Central venous catheter infection: incidence and risk factors

Introduction

We performed a retrospective analysis of central venous catheter (CVC) infection over a 12-month period in a tertiary referral teaching hospital general ICU to establish incidence of infection and clinical factors associated with CVC infection.

Methods

We reviewed data from all patients admitted to the ICU over a 12-month period. CVC tips from surviving patients were cultured. Patient demographic data, diagnoses and therapeutic interventions from our audit database were entered into a spreadsheet. Blood pressure, pulse, temperature and ventilatory data were collected from ICU charts. Haematological and biochemical variables were accessed from the hospital results server. Other potential risk factors entered included the use of steroids, chemotherapy, diabetes, renal replacement therapy, tracheostomy or arterial catheter. Data were anonymised, and nested logic arrays were used for processing and error checking. Risk factor analysis was performed by logistic regression against the presence of a positive CVC culture.

Results

Of 865 patients, 191 had no CVC. Data were inadequate in a further 109 patients. In the remaining 565 patients, 836 CVCs were inserted. The median patient age was 61 years (IQR 49 to 71 years) with 51.6% male. In total, 19.5% of CVCs were two-lumen vascular access catheters for dialysis, and 80.5% were four-lumen CVCs for monitoring and drug infusion. A total of 637 central lines were inserted via the internal jugular route, 106 femoral and 71 subclavian. The mean number of CVCs per person was 1.47, median 1, range 1 to 15. One hundred and nineteen catheters (14.2%) became infected. The median duration of CVC was 4 days (IQR 2 to 8 days). Logistic regression correctly predicted CVC infection on 85.9% of occasions, with a specificity of 97.4%, but a relatively poor sensitivity of 18.6%. Independently predictive factors included subclavian placement (OR = 0.35), standard central line (v dialysis catheter, OR = 0.75); days of catheterisation (1.31), peak temperature (1.42) and peak C-reactive protein (1.002).

Conclusion

In this study, subclavian placement was associated with a threefold reduction in risk of infection. There was a 31% per day increase in infection, and this was likely to be associated with pyrexia and a raised C-reactive protein. Interestingly, disease factors such as diabetes, chemotherapy and steroids were unimportant. These data call into question the common practice of preferentially placing CVCs in the internal jugular vein.