Pseudomonas aeruginosa is a pathogen commonly encountered in clinical practice in
critically ill patients. It is a serious cause of
infection, associated with a high rate of morbidity and mortality. Inappropriate antimicrobial
therapy and delay in starting effective antimicrobial
therapy is associated with worse prognostic. This microorganism is clinically indistinguishable from others forms of
gram-negative bacterial infection. The rate of multidrug-resistant P. aeruginosa has increased in the last years. For these reasons, patients with
Pseudomonas infection might receive empirical
antibiotics that are inactive against Pseudomonas, especially before
antibiotic susceptibility results become available. It remains controversial whether combination
therapy, given empirically or as definitive treatment, for suspected
Pseudomonas aeruginosa infections is justifiable. In the present article, we aimed to review recent studies that have evaluated the impact of combination
therapy on
Pseudomonas infections outcome and we exhibit our point of view in this subject. It seems justifiable to start combination
therapy with two antipseudomonal agents in patients with risk for
Pseudomonas infection during the first 3-5 days, until having microbiological results. This combination
therapy must be changed to monotherapy on the basis on the specific susceptibility pattern of the initial isolate. In cases without microbiological diagnosis and poor outcome, combination
therapy will be maintained and other causes of
infection will be studied. Multicentre prospective randomized trials in
critically ill patients are needed to determine which antimicrobials combinations improve outcome in
Pseudomonas infections.