Perioperative Respiratory FunctionNCT07067684
LTV (Low Tidal Volüme) Ventilation and Diaphragmatic Motion in CABG (Coronary Artery Bypass Grafting)
A study testing Low Tidal Volume Ventilation During CPB in people with Perioperative Respiratory Function and Diaphragmatic Dysfunction, run by Konya City Hospital at 1 site in Turkey (Türkiye).
Trial summary
The goal of this clinical trial is to evaluate whether low tidal volume (LTV) ventilation during cardiopulmonary bypass (CPB) surgery helps preserve diaphragmatic excursion in adult patients undergoing coronary artery bypass grafting (CABG). Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Perioperative Respiratory Function, Diaphragmatic Dysfunction, Low Tidal Volume Ventilation
- What is being tested?
- Low Tidal Volume Ventilation During CPB
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jul 2025to 30 Nov 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age over 18 years
- Male or female patients
- American Society of Anesthesiologists (ASA) physical status class II or III
- Scheduled for elective coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB)
- Provided written informed consent to participate in the study -
Who cannot join
- History of neuromuscular disease
- History of thoracic surgery
- History of pneumothorax or ascites
- Chronic respiratory failure
- Pulmonary hypertension or right ventricular failure
- Emergency surgery
Show all 9Show fewer
- Inability to perform diaphragm ultrasonographic measurements
- Refusal to participate in the study
- -
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effect of Low Tidal Volume Ventilation on Diaphragmatic Excursion in Cardiopulmonary Bypass Surgery
The goal of this clinical trial is to evaluate whether low tidal volume (LTV) ventilation during cardiopulmonary bypass (CPB) surgery helps preserve diaphragmatic excursion in adult patients undergoing coronary artery bypass grafting (CABG). The study will also assess the relationship between LTV ventilation and postoperative pulmonary complications, such as atelectasis, pleural effusion, and pneumonia.
The main questions this trial aims to answer are:
Read more
Does LTV ventilation better preserve diaphragmatic motion compared to apnea during CPB?
Are postoperative pulmonary complications less frequent in patients receiving LTV?
Does LTV contribute to shorter extubation times and ICU stays?
Researchers will compare LTV ventilation with apnea (standard care) during CPB to assess its effects on diaphragmatic excursion, measured via ultrasound, and postoperative respiratory outcomes.
Participants will:
Undergo elective CABG surgery under general anesthesia
Be randomly assigned to receive either LTV ventilation or apnea during CPB
Have diaphragmatic excursion measured by ultrasound before surgery, before extubation, and 24 hours after surgery
Be monitored for postoperative pulmonary complications (atelectasis, effusion, pneumonia), extubation time, and ICU length of stay
Ultrasound will be used to measure diaphragmatic excursion (DE) in quiet and deep breathing. DE below 10 mm will be considered as diaphragmatic paralysis. Postoperative respiratory assessments will include blood gas analysis (PaO₂/FiO₂ ratio), clinical respiratory parameters, and imaging findings.
This is a prospective, single-center, assessor-blinded randomized controlled trial. Patients and outcome assessors will be blinded to group allocation. The study will be conducted at the Anesthesiology Clinic of Konya City Hospital and is expected to enroll 60 patients.
Read the detailed description
oronary artery bypass grafting (CABG) surgery performed under cardiopulmonary bypass (CPB) is a complex procedure frequently associated with postoperative pulmonary complications (PPCs). During CPB, mechanical ventilation is usually paused (apnea), which leads to temporary diaphragmatic inactivity. The diaphragm, being a rhythmically contracting muscle under normal physiological conditions, may experience transient dysfunction or even paralysis due to this intraoperative inactivity. Several mechanisms, including loss of neuromechanical coupling, disrupted neuromuscular signaling, altered venous return, and impaired diaphragmatic oxygenation and metabolism, are thought to contribute to this process.
Reduced diaphragmatic motion can create a favorable condition for atelectasis, impair oxygenation, and increase the risk of infection in the postoperative period. The resulting transient diaphragmatic dysfunction is considered a potential contributor to the development of PPCs such as pneumonia, pleural effusion, and prolonged mechanical ventilation.
Recent research has focused on the protective effects of low tidal volume (LTV) ventilation in surgical and critical care settings. However, limited studies have evaluated its direct impact on diaphragmatic function during CPB, particularly in the context of CABG surgery. There is a need to investigate whether intraoperative application of LTV ventilation during CPB can help preserve diaphragmatic excursion (DE) and reduce PPCs.
- Conditions
- Perioperative Respiratory Function, Diaphragmatic Dysfunction, Low Tidal Volume Ventilation
- Being tested
- Low Tidal Volume Ventilation During CPB
- Keywords
- Low Tidal Volume Ventilation, Diaphragmatic Excursion, Coronary Artery Bypass Grafting (CABG)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low Tidal Volume Ventilation During CPBOther
Group Low: Patients in this group will receive low tidal volume mechanical ventilation during cardiopulmonary bypass (CPB).
Ventilation settings will be:
Tidal Volume: 3-4 mL/kg (ideal body weight)
PEEP: 5-8 cmH₂O
Respiratory Rate: adjusted to maintain normocapnia (PaCO₂ 35-45 mmHg)
| Study group | Role | What they receive |
|---|---|---|
| Group Low | Experimental | Low Tidal Volume Ventilation Group (LTV) Receives: Other: Low Tidal Volume Ventilation During CPB |
| Group Apnea | No intervention | Apnea Group (Control Group) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Diaphragmatic Excursion Measured by Ultrasound
Diaphragmatic excursion (DE) will be measured using M-mode ultrasonography with a 2-5 MHz convex probe placed in the right mid-clavicular subcostal view. Measurements will be performed during both quiet and deep breathing maneuvers. A DE value of ≤10 mm will be considered indicative of diaphragmatic paralysis. The average of three consecutive measurements will be recorded at each time point. The main comparison will assess postoperative DE values between groups receiving low tidal volume ventilation and apnea during CPB.
Measured: Baseline (30 minutes before transfer to the operating room (Preoperative baseline) Postoperative ( Immediately Before Extubation) 24 Hours After Surgery (24 hours after the end of surgery)
Secondary outcomes (2)
Incidence of Postoperative Pulmonary Complications
Measured: First 3 Days After Surgery and Prior to ICU Discharge
Time to Extubation
The time from ICU admission to successful extubation will be recorded in hours. Extubation will be performed based on predefined weaning criteria, including neurological status, respiratory stability, hemodynamic parameters, and oxygenation status. Patients not meeting criteria within 24 hours will be recorded accordingly.
Measured: From ICU Admission to Extubation (Up to 24 Hours Postoperatively)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2025
- Study start1 Jul 2025
- Primary completion5 Nov 2025
- Study completion30 Nov 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Perioperative Respiratory FunctionStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- randomized, controlled, parallel-assignment trial with an assessor-blinded design.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Konya City Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Nuran Akıncı Ekinci, Konya City Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07067684
- Sponsor's protocol ID
- Diaflex
- Status last verified
- Sep 2026
- First submitted
- 2 Jul 2025
- Last updated
- 15 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The plan to share individual participant data has not been determined. No data will be shared at this stage due to institutional policy and ethical concerns.
Publications
Barbariol F, Deana C, Guadagnin GM, Cammarota G, Vetrugno L, Bassi F. Ultrasound diaphragmatic excursion during non-invasive ventilation in ICU: a prospective observational study. Acta Biomed. 2021 Jul 1;92(3):e2021269. doi: 10.23750/abm.v92i3.11609.
PubMed 34212900
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Low Tidal Volume Ventilation on Diaphragmatic Excursion in Cardiopulmonary Bypass Surgery
- ClinicalTrials.gov ID
- NCT07067684
- Acronym / sponsor ID
- Diaflex
- Conditions
- Perioperative Respiratory Function, Diaphragmatic Dysfunction, Low Tidal Volume Ventilation
- Keywords
- Low Tidal Volume Ventilation, Diaphragmatic Excursion, Coronary Artery Bypass Grafting (CABG)
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Konya City HospitalUniversity, hospital or other
- Study start
- 1 Jul 2025 (actual)
- Primary completion
- 5 Nov 2025 (actual)
- Study completion
- 30 Nov 2025 (actual)
- First posted
- 16 Jul 2025 (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 goal of this clinical trial is to evaluate whether low tidal volume (LTV) ventilation during cardiopulmonary bypass (CPB) surgery helps preserve diaphragmatic excursion in adult patients undergoing coronary artery bypass grafting (CABG). The study will also assess the relationship between LTV ventilation and postoperative pulmonary complications, such as atelectasis, pleural effusion, and pneumonia.
The main questions this trial aims to answer are:
Does LTV ventilation better preserve diaphragmatic motion compared to apnea during CPB?
Are postoperative pulmonary complications less frequent in patients receiving LTV?
Does LTV contribute to shorter extubation times and ICU stays?
Researchers will compare LTV ventilation with apnea (standard care) during CPB to assess its effects on diaphragmatic excursion, measured via ultrasound, and postoperative respiratory outcomes.
Participants will:
Undergo elective CABG surgery under general anesthesia
Be randomly assigned to receive either LTV ventilation or apnea during CPB
Have diaphragmatic excursion measured by ultrasound before surgery, before extubation, and 24 hours after surgery
Be monitored for postoperative pulmonary complications (atelectasis, effusion, pneumonia), extubation time, and ICU length of stay
Ultrasound will be used to measure diaphragmatic excursion (DE) in quiet and deep breathing. DE below 10 mm will be considered as diaphragmatic paralysis. Postoperative respiratory assessments will include blood gas analysis (PaO₂/FiO₂ ratio), clinical respiratory parameters, and imaging findings.
This is a prospective, single-center, assessor-blinded randomized controlled trial. Patients and outcome assessors will be blinded to group allocation. The study will be conducted at the Anesthesiology Clinic of Konya City Hospital and is expected to enroll 60 patients.
Detailed description
oronary artery bypass grafting (CABG) surgery performed under cardiopulmonary bypass (CPB) is a complex procedure frequently associated with postoperative pulmonary complications (PPCs). During CPB, mechanical ventilation is usually paused (apnea), which leads to temporary diaphragmatic inactivity. The diaphragm, being a rhythmically contracting muscle under normal physiological conditions, may experience transient dysfunction or even paralysis due to this intraoperative inactivity. Several mechanisms, including loss of neuromechanical coupling, disrupted neuromuscular signaling, altered venous return, and impaired diaphragmatic oxygenation and metabolism, are thought to contribute to this process.
Reduced diaphragmatic motion can create a favorable condition for atelectasis, impair oxygenation, and increase the risk of infection in the postoperative period. The resulting transient diaphragmatic dysfunction is considered a potential contributor to the development of PPCs such as pneumonia, pleural effusion, and prolonged mechanical ventilation.
Recent research has focused on the protective effects of low tidal volume (LTV) ventilation in surgical and critical care settings. However, limited studies have evaluated its direct impact on diaphragmatic function during CPB, particularly in the context of CABG surgery. There is a need to investigate whether intraoperative application of LTV ventilation during CPB can help preserve diaphragmatic excursion (DE) and reduce PPCs.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- randomized, controlled, parallel-assignment trial with an assessor-blinded design.
| Arm | Type | Receives |
|---|---|---|
| Group Low | Experimental | Other: Low Tidal Volume Ventilation During CPBLow Tidal Volume Ventilation Group (LTV) |
| Group Apnea | No intervention | –Apnea Group (Control Group) |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age over 18 years
- Male or female patients
- American Society of Anesthesiologists (ASA) physical status class II or III
- Scheduled for elective coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB)
- Provided written informed consent to participate in the study -
Key exclusion criteria (9 listed)
- History of neuromuscular disease
- History of thoracic surgery
- History of pneumothorax or ascites
- Chronic respiratory failure
- Pulmonary hypertension or right ventricular failure
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 |
|---|---|---|
| Low Tidal Volume Ventilation During CPBGroup Low: Patients in this group will receive low tidal volume mechanical ventilation during cardiopulmonary bypass (CPB). Ventilation settings will be: Tidal Volume: 3-4 mL/kg (ideal body weight) PEEP: 5-8 cmH₂O Respiratory Rate: adjusted to maintain normocapnia (PaCO₂ 35-45 mmHg) | Other | Group Low |
Primary outcome
Change in Diaphragmatic Excursion Measured by Ultrasound
Time frame: Baseline (30 minutes before transfer to the operating room (Preoperative baseline) Postoperative ( Immediately Before Extubation) 24 Hours After Surgery (24 hours after the end of surgery)
Diaphragmatic excursion (DE) will be measured using M-mode ultrasonography with a 2-5 MHz convex probe placed in the right mid-clavicular subcostal view. Measurements will be performed during both quiet and deep breathing maneuvers. A DE value of ≤10 mm will be considered indicative of diaphragmatic paralysis. The average of three consecutive measurements will be recorded at each time point. The main comparison will assess postoperative DE values between groups receiving low tidal volume ventilation and apnea during CPB.
2 secondary outcomes
Incidence of Postoperative Pulmonary Complications
Time frame: First 3 Days After Surgery and Prior to ICU Discharge
Time to Extubation
Time frame: From ICU Admission to Extubation (Up to 24 Hours Postoperatively)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2026.
- Results publication: PubMed 34212900Barbariol F, Deana C, Guadagnin GM, Cammarota G, Vetrugno L, Bassi F. Ultrasound diaphragmatic excursion during non-invasive ventilation in ICU: a prospective observational study. Acta Biomed. 2021 Jul 1;92(3):e2021269. doi: 10.23750/abm.v92i3.11609.
- Individual participant dataSharing planned: No. The plan to share individual participant data has not been determined. No data will be shared at this stage due to institutional policy and ethical concerns.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low Tidal Volume Ventilation During CPB in people with Perioperative Respiratory Function and Diaphragmatic Dysfunction, run by Konya City Hospital at 1 site in Turkey (Türkiye).
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 5 inclusion and 9 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: finished, as of the sponsor's last update on 15 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Diaphragmatic Excursion Measured by Ultrasound (time frame: Baseline (30 minutes before transfer to the operating room (Preoperative baseline) Postoperative ( Immediately Before Extubation) 24 Hours After Surgery (24 hours after the end of surgery)). 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 NCT07067684, which also lists 1 linked publication.
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 15 Sep 2026.