Selective Decontamination of the Digestive Tract during Ventilation in the ICU.

Summary

In a large international cluster randomized trial, SDD did not reduce 90-day in-hospital mortality among mechanically ventilated ICU patients. Although patient-level microbiology suggested fewer bloodstream infections and fewer cultured antibiotic-resistant organisms with SDD, the ecologic noninferiority threshold for resistant organisms was not met.

Key Findings

• No difference in 90-day in-hospital mortality: 27.9% (SDD) vs 29.5% (standard care), OR 0.93 (95% CI 0.84–1.05; P=0.27).
• SDD group had fewer new bloodstream infections (adjusted mean difference −1.30 percentage points) and fewer cultured antibiotic-resistant organisms (−9.60 percentage points) at the patient level.
• In the ecologic assessment, noninferiority for new antibiotic-resistant organisms was not confirmed, leaving ecological safety unresolved.

Clinical Implications

Routine SDD to reduce mortality in ventilated ICU patients is not supported. Centers considering SDD must weigh potential reductions in bloodstream infections against uncertain ecological risks and the inability to confirm noninferiority regarding resistant organisms at the unit level.

Limitations

• Heterogeneity in standard care and antimicrobial ecology across sites may influence generalizability.
• Ecologic noninferiority was not achieved; longer-term or broader ecological consequences remain uncertain.

Future Directions

Further work should refine ecological endpoints and surveillance, evaluate targeted SDD strategies or alternatives, and assess antimicrobial stewardship interactions and cost-effectiveness.