Where to place a central venous catheter is a decision driven mainly by individual preference. The limited evidence available has not established any site as superior; the subclavian position has been reported as being less infection-prone, but more likely to cause pneumothorax, compared to other sites.
Now, the 3SITES study was a prospective, randomized trial of 3471 central venous catheter insertions supervised by experienced operators that provides more information about insertion location. The primary outcome of the trial was a composite endpoint of either a catheter related bloodstream infection (CLABSI), or a deep venous thrombosis at the site. Importantly, ultrasound guidance was only used two-thirds of the time in internal jugular line placements (vs. 16% in subclavian line placements). Also, chlorhexidine antiseptic was used less than half the time (in favor of povidone-iodine) in these central line insertions.
The results of the study subclavian position was by far the superior site for CLABSI or DVTs, with less than half the composite rate (1.5 events per 1,000 catheter days) compared to the internal jugular (3.6) or femoral (4.6) locations.
The subclavian vein insertion site did have a significantly higher rate of pneumothorax compared to the IJ location. The incidence of pneumothorax requiring chest tube placement was 1.5% for subclavian lines vs. 0.5% for internal jugular vein cannulations. This equates to a number needed to harm of 100 patients with subclavian CVL placements to cause an additional pneumothorax.
The femoral location had the highest outcome of adverse events. Despite the widespread taboo against the femoral position for central line placement, rates of CLABSI were no higher for femoral central venous catheters (1.2%) than for the internal jugular position (1.4%). However, femoral catheters produced symptomatic DVT 1.4% of the time, vs. 0.9% for the IJ position and 0.5% subclavians.
These data are intriguing but the standard of care in most U.S. hospitals is to use ultrasound-guidance for both internal jugular and femoral central venous cannulations. The rate of pneumothorax with an ultrasound-guided IJ placement should be essentially 0%. In addition, chlorhexidine antisepsis has been shown to be superior to povidone-iodine antisepsis. Finally, it is unclear if all lines were placed using a wide sterile barrier and a careful line maintenance protocol to minimize the risk of CLABSI.
These data suggest that there is probably no ideal position for central venous catheterization. Pneumothorax is more feared, dramatic, and blame-laden than CLABSI or DVT, leading most intensivists and midlevels to prefer internal jugular placement. Deaths attributable directly to central line placement (by either pneumothorax or CLABSI) are too infrequent to consider one catheter position definitively safer. Although all of these central line placement were supervised by an experienced operator, the operator him/herself could have been an inexperienced trainee so the complication rate could have been affected by this as well.
All central venous catheters should be considered for removal every day, and removed as soon as feasible. Most patients who are not receiving vasopressor infusions do not require a central venous catheter. These factors were not necessarily controlled in the trial.