Catheter Related Bacteremia

Catheters are associated with a high prevalence of catheter-related bacteremia (CRB) and significant morbidity and mortality in hemodialysis (HD) patients1,2,3,4. According to the 2008 United States Renal Data System (USRDS) report, hospital admissions for bacteremia/septicemia in end stage renal disease (ESRD) patients fell in the early part of the decade, but are now at a level 31% higher than in 19935. HD vascular access, and in particular dialysis catheters, has emerged as a major risk factor for infection and bacteremia with numerous reports implicating HD vascular access in 48 to 73% of all bacteremias in the HD population6.

Catheter patients have a greater relative risk (RR) of death than patients with arteriovenous fistula (AVF) or arteriovenous graft (AVG). Analysis of data from the USRDS Dialysis Morbidity and Mortality Study Wave I indicates that non-diabetic patients dialyzing with a catheter had a significantly higher mortality risk when compared with AVF (RR 1.70, p<0.001)7. In a recent retrospective cohort study of 7497 prevalent HD patients, the proportion of patients who died was higher among those who dialyzed with a cuffed catheter (15.2%) as compared to those who dialyzed with either an AVG (9.1%) or an AVF (7.3%)8. This marked difference remains despite demographic and comorbidity adjustments. In the most fully adjusted model, data from the Dialysis Outcomes and Practice Patterns Study I and II demonstrate that the mortality risk for patients using a catheter or graft remained substantially greater (RR 1.32 and RR 1.15, respectively; p<0.001) when compared with an AVF9.

Using results from different epidemiologic studies and assuming a mortality rate of approximately 5 to 10% for each CRB event, there are approximately 2750 to 5500 HD patient deaths per year as a result of CRB1. This increased mortality risk from catheters also explains a significant portion of the lower mortality rate in Europe when compared to the US9.

Several studies have attempted to define the risk factors involved in CRB. Site of insertion, duration of use and influence of comorbidity have been reported to impact the risk of developing CRB. The subclavian location is associated with the highest risk for developing catheter associated central venous stenosis6,10 and femoral catheters are more susceptible to infections than thoracic catheters6,11. The duration of catheter use is also important because the risk of infection increases linearly with time6,12,13. A recent study by Mazonakis et al. demonstrated that patients dialyzing through a tunneled central venous catheter (compared with an AVF) have a significantly higher risk of access-related bacteremia, irrespective of comorbidity14. Among local factors, poor personal hygiene, use of occlusive transparent dressing, and accumulation of moisture around the exit site have been described as risk factors for CRB6,10,15. Nasal and skin colonization with Staphylococcus aureus, as well as bacterial colonization of HD catheters, have also been reported as risk factors for systemic infection6.

The initial management of CRB is through the use of systemic antibiotic therapy. The initial choice of antibiotics is empiric and requires knowledge of the most frequent organisms prevalent in the area and their pattern of sensitivities16. Typically, this includes initial coverage for both gram positive and negative organisms. Once the organism and its sensitivities are known, specific antimicrobial therapy should replace empiric therapy, in order to limit the emergence of highly resistant infections6,16.

The second aspect of CRB management is immediate catheter removal or catheter exchange over a guidewire. Some investigators have demonstrated that infection-free survival for patients with CRB treated with systemic antibiotics alone was inferior to that obtained with either immediate catheter removal or catheter exchange17. However, limited published reports provide a direct comparison of clinical outcomes of CRB managed by means of different treatment strategies17. While various approaches of catheter removal and exchange have been studied, each has resulted in a significantly compromised quality of life for the patient and substantial costs to the healthcare system. Catheter removal with delayed placement of a new catheter involves 3 separate procedures totaling approximately $650/patient in professional fees17. Routine exchange of infected catheters over a guidewire costs approximately $250/patient17. This economic analysis does not include facility fees or miscellaneous expenses incurred for such items as patient transportation.

Another option to decrease catheter morbidity and mortality is the development of antibiotic or antibiotic-anticoagulant catheter lock solutions to decrease the risk of catheter related sepsis and thrombosis18. Catheter biofilm is frequently associated with thrombus or fibrin in the catheter17. Pharmacological eradication of bacteria in the biofilm may permit definitive treatment of the source of CRB while salvaging the dialysis catheter; however, there are striking differences in the likelihood of success depending on the type of pathogen17. These solutions remain under investigation and are not FDA approved for use in the US.

The clinical presentation of the typical patient who develops CRB suggests that the major source for the infection is contamination of the catheter hub at the time of use in the dialysis facility19. Thus, one can presume, the best option to prevent catheter related bacteremia, other than choosing an alternative access type, is implementation and strict adherence to a CRB prophylaxis protocol. In one 24 month study, in which 932 tunneled cuffed dialysis catheters were placed in 402 patients, the incidence of CRB fell from an average of 6.97 per 1000 catheter days during the control period to an average of 1.68 during the study period through the implementation of a strict catheter management program19. More importantly, the decreased infection rate was sustained with an average incidence of 1.28 per 1000 catheter days during the last 18 months of the study period19. Guideline 3 of KDOQI’s Clinical Practice Guidelines for Vascular Access provides a sample protocol for catheter care which is based on the Centers for Disease Control standard practice for accessing catheters and cleansing catheter exit sites20.

Research continues to address not only problems related to CRB, but also catheter tip clotting, catheter fibrous sheathing and central venous stenosis. Until solutions to these issues are found, “fistula first and catheters last21” will remain the best option to provide excellent outcomes and minimize patient complications.

References

  1. Bleyer AJ. Use of antimicrobial catheter lock solutions to prevent catheter-related bacteremia. Clin J Am Soc Nephrol 2:1073-1078, 2007
  2. Oliver MJ. Chronic hemodialysis vascular access: Types and placement. Retrieved from www.uptodate.com on January 14, 2009
  3. Astor BC, Eustace JA, Powe NR, Klag MJ, Fink NE, Coresh J. Type of vascular access and survival among incident hemodialysis patients: The choices for healthy outcomes in caring for ESRD (CHOICE) study. J Am Soc Nephrol 16:1449-1455, 2005
  4. Allon M, Depner TA, Radeva M, Bailey J, Beddhu S, Butterly D, Coyne DW, Gassman JJ, Kaufman AM, Kaysen GA, Lewis JA and Schwab SJ. Impact of dialysis dose and membrane on infection-related hospitalization and death: Results of the HEMO study. J Am Soc Nephrol 14:1863-1870, 2003
  5. United States Renal Data System. Accessed on March 1, 2009
  6. Nassar GM and Ayus JC. Infectious complications of the hemodialysis access. Kidney Int 60:1–13, 2001
  7. Dhingra RK, Young EW, Hulbert-Shearon TE, Leavey SF, Port FK. Type of vascular access and mortality in US hemodialysis patients. Kidney Int 60:1443-1451, 2001
  8. Pastan S, Soucie JM, McClellan WM. Vascular access and increased risk of death among hemodialysis patients. Kidney Int 62:620-626, 2002
  9. Pisoni RL, Arrington CJ, Albert JM, Ethier J, Kimata N, Krishnan M, Rayner HC, Saito A, Sands JJ, Saran R, Gillespie B, Wolfe RA, Port FK.
    Facility hemodialysis vascular access use and mortality in countries participating in DOPPS: An instrumental variable analysis. Am J Kidney Dis 53:475-491, 2009
  10. Schwab SJ and Beathard G. The hemodialysis catheter conundrum: Hate living with them, but can’t live without them. Kidney Int 56:1-17, 1999
  11. Zaleski GX, Funaki B, Lorenz JM, Garofalo RS, Moscatel MA, Rosenblum JD, Leef JA. Experience with tunneled femoral hemodialysis catheters. Am J Roentgenol 172:493−496, 1999
  12. Kairaitis LK and Gottlieb T. Outcome and complications of temporary haemodialysis catheters. Nephrol Dial Transplant 14: 1710−1704, 1999
  13. Hung KY, Tsai TJ, Yen CJ, Yen TS. Infection associated with double lumen catheterization for temporary haemodialysis: Experience of 168 cases. Nephrol Dial Transplant 10:247−251, 1995
  14. Mazonakis E, Stirling C, Booth KL, McClenahan J, Heron N, Geddes CC. The influence of comorbidity on the risk of access-related bacteremia in chronic hemodialysis patients. Hemodialysis Int 13:6-10, 2009
  15. Kaplowitz LG, Comstock JA, Landwehr DM et al. A prospective study of infections in hemodialysis patients: Patient hygiene and other risk factors for infection. Infect Control Hosp Epidemiol 9:534−541, 1988
  16. Allon M. Current management of vascular access. Clin J Am Soc Nephrol 2:786-800, 2007
  17. Allon M. Dialysis catheter-related bacteremia: Treatment and prophylaxis. Am J Kidney Dis 44:779-791, 2004
  18. Sands JJ. Vascular Access: The past, present and future. Blood Purif 27:22-27, 2009
  19. Beathard GA. Catheter management protocol for catheter-related bacteremia prophylaxis. Sem in Dial 16:403-405, 2003
  20. Clinical Practice Guidelines and Clinical Practice Recommendations
    2006 Updates, Vascular Access. Retrieved from www.kidney.org on March 5, 2009
  21. Lacson Jr E, Lazarus JM, Himmelfarb J, Ikizler TA, Hakim RM. Balancing Fistula First with catheters last. Am J Kidney Dis 50:379-395, 2007

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Another topic of interest: Change in vascular access and mortality in maintenance hemodialysis patients. Click here to view.