UMEM Educational Pearls

The morbidity and mortality from pseudomonas aeruginosa infections is high and empiric double-antibiotic coverage (DAC) is sometimes given; quality evidence for this practice is lacking.

Although there is little supporting data, the following reasons have been given for DAC:

  • DAC provides better empiric coverage through differing mechanisms of antibiotic action
  • DAC prevents the emergence of antibiotic resistance during therapy

The potential harm of antibiotic overuse cannot be ignored, however, and include adverse reaction, microbial resistance, risk of super-infection with other organisms (e.g., Clostridium difficile), and cost.

There may be a signal in the literature demonstrating a survival benefit when using DAC for patients with shock, hospital-associated pneumonia, or neutropenia. The IDSA guidelines, however, do not support DAC for neutropenia alone; only with neutropenia plus pneumonia or gram-negative bacteremia.

Bottom line: Little data supports the routine use of DAC in presumed pseudomonal infection. It may be considered in patients with shock, hospital-associated pneumonia, or neutropenia (+/- pneumonia), but consult your hospital’s antibiogram or ID consultant for local practices.