Central venous Line/ Catheter Related Infections In ICU Setting.

Introduction:
Majority of patients in ICU have central venous lines placed in order to provide fluids and medicines. They may be life saving but at the same time these can result in serious blood stream infections. These catheter related blood infections are reported to occur in about 3 to 8% of inserted catheters and are the number one cause of nosocomial infections in ICU settings.

A few Definitions:
1. A central venous catheter or a central venous line is a catheter whose tip resides in a central vein.

                                                       An Adult Central venous catheter 

2. Catheter related blood stream infections refer to an infection that is attributed to an intravenous catheter by quantitative culture of the catheter tip or by difference in growth between catheter and peripheral venipuncture blood culture specimens.

3. Central line associated blood infections is defined as an infection that appears in the presence of a central venous catheter or within 48 hours of removal of a central venous line and which cannot be attributed to an infection unrelated to the catheter.

Risk factors:
The risk factors for these central venous line related blood infections include :

• Patient’s severity of illness
• Compromised immune system
• Presence of a distant skin infection
• Site of the catheter with greatest chances of infection with groin insertions.
• If aseptic techniques are not proper;y used while insertion of the catheter.

Background Information:
Addressing the issue of central venous line associated blood infections is challenging. Different countries and organizations have setup different guidelines to prevent these infections. These include:

• Hand hygiene and decontamination with antiseptic soaps or alcohol based gels before catheter insertion.
• Antiseptic care during insertion, maintenance and replacement of these intravascular central catheters.
• Use of maximum sterile barrier precautions like cap, mask, sterile gloves and gown while inserting central venous catheters.
• Proper education and training for the staff involved in taking care of patients with central venous lines in ICU.
• Catheter material is also very important to take into consideration for prevention of these infections. The material should be biostable and biocompatible. Also the catheter should be flexible, resistant, not altered by drugs, as radio opaque as possible and thin walled with a high internal to external diameter ratio.
• The subclavian vein should be the insertion point of choice.
• It is important to remove the central venous catheters as soon as they are no longer needed. The longer they are in place there are increased chances for infection.
• Although routine antibiotic prophylaxis is not recommended it can be used for high risk patients with central venous lines.

The microorganisms that are most commonly involved in these infections include:

• Staphylococci ( Both Staphylococcus aureus and the coagulase negative staphylococci)
• Enterococci
• Aerobic gram negative bacilli
• Yeasts.

Diagnosis: The diagnosis of catheter related blood stream infection is made if a patient with an intravascular central line develops the clinical or the laboratory criteria of the systemic inflammatory response syndrome . these include:

• A temperature < 36 C or > 38 C
• Heart rate >90/minute
• Respiratory rate >20/ minute
• Peripheral white blood cell count <4000/microliter or > 12,000/microliter.

Catheter-related bloodstream infection remains the most serious complication of central venous access and a leading cause of nosocomial infection in the ICU. It is important to take appropriate measure to prevent it.