EJRC – Article Review

Digestive decontamination in burn patients

Severe infections, sepsis and septic shock are common complications in burn patients, with notable effects on clinical outcomes and mortality. A reasonable approach to prevent infections in the Burn Units is to note they are mainly produced by a small range of pathogens: six community microorganisms present in previously healthy individuals (S. pneumoniae, H. influenzae, Moraxella catarrhalis, Escherichia coli, S. aureus and Candida albicans) and nine healthcare-related bacteria carried by patients with an underlying condition (Klebsiella, Proteus, Morganella, Enterobacter, Citrobacter, Serratia, Pseudomonas, Acinetobacter and MRSA).

These pathogens can cause three types of infections: a) exogenous infections, which appear at any time of ICU stay and can only be controlled by high level hygiene, b) secondary endogenous infections, which appear from the first week of hospitalization and can be controlled by enteral administration of non-absorbable antibiotics, and c) primary endogenous infections, which appear within the first week of admission and can be controlled with immediate administration of systemic antibiotics.

Selective digestive decontamination (SDD) is an infection prevention strategy consisting in the administration of both systemic and enteral antibiotics to cope with the three types of infections, whereas enteral administration of antibiotics (EA) is an alternative approach without the systemic component [1].

Both SDD and EA have been assessed in burn patients in observational studies and in randomized controlled trials (RCTs). Despite the good results of some of these studies in terms of mortality, incidence of pneumonia or Gram-negative bloodstream infections, drop in Candida colonization, and ability to control outbreaks of resistant bacteria, there is a global resistance to use SDD. To explore the evidence on the effects of SDD or EA on the incidence of infections and mortality in burn patients and the side effects of those interventions, Rubio- Regidor M and colleagues performed a systematic review of randomized clinical trials and observational studies [2].

From the 140 primarily identified records, only 10 were included (5 RCTs and 5 observational studies), counting a total of 1680 patients. SDD was used in 1 RCT and 3 observational studies, whereas EA was used in 4 RCTs and 2 observational studies. Mortality was evaluated in 8 out of the 10 studies included, enrolling 806 patients. A reduction in mortality was observed in both SDD and EA groups, except in two small sample size RCTs using EA.

Incidence of bloodstream infections was analyzed in 6 studies, showing a decline in Enterobacteriaceae bloodstream infections (more marked with SDD) and S. aureus bloodstream infections. One of the studies observed a reduction in Pseudomonas spp bloodstream infections and another one in the incidence of candidemia. A decrease in the incidence of pneumonia was observed only in the studies using SDD.

There were no differences between treatment and control groups in terms of cumulative incidence of burn wound colonization, although SDD reduced the incidence of Enterobacteriaceae and Pseudomonas spp in one observational study.Concerning side effects, none of the studies reported an increased incidence of colonization with resistant bacteria. However, one of the RCT observed an increased incidence of MRSA bloodstream infections in the SDD group. Diarrhea was reported as a side effect of EA in two studies, but with similar incidences of rectal colonization by Gram-negative bacilli in the treatment and control groups. Clostridium difficile toxin was not measured in any of those studies.

Study Strengths & Limitations

Strengths of the study were compliant with the PRISMA statement, the analysis of relevant clinical outcomes and mortality and the assessment of methodological quality of the studies included in the review including risk of bias.

Limitations include high heterogeneity in the primary studies included, with high risk of bias (assessment of different endpoints in each study, and possible overestimation of the true effect of the intervention assessed), absence of mortality reporting in almost a half of the patients included, and the intrinsic limitations of systematic reviews.

Take Home Messages 

• Both selective digestive decontamination (SDD) and enteral administration   of antibiotics (EA) are safe infection prevention strategies in the burn patient.
• Both SDD and EA are associated with a decrease in mortality and Gram-negative bloodstream infections. SDD is also associated with a reduction in the incidence of pneumonia.
• Detrimental effects of SDD and EA include a possible increase in the incidence of MRSA infections in some settings (topical mupirocin or enteral vancomycin could complement SDD or EA regimens), and diarrhea (without changes in rectal colonization). Colonization with resistant bacteria was not a side effect.

This article review was prepared and submitted by ESICM NEXT member David Pérez Torres, Department of Intensive Care, Río Hortega University Hospital, Valladolid, Spain, on behalf of the ESICM Journal Review Club.

References

[1] Van Saene HK, Petros AJ, Ramsay G, Baxby D. All great truths are iconoclastic: selective decontamination of the digestive tract moves from heresy to level 1 truth Intensive Care Med. 2003 May;29(5):677-90. DOI:10.1007/s00134-003-1722-2

[2] Rubio-Regidor M, Martín-Pellicer A, Silvestri L, van Saene HKF, Lorente JA, de la Cal MA. Digestive decontamination in burn patients: A systematic review of randomized clinical trials and observational studies. Burns. 2018 Feb;44(1):16-23. DOI:10.1016/j.burns.2017.04.001