FIO2 Influences SvO2 Interpretation and Fick-based Cardiac Output Assessment

Increased FIO2 Influences SvO2 Interpretation and Accuracy of Fick-based Cardiac Output Assessment in Cardiac Surgery Patients

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT04265924

Enrollment

Registered

2020-02-12

Start date

2015-12-01

Completion date

2016-11-30

Last updated

2020-02-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cardiac Output

Brief summary

In this study, the investigators sought to clarify the influence of FIO2 levels on the variables in the Fick equation and then assessed the influence of each variable on the accuracy of Fick-CO measurements in patients undergoing cardiac surgery.

Detailed description

Patients who are aged ≥20 years, are undergoing planned elective cardiac surgery, and provided signed informed consent are included in the present study. Any patients with an intra-cardiac shunt are excluded. The patients are randomly assigned to 2 groups: FIO2 \<0.7 or FIO2 \>0.85. And during the surgery, the oximeter values are kept ≥98%. Intra-operatively, FIO2, PaO2, SaO2, SvO2, PvO2, Hb, blood pH values, body temperature and TD-CO are recorded.

Interventions

OTHERfraction of inspired oxygen (FIO2)

The fraction of inspired oxygen (FIO2) is given accordingly (\>0.85 for the \>0.85 group, and \<0.7 for the \<0.7 group) to the patients during the surgery.

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

SINGLE (Subject)

Eligibility

Sex/Gender

ALL

Age

20 Years to No maximum

Healthy volunteers

Inclusion criteria

* undergoing planned elective cardiac surgery * agree to sign informed consent

Exclusion criteria

* intra-cardiac shunt

Design outcomes

Primary

Measure	Time frame	Description
The PvO2 in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	The patients were divided into two FIO2 groups (FIO2 \>0.85 or \<0.7) during the surgery. We will calculate oxygen consumption in each patient.
The Hemoglobin Values in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	The patients were divided into two FIO2 groups (FIO2 \>0.85 or \<0.7) during the surgery. We will collect hemoglobin data in each patient.
The Oxygen Consumption in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	The patients were divided into two FIO2 groups (FIO2 \>0.85 or \<0.7) during the surgery. We will use the LaFarge equation to calculate oxygen consumption (ml/min/m\^2) in each patient.
The Blood PH Values in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	The patients were divided into two FIO2 groups (FIO2 \>0.85 or \<0.7) during the surgery. We will calculate oxygen consumption in each patient.
The Body Temperatures in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	The patients were divided into two FIO2 groups (FIO2 \>0.85 or \<0.7) during the surgery. We will calculate oxygen consumption in each patient.
The SaO2 in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	The patients were divided into two FIO2 groups (FIO2 \>0.85 or \<0.7) during the surgery. We will calculate oxygen consumption in each patient.
The SvO2 in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	The patients were divided into two FIO2 groups (FIO2 \>0.85 or \<0.7) during the surgery. We will calculate oxygen consumption in each patient.
The PaO2 in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	The patients were divided into two FIO2 groups (FIO2 \>0.85 or \<0.7) during the surgery. We will calculate oxygen consumption in each patient.

Secondary

Measure	Time frame	Description
The Precision of Fick-based Cardiac Output in Different FIO2 Groups during Cardiac Surgeries	under general anesthesia but before surgical incision	After collecting the elements data included in the Fick eqaution (oxygen consumption, hemoglobin, SaO2, SvO2, PaO2, and PvO2), we can calculate the Fick-based cardiac output in each patient. And the pulmonary artery thermodilution is adopted as the standard cardiac output monitoring method. We will calculate the correlation and level of agreement between Fick-based cardiac output and pulmonary artery thermodilution in the two groups.

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 14, 2026