Resting Energy ExpenditureNCT07790341
Comparison of the Effects of SIMV-PC and SIMV-VC Ventilation Modes on Resting Energy Expenditure
An observational study of Resting Energy Expenditure and Indirect Calorimetry, run by Diskapi Yildirim Beyazit Education and Research Hospital.
Trial summary
The primary objective of this prospective observational study is to compare the effects of synchronized intermittent mandatory ventilation in pressure-controlled mode (SIMV-PC) and volume-controlled mode (SIMV-VC) on resting energy expenditure (REE) measured by indirect calorimetry in adult intensive care unit (ICU)… Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Resting Energy Expenditure, Indirect Calorimetry
- How many people
- 41 participants
- Where
- No sites listed yet
- Study dates
- 30 Aug 2026to 15 Jan 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Receiving invasive mechanical ventilation in the intensive care unit. Receiving continuous enteral nutrition during indirect calorimetry measurements.
Who may be able to join
- Adults aged 18 to 80 years.
- Receiving invasive mechanical ventilation in the intensive care unit.
- Receiving continuous enteral nutrition during indirect calorimetry measurements.
- Hemodynamically stable (mean arterial pressure ≥65 mmHg without significant increase in vasopressor requirement).
- Technically suitable for indirect calorimetry measurements.
- Written informed consent obtained from the patient or the legally authorized representative.
Who cannot join
- Age <18 years or >80 years.
- Pregnancy.
- Hemodynamic instability.
- High vasopressor requirement or marked increase in vasopressor dosage.
- Requirement for frequent or major changes in ventilator settings or FiO₂.
- FiO₂ >0.60.
Show all 12Show fewer
- Bronchopleural fistula, significant air leak, or other pulmonary conditions interfering with indirect calorimetry.
- Extracorporeal membrane oxygenation (ECMO).
- Continuous renal replacement therapy (CRRT).
- Significant body temperature fluctuations.
- Active agitation or severe patient-ventilator dyssynchrony.
- Acute metabolic changes that may interfere with indirect calorimetry measurements.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Comparison of the Effects of SIMV-PC and SIMV-VC Ventilation Modes on Resting Energy Expenditure Measured by Indirect Calorimetry and Mechanical Power in Adult Intensive Care Unit Patients Receiving Invasive Mechanical Ventilation
The primary objective of this prospective observational study is to compare the effects of synchronized intermittent mandatory ventilation in pressure-controlled mode (SIMV-PC) and volume-controlled mode (SIMV-VC) on resting energy expenditure (REE) measured by indirect calorimetry in adult intensive care unit (ICU) patients receiving invasive mechanical ventilation.
The primary metabolic parameters to be evaluated are oxygen consumption (VO₂), carbon dioxide production (VCO₂), resting energy expenditure (REE), and respiratory quotient (RQ). Secondary objectives include comparison of respiratory rate, tidal volume, minute ventilation,arterial blood gas parameters, mechanical power, ventilator mechanics, hemodynamic variables, sedation level, and patient-ventilator synchrony between the two ventilation modes.
The results of this study may contribute to identifying ventilation strategies associated with lower energy expenditure while maintaining adequate ventilatory support in critically ill patients and may help optimize individualized ventilator management and nutritional therapy.
Read the detailed description
Mechanical ventilation is a cornerstone of supportive therapy in critically ill patients. Although synchronized intermittent mandatory ventilation in pressure-controlled (SIMV-PC) and volume-controlled (SIMV-VC) modes are widely used in routine intensive care practice, limited data are available regarding their effects on patients' energy expenditure measured by indirect calorimetry.
Indirect calorimetry is recommended by the European Society for Clinical Nutrition and Metabolism (ESPEN) as the reference standard for determining energy expenditure in critically ill patients. Accurate estimation of energy expenditure is essential for optimizing nutritional therapy and avoiding both underfeeding and overfeeding. Overfeeding may increase carbon dioxide production, insulin requirements, respiratory workload, duration of mechanical ventilation, and intensive care unit length of stay.
This is a prospective, observational, repeated-measures study conducted in adult ICU patients receiving invasive mechanical ventilation. The study is non-interventional. Ventilation mode selection and all ventilator adjustments will be determined exclusively by the attending intensive care physician according to routine clinical practice. No study-specific ventilator changes, additional invasive procedures, or additional blood sampling will be performed.
Indirect calorimetry measurements will be performed during clinically stable periods under routine ICU monitoring. Measurements will be obtained only after at least 30 minutes of stabilization following any clinically indicated ventilation mode change. Patients receiving continuous enteral nutrition with no major changes in sedative or analgesic infusions during the preceding two hours will be eligible for metabolic measurements. Sedation level will be documented using the Richmond Agitation-Sedation Scale (RASS).
Metabolic parameters obtained by indirect calorimetry, including oxygen consumption (VO₂), carbon dioxide production (VCO₂), resting energy expenditure (REE), and respiratory quotient (RQ), will be compared between SIMV-PC and SIMV-VC ventilation modes. Ventilator parameters, respiratory mechanics, mechanical power, arterial blood gas findings, hemodynamic variables, and patient-ventilator synchrony will also be evaluated.
Because the study is observational and based entirely on routine clinical care, no additional risks beyond standard intensive care management are anticipated. If hemodynamic or respiratory instability develops during indirect calorimetry measurements, the measurement will be discontinued immediately and routine patient management will continue according to the attending physician's clinical judgment.
- Conditions
- Resting Energy Expenditure, Indirect Calorimetry
- Being tested
- Volume-controlled ventilation, Pressure-controlled ventilation
- Keywords
- Resting energy expenditure, Pressure-controlled mode (SIMV-PC), Volume-controlled mode (SIMV-VC)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Volume-controlled ventilationOther
In intensive care patients monitored with mechanical ventilation, energy consumption will be monitored using indirect calorimetry after volume-controlled ventilation.
Pressure-controlled ventilationOther
In intensive care patients monitored with mechanical ventilation, energy consumption will be monitored using indirect calorimetry after pressure-controlled ventilation.
| Study group | Role | What they receive |
|---|---|---|
| Monitored with mechanical ventilation patients | In intensive care patients monitored with mechanical ventilation, energy consumption will be monitored using indirect calorimetry after volume-controlled or pressure-controlled ventilation. Receives: Other: Volume-controlled ventilation; Other: Pressure-controlled ventilation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Resting energy expenditure (REE) measured by indirect calorimetry.
Resting energy expenditure (REE) measured by indirect calorimetry.
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Secondary outcomes (9)
Respiratory rate
Respiratory rate
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Tidal volume
Tidal volume
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Peak inspiratory pressure (Ppeak)
Peak inspiratory pressure (Ppeak)
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Positive end-expiratory pressure (PEEP)
Positive end-expiratory pressure (PEEP)
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Fraction of inspired oxygen (FiO₂)
Fraction of inspired oxygen (FiO₂)
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Arterial blood gas parameters (pH)
Arterial blood gas parameters (pH)
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Arterial blood gas parameters (PaCO₂)
Arterial blood gas parameters (PaCO₂)
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Arterial blood gas parameters (PaO₂)
Arterial blood gas parameters (PaO₂)
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Arterial blood gas parameters (Lactate)
Arterial blood gas parameters (Lactate)
Measured: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Aug 2026
- Study start30 Aug 2026 (estimated)
- Primary completion15 Dec 2026 (estimated)
- Study completion15 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Resting Energy ExpenditureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 41 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Diskapi Yildirim Beyazit Education and Research Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Savas Altinsoy, Diskapi Yildirim Beyazit Education and Research Hospital
- Investigators
- Savaş Altınsoy, Principal investigator, Ankara Etlik City Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07790341
- Sponsor's protocol ID
- Esra Selçuk Tez
- Status last verified
- Aug 2026
- First submitted
- 7 Aug 2026
- Last updated
- 27 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Clapis FC, Auxiliadora-Martins M, Japur CC, Martins-Filho OA, Evora PR, Basile-Filho A. Mechanical ventilation mode (volume x pressure) does not change the variables obtained by indirect calorimetry in critically ill patients. J Crit Care. 2010 Dec;25(4):659.e9-16. doi: 10.1016/j.jcrc.2009.11.010. Epub 2010 Jan 15.
PubMed 20080021Chen YH, Hsiao HF, Hsu HW, Cho HY, Huang CC. Comparisons of Metabolic Load between Adaptive Support Ventilation and Pressure Support Ventilation in Mechanically Ventilated ICU Patients. Can Respir J. 2020 Jan 28;2020:2092879. doi: 10.1155/2020/2092879. eCollection 2020.
PubMed 32076468dos Santos LJ, Hoff FC, Condessa RL, Kaufmann ML, Vieira SR. Energy expenditure during weaning from mechanical ventilation: is there any difference between pressure support and T-tube? J Crit Care. 2011 Feb;26(1):34-41. doi: 10.1016/j.jcrc.2010.05.032. Epub 2010 Jul 8.
PubMed 20619600
Study at a glance
From the registry record, last updated by the sponsor on 27 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of the Effects of SIMV-PC and SIMV-VC Ventilation Modes on Resting Energy Expenditure Measured by Indirect Calorimetry and Mechanical Power in Adult Intensive Care Unit Patients Receiving Invasive Mechanical Ventilation
- ClinicalTrials.gov ID
- NCT07790341
- Acronym / sponsor ID
- Esra Selçuk Tez
- Conditions
- Resting Energy Expenditure, Indirect Calorimetry
- Keywords
- Resting energy expenditure, Pressure-controlled mode (SIMV-PC), Volume-controlled mode (SIMV-VC)
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 41 participants (estimated)
- Lead sponsor
- Diskapi Yildirim Beyazit Education and Research HospitalOther government
- Study start
- 30 Aug 2026 (estimated)
- Primary completion
- 15 Dec 2026 (estimated)
- Study completion
- 15 Jan 2027 (estimated)
- First posted
- 27 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary objective of this prospective observational study is to compare the effects of synchronized intermittent mandatory ventilation in pressure-controlled mode (SIMV-PC) and volume-controlled mode (SIMV-VC) on resting energy expenditure (REE) measured by indirect calorimetry in adult intensive care unit (ICU) patients receiving invasive mechanical ventilation.
The primary metabolic parameters to be evaluated are oxygen consumption (VO₂), carbon dioxide production (VCO₂), resting energy expenditure (REE), and respiratory quotient (RQ). Secondary objectives include comparison of respiratory rate, tidal volume, minute ventilation,arterial blood gas parameters, mechanical power, ventilator mechanics, hemodynamic variables, sedation level, and patient-ventilator synchrony between the two ventilation modes.
The results of this study may contribute to identifying ventilation strategies associated with lower energy expenditure while maintaining adequate ventilatory support in critically ill patients and may help optimize individualized ventilator management and nutritional therapy.
Detailed description
Mechanical ventilation is a cornerstone of supportive therapy in critically ill patients. Although synchronized intermittent mandatory ventilation in pressure-controlled (SIMV-PC) and volume-controlled (SIMV-VC) modes are widely used in routine intensive care practice, limited data are available regarding their effects on patients' energy expenditure measured by indirect calorimetry.
Indirect calorimetry is recommended by the European Society for Clinical Nutrition and Metabolism (ESPEN) as the reference standard for determining energy expenditure in critically ill patients. Accurate estimation of energy expenditure is essential for optimizing nutritional therapy and avoiding both underfeeding and overfeeding. Overfeeding may increase carbon dioxide production, insulin requirements, respiratory workload, duration of mechanical ventilation, and intensive care unit length of stay.
This is a prospective, observational, repeated-measures study conducted in adult ICU patients receiving invasive mechanical ventilation. The study is non-interventional. Ventilation mode selection and all ventilator adjustments will be determined exclusively by the attending intensive care physician according to routine clinical practice. No study-specific ventilator changes, additional invasive procedures, or additional blood sampling will be performed.
Indirect calorimetry measurements will be performed during clinically stable periods under routine ICU monitoring. Measurements will be obtained only after at least 30 minutes of stabilization following any clinically indicated ventilation mode change. Patients receiving continuous enteral nutrition with no major changes in sedative or analgesic infusions during the preceding two hours will be eligible for metabolic measurements. Sedation level will be documented using the Richmond Agitation-Sedation Scale (RASS).
Metabolic parameters obtained by indirect calorimetry, including oxygen consumption (VO₂), carbon dioxide production (VCO₂), resting energy expenditure (REE), and respiratory quotient (RQ), will be compared between SIMV-PC and SIMV-VC ventilation modes. Ventilator parameters, respiratory mechanics, mechanical power, arterial blood gas findings, hemodynamic variables, and patient-ventilator synchrony will also be evaluated.
Because the study is observational and based entirely on routine clinical care, no additional risks beyond standard intensive care management are anticipated. If hemodynamic or respiratory instability develops during indirect calorimetry measurements, the measurement will be discontinued immediately and routine patient management will continue according to the attending physician's clinical judgment.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Monitored with mechanical ventilation patients | – | Other: Volume-controlled ventilation, Other: Pressure-controlled ventilationIn intensive care patients monitored with mechanical ventilation, energy consumption will be monitored using indirect calorimetry after volume-controlled or pressure-controlled ventilation. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Receiving invasive mechanical ventilation in the intensive care unit. Receiving continuous enteral nutrition during indirect calorimetry measurements.
Key inclusion criteria (6 listed)
- Adults aged 18 to 80 years.
- Receiving invasive mechanical ventilation in the intensive care unit.
- Receiving continuous enteral nutrition during indirect calorimetry measurements.
- Hemodynamically stable (mean arterial pressure ≥65 mmHg without significant increase in vasopressor requirement).
- Technically suitable for indirect calorimetry measurements.
Key exclusion criteria (12 listed)
- Age <18 years or >80 years.
- Pregnancy.
- Hemodynamic instability.
- High vasopressor requirement or marked increase in vasopressor dosage.
- Requirement for frequent or major changes in ventilator settings or FiO₂.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Volume-controlled ventilationIn intensive care patients monitored with mechanical ventilation, energy consumption will be monitored using indirect calorimetry after volume-controlled ventilation. | Other | Monitored with mechanical ventilation patients |
| Pressure-controlled ventilationIn intensive care patients monitored with mechanical ventilation, energy consumption will be monitored using indirect calorimetry after pressure-controlled ventilation. | Other | Monitored with mechanical ventilation patients |
Primary outcome
Resting energy expenditure (REE) measured by indirect calorimetry.
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Resting energy expenditure (REE) measured by indirect calorimetry.
9 secondary outcomes
Respiratory rate
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Tidal volume
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Peak inspiratory pressure (Ppeak)
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Positive end-expiratory pressure (PEEP)
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Fraction of inspired oxygen (FiO₂)
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Arterial blood gas parameters (pH)
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Arterial blood gas parameters (PaCO₂)
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Arterial blood gas parameters (PaO₂)
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Arterial blood gas parameters (Lactate)
Time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Aug 2026.
- Background: PubMed 20080021Clapis FC, Auxiliadora-Martins M, Japur CC, Martins-Filho OA, Evora PR, Basile-Filho A. Mechanical ventilation mode (volume x pressure) does not change the variables obtained by indirect calorimetry in critically ill patients. J Crit Care. 2010 Dec;25(4):659.e9-16. doi: 10.1016/j.jcrc.2009.11.010. Epub 2010 Jan 15.
- Results publication: PubMed 32076468Chen YH, Hsiao HF, Hsu HW, Cho HY, Huang CC. Comparisons of Metabolic Load between Adaptive Support Ventilation and Pressure Support Ventilation in Mechanically Ventilated ICU Patients. Can Respir J. 2020 Jan 28;2020:2092879. doi: 10.1155/2020/2092879. eCollection 2020.
- Results publication: PubMed 20619600dos Santos LJ, Hoff FC, Condessa RL, Kaufmann ML, Vieira SR. Energy expenditure during weaning from mechanical ventilation: is there any difference between pressure support and T-tube? J Crit Care. 2011 Feb;26(1):34-41. doi: 10.1016/j.jcrc.2010.05.032. Epub 2010 Jul 8.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Savaş Altınsoy principal investigator
Ankara Etlik City Hospital
Questions about this trial
What is this clinical trial studying?
An observational study of Resting Energy Expenditure and Indirect Calorimetry, run by Diskapi Yildirim Beyazit Education and Research Hospital.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 27 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Savaş Altınsoy (05332257104, savasaltinsoy@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Resting energy expenditure (REE) measured by indirect calorimetry. (time frame: After being monitored in mechanical ventilation mode (volume or pressure controlled) for 2 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07790341, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Aug 2026.