LTV (Low Tidal Volüme) Ventilation and Diaphragmatic Motion in CABG (Coronary Artery Bypass Grafting)

NCT07067684 | Completed

• 1 other identifier: Diaflex
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief 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). 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.

Conditions

Perioperative Respiratory Function; Diaphragmatic Dysfunction; Low Tidal Volume Ventilation

Keywords

Low Tidal Volume Ventilation; Diaphragmatic Excursion; Coronary Artery Bypass Grafting (CABG)

Outcome Measures

Primary Outcomes (1)

• 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.

  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

  First 3 Days After Surgery and Prior to ICU Discharge

• Time to Extubation

  From ICU Admission to Extubation (Up to 24 Hours Postoperatively)

Study Arms (2)

Group Low

EXPERIMENTAL

Low Tidal Volume Ventilation Group (LTV)

Other: Low Tidal Volume Ventilation During CPB

Group Apnea

NO INTERVENTION

Apnea Group (Control Group)

Interventions

Low Tidal Volume Ventilation During CPB OTHER

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)

Group Low

Eligibility Criteria

• Age: 18 Years - 75 Years
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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 -

You may not qualify if:

• History of neuromuscular disease
• History of thoracic surgery
• History of pneumothorax or ascites
• Chronic respiratory failure
• Pulmonary hypertension or right ventricular failure
• Emergency surgery
• Inability to perform diaphragm ultrasonographic measurements
• Refusal to participate in the study

Sponsors & Collaborators

• Konya City Hospital: lead

Study Sites (1)

Konya City Hospital

Konya, Konya, 42020, Turkey (Türkiye)

Location

Related Publications (1)

• 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.

  PMID: 34212900 RESULT

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: Only participants and outcome assessors are masked in this study. No additional masked parties beyond those listed.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD, Anesthesiologist, Department of Anesthesiology

Model Details: randomized, controlled, parallel-assignment trial with an assessor-blinded design.

Study Record Dates

• First Submitted: July 2, 2025
• First Posted: July 16, 2025
• Study Start: July 1, 2025
• Primary Completion: November 5, 2025
• Study Completion: November 30, 2025
• Last Updated: March 18, 2026

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)