected in mixed venous oxygen saturation and cerebral regional oxygen saturation, according to hemoglobin level.

Study Overview

• Status: Completed
• Conditions: Anemia
• Intervention / Treatment: Other: Change of the fraction of inspired oxygen

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of, 03080
    • Seoul National University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Patients that scheduled to undergo cardiac surgery using cardiopulmonary bypass.

Exclusion Criteria:

• Emergent surgery
• Symptomatic carotid artery stenosis or carotid artery stenosis of ≥50%
• Preoperative oxygen therapy that is equivalent to the inspired oxygen fraction of 0.5.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Fraction of inspired oxygen setting change

Other: Change of the fraction of inspired oxygen; After the stabilization of cardiopulmonary bypass, in the first half of patients, fraction of inspired oxygen would be set at 0.5 and maintained for 5 minutes (T0), then it would be changed to 1.0 and maintained for 5 minutes (T1). Again, fraction of inspired oxygen would be resumed to be 0.5 and maintained for 5 minutes (T2). In the other half of patients, the direction of change in fraction of inspired oxygen will be reversed as follows. It will be set at 1.0 and maintained for 5 minutes (T0), then changed to 0.5 and maintained for 5 minutes (T1), and finally to 1.0 and maintained for 5 minutes (T2).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mixed venous oxygen saturation	Change of mixed venous oxygen saturation according to the fraction of inspired oxygen	From the beginning and the stabilization of cardiopulmonary bypass to 15 minutes thereafter.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cerebral regional oxygen saturation	Change of cerebral regional oxygen saturation according to the fraction of inspired oxygen	From the beginning and the stabilization of cardiopulmonary bypass to 15 minutes thereafter.

Collaborators and Investigators

• Sponsor: Seoul National University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): November 4, 2019
• Primary Completion (Actual): February 11, 2020
• Study Completion (Actual): February 11, 2020

Study Registration Dates

• First Submitted: October 28, 2019
• First Submitted That Met QC Criteria: October 28, 2019
• First Posted (Actual): October 30, 2019

Study Record Updates

• Last Update Posted (Actual): February 24, 2020
• Last Update Submitted That Met QC Criteria: February 20, 2020
• Last Verified: February 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: PaO2 and SvO2

Drug and device information, study documents

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