Factors associated with severe sepsis: prospective study of 94 neutropenic febrile episodes

Severe sepsis defined as infection-induced organ dysfunction or hypoperfusion abnormalities predispose to septic shock and increased mortality in neutropenic setting. We aimed at determining predictors of severe sepsis in neutropenic patients. Between 1 October and 31 December 2007, 41 patients (21 with acute myeloid leukemia, 19 with acute lymphoid leukemia and one with autologous stem cell transplantation for a mantle cell lymphoma) with chemotherapy-induced neutropenia (<0.5 x 10(9)/l) lasting for more than 7 days were included in this study. The median age was 28 years (range: 3-58 years). All patients were on oral antibacterial (colistin and gentamicin) and anti-fungal (amphotericin B) prophylaxis. The first neutropenic febrile episode was treated with piperacillin/tazobactam and colistin IV; if the patient remains febrile at 48 h from the start of this first line of treatment, amphotericin B i.v. is added. Imipenem was introduced in the case of non-response and finally glycopeptides were introduced according to the IDSA criteria. Severe sepsis and septic shock are defined according to the criteria of the consensus conference of the ACCP/SCCM excluding the leukocyte count since all the patients were neutropenic. Ninety-four febrile episodes were observed: 27 microbiologically documented (28.7%), six clinically documented (6.3%) and 61 fever of unknown origin (65%). Microbiologically documented infections were: 13 Gram-negative organisms, 11 Gram-positive organisms and three combined (Gram+ and -). Clinically documented infections were pneumonia (two), neutropenic enterocolitis (one), sinuses infection (one) and cutaneous infection (two). Severe sepsis accounted for 22 febrile episodes. Factors associated with the occurrence of severe sepsis were: hypophosphatemia (<0.8 mmol/l; p=0.05, OR=3.9, 95% CI: 1.3-45.7), hypoproteinemia (<62 g/l; p=0.006, OR=4.1, 95% CI: 1.4-11.4) and non-adapted anti-biotherapy at the onset of severe sepsis (p=0.019, OR=2.7, 95% CI: 1.02-7.39). However, heart rate/systolic blood pressure ratio <1.1 (p<0.001, OR=0.1, 95% CI: 0.03-0.31) and C-reactive protein <80 mg (p=0.001, OR=0.14, 95% CI: 0.04-0.54) were not predictive.