The Effect of Ultra-Low Tidal Volume Ventilation on Mechanical Power in Coronary Artery Bypass Graft Surgery
The Effect of Ultra-Low Tidal Volume Ventilation on Mechanical Power in Coronary Artery Bypass Graft Surgery
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.
This is a prospective, randomized, assessor-blinded, single-center clinical trial designed to evaluate the effects of ultra-low tidal volume (ULTV) ventilation on intraoperative mechanical power (MP) and postoperative pulmonary outcomes in patients undergoing elective coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB).
After obtaining informed consent, eligible adult patients (ASA II-IV) scheduled for elective CABG will be randomly assigned to one of two groups:
ULTV Group: Ventilation will be continued after aortic cross-clamping using volume-controlled ventilation with a tidal volume of 3-4 mL/kg ideal body weight, 12-15 breaths per minute, 5 cm H₂O PEEP, and 50% FiO₂.
Apnea Group: Mechanical ventilation will be discontinued after aortic cross-clamping, and patients will remain apneic during CPB.
Mechanical power will be calculated using a validated surrogate formula and measured at three key time points: pre-CPB (baseline), post-CPB (before ICU transfer), and at the 2nd postoperative hour in the ICU (before extubation). Arterial blood gases will be obtained to determine PaO₂/FiO₂ ratios at these time points and 24 hours post-extubation.
Secondary outcomes include extubation time and length of ICU stay.
This study aims to generate evidence supporting the potential protective effects of continued low-volume ventilation during CPB, with a focus on reducing ventilator-induced lung injury by limiting mechanical power and preserving alveolar integrity.
Inclusion Criteria:
Exclusion Criteria: