Treatment of CLABSIs in Children
ABSTRACT & COMMENTARY
By Philip R Fischer, MD, DTM&H
Professor of Pediatrics, Department of Pediatric and Adolescent, Medicine, Mayo Clinic, Rochester, MN.
Dr. Fischer reports no financial relationships in this field of study.
Source: Wolf J, et al. Central line-associated bloodstream infection in children: An update on treatment. Pediatr Infect Dis J 2013;32:905-910.
Wolf and colleagues reviewed the current management of central line-associated bloodstream infection (CLABSI) in children, primarily focusing on non-neonates with long-term tunneled central venous catheters. Current treatments have a high failure rate predominantly due to relapse and reinfection because of the difficulty in preventing and eradicating intraluminal biofilm.
Infection rates vary depending on device type and patient characteristics; infection rates of 11 per 1000 catheter days are reported in infants with intestinal deficiency. Coagulase-negative and coagulase-positive staphylococci, enterococcus, and gram negative enteric bacteria join Candida as likely microbial etiologies of the infections. After the initial weeks following catheter insertion, intraluminal colonization is the most important source of infection, and bacteria can "hide" in biofilms along the catheter walls. CLABSI accounts for prolonged hospitalizations (median of 12 days in 1 study1), additional costs, missed medication doses, removal/replacement of central venous catheters, some intravascular thrombosis and rarely, death.
CLABSI typically, but not always, presents with fever and chills. The cutaneous insertion site does not usually appear to be abnormal. When simultaneously obtained blood cultures show growth more than 2½ hours sooner when drawn from the catheter than from a peripheral vein, the infection is assumed to be related to (and not just associated with) the catheter. Similarly, variations of three hours or more in the delay to positivity between samples taken from different lumens are strongly associated the more rapidly positive site being in causal relation to the bloodstream infection.
Catheter salvage is often desirable, especially when a complicated child has limited potential replacement sites for another catheter and when the costs and medical risks of catheter replacement are high. Of course, catheters that are not being used for essential treatment can be removed, whether infected or not.
Catheters associated with tunnel infections and thrombophlebitis carry higher risk of adverse outcomes and should be removed. CLABSI due to fungi and mycobacteria have approximately 70% recurrence rates when catheters are left in place; recurrence rates for S. aureus CLABSI are around 50%. Children with infections due to other microbes could be candidates for ongoing catheter salvage attempts if the infection clears within 72 hours. If the catheter is removed, it should not be replaced until blood cultures demonstrate clearance of the blood stream infection.
Initial antibiotic therapy of a child with CLABSI should usually include vancomycin and broad-spectrum Gram-negative coverage (such as gentamicin or piperacillin-tazobactam or cefepime). If multiresistant Gram-negative infection is considered to be likely, meropenem could be used. If the patient is clinically septic, coverage with a second agent of a different class that provides broad spectrum Gram-negative activity could be considered. Antibiotic doses can be administered by rotating injection sites between the different lumens of the potentially infected catheter. Treatment should continue for 10 to 14 days after the infection is cleared (or the catheter removed); however, post- line removal treatment for "just" 5 to 7 days might be adequate for infections with coagulase-negative staphylococci.
In addition, treatment failures might be avoided by adding catheter lock therapy to systemic antibiotic therapy. An antimicrobial agent can be instilled into a potentially infected lumen in a volume adequate to fill that lumen. This can provide hours (or even days) of contact between high levels of anti-microbials and bacteria in the intraluminal biofilm. Various antibiotics and ethanol have been tried for this purpose. Catheter lock therapy seems safe, but studies so far have been small and inadequately powered to conclusively prove superiority of catheter lock therapy over "just" conventional systemic therapy. (Initial studies with hydrochloric acid lock therapy raised concern for mechanical complications.) Nonetheless, antibiotic lock therapy is recommended for adults and children with CLABSI.
COMMENTARY
Children are reaping the benefits of powerful advances in medical technology. At the same time, however, they may serve as proverbial lightning rods taking the heat before others know of danger. Children help us learn of the impact of anesthesia on brains,2 CT scans on developing cells,3 and indwelling venous catheters on microbial stability.
