Sampling

Sampling advice for all conditions covered by the NHS Ayrshire & Arran Empirical Antimicrobial Guidance can be found in the respective organ-system sections of this guide. 

Detailed information on sampling requirements and processing (incl. tests sent to other laboratories) is available in the NHS Ayrshire & Arran Laboratory Handbook (desktop access only link).

Empirical treatment relies on more broad spectrum, more toxic agents, or agents associated with a high risk of C. difficile infection, and should not be regarded as a definitive treatment regimen in most cases of infection.

Susceptibility information is only available after culture and allows de-escalation to narrow spectrum, effective alternatives. 

Empirical therapy should be reviewed and replaced with a culture-based regimen as soon as results become available.

Good Practice

  • The empirical policy only applies in the absence of previous results. 
  • Sampling of the suspected focus of infection before antimicrobials are started or changed should be undertaken wherever possible.
  • Do not obtain blood cultures at insertion of a peripheral venous cannula - this practice is associated with high rates of contamination.  
  • Samples from sterile sites should be sent to the laboratory in a sterile universal container (white top). If the sample is injected into a blood culture bottle, it is not possible to perform cell counts or microscopy on receipt. 
  • Samples of pus or fluids in a universal container are preferable to swabs.