Month: November 2020

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A Practical Guide to Placing Ultrasound-Guided Peripheral IVs

ultrasound iv

Background

 

Peripheral IV placement is one of the most common procedures performed in hospitals, with hundreds of millions performed each year. For the most part, IVs are successfully placed in the traditional way - using landmarks and visualization/palpation of the vessels. But as we all know, there are several patient factors that can make peripheral IV placement more difficult, including obesity, edema, a history of IV drug use, sickle cell disease, lupus, diabetes, etc.

Ultrasound-guided IV placement is increasingly used in the emergency room, medicine floors and ICUs in patients with difficult IV access, but  the research is clear that there is a higher premature failure rate with ultrasound-guided IVs (1). 

This practical guideline details several considerations that may help reduce the premature failure rate of ultrasound-guided IV catheter placement.  

 

Ultrasound-Guided Peripheral Venous Cannulation in Critically Ill Patients: a Practical Guideline

Clinical Question

What are key concepts to help reduce ultrasound guided peripheral IV catheter complications, prolong life of catheters, and increase rate of successful placement?

Methods & Study Design

• Design 

Review paper

Results

There are six key concepts to help minimize complications and increase duration of ultrasound-guided peripheral IV catheter placement.

Strength & Limitations

Potential limits to these guidelines include ultrasound experience level of a person placing IV catheters, whether the necessary equipment is routinely available at lower resource centers, and the setting in which IV cannulation takes place (e.g. trauma or non-trauma). The access and cost of ultra-long peripheral and midline catheters may limit use given potential for high utilization. 

Authors Conclusion

“Practitioners should consider several issues when inserting intravenous peripheral catheters under ultrasound guidance, aiming to improve success rate, avoid complications and lengthen the survival of the catheter. Based on available data and everyday practice, all indicate that catheters longer than standard size are needed for US-guided peripheral venous cannulation, with the purpose of minimizing premature catheter failure. This is a call for attention to catheter manufacturers, since a more affordable solution at hand is expected from them shortly.”

Our Conclusion

For placement of ultrasound-guided peripheral IVs consider these rules:

    • Always use a long IV catheter, preferably 6 cm or longer
    • Choose veins that are:
      • At least 4 mm in diameter
      • At most 1.5 cm deep
      • As distal as possible, preferably distal to the antecubital fossa
    • At last 2.75 cm of the catheter should be in the vein
    • Check IV placement by flushing saline and use the ultrasound to watch a proximal vessel for turbulent flow

The Bottom Line 

When identifying an appropriate vein for ultrasound guided IV access, choose a superficial, patent, large, distal vein to minimize distance needed for the catheter to travel. Ensure adequate catheter length and confirm catheter position after placement to decrease failure rate.

Authors

This post was written by Tori Speck, MS4 at UCSD School of Medicine, Charles Murchison, MD and Amir Aminlari, MD. 

References

Blanco, Pablo. “Ultrasound-Guided Peripheral Venous Cannulation in Critically Ill Patients: a Practical Guideline.” The Ultrasound Journal, Springer Milan, 17 Oct. 2019, www.ncbi.nlm.nih.gov/pubmed/31624927. 

1. Bahl, Amit, et al. “Ultralong Versus Standard Long Peripheral Intravenous Catheters: A Randomized Controlled Trial of Ultrasonographically Guided Catheter Survival.” Annals of Emergency Medicine, Mosby, 16 Jan. 2020, www.sciencedirect.com/science/article/pii/S0196064419313836. 

2. Gottlieb, Michael et al. “Comparison of Short- vs Long-axis Technique for Ultrasound-guided Peripheral Line Placement: A Systematic Review and Meta-analysis.” Cureus vol. 10,5 e2718. 31 May. 2018, doi:10.7759/cureus.2718

3. Presley, Brad. “Ultrasound Guided Intravenous Access.” StatPearls [Internet]., U.S. National Library of Medicine, 31 July 2020, www.ncbi.nlm.nih.gov/books/NBK525988/.

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Will Ultrasound Help Your Success with Arterial Lines?

radial a line

Background

 

Traditionally, we are taught to place radial artery catheters - A lines - using anatomy and pulse palpation. First-time success rate varies in the literature from as low as 15% to about 70%, with complications including hemorrhage or hematoma. Patients with particularly challenging insertions include small children, as well as adults with hypotension, obesity, or peripheral edema.

Improved procedural success rates, safety and cost effectiveness using ultrasound guidance has been demonstrated extensively in central venous catheterization, however, this has not yet been established for arterial catheterization, as literature for US guided radial artery catheterization has been both limited and presents conflicting results.

Efficacy of ultrasound-guided radial artery catheterization: a systematic review and meta-analysis of randomized controlled trials. 

Clinical Question

Is US guidance of radial artery catheterizations effective compared to standard methods of palpation/Doppler in either adult or pediatric patients?

Methods & Study Design

• Design 

Systematic review and meta-analysis 

• Population 

Adult or pediatric patients requiring radial artery catheterization, inclusion criteria varied by study. 

• Intervention 

Ultrasound-guided radial artery catheterization compared to doppler-assisted or landmark technique.

• Outcomes  

First attempt success rate and complications from attempts at radial artery catheterization.

Results

7 RCTs were used to calculate a pooled estimate of first-attempt success

    • Rate of first-attempt success in US group: 48.5%
    • Rate of first-attempt success in control group: 30.7%
    • US-guided radial arterial catheterization was associated with increased first-attempt success (RR 1.55, 95% CI, 1.02 to 2.35, P = 0.04)
    • US-guided radial arterial catheterization significantly reduced mean attempts to success (WMD −1.13, 95% CI −1.58 to −0.69, P <0.001), mean time to success (WMD −72.97 seconds, 95% CI −134.41 to −11.52, P = 0.02), and incidence of hematoma (RR 0.17, 95% CI 0.07 to 0.41, P <0.001)

Subgroup Analyses

    • No difference in primary outcome between elective insertion (five trials, RR 1.91, 95% CI, 1.45 to 2.53) and emergency insertion (two trials, RR 1.05, 95% CI, 0.38 to 2.83) 
    • US-guided radial arterial catheterization was associated with significantly increased first-attempt success in small children/infants (RR 1.94, 95% CI, 1.31 to 2.88, P = 0.001)

Strength & Limitations

Strengths:

Well-performed systematic review and meta-analysis with a clear primary outcome and relevant secondary outcomes.

Limitations:

    • There were major differences in ultrasound experience of operators, ranging from those without any experience and only an observational training period to expert operators.
    • Overall, the studies had small sample sizes and only a small number of studies met inclusion criteria for the review.
    • Not enough samples to conduct additional subgroup analyses of patients who might be characterized as difficult-to-insert, including hypotension, obesity, edematous, and pulseless.
    • Lack of inclusion of other potential factors including patient pain or patient/operator satisfaction.
    • Lack of comment and description on specific US-guidance techniques

 

Authors Conclusion

"US guidance is an effective and safe technique for radial artery catheterization, even in small children and infants. However, results should be interpreted cautiously due to the heterogeneity among studies."

Our Conclusion

Though data from RCTs is limited, with proper operator training US-guidance can be an effective method of improving radial artery catheterization accuracy, especially in small children/infants with smaller and more difficult-to-palpate anatomy.

Conflicting results in previously conducted RCTs may be attributed to differences in operator training or lack of a proper observational training period and thus careful consideration of the operator should be conducted in future RCTs. A physician who has performed dozens of A-lines using the palpation technique, who is unfamiliar with bedside ultrasonography, is unlikely to benefit significantly from adding this modality to their procedure, while residents who are trained with ultrasounds in their hands will likely benefit more. 

Future RCTs should focus on patient populations that have been characterized as difficult-to-insert including hypotension which is in particular significant to emergency medicine, as well as edematous or obese patients.

The Bottom Line 

Ultrasound-guided placement of radial artery catheters is effective compared to standard palpation techniques, and should be taught to current Emergency Medicine residents. Further studies are needed to elucidate the effect of US on difficult-to-cath patients, as the effect is hypothesized to be magnified in patients who are hypotensive or edematous.

Authors

This post was written by Jessica Wen, MS4 at UCSD School of Medicine, Charles Murchison, MD and Amir Aminlari, MD. 

References

Gu W, Tie H, Zeng X. Efficacy of ultrasound-guided radial artery catheterization: a systematic review and meta-analysis of randomized controlled trials. Critical Care. 2014; 18(3): R93 doi:10.1186/cc13862

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