Evaluation of Indirect Measurement of Respiratory Quotient in Non-cardiac Major Surgery (The BAR Study)

Evaluation of Indirect Measurement of Respiratory Quotient in Non-cardiac Major Surgery as a Predictor of Anaerobic Metabolism (The BAR Study) Indirect Respiratory Quotient as a Predictor of Anaerobic Metabolism

Demonstrate the ability of the RQ, measured indirectly from the anesthesia ventilator, to predict the occurrence of anaerobic metabolism in patients operated of major non-cardiac surgical operation in the operating room

Study Overview

• Status: Completed
• Conditions: Surgery
• Intervention / Treatment: Other: surgery

Detailed Description

Indirect respiratory quotient (RQ) measurement involves indirect calorimetry, which measures O2 and CO2 inspired and expired fractions. This measurement is usually used to estimate energy expenditure and which energetic substrate is preferentially used in resuscitation patients. Litterature demonstrated in a mouse model that the formation of hemorrhagic shock was associated with a change in RQ due to VCO2 and VO2 imbalance. RQ was able to distinguish anaerobic metabolism and corrected itself with correction of shock. Recently in Litterature showed a link between lactate production, cardiac output and the evolution of the RQ measured by indirect calorimetry in a resuscitation patient. Also, these authors raise the question of a possible use of the RQ in intensive care as an early non-invasive marker of anaerobic metabolism that can replace the invasive ones usually used (arterial lactate, venoarterial PCO2 gradient, venoarterial PCO2 gradient/ arteriovenous O2 content difference, ScVO2). However, the measurement of inspired and expired fractions in O2 and CO2 is part of the systematic monitoring of the intubated-ventilated patient in the operating room. The measurement of the VO2, VCO2 and the RQ could therefore be done from these fractions inspired and expired in O2 and CO2 by the following equation:

RQ = (FeCO2-FiCO2) / (FiO2-FeO2) The main objective of our work is to demonstrate the ability of the RQ, measured indirectly from the anesthesia ventilator, to predict the occurrence of anaerobic metabolism in patients operated of major non-cardiac surgical operation in the operating room. Secondly, the objective is to evaluate the association between the variations of the RQ, EtCO2, Dc, ScVO2, venoarterial PCO2 gradient, venoarterial PCO2 gradient/arteriovenous O2 content difference and lactate levels at different times during the surgical procedure and depending on the occurrence of postoperative complications.

• Study Type: Observational
• Enrollment (Actual): 110

Contacts and Locations

Study Locations

• France
  • Amiens, France, 80054
    • CHU Amiens-Picardie

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Adult patients admitted to the operating room of Amiens University Hospital supported for major non-cardiac surgery (abdominal, orthopedic, vascular) for which the practitioner had decided in accordance with the care protocols of the department to carry out an hemodynamic optimization

Description

Inclusion Criteria:

• Adult patients admitted to the operating room of Amiens University Hospital supported for major non-cardiac surgery (abdominal, orthopedic, vascular) for which the practitioner had decided in accordance with the care protocols of the department to carry out an hemodynamic optimization,
• Patients monitored by a central venous catheter and an invasive measurement of blood pressure,
• Ventilated patients in controlled mode,
• Major patients.

Exclusion Criteria:

• Cardiac surgery with the need of extracorporeal circulation
• Thoracic surgery with the need of unipulmonary ventilation
• Permanent laparoscopic surgery and up to 30 minutes after exsufflation of CO2
• Acute or chronic respiratory insufficiency documented
• Interstitial lung disease with diffusion disorders
• Preoperative oxygen therapy
• Acute Respiratory Distress Syndrome with FiO2> 60%.
• Refusal of patient participation.
• Pregnant woman.
• Patient under guardianship or curatorship or deprived of public right.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Respiratory Quotient (RQ)	indirectly measured from the anesthetic respirator, and its predictive ability to develop anaerobic metabolism.	1 Month

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire, Amiens
• Investigators: Principal Investigator: Stéphane BAR, Dr, CHU Amiens-Picardie

Publications and helpful links

General Publications

• Bar S, Grenez C, Nguyen M, de Broca B, Bernard E, Abou-Arab O, Bouhemad B, Lorne E, Guinot PG. Predicting postoperative complications with the respiratory exchange ratio after high-risk noncardiac surgery: A prospective cohort study. Eur J Anaesthesiol. 2020 Nov;37(11):1050-1057. doi: 10.1097/EJA.0000000000001111.

Study record dates

Study Major Dates

• Study Start (ACTUAL): May 4, 2017
• Primary Completion (ACTUAL): August 30, 2018
• Study Completion (ACTUAL): August 30, 2018

Study Registration Dates

• First Submitted: March 14, 2018
• First Submitted That Met QC Criteria: March 14, 2018
• First Posted (ACTUAL): March 21, 2018

Study Record Updates

• Last Update Posted (ACTUAL): September 18, 2018
• Last Update Submitted That Met QC Criteria: September 17, 2018
• Last Verified: August 1, 2018

More Information

Terms related to this study

• Keywords: major surgery; respiratory quotient (RQ); anaerobic metabolism
• Other Study ID Numbers: PI2017_843_0006

Drug and device information, study documents

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