Gram-negative organisms predominate in Hickman line-related infections in non-neutropenic patients with hematological malignancies.

BACKGROUND: Catheter-related blood stream infections (CRBSI) cause significant morbidity and mortality in patients with hematological malignancies. Previous studies have identified a predominance of gram-positive organisms causing CRBSI but they included both neutropenic and non-neutropenic patients with solid organ and hematological malignancies. The aim of our study was to evaluate the incidence and microbiological profile of CRBSIs in a specific cohort of patients with hematological malignancies in their non-neutropenic phase of illness.
METHODS: A detailed retrospective review was done from January 2003 to December 2005 on all patients with hematological malignancies who had double-lumen non-antibiotic impregnated tunneled CVCs (Hickman catheters) inserted in our hospital to identify those fulfilling our criteria for CRBSI episodes.
RESULTS: Amongst 273 evaluable patients, 61 developed CRBSI on 70 occasions. In contrast to previous studies, there was a predominance of gram-negative infections (68%). The majority (73%) of initial CRBSI episodes required catheter removal within 7 days of onset. Vancomycin and cefepime was the most common initial antibiotic regimen used.
CONCLUSIONS: This study highlights the predominance of gram-negative infections in our cohort of non-neutropenic patients with underlying hematological malignancies who had Hickman catheters whose lines were not salvageable in the majority of cases. Empiric monotherapy with an antimicrobial agent with broad spectrum gram-negative cover needs to be given upfront pending results of the nature and sensitivity of organisms identified.