Australian Regenerative Medicine Institute

The Role of Selective Digestive Tract Decontamination on Mortality and Respiratory Tract Infections: Comment

The present analysis differs from previous analyses of SDD in that it includes new information from four recent prospective controlled trials, one of which was a large multicenter randomized placebo-blinded study. A specific effort was made in this meta-analysis to identify potential explanations for the observed discrepancy between mortality rates and respiratory infection rates. The importance of emerging infections due to antibiotic-resistant Gram-positive bacteria in SDD-treated patients is one potential explanation that has been minimized or overlooked by earlier reviewers in detail. Additionally, the larger size of the groups examined in this analysis compared with previous ones supports the lack of benefit from SDD on mortality, a point of continued debate.
Several limitations of this analysis should be emphasized. The analyzed studies involved heterogeneous patient populations (Table 1), which limits the overall applicability of these findings to any specific ICU population. Additionally, outcomes other than mortality such as ICU lengths of stay and ICU costs could not be investigated thoroughly. The results of one study suggest that antibiotic costs for SDD-treated patients may be higher, although overall ICU costs of care were not examined Examination of these secondary outcomes could identify ICU populations potentially benefiting from the use of SDD.
In summary, SDD appears to decrease respiratory infection rates despite no demonstrable effect on overall patient mortality. Evidence suggesting the emergence of colonization and infection with Gram-positive bacteria and antibiotic-resistant bacteria in SDD-treated patients offers one potential explanation for this outcome disparity. In light of these data, the routine use of SDD in critically ill patients cannot be recommended. Future studies examining SDD should be carefully designed to determine the contribution of Gram-positive bacteria and antibiotic-resistant bacteria to patient outcome. Targeting SDD to specific patient populations, such as trauma patients or patients following solid organ transplantation, may identify a group where this intervention has a beneficial effect. The examination of secondary outcomes such as length of hospital stay and hospitalization costs should also be included in future studies of SDD.

Category: Respiratory Symptoms

Tags: acquired infections, gram-positive bacteria, pneumonia, respiratory infection, tracheobronchitis