by Catheter related bloodstream infections (CRBSI) are one of the most common healthcare-associated infections that occur in patients with central venous catheters. CRBSI can cause prolonged hospitalization, increased healthcare costs, and elevated mortality. It is important for healthcare professionals and caregivers to understand the causes, risk factors, symptoms, treatment and prevention of CRBSI.
Causes of CRBSI
The primary cause of CRBSI is the microorganisms entering the bloodstream from external sources through the catheter. Some of the common microorganisms that cause CRBSI include:
– Coagulase-negative staphylococci such as Staphylococcus epidermidis which normally inhabit the skin. They are the most frequently identified organisms in CRBSI and account for approximately 50% of all cases.
– Staphylococcus aureus which lives on the skin or in the nose of around 30% of people. It is the second most common cause.
– Enterococci such as Enterococcus faecalis and Enterococcus faecium which reside in the gastrointestinal tract.
– Candida species like Candida albicans which is part of the normal oral and gastrointestinal microflora.
– Gram-negative bacilli including Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. These usually enter the bloodstream from other sites of infection in the body.
Risk Factors for CRBSI
Some of the main risk factors that increase the likelihood of developing a CRBSI include:
– Prolonged use of the catheter – The longer a catheter remains in place, the higher the risk. Risk increases 5% each day after catheter insertion.
– Type of catheter – Non-tunneled catheters like peripheral intravenous catheters carry higher risk than midline or central line catheters.
– Multiple manipulations or breaks in aseptic technique during catheter insertion or maintenance.
– Severe underlying illness – Patients with chronic conditions like cancer are more susceptible due to their weakened immune system.
– Precipitated infection at another site in the body.
– Use of antibiotics – Broad-spectrum antibiotic use allows more resistant organisms to proliferate.
Signs and Symptoms of CRBSI
Some of the common signs and symptoms of CRBSI include:
– Fever – Fever is present in 90% of cases and is usually the earliest symptom.
– Chills – Repeated chills or rigors often accompany the fever.
– Hypotension – Low blood pressure can develop as sepsis worsens.
– Changes at the insertion site – Erythema, tenderness, or purulent discharge may be seen.
– Changes in mental status – Confusion, lethargy due to sepsis affecting the brain.
– Decreased urine output – Kidney dysfunction from infection in severe cases.
Diagnosis of CRBSI
The diagnosis of CRBSI involves both clinical assessment and microbiological testing:
– Clinical examination to check for fever and local signs of infection.
– Blood cultures samples taken through the catheter and a peripheral vein. A culture growing the same organism from both suggests CRBSI.
– Quantitative or semiquantitative cultures of the catheter tip. A threshold of >15 CFU suggests infection of the internal surface.
– Consideration of other potential sources of bloodstream infection by radiological imaging if needed.
Treatment of CRBSI
The goals of treatment are to eliminate the infection, prevent complications and reduce mortality risk:
– Removal of the infected catheter is necessary for most cases to stop ongoing biofilm contamination.
– Empirical broad-spectrum antibiotics are started once blood cultures are taken, then de-escalated based on susceptibility results.
– Common choices include vancomycin, linezolid, daptomycin or beta-lactams for gram-positive organisms and antipseudomonal penicillins, carbapenems, or fluoroquinolones for gram-negatives. Therapy is usually 10-14 days.
Prevention of CRBSI
Several measures can be taken to reduce the incidence of CRBSI:
– Aseptic technique and strict sterile barrier precautions during catheter insertion and maintenance.
– Use of optimal insertion site (subclavian preferable to femoral or jugular).
– Daily review of line necessity with prompt removal of unnecessary catheters.
– Adequate staff education and training on infection control practices for central lines.
– Use of chlorhexidine for skin antisepsis prior to needleless connector access.
– Consideration of antimicrobial or antiseptic impregnated catheters in high risk settings.
In conclusion, CRBSI is a serious yet often preventable complication of central venous catheters. Following strict infection control practices along with prompt identification and treatment can significantly reduce the morbidity, mortality and costs associated with these healthcare-associated infections. Increased awareness among healthcare workers plays a key role in preventing CRBSI.
