Clinical trial NCT02790697: The ICALIC Accuracy Validation in Geneva Study
Official title: Clinical Evaluation of the Ease of Use of a New Indirect Calorimeter for Energy Expenditure Measurement in ICU Patients: The ICALIC International Multicentric Study
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Critical Illness
Keywords: Indirect calorimetry
ICALIC Study
Energy expenditure
VO2
VCO2
Respiratory quotient
Lead sponsor: University Hospital, Geneva
Sponsor class: OTHER
First posted: 2016-06-06
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Mechanically ventilated adult ICU patients

Brief summary: This study aims at validating the accuracy of the new indirect calorimeter (Q-NRG, COSMED, Italy), developed for the ICALIC multicenter study. The validation of accuracy will only be conducted in Geneva center.

The measurements made with the new calorimeter will be compared to the measurements by the mixing chamber method using a mass spectrometer (MAX300-LG, Extrel, USA) for gas composition analysis.

Detailed description: Indirect calorimetry is a method to measure energy expenditure of human subjects by analyzing patient breath gas to measure the amount (volume) of oxygen consumption (VO2) and CO2 production (VCO2). Energy expenditure is calculated by the Weir's equation using the measured VO2 and VCO2 values.

The new calorimeter is equipped with a disposable in-line pneumotach flowmeter, which measures the flow of exhaled gas of patients directly within the mechanical ventilator circuit. It also samples small amount of inhaled and exhaled gas to measure the inhaled and exhaled O2 and CO2 compositions. The new dynamic micro-mixing chamber technique is used to meaure VO2 and VCO2 to derive the energy expenditure.

The mass spectrometer measures the inhaled and exhaled gas compositions. The mass spectrometer samples inhaled gas from the mechanical ventilator circuit. A mixing chamber system is used to collect the expired gas from the outlet of the mechanical ventilator. The collected gas is measured for the second time after diluting with a constant flow of ambient air, which is monitored by an independent mass flow meter. The volume of the expired gas is calculated by comparison of the concentrations of exhaled gas before and after the dilution. The measurements will be used to calculate the VO2 and VCO2 to derive the energy expenditure.

Eligibility criteria: Inclusion Criteria:

• Mechanically ventilated adult ICU patients

Exclusion Criteria:

* Fraction of inhaled oxygen (FIO2) \> 70%
* Positive end expiratory pressure (PEEP) \>10cmH2O
* Peak ventilatory pressure \> 30cmH2O
* Presence of air leaks from thoracic drain tube
* Changes in vasoactive agent dose (\>20%, \<1 hr before and/or during IC)
* Agitation or change in sedative dose (\>20%, \<1 hr before and/or during IC)
* Change in body temperature (\>0.5°C, \<1 hr before and/or during IC)
* Expected duration of ICU stay \< 24 hours
* Expected survival of the patient \< 24 hours

Primary outcomes:
measure: Accuracy of Energy expenditure
timeFrame: immediately after the measurement
Secondary outcomes:
measure: Accuracy of VO2
timeFrame: immediately after the measurement
measure: Accuracy of VCO2
timeFrame: immediately after the measurement
measure: Respiratory quotient (RQ)
timeFrame: immediately after the measurement
Other outcomes:
Locations:
city: Geneva
country: Switzerland
facility: Service of Intensive Care, Geneva University Hospital
Study officials:
affiliation: Clinical Nutrition, Geneva University Hospital
name: Claude Pichard, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: