Ultrasound-Guided Central Venous Catheter Placement

A Structured Review and Recommendations for Clinical Practice

Bernd Saugel; Thomas W. L. Scheeren; Jean-Louis Teboul


Crit Care. 2017;21(225) 

In This Article

Ultrasound for Central Venous Catheter Placement: Basic Principles and Techniques

Ultrasound Probe

US probes best suited for CVC placement are small linear array probes with high-frequency transducers (5–15 MHz).[13] These probes usually have a scanning surface of about 20–50 mm and allow high-resolution imaging of superficial anatomic structures.[13] 2D imaging (complemented by Doppler US functions) is currently the standard technique used for US-guided central venous access.[13] All US probes have an index mark (a small physical notch on one side of the probe) that corresponds with an orientation marker on one side of the US scan sector shown on the US device screen and thus helps to obtain the correct probe orientation during US examination. Preferably, US machines should have the ability to record and save US images and loops for clinical documentation (and teaching purposes).[13]

Ultrasound Techniques for Central Venous Catheter Placement

US can be used in different ways to facilitate CVC placement. "Static" US (also called indirect US) describes a technique using US only before CVC placement to identify the anatomy of the target vein and adjacent anatomic structures (including the patency of the vein and its dimensions and depth from the skin).[14] This approach of preprocedural US evaluation is also referred to as "US-assisted" CVC placement.

In contrast, "real-time" US (also called direct US) describes a technique of needle advancement and vessel puncture under permanent US control (i.e., the needle is permanently visualized on the US screen). This is also referred to as "US guidance".[14]

Short-axis/Long-axis and Out-of-plane/In-plane Views

The US probe can be placed in a transverse position relative to the vessel, resulting in a "short-axis" view on the US screen (i.e., a cross-sectional image of the vessel). A "long-axis" view (i.e., a longitudinal image of the vessel) is obtained by placing the US probe in a parallel position relative to the course of the vessel. Short-axis and long-axis views can be used for both US assistance and guidance of CVC placement. Of note, the terms "out-of-plane" and "in-plane" describe the direction of the needle relative to the US plane, refer to US-guided needle advancement, and should not be mixed up with the terms "short-axis" and "long-axis".

For real-time US guidance, different US approaches can be used. US guidance during needle advancement can be performed using: a short-axis probe orientation and an out-of-plane view of the needle (Figure 1a); a long-axis probe orientation and an in-plane view of the needle (Figure 1b); or a so-called oblique orientation.[15] It is important to understand that the user needs to align the US plane and the needle plane containing the needle that appears on the screen as a point (short-axis/out-of-plane) or an echogenic line (long-axis/in-plane) with ring-down artifacts.[14]

Figure 1.

Ultrasound probe orientation and view of the needle. Ultrasound guidance during needle advancement can be performed using a short-axis probe orientation and an out-of-plane view of the needle (a) or a long-axis probe orientation and an in-plane view of the needle (b)

Whether or not one approach is superior to the other cannot be answered rigorously based on the existing data. The advantage of the short-axis/out-of-plane view is that it allows better visualization of the vein in relation to the artery and other anatomic structures, and thus might more sufficiently help to avoid accidental arterial puncture.[15] The short-axis/out-of-plane approach is easier to learn for physicians not familiar with US.[16] Among experienced US users, the short-axis/out-of-plane approach seems to result in a higher success rate with the first attempt for CVC placement in the IJV and SV.[17,18] However, in the short-axis view, the needle is only visualized as an echogenic point (that must not necessarily be the tip of the needle). In contrast, when using the long-axis/in-plane view, the entire needle in its complete course and the depth of the needle tip can be visualized on the US image, thus reducing the risk of penetration of the posterior vessel wall.[15,19]

Combining advantages of both techniques, the oblique axis view (a view that is halfway between the short-axis and the long-axis view with the US probe placed at approximately 45° with respect to the target vessel) can be used by experienced US users.[20,21]

Can Ultrasound Make Central Venous Catheter Placement Safer? What is the Evidence?

The use of US to reduce the number of complications related to vascular access for CVC placement has been evaluated in numerous previous studies in a variety of clinical settings. Recent Cochrane systematic reviews and meta-analyses summarize the current evidence for US guidance versus anatomic landmark techniques for CVC placement in the IJV,[22] SV,[23] and FV[23] with regard to complications of CVC placement. These meta-analyses included adult and pediatric patients treated in the intensive care unit or the operating room and compared conventional landmark techniques with techniques using static or real-time US or Doppler US. The primary outcome measure was the total rate of peri-interventional complications and adverse events.

For the IJV, 35 trials enrolling a total of 5108 patients were included in the meta-analysis.[22] The analysis demonstrated that the use of US for CVC placement in the IJV reduces the total rate of complications compared with conventional landmark techniques (US, 48 complications in 1212 patients (4.0%) vs landmark, 161/1194 (13.5%); risk ratio (95% confidence interval (CI)) 0.29 (0.17–0.52)). The overall success rate was higher when US was used (US, 2120/2172 (97.6%) vs landmark, 1900/2168 (87.6%); risk ratio (95% CI) 1.12 (1.08–1.17)).[22] In addition, the use of US resulted in a decrease in the rate of arterial puncture, hematoma formation, and number of attempts and time until successful cannulation, and in an increase in the success rate with the first attempt of puncture.[22] The benefits of US-guided or US-assisted CVC placement with regard to the total complication rate, overall success rate, and number of attempts until success were consistent across experienced and inexperienced operators. Thus, this meta-analysis clearly provides evidence that US offers gains in safety and quality during CVC placement in the IJV. The quality of the evidence, however, was very low for most outcome measures and the heterogeneity among the studies was high.

For the SV, a meta-analysis including nine studies with 2030 patients showed that the use of US resulted in a reduced rate of accidental arterial puncture (US, 2/242 (0.8%) vs landmark, 15/256 (5.9%); risk ratio (95% CI) 0.21 (0.06–0.82)) and hematoma formation (US, 3/242 (1.2%) vs landmark, 17/256 (6.6%); risk ratio (95% CI) 0.26 (0.09–0.76)).[23] However, no statistically significant difference was found between the use of US and the conventional landmark technique with regard to the total complication rate, the overall success rate, the number of attempts until success, the time to successful cannulation, and the success rate with the first attempt.[23]

For CVC placement in the FV, the use of US compared with the landmark technique increased the overall success rate (US, 134/150 (89.0%) vs landmark, 127/161 (78.9%); risk ratio (95% CI) 1.11 (1.00–1.23)) and the success rate with the first attempt (US, 91/107 (85.0%) vs landmark, 57/117 (48.7%); risk ratio (95% CI) 1.73 (1.34–2.22)).[23]

Although the use of US offers small gains in safety and quality, the authors conclude that the meta-analysis does not generally support the use of US for CVC placement in the SV and FV.[23]

On behalf of the Canadian Perioperative Anesthesia Clinical Trials Group, Lalu et al.[24] performed a systematic review and meta-analysis of US-guided SV catheterization. Based on data from 10 studies (including 2168 patients; six real-time US studies, one static US study, three Doppler US studies), the authors revealed that US reduced the overall complication rate compared with the landmark technique (odds ratio (95% CI) 0.53 (0.41–0.69)). Real-time US particularly reduced accidental arterial puncture, pneumothorax, and hematoma formation.

A CVC via the SV can be placed using either an infraclavicular (most commonly used) or a supraclavicular approach. To the best of our knowledge there are no randomized controlled trials on US-guided CVC placement via the SV comparing the supraclavicular and the infraclavicular approach. The supraclavicular approach (using different US probes) needs to be evaluated in future studies.

When discussing the evidence for US during CVC placement at the different anatomic sites based on the available studies and meta-analyses, one needs to keep in mind that—compared to the IJV—it might be more challenging to prove the advantages of US for CVC placement in the SV, because the ultrasound approach is technically more challenging, and in the FV, because severe complications other than arterial puncture occur infrequently.