Infectious Diseases in Critical Care Medicine

BSIs may occur spontaneously or are secondary to a variety of invasive procedures (78).
Transient bacteremias occur in 10% of patients with severe gingival disease (79). Two percent
of patients with extensive burns (greater than 60% of body surface area) develop right-sided IE
secondary to the BSI’s complicating septic thrombophlebitis.S. aureusis usually involved (80).
Other infections, most commonly pneumonia and pyelonephritis, may give rise to BSIs (66).
Table 5 presents the risk of developing of a BSI following a variety of planned invasive
procedures (81).
Currently, the chief source of BSIs in the CCU is the non-cuffed, nontunneled, and
nonmedicated central venous catheter. The three major determinants of catheter infections are:
the type of catheter, the site of insertion, and the duration of the catheter, Table 6 presents the
risk of CRBSI of various types of devices (82–84). There are four possible sources of infection of
intravascular catheters (85): the insertion site, the hub of the catheter, seeding of the catheter
from a BSI, and contamination of the infusate.
Bacterial infection of intravascular catheters depends on the response of the host to the
presence of the foreign body, the pathogenic properties of the organisms, and the site of

Table 5 Risk of Bacteremia Associated with Various Procedures

Low (0%–20%) Moderate (20%–40%) High (40%–100%) Organism

Tonsillectomy
Bronchoscopy (rigid)
Bronchoscopy (flexible) Streptococcal sp. orS. epidermidis
Endoscopy S. epidermidis, streptococci, and
diphtheroids
Colonoscopy Escherichia coliandBacteroidessp.
S. epidermidis
Barium enema Enterococci; and aerobic gram-
negative rods
Transurethral
resection of the
prostate

Coliforms, enterococci, S. aureus

Cystoscopy Coliforms and gram-negative rods
Traumatic dental
procedures

Streptococcus viridans

Liver biopsy (in setting
of cholangitis)

Coliforms and enterococci

Sclerotherapy of
esophageal varices

S. viridans, gram-negative rods,
S. aureus
Esophageal dilatation S. aureus,S. viridans
Suction abortion S. viridansand anaerobes
Transesophageal
echocardiography

Streptococcal sp.

Table 6 Risk and Rates of Bloodstream Infections Produced by Intravascular Catheters

Types of vascular catheters Risk For BSIa/catheter (%)

Rates of catheter BSI/

1000 catheter days

Standard CVCb 3.3 2.3–2.7
Antibiotic coated CVCb 0.2 0.2
Piccc 1.2 0.4–1.1
Tunnel and cuffed CVCb 20.9 1.2
Swan–Ganz CVCb 1.9 3.7–5.5
Hemodialysis catheters – 2.8
Arterial catheters – 1.7

aBloodstream infection.
bCentral venous catheter.
cPeripherally inserted central venous catheter.

Source: From Refs. 82–84.

Infective Endocarditis and Its Mimics in Critical Care 225