12
Intravenous Central Line Infections
in Critical Care
Burke A. Cunha
Infectious Disease Division, Winthrop-University Hospital, Mineola, New York, and State University of
New York School of Medicine, Stony Brook, New York, U.S.A.INTRODUCTION
Intravenous central venous catheters (CVCs) are used for medication, fluid, or nutritional
delivery to large vessels. Intravenous CVCs may be inserted centrally, i.e., internal jugular (IJ)
vein, subclavian (SC) vein, or femoral vein, or may be inserted peripherally, i.e., peripherally
inserted central catheters (PICC) into central veins. Complications of CVCs may be
mechanical/infectious. The three most common infectious complications of CVC include
line-associated bacteremias, septic thrombophlebitis, and acute bacterial endocarditis (ABE).
The most common organisms associated with CVC infections are methicillin-sensitive
Staphylococcus. aureus (MSSA)/methicillin-resistant S. aureus (MRSA), S. epidermitis also
known as coagulase-negative staphylococci (CoNS), and less commonly aerobic gram-negative
bacilli (GNBs). Excluding femoral CVC, enterococci are uncommon causes of CVC. Fungal
CVC infections may occur with CVCs in place for an extended period of time or when
receiving total parental nutrition (TPN). Because most patients in CCUs often have one or more
CVCs, clinicians caring for patients with CVCs should be familiar with the differential
diagnosis, complications, and therapy of CVC infections (1–10).
There are several factors that predispose to CVC infections. After careful aseptic insertion
technique, the most important factors predisposing to CVC infection are duration and location
of insertion of CVCs. IV CVC-line infections are also a function of time. CVC-related line
infection is uncommon before seven days, but after seven days, there is a gradual increase over
time in the incidence of CVC-line infections. The number of CVC lumens may increase the
potential for infection. In a patient with otherwise unexplained fever in the CCU, the longer a
CVC is in place, the more likely the CVC is the cause of fever. An important determinant of
CVC-line infections is the anatomical location of CVC insertion. The best anatomical location
with the lowest potential for infection is the SC vein, followed by the IJ vein. From an infectious
perspective, the least-desirable location is the femoral vein. Peripheral IV lines rarely result in
intravenous line bacteremias. Resultant bacteremia, i.e., intermittent/low blood culture
positivity, will not result in ABE. In the unlikely event that peripheral IV lines are the source
of any intermittent/low blood culture positivity, bacteremias will not result in ABE
subsequently (1–5,11–15) (Tables 1 and 2).
DIAGNOSIS OF CVC INFECTIONS
The main diagnostic difficulty with CVC infections is that, only 50% of CVC infections have
any local indication of infection. When the insertion site is red/painful, the diagnosis of CVC
infection is obvious. Differentiating chemical phlebitis /IV line infiltration from cellulitis is
usually straightforward. The skin at the IV insertion site with IV infiltration/phlebitis is
swollen and painful but not erythematous. IV line infections secondary to CVC should be
suspected where the other causes of fever have been ruled out. As mentioned, the likelihood of
CVC-related infection increases over time, the longer the CVC has been in place as well as
anatomical location of the insertion (1,4,11,16).
In the absence of local signs of infection, CVC infections may be diagnosed by blood
cultures and semi-quantitative (SQ) catheter tip cultures. If CVC infection is suspected, the
catheter should be removed and the tip sent for an SQ culture. Simultaneously, blood cultures
should be drawn from a peripheral vein, not through the CVC. Excluding skin contaminants