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We learn the vanishing art of placing the PA (Swan-Ganz) catheter, with intensivist and friend of the podcast Matt Siuba (@msiuba).
Learn more at the Intensive Care Academy!
Takeaway points
- Good sheath placement: ensure your skin nick is in the same hole as your dilator; use patient, steady pressure, especially as the “shoulder” (where the dilator meets the sheath) reaches the skin; insert the dilator completely into the sheath so you can see if it shifts, and dilate using both hands (one near the tip, one at the back holding the sheath and wire).
- The right IJ is best (try to leave this open when placing non-positional lines like a triple lumen), left subclavian next best, third choice left IJ or right subclavian. Femoral placement is very tough without fluoroscopy; it requires two turns (into the RV, then out into the PA) and can be challenging to escape the RV. A brachial vein in the arm can occasionally be used as well.
- Floating out of the left IJ is often obstructed by bumping into the innominate-SVC junction. Instilling just 0.5-1 cc of air in the balloon is often enough to float around this turn. This occurs less from the left subclavian or brachials, but if it does occur, the same maneuver may help.
- Remember to place the contamination sleeve (Swandom) before inserting the Swan! Once you’re in, it’s too late; you’ll need to remove it and refloat. You don’t need to seal it, just get it around the catheter.
- Flush each lumen before inserting and cap each one, except the distal/PA port. Connect that to your transducer and flick it to test transduction. Check the balloon; rarely, but sometimes, they will fail. Remember to always inflate the balloon using the included volume-limited syringe, and allow it to passively deflate from its elasticity.
- If a balloon does not self-deflate, replace the catheter; the balloon is not reliable.
- Once you reach 15 cm, inflate the balloon. By 15-20 cm, you should be in the RA; measure your RA pressure (overall mean is fine for ICU purposes). If the waveform is not distinct with clear components, flush the catheter; it may be damped by clots.
- Tricuspid pathology (TR, stenosis) can make a Swan challenging, but not as often as people think. And the harder the Swan, often, the more important the data.
- If you reach 30 cm without an RV tracing (except in some very large or very end-stage PH patients), you have probably gone astray, either coiled in the RA or gone through to the IVC.
- Once in the RA, make a quarter rotation counter-clockwise (assuming you started with the tip curved medially). This will help orient the tip towards the tricuspid valve. If it’s not getting through, drop the balloon, come back to 20, readvance, repeat as needed.
- If still not going, sometimes the tip has looped back into the RA while the middle of the catheter has “elbowed” through the tricuspid into the RV. If this happened, retract the catheter, and the tip may flop through as you come back. You’ll know this as the RV waveform will appear during retraction; inflate the balloon then and drive forward fast.
- If you can’t get through a regurgitant valve, a faster/more aggressive advancement through the tricuspid valve may help. You need to launch through before it kicks you out.
- Once you get an RV tracing, run! The faster you get through, the less likely you’ll have trouble. Most people who think they’re coiled in the RV are really coiled in the RA. The main exception is when the tip is pointed into the apex, and further advancement is just squishing you into that blind cul-de-sac. The other possibility is that you coiled in the RA, then the tip entered the RV; this usually manifests as difficulty wedging or reliably entering the PA, with all your slack in the RA. The only way out of these is to drop balloon and retract (to perhaps 35–45 cm), ideally not exiting the RV, but enough to change direction and readvance.
- There should be a clear diastolic step-up as you enter the PA, with a change in diastolic shape (downsloping, not upsloping); there may or may not be a dicrotic notch.
- Once you enter the PA, slow down. Advance a centimeter at a time. Wedge will usually occur around 50–51 cm; if you reach 55 cm without wedge, something has gone wrong.
- Occasionally, the balloon size is inappropriate for the PA branch you’re in. Try deflating the balloon, then reinflate; you may find that it wedges before fully inflating (probably the catheter moved forward once you deflated it). You may also be in the wrong branch; come back to the main PA (around 45-50 cm), reinflate and readvance.
- As you wedge, the pressure drop will be massive and obvious in pre-capillary/PAH disease; it may be less notable when PA pressures are elevated due to left heart disease. (Rarely the wedge may even be higher than the PA diastolic.) However, the waveform should significantly change.
- If unsure if you’re fully wedged, drop balloon and readvance, see if it changes. When in doubt, draw a blood gas from the tip. The specimen should be arterial in oxygenation (eg SaO2 >92%). It is usually not needed to draw a simultaneous ABG peripherally to compare, and two simultaneous gasses may be easily mixed up in the lab. A “wedge gas” will have some resistance to aspirating the blood.
- Once wedged and deflated, you can leave the catheter, or withdraw a little. If quite deep, maybe withdraw; the CXR will help guide you. The catheter will usually advance itself somewhat as it softens in the body, so if left quite deep it may auto-wedge later. If left too proximal, though, especially with high PA pressures, it may flop out of the PA. It is often necessary to leave a catheter in a spot where it needs to be floated forward a couple centimeters each time you want to rewedge, which is fine.
- Once left in the body for a while (~30 minutes), it is nearly impossible to readvance into the PA (if it escapes) due to increased catheter floppiness.
- Daily CXRs are still the standard in patients with a Swan to monitor for tip migration.
- All measurements are ideally taken at end expiration, but for bedside purposes, this is often not too important; the mean monitor number may be adequate.
- The best way to avoid PA injury during wedging is to check your tip position and ensure it’s not too deep or auto-wedged before you inflate. Remember that you don’t need a full syringe to wedge everyone; once you wedge, stop inflating. Use good communication with your team during insertion, to ensure the balloon is down and the catheter position locked when you leave it.
- An overwedged waveform will show continuously rising pressures, often very high (either it’s too deep or turned into the wall). Deflate and retract. If your wedge keeps rising as you measure it, you’re probably overwedging.
- A TTE view of the RV base/RVOT view (parasternal or subcostal – latter may even be better) might be helpful for guidance in the absence of fluoroscopy, as you’ll see the tricuspid valve, RV, and pulmonic valve.
- Tricuspid valve issues are the most important relative contraindications for a Swan without guidance, particularly an artificial valve or tricuspid endocarditis.
- If you don’t need to monitor PA pressures/wedge, probably remove the Swan; you can leave the sheath if you think you might want to measure later. Retracting it to an RA position will probably not leave the possibility of refloating later, as it will be all floppy by then; just remove it and float a new one later if needed.