Effect of Ultra-Low Tidal Volume on Mechanical Power During Heart Bypass Surgery

NCT07073885 | Completed

• 1 other identifier: CABGO-MP
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to evaluate whether ultra-low tidal volume (ULTV) ventilation during cardiopulmonary bypass (CPB) can reduce mechanical power (MP) and improve postoperative respiratory outcomes in adult patients undergoing elective coronary artery bypass graft (CABG) surgery. The main questions it aims to answer are: Does ULTV ventilation during CPB result in lower intraoperative mechanical power compared to apnea? Can ULTV ventilation reduce extubation time and ICU (Intensive Care Unit) stay and improve the PaO₂/FiO₂ ratio (Partial Pressure of Arterial Oxygen / Fraction of Inspired Oxygen Ratio)? Researchers will compare patients receiving ULTV ventilation to those undergoing apnea after aortic cross-clamping to assess the effects on mechanical power and postoperative outcomes. Participants will: Be randomized to either ULTV ventilation or apnea group Undergo standard general anesthesia and CABG surgery Have mechanical power measured at three time points (pre-CPB, post-CPB, and ICU pre-extubation) Have arterial blood gases evaluated for PaO₂/FiO₂ ratios Be monitored for extubation time and ICU length of stay This study aims to generate evidence that could inform safer and more protective intraoperative ventilation strategies during cardiac surgery.

Conditions

Coronary Artery Disease

Outcome Measures

Primary Outcomes (1)

• Mechanical Power

  Primary Aim Measurements Calculation of Mechanical Power (MP) Several methods exist for measuring MP. In this study, a simplified and validated method will be employed. The formula is expressed as follows: MP (J/min) = 0.098 × RR × Vt × (PEEP + ½\[Pplat - PEEP\] + \[Ppeak - Pplat\]) (RR: Respiratory Rate, Vt : Tidal Volume, PEEP: Positive End-Expiratory Pressure, Pplat: Plateau Pressure, Ppeak: Peak Inspiratory Pressure). Thus, MP is calculated as the product of the work per individual breath (volume × pressure) multiplied by the respiratory rate. Primary evaluation parameters will be computed using ventilator settings, with three consecutive measurements taken and averaged for accuracy.

  MP Measurements (Mechanical Power)MP 1: Baseline (after intubation and before surgical incision)MP 2: At the end of surgery (prior to ICU admission)MP 3: Postoperative 2nd hour in ICU (prior to extubation)

Secondary Outcomes (3)

• extubation time

  From the end of surgery until the time of tracheal extubation, assessed up to 24 hours postoperatively.

• duration of intensive care unit (ICU) stay.

  From ICU admission following surgery until ICU discharge, assessed up to 7 days postoperatively.

• PaO₂/FiO₂ ratio.

  1. Baseline (after intubation, before surgical incision)2. At the end of surgery (prior to ICU admission)3. Postoperative 2nd hour in ICU (prior to extubation)4. 24 hours after extubation

Study Arms (2)

Group ULTV

EXPERIMENTAL

Participants in this group will continue to receive mechanical ventilation after aortic cross-clamping during cardiopulmonary bypass (CPB). Ventilation will be provided in volume-controlled mode with a tidal volume of 3-4 mL/kg ideal body weight, respiratory rate of 12-15 breaths/min, 5 cm H₂O PEEP (Positive End-Expiratory Pressure), and 50% FiO₂. .

Other: Ultra-Low Tidal Volume Ventilation

Apnea Group

ACTIVE COMPARATOR

After the application of the aortic cross-clamp, mechanical ventilation will be discontinued, and apnea will be maintained.

Other: Apnea Group

Interventions

Ultra-Low Tidal Volume Ventilation OTHER

Ventilation continued during CPB using volume-controlled mode with ultra-low tidal volume (3-4 mL/kg IBW(Ideal Body Weight)), 12-15 breaths/min, 5 cm H₂O PEEP, and 50% FiO₂.

Group ULTV

Apnea Group OTHER

In this group, mechanical ventilation will be discontinued after aortic cross-clamping during CPB, and apnea will be maintained throughout the bypass period.

Apnea Group

Eligibility Criteria

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

You may qualify if:

• Patients of either sex aged over 18 years
• Patients classified as ASA II-IV
• Patients scheduled for elective CABG

You may not qualify if:

• Presence of severe COPD
• Uncontrolled bronchial asthma
• Decompensated heart failure (NYHA class III-IV)
• Pulmonary hypertension
• History of lung surgery
• Morbid obesity (BMI \>35)
• Emergency surgery cases
• Patients who decline to participate in the study

Sponsors & Collaborators

• Konya City Hospital: lead

Study Sites (1)

Konya City Hospital

Konya, 42020, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Coronary Artery Disease

Condition Hierarchy (Ancestors)

Coronary Disease; Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Vascular Diseases

Study Officials

• Esma karaarslan, MD

  Konya City Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Medical Doctor (MD), Department of Anesthesiology and Reanimation, Konya City Hospital

Study Record Dates

• First Submitted: July 2, 2025
• First Posted: July 18, 2025
• Study Start: October 10, 2025
• Primary Completion: February 15, 2026
• Study Completion: February 20, 2026
• Last Updated: March 2, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: The exact time frame for data sharing will be determined after the study is completed and the results are published.
• Access Criteria: we can share the data by using e-mail

Locations

TU (1)