Duration of antibiotic therapy in the intensive care unit

There are certain well defined clinical situations where prolonged therapy is beneficial, butprolonged duration of antibiotic therapy is associated with increased resistance, medicalising effects, highcosts and adverse drug reactions. The best way to decrease antibiotic duration is both to stop antibioticswhen not needed (sterile invasive cultures with clinical improvement), not to start antibiotics when notindicated (treating colonization) and keep the antibiotic course as short as possible. The optimal duration ofantimicrobial treatment for ventilator-associated pneumonia (VAP) is unknown, however, there is a growingevidence that reduction in the length of antibiotic courses to 7-8 days can minimize the consequences ofantibiotic overuse in critical care, including antibiotic resistance, adverse effects, collateral damage and costs.Biomarkers like C-reactive protein (CRP) and procalcitonin (PCT) do have a valuable role in helping guideantibiotic duration but should be interpreted cautiously in the context of the clinical situation. On the otherhand, microbiological criteria alone are not reliable and should not be used to justify a prolonged antibioticcourse, as clinical cure does not equate to microbiological eradication. We do not recommend a 'one size fitsall' approach and in some clinical situations, including infection with non-fermenting Gram-negative bacilli(NF-GNB) clinical evaluation is needed but shortening the antibiotic course is an effective and safe way todecrease inappropriate antibiotic exposure.