In defense of evidence: the continuing saga of selective decontamination of the digestive tract

[Selective digestive decontamination. Why don't we apply the evidence in the clinical practice?]

Selective digestive decontamination (SDD) is a prophylactic strategy whose objective is to reduce the incidence of infections, mainly mechanical ventilation associated pneumonia in patients who require intensive cares, preventing or eradicating the oropharyngeal and gastrointestinal carrier state of potentially pathogenic microorganisms. Fifty-four randomized clinical trials (RCTs) and 9 meta-analysis have evaluated SDD. Thirty eight RCTs show a significant reduction of the infections and 4 of mortality. All the meta-analyses show a significant reduction of the infections and 5 out of the 9 meta-analyses report a significant reduction in mortality. Thus, 5 patients from the ICU with SDD must be treated to prevent pneumonia and 12 patients from the ICU should be treated to prevent one death. The data that show benefit of the SDD on mortality have an evidence grade 1 or recommendation grade A (supported by at least two level 1 investigations). The aim of this review is to explain the pathogeny of infections in critical patients, describe selective digestive decontamination, analyze the evidence available on it efficacy and the potential adverse effects and discuss the reasons published by the experts who advise against the use of SDD, even though it is recognized as the best intervention evaluated in intensive cares to reduce morbidity and mortality of the infections.

Fluconazole prophylaxis in critically ill surgical patients: A meta-analysis*

OBJECTIVE

To evaluate the impact of fluconazole prophylaxis on the incidence of fungal infections and on mortality among critically ill surgical patients.

DESIGN

Meta-analysis of randomized, placebo-controlled trials of fluconazole prophylaxis.

PATIENTS

Subjects participating in the clinical trials in this area.

MEASUREMENTS AND MAIN RESULTS

We identified four randomized studies comparing fluconazole to placebo for prevention of fungal infections in the surgical intensive care unit (SICU). The studies enrolled 626 patients and used differing dosing regimens of fluconazole. All trials were double-blind and two were multicenter studies. Fluconazole administration significantly reduced the incidence of fungal infections (pooled odds ratio, 0.44; 95% confidence interval, 0.27-0.72; p < .001). However, fluconazole prophylaxis was not associated with a survival advantage (pooled OR for mortality, 0.87; 95% confidence interval, 0.59-1.28; p = NS). Fluconazole did not statistically alter the rate of candidemia, as this was low across the studies and developed in only 2.2% of all participants. Performing a sensitivity analysis and including two additional studies that indirectly examined fluconazole prophylaxis in the critically ill did not change our observations. Data from the reports reviewed were insufficient to allow comment on the impact of fluconazole prophylaxis on resource utilization, the distribution of non-albicans species of Candida, and the emergence of antifungal resistance. Generally, fluconazole appeared to be safe for SICU patients.

CONCLUSIONS

Prophylactic fluconazole administration for prevention of mycoses in SICU patients appears to successfully decrease the rate of these infections, but this strategy does not improve survival. The absence of a survival advantage may reflect the few studies in this area and the possibility that this issue has not been adequately studied. Because of the potential for both resistance and emergence of non-albicans isolates, clinicians must consider these issues when evaluating fluconazole prophylaxis in the SICU. Future trials should focus on more precisely identifying patients at high risk for fungal infections and on determining if broader use of fluconazole alters the distribution of candidal species seen in the SICU and impacts measures of resource utilization such as length of stay and duration of mechanical ventilation.