INTRODUCTION: Carbapenem-resistant gram-negative bacilli (CRGNB) are one of the main causes of nosocomial infections, posing a major public health challenge. Blood stream infections (BSI) require special attention because of the higher morbidity and mortality associated. OBJECTIVE: To assess the impact of initial adequate or inadequate antibiotic treatment on the length of stay (LOS) and healthcare resource utilisation of patients with bloodstream infections (BSI) caused by a Carbapenem-resistant gram-negative bacilli (CRGNB) in the Spanish clinical practice. METHODS: A descriptive, observational, retrospective chart review study of patients diagnosed with CRGNB bacteriemia in 6 Spanish public hospitals. RESULTS: The overall median LOS of the total population (n=64) was 26.5 days (Q1: 16 days
Q3: 40 days). The median LOS for the initially adequately treated group was 27 days (Q1: 17
Q3: 50), and 24 days (Q1: 15
Q3: 38) for the initially inadequately treated (t-test p= 0.5031). In the Hospital Ward group (n=44), initially adequately treated patients spent hospitalised a median of 6 days less than the initially inadequately treated patients (18 days [Q1: 12
Q3: 27] vs 24 days [Q1: 15
Q3: 38] respectively, p=0.0269). In the total population analysis, initially adequately treated patients had a lower use of resources (20,895.02 € [Q1: 11,543.67 €
Q3: 61,773.17 €]) compared to initially inadequately treated patients (24,444.02 € [Q1: 11,571.63 €
Q3: 40,790.64 €). CONCLUSIONS: Results suggest that inadequate empirical treatment for BSI caused by CRGNB in the hospital ward could be associated with an increase in the LOS and resource utilization of these patients.