The Role of Selective Digestive Tract Decontamination on Mortality and Respiratory Tract Infections: Discussion
Several possible explanations for the discrepancy between patient mortality rates and the rates of acquired respiratory infections emerged from this analysis. For one, the indiscriminant use of SDD may result in the emergence of infection with bacteria not covered by the prophylaxis regimen or antibiotic-resistant bacteria. This is supported by the findings of this meta-analysis that suggest that the incidence of acquired pneumonia due to Gram-positive bacteria was unaffected by SDD except for the emergence of antibiotic-resistant Gram-positive bacteria. Recently a group from the Netherlands described their experience with SDD in 61 mechanically ventilated patients. Eight of these patients developed nosocomial pneumonia (five patients) or bacteremia (three patients) due to Enterococcus faecalis. Similarly, Brun-Buisson and coworkers found that overgrowth of Gram-positive cocci (staphylococci and enterococci) occurred significantly more often in the SDD-treated group (26 of 115 samples) than in the control group (14 of 176 samples) (p=0.0004). Canadian family pharmacy in detail These reports support the possibility of emerging infections with Gram-positive bacteria as a potential problem of SDD.
Several authors have reported higher recovery rates of antibiotic-resistant Gram-positive bacteria in their SDD patients. Unertl and colleagues described two respiratory infections with S aureus resistant to gentamicin and polymyxin В in SDD-treated patients while no infections or episodes of colonization with antibiotic-resistant Gram-positive cocci occurred in control patients. Similarly, Gastinne et al found a trend (p=0.06) toward an increased incidence of staphylococcal pneumonia in their SDD-treated group compared with the control group. In that same study, 2 of the 10 (20 percent) episodes of pneumonia in the control group due to staphylococci were methicillin resistant compared with 6 of 16 (37.5 percent) staphylococcal pneumonias in the SDD-treated group. Two recent reports from Europe describing increased rates of colonization and infection with antibiotic-resistant Gram-positive bacteria prompted an editorial urging restraint in the routine use of SDD.
Another potential explanation for the discrepancy between mortality rates and the rates of acquired respiratory infection is that the diagnosis of these infections may have been inaccurate in these different studies.
Category: Respiratory Symptoms
Tags: acquired infections, gram-positive bacteria, pneumonia, respiratory infection, tracheobronchitis