Infectious Diseases in Critical Care Medicine

acquired during venipuncture, CVC infection is diagnosed if the blood culture isolate is the

same organism recovered from the removed CVC SQ tip culture. For the CVC tip culture to be

considered positive, 15 colonies should be present. Positive CVC tip cultures without

bacteremia indicate the catheter colonization and not CVC infection. Bacteremia without a

positive CVC tip culture indicates bacteremia unrelated to the CVC (1,4,11,16).

The empiric therapy of CVC infections is usually two weeks with antibiotics, with MSSA/

MSRA, and anti-GNB activity if CVC-related bacteremia is due to MSSA/MRSA and ABE (11).

Near the end of the therapy, MSSA/MSRA ABE should be ruled out by transthoracic

echocardiography (TTE)/transesophageal echocardiography (TEE). Teichoic acid antibody

(TAA) should be obtained. If TAA titers two weeks after bacteremia/CVC removal are elevated

(i.e.,>1:8), then anti-MSSA/MRSA therapy should be continued for four weeks. Cardiac

echocardiography (TTE/TEE) should be done to rule out ABE in those with high-grade/persistent

MSSA/MRSA bacteremia during/following an MSSA/MRSA CVC infection. For ABE screening

purposes, a TTE is sufficiently sensitive/specific to detect vegetations on native heart valve. For

prosthetic valves, TEE is preferred to detect vegetations (17–39) (Table 3).

COMPLICATIONS OF CVC INFECTIONS

Septic Thrombophlebitis

Simple or uncomplicated phlebitis may be associated with low-grade fevers (102 8 F) but not

usually bacteremia. If bacteremia due to skin organisms usuallyS. aureusor CoNS complicates

phlebitis, the bacteremia is intermittent/low intensity. Septic thrombophlebitis is an

intraluminal infection within the vein. Clinical findings resemble phlebitis except that patients

Table 1 Pathogens Associated with CVC Infections

Most common pathogens

S. aureus(MSSA/MRSA)

S. epidermidis(CoNS)

Enterobacter sp.

K. pneumoniae

Uncommon pathogensa

EnterococciE. faecalis(VSE) orE. faecium(VRE)

Burkholderia(Pseudomonas)cepaciab

Stenotrophomonas(Xanthomonas)maltophiliab

Citrobacter freundiib

Serratia marcescensb

aPseudomonas aeruginosais a rare CVC pathogen.

bOften associated with contaminated infusalate

Abbreviations: CoNS: coagulase-negative staphylococci; MSSA/MRSA, methicillin-sensitiveS. aureus/methicillin-

resistantS. aureus; VRE, vancomycin-resistant enterococci; VSE, vancomycin-susceptible enterococci.

Source: Adapted from Ref. 1.

Table 2 Risk Factors Associated with CVC Infections

Key risk factors for CVC infections
l Aseptic insertion technique
l Duration of catheterization (catheter days)
l Anatomical location of catheter insertion (femoral vein>IJ vein>SC vein)
l CVC maintenance care

Other factors in CVC infections
l Number of catheter lumens (single vs. triple lumen)
l Secondary bacteremias
l CVC junctional disconnects/medication injections
l Contaminated infusate

Abbreviations: CVC, central venous catheters; IJ, internal jugular; SC, subclavian.

Source: Adapted from Ref. 1.

Intravenous Central Line Infections in Critical Care 209