Patients in whom short antibiotic treatment is not possible and in whom treatment should be individualised, and in whom procalcitonin may be useful to assess the efficacy and duration of antibiotic treatment

Inadequate initial antibiotic treatment
Severely immunocompromised patients (neutropenia or stem cell transplant)
Highly antibiotic-resistant pathogens
 Pseudomonas aeruginosa
 Carbapenem-resistant Acinetobacter spp.
 Carbapenem-resistant Enterobacteriaceae
Second-line antibiotic treatment (e.g. colistin, tigecycline)