Authors: Becker S et al.
Anesthesiology, November 17, 2025 DOI: 10.1097/ALN.0000000000005851
Summary
This single-center randomized controlled trial compared Flow-Controlled Ventilation (FCV) with conventional Pressure-Controlled Ventilation (PCV) in 140 adults undergoing on-pump cardiac surgery. These patients are especially vulnerable to perioperative lung injury and systemic inflammation, and the investigators hypothesized that FCV—by precisely regulating inspiratory and expiratory airflow and reducing mechanical power—might blunt the postoperative inflammatory response.
Patients were randomized 1:1 to FCV or PCV, with both groups receiving compliance-guided PEEP and driving pressure. The primary endpoint was plasma interleukin-8 (IL-8) concentration six hours after cardiopulmonary bypass.
The primary outcome showed no difference: postoperative IL-8 levels were similar between FCV and PCV. However, ventilation characteristics differed substantially. FCV resulted in higher driving pressures and tidal volumes, but significantly lower respiratory rates and minute ventilation to maintain normocapnia. Critically, FCV reduced the mechanical power delivered to the lungs by 55%.
Although exploratory, secondary outcomes favored FCV: lower rates of postoperative pulmonary complications (such as pneumonia and hypoxemia), fewer extrapulmonary complications, and a shorter hospital stay. These findings suggest possible clinical benefits despite no change in IL-8 at the six-hour mark.
The trial did not confirm the hypothesized reduction in early inflammation, but the physiological advantages of FCV and the improved exploratory clinical outcomes support further investigation in larger, multicenter trials.
What You Should Know
• 140 cardiac surgery patients randomized to FCV vs PCV.
• No difference in IL-8 levels at 6 hours post-bypass (primary outcome).
• FCV produced lower respiratory rates and minute ventilation but higher ΔP and tidal volumes.
• FCV reduced mechanical power by 55% compared to PCV.
• Exploratory results favored FCV: fewer pulmonary and extrapulmonary complications and shorter hospital stay.
• Findings justify larger confirmatory trials evaluating FCV in cardiac surgery.
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