Selective Decontamination The Concept

Selective decontamination of the digestive tract is based on the concept of colonization resistance. Studies in mice revealed that the autochthonous intestinal flora protects against colonization with exogenous flora 

Marcel Dekker, Inc. 270 Madison Avenue, New York, New York 10016 

Oropharyngeal decontamination was not included in the first protocol of SDD in mechanically ventilated patients. However, gastrointestinal decontamination alone did not influence the incidence of respiratory tract infections among multiple trauma patients when compared to a historical control group (27). Addition to the SDD regimen of an oropharyngeal paste containing topi- 

Marcel Dekker Inc. 270 Madison Aviraiiie, New Yaifc, New Yoik 10016 

The use of the combination of intestinal and oropharyngeal decontamination still did not significantly reduce the overall incidence of respiratory tract infections (27), because a large proportion of respiratory tract infections occurred within the first 4 days of mechanical ventilation, before decontamination was established. These cases of early-onset pneumonia were caused by pathogens that had already contaminated patients lower respiratory tract in the period shortly before, or after, ICU admission, and therefore could not be eradicated by intestinal and oropharyngeal decontamination. Addition of 3 to 7 days (28) of systemic prophylaxis to the SDD regimen resulted in a further reduction of the early-onset infections (27), presumably as a result of preemptive therapy of incubating pneumonia. 

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