De-Escalation and Escalation

De-escalation of antimicrobial therapy

Early appropriate de-escalation improves outcomes, reduces the risk of adverse effects, such as C. difficile infection, and preserves the utility of broad spectrum antimicrobials for resistant infections.

In uncomplicated infections without bacteraemia, switch to oral therapy after 48hrs of IV therapy. Complicated and bacteraemic infections usually require courses of IV treatment >48hrs.

CRP does not reflect the severity of infection and may remain elevated even when infection is resolving. It cannot be used in isolation to assess the severity of infection and hence the need for IV therapy.

Once culture results are available, antimicrobial therapy should be adjusted to the most narrow-spectrum effective agent.

In the absence of culture results, the IV-to-oral switch therapy (IVOST) section provides guidance on oral conversion of the most commonly used empirical intra-venous regimens.

Stopping antimicrobial therapy

Uncomplicated, non-bacteraemic infections should be treated with the shortest possible effective course if the patient is showing clinical improvement on the chosen antimicrobial regimen; suggested durations for the most common infections are given in the Empirical Antimicrobial Guidelines.

Infections associated with bacteraemia usually require courses of intravenous antimicrobials >48hrs; the duration is organism-dependent. Clinical advice regarding the management of any significant bacteraemia is routinely provided by a consultant microbiologist when the result is communicated to the clinical team.

Complicated or deep seated infections often require several weeks of intravenous antimicrobial treatment, especially if associated with sources that are inaccessible to surgical or radiological intervention. Advice can be sought from an infection specialist.

Escalation of antimicrobial therapy

Consider a change in antimicrobial therapy if:

  • the patient is deteriorating clinically with new onset of severe sepsis, septic shock, or rapidly spreading severe skin and soft tissue infection
  • no clinical improvement is observed after 72 hours of appropriate empirical or culture guided antimicrobials. 

If the patient is not clinically improving after 72 hours of antimicrobial therapy, but does not have severe sepsis or septic shock, continue current antimicrobials initially and:

  • review the clinical diagnosis
  • review microbiology results
  • review dosing of antimicrobials
  • ensure appropriate samples have been obtained
  • re-culture if clinically indicated
  • ensure source control.

Advice on “blind” escalation of antimicrobial therapy in the absence of culture results can be sought from the duty or on-call microbiologist.

  Antimicrobial prescribing tips

  • Raised inflammatory markers and Systemic Inflammatory Response Syndrome (SIRS) are not specific to infection.  If you suspect infection:  identify the clinical source, sample and treat accordingly. If no clinical source of infection can be identified, also consider non-infective causes of inflammation.
  • Review previous microbiology results before prescribing antimicrobials. Empirical antimicrobial guidelines apply only in the absence of previous microbiology results indicating resistance to the empirical regimen.
  • Patients fulfilling sepsis criteria should initially receive intra-venous antimicrobial therapy.
  • Ensure appropriate dosing and consider drug interactions. Factors such as age, body weight, renal, and hepatic function may require dose adjustments.
  • Review allergy history and ascertain the nature of drug reactions. Many reported allergies are intolerances or expected side effects.
  • Review antimicrobial prescriptions daily. Review clinical response and new culture results and adjust antimicrobial therapy accordingly.
  • Adhere to suggested duration of treatment. The majority of uncomplicated infections require ≤7 days of antimicrobial treatment.