#FridayImageChallenge (with answer)

Happy Halloween! Click on the “continue reading” link below to see the answer to this weeks spooky CXR.

It’s Halloween night in the CUH MICU, you admit a lady dressed as an eclipse for  septic shock and unknown pulmonary process. You put in a left IJ triple lumen for pressor support. Happy with your smooth procedure you head back to the rounding room thinking about her clever costume and the cup of gummy bears waiting for you. The nurse calls asking you to clear the line as her MAPs are now in the 50s, her CXR is below.

anom-pulm-v


Answer: assess for venous vs arterial placement, line is positioned in a partial anomalous pulmonary vein connection (PAPVC)

A few came close with left SVC as an answer, key point of differentiation is in left SVC catheter will run towards the coronary sinus vs our CXR where the line turns laterally towards the lung parenchyma at the level of the hilum.

Key points

when you are concerned about placement of the line because of intra-procedural complication or an abnormal post-procedure CXR you must assess venous vs aterial positioning. DON’T pull the line before you know this. 

Ways to assess venous vs arterial placement

  1. assess with US
  2. send blood gas (one from line, one from a-line or straight stick for comparison)
  3. hook up to a-line kit to observe tracing (or more simply hook up to short piece of sterile IV tubing and use as manometer, think of LP opening pressure). If venous it will be at same height as CVP with slight respiratory variation. If arterial will be pulsatile and will be much higher than CVP (often comes out top of manometer…depending on patient’s MAP).

If you confirm arterial placement DO NOT pull the line, call vascular surgery for operative removal

Pro-tip, if you are concerned about positioning intra-procedurally, the central line kit contains a short angiocath which can be threaded over the wire without dilation, and the wire holder actually is a sheath manometer which can be uncurled and used as below

mano1mano2

For our patient

US confirmed proximal placement in LIJ, bedside manometer showed a height c/w JVP and small respiratory variation. Interestingly the blood gas was not helpful (and frightening!) as PAPVC returns oxygenated blood to the right atrium. Reviewing the patients old CT scan revealed a left partial anomalous pulmonary venous connection.

Similar to the image below, the line coursed through the LIJ entering the anomalous pulmonary vein and towards the lung parenchyma rather than entering the brachiocephalic vein towards the SVC.

svcImage: IJ entering left anomalous pulm vein

High on the differential of ‘malpositioned’ central lines that remain venous includes persistent left sided SVC. This variant occurs in .4-2% of the population, the persistent SVC receives blood from the L subclavian and IJ, draining directly into the coronary sinus.

svc2

Image: Left IJ central line in persistent left SVC.

Notably a line within a persistent L SVC will course along the heart border and terminate in the coronary sinus (depending on how far it was advanced), if in PAPVC the line will head to the lung parenchyma at the level of the hilum (as in our case).

Sources and further reading:

Short review on possible central line malpositioning
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4799551/

case report of central line placement in a PAPVC
http://icvts.oxfordjournals.org/content/11/6/846.full.pdf

Pearls and Pitfalls in Cardiovascular Imaging. Zimmerman et al. 2015.

Persistent SVC. Southwest journal Pulmonary/ crit care. 2013. 
http://www.swjpcc.com/imaging/2013/4/10/medical-image-of-the-week-duplicate-superior-vena-cava.html

 

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