In the 2011 recommendations from the Centers for Disease Control and Prevention and the Infectious Diseases Society of America, avoidance of the femoral vein for central venous access is listed as a class 1A recommendation for the prevention of catheter-related bloodstream infections (CRBIs). In the August issue of Critical Care Medicine, Marik and colleagues conduct a systematic review and meta-analysis to compare the risk of CRBI for catheters placed in the femoral versus the subclavian and internal jugular (IJ) veins. 
The authors searched MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, and Google to locate cohort studies and randomized controlled trials (RCTs) that reported or compared the rate of CRBI at the femoral versus other sites of central venous cannulation. A systematic review and meta-analysis was performed in accordance with the Quality of Reporting of Meta-analyses guidelines. 

Ten studies, consisting of eight cohort studies and two RCTs, were included with data from 17,376 catheters. There was no significant difference in the risk of CRBI between the femoral compared to the subclavian site (risk ratio [RR] 1.75; 95% confidence interval [CI], 0.80-3.8; P = 0.16).  The IJ site was associated with an overall lower risk of CRBI compared to the femoral site (RR 1.9; 95% CI, 1.21-2.97; P=0.005); however, when two cohort studies were excluded in a sensitivity analysis, there was no significant difference (RR 1.35; 95% CI, 0.84-2.19; P=0.20).  Meta-regression showed a significant interaction between the risk of infection and the year of publication, with earlier studies favoring the IJ site. The authors concluded that recent evidence demonstrates no difference in the risk of CRBI between the femoral, subclavian and IJ sites.

With the advent of maximum barrier precautions, the use of ultrasound and vigilant management of catheter exit sites, the CRBI rate in many intensive care units has decreased in recent years, perhaps independently of catheter insertion site. Only two RCTs were included in this review, but both supported the author’s conclusion that there is no greater risk of a CRBI when the femoral site is used. It is unclear how the cohort studies were assessed for risk of bias, but several sensitivity analyses were conducted when significant heterogeneity was found. Based on the results of this systematic review and meta-analysis, recent studies do not appear to support the notion that the femoral site is associated with significantly more CRBIs.

Concise Critical Appraisal is a regular feature authored by SCCM member Samuel M. Galvagno Jr., DO, PhD. Each installment highlights journal articles most relevant to the critical care practitioner.