Background: The 2009 Infectious Diseases Society of America management guidelines for catheter-related bloodstream infection (CR-BSI) recommend the use of central venous catheter (CVC) tip cultures (TC) to aid in diagnosing CR-BSI. However, reimbursement penalties for CR-BSI and emerging evidence supporting watchful waiting rather than removing CVCs may have impacted sampling tendencies, and as such, the uptake of this recommendation and its clinical utility remain unknown.
Methods: Inpatient encounters with ≥1 orders for CVC TC and blood culture (BC; irrespective of collection site) respectively were identified in the Cerner Health Facts electronic health record database. Five-year trends (20092014) in TC sampling per 10,000 patients were analyzed and annual percent change (APC) in TC vs. BC sampling were compared. The proportions of (a) TCs with growth of non-contaminant microbial taxa and (b) taxon concordant TCBC pairs sampled within 2 days of each other were calculated.
Results: Between 2009 and 2014, 18,080 TCs were sampled during 16,092 encounters among 14,844 patients at 128 US hospitals. Over the 5-year period, TC sampling decreased from 22/10,000 patients in 2009 to 8/10,000 patients in 2014 (APC: -14.7% [95% CI -22.3% to -6.4%], p<0.01), representing a five-fold decrease compared to BC sampling (APC: -2.5% [-5.0% to 0%], p=0.05; Fig.1). Only 3,561 (20%) TCs displayed any growth of non-contaminant taxa (Fig 2.); the most common taxa isolated from TCs were S. aureus (56.5%), Enterobacteriaceae (16%), Candida sp. (13%), and P. aeruginosa (6%). Of the 3,651 positive TCs, 1631 (46%) were not accompanied by growth in BCs; S. aureus represented 471 (29%) and Candida spp. represented 121 (7%) of isolated TC growth. Of the remaining 1930 (54%) positive TCs that were accompanied by positive BCs, only 874 (45%) displayed species concordance.
Conclusion: The practice of sampling CVC tips for culture is steadily declining at US hospitals. The majority of pathogenic species cultured from CVC tips are either unaccompanied by, or are discordant with, growth in the bloodstream. Barring the isolation of S. aureus or Candida spp. from CVC tips alone, which may represent opportunities to treat, there appears to be limited clinical utility to TC sampling for diagnosing CR-BSI.
Y. L. Lai,
E. Ricotta, None
L. Mathew, None
N. O'Grady, None
S. S. Kadri, None