Purpose The authors intended to determine the predictive factors of bacteraemia in low-risk febrile neutropenia (FN) classified by the Multinational Association for Supportive Care in Cancer Risk Index score.

Methods FN episodes managed in an emergency department from June 2009 to May 2010 were included. Clinical and laboratory features including procalcitonin (PCT) and C reactive protein (CRP) were retrospectively analysed.

Results Of the total 285 episodes, 243 (85.3%) were classified as low risk. In this group, 19 (7.8%) had bacteraemia. There was a significant difference (p<0.05) in age, respiration rate ≥24 (36.8% vs 7.6%), Eastern Cooperative Oncology Group performance status (PS) ≥2 (42.1% vs 11.6%), platelet counts (107.0±42.4 vs 131.8±73.7 ×10³/mm³), serum aspartate aminotransferase (42.3±30.7 vs 28.7±17.4 IU/litre) and blood urea nitrogen (19.6±9.8 vs 11.6± 8.6 mg/dl) between episodes with and without bacteraemia. PCT ≥0.5 ng/ml and CRP ≥10 mg/dl had higher rates of bacteraemia than PCT <0.5 ng/ml (28.2% vs 3.9%, p<0.001) and CRP <10 mg/dl (13.9% vs 5.3%, p=0.022) did. On multivariate analysis, PCT ≥0.5 ng/ml (OR 4.7, 95% CI 1.38 to 16.29), respiration rate ≥24 (OR 4.1, 95% CI 1.20 to 13.63) and Eastern Cooperative Oncology Group PS ≥2 (OR 3.2, 95% CI 1.02 to 10.10) were predictive of bacteraemia in the low-risk group.

Conclusion PCT, tachypnoea and PS were predictive of bacteraemia in the low-risk patients with FN. If the patient has high probability of bacteraemia, the patient could benefit from parenteral antibiotic treatment while awaiting the blood culture results.