The Role of Selective Digestive Tract Decontamination on Mortality and Respiratory Tract Infections: Ananlysis
Six studies described potentially important differences in Gram-positive colonization and infection rates between study groups. Two studies demonstrated trends favoring increased colonization of SDD-treated patients with enterococci and antibiotic-resistant co-agulase-negative staphylococci. Two studies found significantly increased colonization with methicillin-resistant Staphylococcus aureus and Gram-positive cocci, respectively, while two studies described more patients with pneumonia due to antibiotic-resistant Gram-positive bacteria in their SDD-treated group.
The results of this meta-analysis suggest that SDD can decrease the incidence of respiratory infections, yet does not affect overall patient hospital mortality. Canadian health care mall in detail A trend favoring a decreased mortality from acquired infection in SDD-treated patients was heavily dependent on the results of one study raising significant question about the validity of this result. Additionally, clear guidelines for establishing causal relationships between acquired infection and mortality were not given in the studies examined, further complicating the interpretation of these data. The overall occurrence of acquired infections with Gram-positive and Gram-negative bacteria was lower in SDD-treated patients while the incidence of acquired pneumonia due to Gram-positive bacteria was identical between SDD-treated and control patients.
At first glance, these results appear to be at odds with previous reports that indicate nosocomial pneumonia increases mortality rates among critically ill patients. For instance, Craven et al found the mortality rate to be 55 percent for mechanically ventilated patients acquiring nosocomial pneumonia compared with a mortality rate of 25 percent for mechanically ventilated patients who did not develop nosocomial pneumonia. Similar results were described by Stevens et al who showed that patients in the ICU with nosocomial pneumonia had a mortality rate of 50 percent compared with a mortality rate of 3.5 percent for patients who did not develop nosocomial pneumonia. If one assumes that the development of nosocomial pneumonia is associated with a significant increase in the patient mortality rate, then it seems reasonable to assume that measures aimed at decreasing the incidence of nosocomial pneumonia should be associated with a reduced patient mortality rate. Despite the relatively large patient population examined in this meta-analysis (power=0.84), SDD had no apparent impact on overall hospital mortality despite a reduced rate of respiratory infections.
Category: Respiratory Symptoms
Tags: acquired infections, gram-positive bacteria, pneumonia, respiratory infection, tracheobronchitis