Objective: To evaluate the influence of a rapid diagnostic test (RDT) in antibiotic therapeutic decisions in non-paediatric patients with Gram-negative bacteraemia (GNB).
Patients and methods: A RDT consisting of a direct antibiogram was used on blood isolates of GNB. GNB were also identified and sensitivity tests were performed according to standard criteria. Information on empirical treatment was registered (T1), as well as the antibiotic administered once the results of the RDT were available (T2). Finally, we noted the ideal antibiotic that the infectious diseases specialist (IDS) would have prescribed (T3). The decision regarding T2 was always taken by the patient's physician or the physician on duty.
Results: A RDT was performed for 248 patients. The most frequently isolated bacterium was Escherichia coli (13% producing extended-spectrum beta-lactamase). T1 was considered appropriate in 74% and appropriate but optimizable in 43%. T2 was considered appropriate in 95%, appropriate but optimizable in 36%, and inappropriate in 5%. The cost of the optimizable treatment (T2) was € 2210, while the cost of the ideal treatment would have been € 416; the saving in antibiotic cost of 1 day of treatment would have been € 1694.
Conclusions: Treatment prescribed by a non-IDS after a RDT was inappropriate in 5% and optimizable in 36%. It is our recommendation that information provided by a RDT should be interpreted by an IDS to make the information more beneficial both economically and 'ecologically'.