Pulmonary Artery Catheter Insertion

The PAC is also known as the Swan-Ganz catheter, or “The Yellow Snake”.

The pulmonary artery catheter is a 60-110cm long balloon-tipped catheter which is inserted into a central vein and ‘floated’ into the pulmonary artery. The PAC allows measurement of:

Indications

A PAC can be useful to assess:

  • Shock states
    Particularly undifferentiated/multifactorial shock states.
  • Cardiovascular function
    • Right heart failure
    • Pulmonary hypertension
    • Peri-cardiac surgery
  • Lung function
  • Volume state
  • Multiorgan dysfunction

Contraindications

Insertion of a PAC may be contraindicated in:

  • Coagulpathy
  • Previous TV or PV replacements
  • Current LBBB
    There is a risk of rupturing the moderator band during PAC insertion, which will convert a LBBB to CHB.

Equipment

The PAC contains:

  • A wedge port
    Allows the balloon to be inflated with air. The port is paired with a special syringe that allows only the amount of air designed for the catheter to be used to inflate the balloon.
  • Distal (yellow) lumen
    Monitors the PAP when sited correctly, and allows mixed-venous gas samples to be taken.
  • Proximal (blue) lumen
    Lies in the RA when sited correctly, and monitors CVP. Cardiac output syringe should be attached here.
  • Proximal (white) lumen
    Can be used for drug infusions.
  • Temperature port
    Used to monitor core temperature and compute cardiac output.

Technique

A PAC is inserted through a sheath:

  • Sheaths are usually placed in the right IJV or left SCV as these form a natural angle for the curved PAC to enter the RA

Once the sheath is in situ, open the PAC:

  • Remove the catheter tip from its cover
  • Check integrity of the PAC balloon by inflating it
  • Feed the PAC cover over the cathether and secure it in place
  • Cap off any unused lumens
  • Pass the PAC hub to the assistant
    • Have the assistant prime each catheter lumen and zero each transducer
    • Confirm that each lumen is being transduced correctly by rotating the catheter tip
      If the CVP lumen remains at the same elevation but the catheter tip is raised, the measured PAP should fall but the CVP should remain the same.
    • Confirm that the zero on each line is correct
      Both should measure the same pressure at the same elevation.
  • Float the PAC:
    • Insert PAC to 20cm
    • Have assistant inflate balloon
      Ensure closed-loop communication whilst floating. Never withdraw the catheter with the balloon inflated.
    • Smoothly insert the catheter at a rate of ~3cm/second whilst watching the PA waveform
      For an IJ approach, the RV should be reached at ~30cm mark, PA should be reached at ~40cm mark, and a wedge (if desired) achieved at the 50cm mark.
      • If the correct waveforms are not being seen, then deflate the balloon, withdraw and reattempt
    • Once a PA waveform is seen, advance 1cm further and then deflate the balloon
      • This is to ensure that the catheter does not end up in the RVOT, where it will cause arrythmias
      • Note that the catheter will expand as it warms, and can spontaneously wedge if it is inserted too far
    • Ensure the catheter is left with the balloon deflated, the syringe empty, and the tap open to prevent accidental balloon inflation

Complications

Use of a PAC is associated with several complications:

  • Dysrhythmia
    May be atrial or ventricular, and during insertion or afterwards.
    • RBBB Up to 5%.
  • Pulmonary Artery Haemorrhage
    Up to 50% mortality. Predominantly associated with wedging.
  • Infection
  • Thrombus
  • Access complications
    • PTHx
    • Arterial puncture
    • Air embolus

Key Studies

  • PAC-MAN (2005)
    • 1041 adult Britons admitted to ICU, who were felt to need a PAC
    • Multicentre (65), unblinded, randomised trial
    • PAC vs. no PAC
      • PAC
        • Placed within 1.7 hours
        • Used for 3 (2-4) days
        • 80% had >1 change in management within 2 hours due to PAC-derived data
          • Fluid bolus
          • Change in vasoactive drug
          • Introduction of vasoactive drug
      • No PAC
        • 5% received PAC
    • No difference (68% vs. 66%) in hospital mortality
    • Complications in 10% (46) of PAC cases
      • Arterial puncture (16)
      • Arrhythmias (3, 1 arrest)
      • Pneumothorax (2)
      • Haemothorax (1)
      • Lost guidewire (2)
    • Most complications related to central venous access, rather than PAC-specific
    • No benefit (or harm) seen with use

References

  1. Liverpool Hospital. Pulmonary Artery Catheter Learning Package. 2016.
  2. Harvey S, Harrison DA, Singer M, et al. Assessment of the clinical effectiveness of pulmonary artery catheters in management of patients in intensive care (PAC-Man): a randomised controlled trial. The Lancet. 2005;366(9484):472-477. doi:10.1016/S0140-6736(05)67061-4