Overview
Central venous (CV) access is a commonly performed procedure with multiple indications in routine and emergent situations. Access to the internal jugular vein (IJV),
subclavian vein (SV),
and femoral vein (FV) has typically been described in the emergency medicine and critical care literature using the traditional landmark-based approach. Studies using landmark-based methods have reported failure rates and complication rates as high as 30%
and 18.8%, respectively. One study looked at femoral venous access during cardiopulmonary resuscitation (CPR) and found that 31% of catheters were not in the femoral vein.
The use of ultrasonography for CV access was first described in 1978;
Doppler localization was used to mark the skin overlying the IJV. Not until 1986 was the use of real-time ultrasonographic guidance for IJV cannulation reported.
In 2001, an Agency for Healthcare Research and Quality Evidence Report listed bedside ultrasonography during CV access as one of 11 practices with “strength of evidence for supporting more widespread implementation.”
In the 2008 Emergency Ultrasound Guidelines from the American College of Emergency Physicians (ACEP), ultrasonographic guidance for CV access was listed as a “core or primary emergency ultrasound application.”
In 2010, Ortega et al elaborated the methodology to employ ultrasonography for locating the IJV, underlining the safety and reliability of the technique.
The authors also detailed the intraoperative use of sterile ultrasonography.
Guidelines and practical advice for ultrasound-guided CV access have been published by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). They recommend real-time ultrasound (RTUS) for central venous access as a key safety measure, as well as for detecting complications of vascular access and treatment of arterial pseudoaneurysms.
The EFSUMB suggests the following steps for avoiding risks and complications
:
Check the equipment and its function during preparation.
Optimize the B-mode picture of the target vessel.
Optimize positioning of the patient (eg, Trendelenburg position), of the examiner, and of the US device relative to the puncture site (aim for a comfortable working environment for the interventionalist).
Choose the most appropriate head position in order to locate the target vein laterally rather than anterior to the artery.
Skills training on appropriate phantoms and in normal patient conditions prior to emergency situations.
In hypovolemic patients, give intravenous fluid before puncture.
The indication for central lines must be well considered—sometimes peripheral vascular access meets the needs of the condition.
The use of ultrasonographic guidance during CV line placement has been demonstrated to significantly decrease the failure rate, complication rate, and number of attempts required for successful access.
A recent randomized, multicenter trial using point-of-care limited ultrasonography assistance of CV cannulation reported that ultrasonographic guidance had an odds improvement of 53.5 (6.6-440) times higher than landmark-based technique for success of cannulation.
The average number of attempts and the average time to cannula placement were also significantly lower in the ultrasonographically guided group.
Ultrasonographic guidance can aid in the establishment of CV access from multiple sites.
Ultrasonographic guidance is most useful for cannulation of the IJV and FV.
Beaudoin et al found anatomic variability of the femoral vasculature where landmark-based FV cannulation is often attempted. They suggested that ultrasound guidance would improve cannulation and reduce complications during the procedure.
A recent prospective trial of ultrasound-guided femoral CV access demonstrated a trend toward a decreased rate of complications.
Access to the SV is more difficult because of its deeper location and the presence of the overlying clavicle, which can prevent the transmission of ultrasound waves. However, ultrasonographic guidance at the midpoint of the clavicle, using the long-axis approach, has been described, as has the supraclavicular approach. A 2010 observational study suggested that using ultrasonographic guidance to cannulate the IJV may result in fewer adverse events than a landmark-guided approach to the SV.
Additionally, infraclavicular axillary vein cannulation, performed a few centimeters lateral but otherwise in a similar fashion to the infraclavicular approach to the SV, can be performed using either long-axis or short-axis ultrasound. A recent ultrasound phantom-based study of this approach found that the long-axis approach was associated with greater first attempt success and fewer arterial punctures.