Impact of Multidrug-resistant Pseudomonas aeruginosa Infection on Patient Outcomes

Elizabeth B Hirsch; Vincent H Tam


Expert Rev Pharmacoeconomics Outcomes Res. 2010;10(4):441-451. 

In This Article

Expert Commentary

The true impact of MDR P. aeruginosa infection on patient outcomes remains controversial. The conventional notion that MDR pathogens are associated with reduced biofitness and/or virulence (and thus unlikely to negatively influence patient outcomes) has been challenged. Available clinical data suggest that MDR P. aeruginosa infections may be associated with worse outcomes (mortality, morbidity, requirement for surgical intervention, prolonged length of hospital stay and so on). However, these clinical investigations are often confounded by inconsistency in the definition of MDR pathogens, variable mechanism(s) of resistance, retrospective study design and publication bias. In addition to intrinsic biofitness and/or virulence, an additional critical factor to be considered is the appropriateness of empirical therapy, which may be difficult to adjust clinically. Despite these limitations, we may have to make an educated assessment based on such 'best-available' data. Well-designed prospective clinical studies addressing these drawbacks are unlikely to be performed in view of ethical concerns. Molecular investigations may be useful to delineate/de-couple the association of various mechanism(s) of resistance and expression of virulence factors. Appropriately designed animal studies (in experimental therapeutics) may also be helpful in bridging the knowledge gap in clinical scenarios where there could be ethical concerns (i.e., exact infection time before treatment, identical baseline inoculum and so on).