Background: To evaluate the diagnostic value of Gram stain of pericatheter skin swabs and the intravascular device hub in detecting catheter-related bacteremia (CRB) in critically-ill patients.
Methods: Over a 12-month period, 170 intravascular catheters (> 7 days in place) suspected as being the primary source of CRB were prospectively examined in adult patients admitted to 10 intensive care units of different hospitals in Spain. Blood cultures, Gram staining and culture of swabs obtained from skin entry side and catheter hub were performed before catheter removal. A semiquantitative culture of the catheter tip was carried out. Catheter-associated bacteremia was considered to be present if the same organism was isolated from the catheter tip, skin and/or hub, and blood cultures.
Results: The incidence rate of CRB was 15%. Staphylococcus epidermidis was the most frequently isolated microorganism. Considered together, the sensitivity, specificity, positive predictive value and negative predictive value for Gram staining of the skin and hub were 80, 81.9, 35.3 and 97.1%, respectively.
Conclusions: The Gram stain of skin and hub swabs has a great utility in predicting CRB, specially in the absence of microorganisms. Gram stains of the above mentioned sites could be recommended as an easy and fast method to rule out the presence of CRB.