The following is a summary of “Gut colonization with multidrug resistant organisms in the intensive care unit: a systematic review and meta-analysis,” published in the June 2024 issue of Critical Care by Heath et al.

In patients with critical illness, gut colonization by multidrug-resistant organisms (MDRO) precedes infection, with the process behind the colonization remaining largely unclear.

Researchers conducted a retrospective study reviewing and meta-analyzing ICU studies reporting the cumulative incidence and rates of MDRO gut acquisition.

They searched major databases (PubMed, Embase, and Web of Science) for observational studies published (2010 and 2023). MDRO were characterized as resistant to multiple drugs, including non-Pseudomonas Gram-negative bacteria (NP-GN), Pseudomonas spp., and vancomycin-resistant Enterococcus (VRE). The inclusion criteria were if the study assessed patients for MDRO colonization in the gut (via perianal or rectal swabs) upon ICU admission (within 48 hours) and at least one additional time point afterward. The main focus was determining the rate at which MDRO was acquired in the gut, MDRO after ICU admission, which was not initially present, and calculated across all patient times at risk. 

The result showed that in 482 studies, only 14 studies involving 37,305 patients were included in the final analysis. The study found that 5% (range: 1–43%) of patients acquired gut MDROs during hospitalization, with a rate of 12.2 (95% CI 8.1–18.6) acquisitions per 1,000 patient days. The time to acquire MDROs ranged from 4 to 26 days after ICU admission. Similar results were observed for both NP-GN and Pseudomonas spp., but data for VRE was limited. Based on a small subset of studies, the analysis suggests a steady increase of 1.41% per day in gut MDRO colonization up to 30 days in ICU (R² = 0.50, P<0.01).

Investigators concluded that gut acquisition of MDRO was prevalent in the ICU and escalated with prolonged ICU stays over a 30-day follow-up period, suggesting potential strategies for intervention to mitigate MDRO acquisition.

Source: ccforum.biomedcentral.com/articles/10.1186/s13054-024-04999-9