Intravascular catheters are used for a wide range of therapies in pediatric patients, such as administering total parenteral nutrition and chemotherapy, providing reliable access for hemodynamic monitoring, blood drawing, and performing interventions such as hemodialysis. No longer limited to the acute care setting, intravascular catheters are also used in outpatient settings. For the purposes of discussing management, complication risks, and preventive strategies, these catheters can be subdivided into short-term, intermediate-term, and long-term devices based on planned duration of use. While there is overlap between catheter types used for given planned durations, it is generally accepted that nontunneled central venous catheters are used for short-term access, peripherally inserted central catheters (PICCs) are often used as intermediate-term catheters, and long-term catheters include tunneled catheters and implantable ports.
PATHOGENESIS AND EPIDEMIOLOGY
Catheter-related bloodstream infections (CR-BSIs) are one of the more common types of healthcare-associated infections and result in increased healthcare costs, increased use of antimicrobials, prolonged hospital stays, morbidity, and death. The pathogenesis of CR-BSI varies. Different types include migration of potential pathogens from the skin at the exit site along the external surface of the catheter to the catheter tip; intraluminal migration of organisms from the catheter hub; contaminated infusates; and rarely, seeding of the catheter hematogenously from a distant focus. Current evidence suggests that migration of pathogens along the external surface of the catheter is more common in CR-BSIs associated with short- and intermediate-term, nontunneled catheters, with a higher rate of extraluminal source of infection in the first 1 to 2 weeks after placement of the central line. In contrast, intraluminal migration of organisms is more commonly seen in CR-BSIs associated with long-term, tunneled catheters. This differential is due in part to mechanical differences in the lines with the presence of a cuff on tunneled catheters acting as a fibrotic dam to migration of organisms along the external lumen. That said, external migration of organisms is possible in tunneled catheters and is associated with tunnel infections. Hematogenous seeding is one proposed mechanism of CR-BSIs in children with dysfunctional bowel; however, the true incidence of bowel translocation of microorganisms with subsequent seeding of the catheter is unknown.
The most commonly reported organisms implicated in CR-BSIs include skin flora such as coagulase-negative Staphylococcus and Staphylococcus aureus, Enterococcus species, enteric gram-negative organisms (particularly in patients with gastrointestinal dysfunction), and Candida species. Of concern is the growing number of CR-BSIs due to multidrug-resistant organisms.
Risk factors for CR-BSIs include prolonged use of systemic antimicrobials, catheter location (short- and intermediate-term lines placed in the femoral vein compared to other sites are more prone to infection in some pediatric studies), infusion of hyperalimentation with lipids, prolonged duration of catheterization (associated with increased formation of pathogenic biofilm), age < 2 years (especially premature infants with immature skin integrity), burn patients, immunocompromised patients, and those with intestinal integrity issues.