UMEM Educational Pearls

Category: Critical Care

Title: Ultrasound Central Line Confirmation

Keywords: ultrasound, central Line, confirmation, venous, cavoatrial junction, agitated saline, pneumothorax (PubMed Search)

Posted: 8/30/2022 by Zach Rogers, MD
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Traditionally, internal jugular and subclavian central line placement has required chest x-ray confirmation of correct placement (venous cavoatrial junction placement) as well as demonstrating lack of complication (no pneumothorax) prior to use of that central line. However, current evidence supports similar if not superior complication identification and placement confirmation with ultrasound,(1-7) allowing for a much quicker confirmation time than traditional chest x-ray, which can be vital in critically ill patients who need immediate medication administration.

Venous placement is confirmed with prompt visualization of microbubbles in the right atrium and ventricle with a rapid flush of 5-10 ml of agitated saline via the distal central line port. Additionally, if the opacification occurs <2 seconds after injection then the catheter tip is sufficiently distal in the central venous system to not require additional verification. Additional confirmation of lung sliding in both lung apices will rule out pneumothorax.

Some authors recommend checking the contralateral internal jugular vein to ensure that the central line catheter has not traveled up the internal jugular towards the head, however this may be redundant as long as the time from agitated saline injection to right atrial visualization of microbubbles is clearly less than 2 seconds.

Bottom Line: Utilization of ultrasound for central line placement confirmation is a relatively simple, rapid, safe, and accurate means of confirmation of venous catheter placement and catheter tip location, as well as ruling out pneumothorax complications.



1) Jasper M. Smit, Mark E. Haaksma, Endry H. T. Lim, Thei S. Steenvoorden, Michiel J. Blans, Frank H. Bosch, Manfred Petjak, Ben Vermin, Hugo R. W. Touw, Armand R. J. Girbes, Leo M. A. Heunks, Pieter R. Tuinman; Ultrasound to Detect Central Venous Catheter Placement Associated Complications: A Multicenter Diagnostic Accuracy Study. Anesthesiology 2020; 132:781–794 doi:

2) Wilson SP, Assaf S, Lahham S, Subeh M, Chiem A, Anderson C, Shwe S, Nguyen R, Fox JC. Simplified point-of-care ultrasound protocol to confirm central venous catheter placement: A prospective study. World J Emerg Med. 2017;8(1):25-28. doi: 10.5847/wjem.j.1920-8642.2017.01.004. PMID: 28123616; PMCID: PMC5263031.

3) Vezzani A, Brusasco C, Palermo S, Launo C, Mergoni M, Corradi F. Ultrasound localization of central vein catheter and detection of postprocedural pneumothorax: an alternative to chest radiography. Crit Care Med. 2010 Feb;38(2):533-8. doi: 10.1097/CCM.0b013e3181c0328f. PMID: 19829102.

4) Gekle R, Dubensky L, Haddad S, Bramante R, Cirilli A, Catlin T, Patel G, D'Amore J, Slesinger TL, Raio C, Modayil V, Nelson M. Saline Flush Test: Can Bedside Sonography Replace Conventional Radiography for Confirmation of Above-the-Diaphragm Central Venous Catheter Placement? J Ultrasound Med. 2015 Jul;34(7):1295-9. doi: 10.7863/ultra.34.7.1295. PMID: 26112633.

5) Zanobetti M, Coppa A, Bulletti F, Piazza S, Nazerian P, Conti A, Innocenti F, Ponchietti S, Bigiarini S, Guzzo A, Poggioni C, Taglia BD, Mariannini Y, Pini R. Verification of correct central venous catheter placement in the emergency department: comparison between ultrasonography and chest radiography. Intern Emerg Med. 2013 Mar;8(2):173-80. doi: 10.1007/s11739-012-0885-7. Epub 2012 Dec 16. PMID: 23242559.

6) Duran-Gehring PE, Guirgis FW, McKee KC, Goggans S, Tran H, Kalynych CJ, Wears RL. The bubble study: ultrasound confirmation of central venous catheter placement. Am J Emerg Med. 2015 Mar;33(3):315-9. doi: 10.1016/j.ajem.2014.10.010. Epub 2014 Oct 13. PMID: 25550065.

7) Weekes AJ, Johnson DA, Keller SM, Efune B, Carey C, Rozario NL, Norton HJ. Central vascular catheter placement evaluation using saline flush and bedside echocardiography. Acad Emerg Med. 2014 Jan;21(1):65-72. doi: 10.1111/acem.12283. PMID: 24552526.