Emergence of Gram-Positive Infections: Relationship to Indwelling Catheters and Management During Chemotherapy-Induced Aplasia

Abstract

The empiric use of broad-spectrum antibacterial antibiotics for first fever in the granulocytopenic patient has had a major impact in lowering mortality from overwhelming infection caused by aerobic Gram-negative bacteria (Schimpff et al. 1971; Hathorn et al. 1987; Klastersky 1989; Karp et al. 1990). Despite this decrease in early infectious death, there has been an increased prevalence of Gram-positive (GP) infections in this same population which, while less life-threatening than their Gram-negative counterparts, can result in significant morbidity. Several factors are likely responsible for the emerging prominence of GP infections in this clinical setting (Table 1). In particular, the use of indwelling, multiport central venous catheters (CVC) as a routine adjunct to optimize venous access during lengthy aplasia has accentuated the problems of GP infection (Lowder et al. 1982; Lokich et al. 1985; Dickinson and Bisno 1989). Both initial catheter placement and long-term catheterization are accompanied by skin barrier invasion. The mechanical interruption of barrier integrity predisposes to local infection at exit and/or tunnel sites, thrombophlebitis, and sepsis from colonization along the entire catheter tract by common skin organisms including coagulase-negative staphylococci and Corynebacterium jeikeium. These bacteria are often resistant to beta lactam antibiotics and other antibiotics commonly used in empiric regiments for treatment of first infectious fever during aplasia (Karp et al. 1986; Anaissie et al. 1988a; Shenep et al. 1988). They are susceptible, however, to vancomycin, a cell wall-acting glycopeptide antibiotic with efficacy against both beta lactam-susceptible and resistant staphylococci and corynebacteria.