Will the Use of Respiratory Quotient ''RQ'' Improve Treatment Outcomes for Intensive Care Unit (ICU) Patients? (RQCal)

March 3, 2026 updated by: ek. Woźniak Amadeusz, Poznan University of Medical Sciences

Will the Use of Respiratory Quotient "RQ" to Optimize Nutrition Therapy With Indirect Calorimetry Improve Treatment Outcomes for Intensive Care Unit (ICU) Patients?

Introduction and assumptions of the research project:

Patients treated in intensive care units (ICUs) require comprehensive treatment. Nutrition is an important and integral part of this therapy. Both insufficient and excessive calorie intake are associated with poorer prognosis and increased mortality in ICU patients. Furthermore, the caloric requirements of patients in life-threatening conditions in the ICU are characterized by periods of hypo- and hypermetabolism, which, if nutrition is not optimized, expose patients to overfeeding or underfeeding. Therefore, monitoring resting energy expenditure (REE) using indirect calorimetry has become the "gold standard" in the ICU. Previous methods based on mathematical formulas for calculating REE were characterized by insufficient correlation with actual demand. Indirect calorimetry uses measured exhaled carbon dioxide and the concentration of oxygen administered. Then, taking into account patient-dependent parameters such as gender, height, and weight, it indirectly calculates energy expenditure, which corresponds to caloric demand. By dividing the volume of CO2 released by the volume of O2 absorbed, investigators can obtain the respiratory quotient (RQ). This quotient is related to the type of diet and is, for example, 0.7 for fats, 0.8 for proteins, and 1.0 for carbohydrates. Its value also changes with nutritional status. High values may suggest an excessive energy supply (relative to demand), while low values may indicate a calorie deficit. Some authors suggest that the RQ ratio could potentially be used to further optimize nutritional status. Currently, however, due to insufficient research, it is mainly used in clinical practice to assess the accuracy of recording and monitoring calorimetry. This study, is trying to assess the usefulness of RQ for optimizing nutrition in patients treated in the ICU.

Methodology:

Study group:

This will be a randomized study with a study group and a control group in patients treated in the ICU. All patients participating in the study are patients who, at the time of qualification, are mechanically ventilated and treated in the ICU. These will be patients of both sexes, aged 18-85 years. The control group will be fed under the supervision of indirect calorimetry and REE, in accordance with current ICU nutrition guidelines. In the study group, nutritional preparations will be additionally systematized and selected for each patient depending on their RQ value, and caloric requirements will be controlled by indirect calorimetry and REE, as in the control group. Regular assessments of albumin, total protein, total cholesterol, LDL, HDL, iron, glycemia, Na+, K+, and triglycerides will be conducted, collected along with the routine test package. In addition, typical endpoints for patients treated in the ICU will be assessed, such as length of stay in the ICU, length of mechanical ventilation, number of days without a ventilator, 28-day survival, and survival to hospital discharge.

Expected duration of the study: October 2024 to October 2026 (2 years) Conditions for inclusion in the study: patients > 18 years of age, treated in the ICU, mechanically ventilated, covered by universal health insurance Conditions for exclusion from the study: ECMO therapy, the need for mechanical ventilation with an oxygen concentration in the breathing mixture FiO2 > 60%, patients breathing independently without the aid of a ventilator, critically ill patients who are not expected to survive the next 48 hours, pregnant women, patients < 18 years of age or > 85 years of age

Reasons for discontinuing the study:

  1. if, during the course of the study, there are clear indications that one of the groups will experience or worsen final outcomes such as mortality, 28-day mortality, length of stay in the ICU - which would suggest a clear advantage of one of the chosen strategies, along with an increase in the number of patients included in the study, a regular analysis of the current effects of both strategies will be conducted,
  2. the patient develops hypersensitivity/intolerance to nutritional preparations, with no possibility of switching to another preparation used in the study,

Expected results and their planned subsequent use:

Patients from the control group, should achieve faster stabilization of nutritional parameters and fewer episodes of underfeeding and overfeeding. This should translate into improved endpoints such as mortality, length of stay in the ICU, and shorter mechanical ventilation time. In addition, the systematization and algorithms for the use of nutritional products developed during the study can be further used in department of the study and other departments around the world.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

200

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Poland
    • Wielkopolska
      • Poznan, Wielkopolska, Poland, 60-355
        • Recruiting
        • University Clinical Hospital in Poznań, ul. Przybyszewskiego 49, Clinical Department of Anesthesiology, Intensive Care, and Pain Management
        • Contact:
        • Principal Investigator:
          • Amadeusz Juliusz Woźniak, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • patient treated in the ICU
  • mechanically ventilated
  • covered by universal health insurance

Exclusion Criteria:

  • ECMO therapy
  • mechanical ventilation with an oxygen concentration in the breathing mixture FiO2 > 60%
  • breathing independently without the aid of a ventilator
  • critically ill patients who are not expected to survive the next 48 hours
  • pregnant women

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Control
Dietary supplement: Standard Treatment (Guideline-Based)
Standard treatment according to ESPEN guidelines.
Experimental: Research group
Dietary supplement: RQ guided nutrition
In the study group, nutritional preparations will be additionally systematized and selected for each patient depending on their RQ value, and caloric requirements will be controlled by indirect calorimetry and REE, as in the control group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
28-day survival rate
Time Frame: 28 days after initial admission to ICU and inclusion in the study.
If the patients survives 28 days after initial admission to ICU and inclusion in the study.
28 days after initial admission to ICU and inclusion in the study.
Survival rate until hospital discharge.
Time Frame: From initial admission to ICU and inclusion in the study to hospital discharge, assessed up to 120 days from the randomisation.
: If the patients survives until hospital discharge after initial admission to ICU and inclusion in the study.
From initial admission to ICU and inclusion in the study to hospital discharge, assessed up to 120 days from the randomisation.
Survival rate in an ICU.
Time Frame: From initial admission to the ICU and inclusion in the study to discharge from the ICU, assessed up to 120 days from the randomisation.
If the patients survives until discharge from an ICU after initial admission to ICU and inclusion in the study.
From initial admission to the ICU and inclusion in the study to discharge from the ICU, assessed up to 120 days from the randomisation.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Length of stay in the ICU.
Time Frame: From initial admission to the ICU and inclusion in the study to discharge from the hospital or death, assessed up to 120 days from the randomisation.
Measured total length of stay in the ICU until discharge from hospital.
From initial admission to the ICU and inclusion in the study to discharge from the hospital or death, assessed up to 120 days from the randomisation.
Ventilator free days
Time Frame: From initial admission to the ICU and inclusion in the study to discharge from the ICU, assessed up to 120 days from the randomisation.
Number of days without mechanical ventilation during ICU stay.
From initial admission to the ICU and inclusion in the study to discharge from the ICU, assessed up to 120 days from the randomisation.
Ventilator-associated pneumonia (VAP)
Time Frame: From initial admission to the ICU and inclusion in the study to discharge from the ICU, monitored up to 120 days from the randomisation.
Occurrence of VAP during ICU stay
From initial admission to the ICU and inclusion in the study to discharge from the ICU, monitored up to 120 days from the randomisation.

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Sequential Organ Failure Assessment (SOFA) score
Time Frame: Measurements on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study.
Measurement of Sequential Organ Failure Assessment (SOFA) score , on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study. The scale ranges from 0 to 24 points, where 0 represents the lowest predicted mortality and 24 represents the highest predicted mortality.
Measurements on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study.
Acute Physiology and Chronic Health Evaluation II (APACHE II) score
Time Frame: Measurements on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study.
Measurement of Acute Physiology and Chronic Health Evaluation II (APACHE II) score , on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study. The scale ranges from 0 to 71 points, where 0 represents the lowest predicted mortality and 71 represents the highest predicted mortality.
Measurements on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study.
Simplified Acute Physiology Score II (SAPS II)
Time Frame: Measurements on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study.
Measurement of Simplified Acute Physiology Score II (SAPS II) , on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study. The scale ranges from 0 to 163 points, where 0 represents the lowest predicted mortality and 163 represents the highest predicted mortality.
Measurements on a day of admission and on days 3., 7., and 10. from initial admission and inclusion in the study.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Poznan University of Medical Sciences

Investigators

  • Study Director: Zbigniew Żaba, PhD, University Clinical Hospital in Poznań, ul. Przybyszewskiego 49, Clinical Department of Anesthesiology, Intensive Care, and Pain Management Departments of Emergency Medicine,
  • Principal Investigator: Amadeusz Juliusz Woźniak, MD, University Clinical Hospital in Poznań, ul. Przybyszewskiego 49, Clinical Department of Anesthesiology, Intensive Care, and Pain Management

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 1, 2024

Primary Completion (Estimated)

October 31, 2026

Study Completion (Estimated)

November 30, 2026

Study Registration Dates

First Submitted

February 3, 2026

First Submitted That Met QC Criteria

March 3, 2026

First Posted (Actual)

March 9, 2026

Study Record Updates

Last Update Posted (Actual)

March 9, 2026

Last Update Submitted That Met QC Criteria

March 3, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • RQ 447/24

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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