Did selective decontamination of the digestive tract show any benefit over standard care for mechanical ventilation patients?
Selective decontamination of the digestive tract (SDD) is a preventive strategy where non-absorbable antibiotics are applied to the mouth and stomach, sometimes with a short course of intravenous antibiotics, to reduce infections in patients on mechanical ventilation. The question is whether this approach improves survival compared to standard care. Overall, large analyses suggest a mortality benefit, but some individual trials have not confirmed this, making the evidence somewhat mixed.
What the research says
A 2025 meta-analysis of 32 randomized trials (over 27,000 patients) found that SDD was associated with a 9% relative risk reduction in hospital mortality compared to standard care, with a 99.2% probability of benefit 1. This supports earlier meta-analyses that also suggested a mortality reduction 11. However, a large 2022 cluster-randomized trial in Australia (nearly 6000 patients) found no significant difference in in-hospital mortality between SDD and standard care 10. Another trial from Australia and Canada also reported no mortality benefit 4. These conflicting results may be due to differences in study design, patient populations, or the specific SDD regimen used. Notably, SDD is primarily aimed at preventing ventilator-associated pneumonia, and while it consistently reduces pneumonia rates, translating this into a survival benefit has been debated 11. The most recent meta-analysis, which included the latest trial, strengthens the case for a mortality benefit, but the evidence is not uniform across all settings.
What to ask your doctor
- What is the current evidence on SDD for reducing mortality in mechanically ventilated patients?
- Does our ICU use SDD, and if not, why?
- Are there any risks, such as promoting antibiotic resistance, that I should be aware of?
- How does SDD compare to other infection prevention strategies like oral chlorhexidine or selective oropharyngeal decontamination?
- Would SDD be appropriate for my specific condition or the condition of my family member?
This question is drawn from common patient questions about this topic and answered using cited medical research. We do not provide individualized advice.