A 55-year-old obese male with dysuria and hypotension was admitted to the ICU 12 hours previously. He had a femoral central venous catheter inserted in the Emergency Department on admission. Your registrar has reported that blood cultures collected through the CVC at the time of insertion growing Staphylococcus epidermidis.
- What advice will you give the registrar regarding the blood culture result?
- List two groups of patients in whom this result would be a concern.
Not to give additional antibiotics
Consider removing / re-siting the femoral CVC depending on the patient’s condition
- Immunocompromised patients with intravascular devices
- Patients with surgical implants
- Patients high risk for endocarditis
- Low weight neonates and elderly
Key points about the first part of this question:
- Coagulase-negative staph bacteraemia might sound quite rare (7 per 10,000 admissions) but is in fact the most common catheter-related bacteraemia.
- Cultures collected during CVC insertion are more likely to yield contaminants than peripheral blood cultures
- Significance of a coagulase-negative staph in a blood culture is determined by the presence of the clinical features of infection and in those cases one would be obliged to change the line. If it was a true bacteraemia, it will occur again in 20% of patients in whom the catheters remain in situ, compared to 3% in patients whose lines are changed.
Key points about the risk factors for clinically significant S.epidermidis bacteraemia:
- Anyone at risk of native valve endocarditis
- Anyone with artifical valves
- Anyone with a history of rheumatic heart disease
- Anyone who is immunosuppressed
- Anyone with an implated pacemaker, or any other surgical implant
- Any low birth infant
- Any elderly person (>65 years of age)
In any case, the question clearly points our way to urosepsis. The guy had dysuria, which is not usually a feature of staphylococcal endocarditis so severe that it would cause haemodynamic collapse and ICU admission.
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