IMPROVE: Lung-Protective Ventilation in Intermediate-Risk Surgery

VT 6-8 mL/kg IBW + PEEP 6-8 + recruitment cut postop pulmonary complications by 70%.

Population

400 adults at intermediate-to-high risk for postop pulmonary complications undergoing major abdominal surgery in France.

Intervention

VT 6-8 mL/kg IBW + PEEP 6-8 cmH₂O + recruitment maneuvers q30 min.

Comparison

Conventional VT 10-12 mL/kg IBW + zero PEEP, no recruitment.

Outcome

Composite of major pulmonary + extrapulmonary complications within 7 days.

Double-blind (clinicians blinded to ventilator settings via opaque dial covers — clever methodology), multicenter RCT. Randomization at induction.

• Composite primary: 10.5% lung-protective vs 27.5% conventional (RR 0.40, P<0.001).
• Pneumonia: 1.5% vs 8.0% (P=0.005).
• Hospital LOS: median 12 vs 14 days (P=0.04).
• Need for non-invasive ventilation: 1.5% vs 8.0%.

Lung-protective ventilation (VT 6-8 mL/kg IBW + PEEP 5-8 + recruitment) is now standard for ALL intraoperative ventilation, not just ARDS. The cost is zero, the benefit is large. PROBESE 2018 confirmed PEEP titration > fixed PEEP in obese patients. Modern practice: calculate IBW from height (NOT weight), set VT, set PEEP 5-10 supine, recruit at 30-40 cmH₂O × 30 sec at induction + before extubation, target plateau <30, allow PaCO₂ 40-50 (permissive hypercapnia).

• Single-country (France) — surgical practices/recovery patterns may differ.
• Composite endpoint includes both pulmonary + extrapulmonary — clean pulmonary signal is the dominant driver.
• Did not separate effects of VT vs PEEP vs recruitment (later trials addressed each).

1. What's your default intraop tidal volume formula? IBW or actual?
2. Do you use a fixed PEEP (5) or titrate? PROBESE-style or compliance-guided?
3. Are recruitment maneuvers part of your routine extubation prep, or only on demand for desaturation?