Antibiotic Decision Steps in the ICU

ICU Antibiotic Use: Step-by-Step

1. Identify Infection

Confirm clinical suspicion of infection

Obtain appropriate cultures before antibiotics

Do not delay treatment in sepsis or septic shock

CRP and PCT may support diagnosis but are not definitive

Rapid test may aid early pathogen identification

2. Start Empirical Antimicrobial Therapy

• Base choice on:

  • Local ICU antibiogram

  • Site of infection

  • Community vs hospital-acquired infection

  • Recent antibiotic exposure

• Avoid unnecessary broad-spectrum antibiotics

3. Timing of Antibiotics

• Sepsis / septic shock: start within 1 hour

• Stable patients: brief assessment acceptable before initiation

4. Dose Optimisation

• Individualise dose based on:

  • Renal function

  • Body weight

  • Organ dysfunction

  • Pharmacokinetic / pharmacodynamic properties

5. Review and De-escalation (24–72 hours)

• Review:

  • Culture and sensitivity results

  • Clinical response

• Actions:

  • De-escalate therapy

  • Narrow antibiotic spectrum

  • Stop antibiotics if infection unlikely

  • Optimise duration