An Improved Method for the Measurement of Oxygen and Anaesthetic Agent Uptake in Patients Using the Foldes-Biro Equation

E03.155.253 Clinical Trial

Official title:

The Modified Foldes-Biro Equation Used in Patients Under General Anaesthesia for the Measurement of Oxygen and Anaesthetic Agent Uptake

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02003300
• Other study ID #: 177/03
• Secondary ID: GE/ASA Research
• Status: Completed
• Phase: N/A
• First received: December 3, 2013
• Last updated: December 5, 2013
• Start date: April 2005
• Est. completion date: November 2006

Study information

• Verified date: December 2004
• Source: Bayside Health
• Contact: n/a
• Is FDA regulated: No
• Health authority: Australia: National Health and Medical Research Council
• Study type: Observational

Clinical Trial Summary

The primary aim is to confirm the efficacy of a new non-invasive method for measuring the oxygen uptake during general anesthesia of patients undergoing surgery under cardiopulmonary bypass. The method has already been successfully tested in the laboratory under controlled conditions. In the patient group chosen, oxygen uptake is simultaneously calculated, for comparison purposes, from monitoring measurements made routinely as part of normal patient care in these cases, using a pulmonary artery catheter - an invasive technique from which severe complications occasionally arise, including death.

A secondary aim is to elucidate the time course of uptake of the anaesthetic vapor, isoflurane, during this kind of surgery.

Description:

In a series of 30 patients undergoing cardiopulmonary bypass, the change in nitrogen concentration between fresh gas entering the anesthetic breathing system and the exhaust gas leaving it in an otherwise closed system is used to determine total gas uptake by the principle of insoluble gas dilution. Oxygen and anaesthetic agent uptakes are then automatically determined by a computer directly linked to a rapid gas analyzer, every 15 seconds.

As a control, oxygen is calculated using the reverse Fick method. Measured arterial and mixed venous oxygen saturations were used to do this, and the cardiac output which was determined by thermodilution.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 30
• Est. completion date: November 2006
• Est. primary completion date: November 2006
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 18 Years

Eligibility

Inclusion Criteria:

• Patients undergoing non-emergency procedures using cardiopulmonary bypass in whom pulmonary artery catheterization was to be performed for routine monitoring purposes, including mixed venous oxygen determinations and thermodilution cardiac output determinations.

Exclusion Criteria:

• High risk patients (ASA 4+)

• Acute lung injury, sepsis

• Tricuspid regurgitation

• Patients under 18 years of age

• Patients unable to give informed consent

Study Design

Time Perspective: Prospective

Related Conditions & MeSH terms

• E03.155.197
• E03.155.253

Locations

Country	Name	City	State
Australia	The Alfred	Melbourne	Victoria

Sponsors (1)

Lead Sponsor	Collaborator
Bayside Health

Country where clinical trial is conducted

Australia, 

References & Publications (1)

Biro P. A formula to calculate oxygen uptake during low flow anesthesia based on FIO2 measurement. J Clin Monit Comput. 1998 Feb;14(2):141-4. Erratum in: J Clin Monit Comput 1998 May;14(4):295. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	oxygen uptake		During surgery	No