Selective decontamination of digestive tract may lower hospital mortality in ICU patients: JAMA

SDD is a preventive infection control strategy consisting of administering topical, nonabsorbable antimicrobial agents to the upper gastrointestinal tract and the oropharynx, with or without administering a short-term course of broad-spectrum intravenous (IV) antibiotics.

Since the 1980s, researchers have encouraged SDD use in ICU patients receiving mechanical ventilation, primarily to reduce the risk of ventilator-associated pneumonia. At the same time, some studies have indicated a reduction in ventilator-associated pneumonia and hospital mortality. However, concerns regarding SDD's effect on antibiotic resistance development have made international guideline panels reluctant to recommend SDD and clinicians to implement it in practice.

Naomi E. Hammond and colleagues aimed to examine whether SDD is associated with reduced death risk in adults receiving mechanical ventilation in ICUs compared with standard care to clarify the uncertainty described above.

For this purpose, the researchers conducted a primary search using online databases until September 2022. Randomized clinical trials that included adults receiving mechanical ventilation in the ICU comparing SDD versus standard care or placebo were selected for the analysis.

The study's primary outcome was hospital mortality. Secondary outcomes were ICU-acquired bacteremia, the incidence of ventilator-associated pneumonia, and the incidence of positive cultures of antimicrobial-resistant organisms. Subgroups included SDD with an IV agent compared with SDD without an IV agent.

The analysis included 32 randomized clinical trials comprising 24 389 participants. The participants' median age was 54 years.

The study demonstrated the following findings:

• Data from 30 trials comprising 24 034 participants contributed to the main outcome, i.e., hospital mortality.
• For mortality for SDD, the pooled estimated risk ratio (RR) versus the standard care was 0.91, with a 99.3% posterior probability that SDD lowered hospital mortality.
• A favorable association of SDD was clear in trials with an IV agent (RR, 0.84) but not in trials without an IV agent (RR, 1.01).
• SDD was linked with a lower risk of ventilator-associated pneumonia (RR, 0.44) and ICU-acquired bacteremia (RR, 0.68).
• Data concerning the incidence of positive antimicrobial-resistant organism culture needed to be more compliant with pooling and had very low certainty.

"The use of SDD versus standard care or placebo in adults in the ICU treated with mechanical ventilation was tied to a lower hospital mortality," the researchers wrote in their conclusion. "There is a very low certainty on the evidence regarding SDD's effect on antimicrobial resistance."

Reference:

Hammond NE, Myburgh J, Seppelt I, et al. Association Between Selective Decontamination of the Digestive Tract and In-Hospital Mortality in Intensive Care Unit Patients Receiving Mechanical Ventilation: A Systematic Review and Meta-analysis. JAMA. Published online October 26, 2022. doi:10.1001/jama.2022.19709