One-Pager

Swan-Ganz (PA Catheter): Waveforms, Wedge and Normal Values

Normal pressures and flows, insertion waveforms RA to wedge, safe wedging, end-expiration reads, complications and shock profiles

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · Checked against current sources October 2026

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PA catheter normal values

A Swan-Ganz (pulmonary artery) catheter floats through the right heart into the pulmonary artery to measure right-sided pressures, wedge pressure, cardiac output and mixed venous oxygen saturation. Normal adult values: CVP 2–6, PA 15–30/8–15, wedge (PAOP) 6–12 mm Hg, cardiac index 2.5–4.0 L/min/m², SvO₂ 60–80%.

Pressure	Normal (mm Hg)	Reflects
CVP / RA	2–6	Right-sided filling
RV	15–30 / 2–8	RV systolic = PA systolic
PA	15–30 / 8–15	Pulmonary vascular load
PA mean	About 10–22	Pulmonary hypertension if high
Wedge (PAOP, PCWP)	6–12	Left atrial and LV filling

Adult ranges from Bootsma 2021 (Edwards-based). Ranges differ a little between references.
Flow and resistance	Normal	How it is figured
Cardiac output	4–8 L/min	Thermodilution or continuous
Cardiac index	2.5–4.0 L/min/m²	CO ÷ BSA
Stroke volume	60–100 mL	CO ÷ HR × 1000
SVR	800–1200 dyn·s/cm⁵	(MAP − CVP) × 80 ÷ CO
PVR	Under 250 dyn·s/cm⁵	(mean PA − PAOP) × 80 ÷ CO
SvO₂	60–80%	Distal port sample or fiberoptic

Swan-Ganz waveforms during insertion

Insertion: RA, RV (diastolic near 0), PA (diastolic step-up, dicrotic notch), then wedge.

Add about 5 cm from the left internal jugular. Depths vary with body size and a dilated RV.
Chamber	Depth (right IJ)	Waveform
RA	About 20 cm	Low pressure, a and v waves
RV	30–35 cm	Tall systolic, diastolic near 0 and flat or rising
PA	40–45 cm	Diastolic steps up and falls; dicrotic notch after the T wave
Wedge	About 50 cm	Low, damped trace with a and v waves

The balloon goes up once the catheter is past the sheath (at least 20 cm in) and stays up while advancing; deflate it before pulling back.
No RV trace by 40–45 cm, or no PA trace by 50–55 cm: deflate, pull back to about 20 cm and try again (likely coiling).
Ectopy is common as the tip crosses the RV and settles once it reaches the PA. The catheter can cause right bundle branch block, and in a patient with left bundle branch block insertion may cause complete heart block: have pacing ready.

Wedge pressure: technique and safety

Balloon up: the PA trace drops to the wedge, which sits below PA diastolic.

Confirm a clean PA waveform first. If it is damped or already looks wedged, do not inflate.
Inflate with the catheter syringe only until the trace changes to wedge; never past the 1.5 mL the balloon holds.
Read at end-expiration on a frozen or printed trace, at the end of the a wave (just before the QRS).
Deflate as soon as the reading is taken, following your unit's technique, and confirm the PA trace returns. If it does not, the catheter may need pulling back about 2 cm.
Never flush the distal port while wedged.

Reading at end-expiration

At end-expiration, pleural pressure is closest to atmospheric, so CVP, PA and wedge are read there in every patient.
Breathing on their own: just before the pressure dips with inspiration. On the ventilator: just before it rises with the breath.
The digital number averages the whole breath and can be wrong; use the graphic trace, ideally next to the airway pressure or capnography waveform.
Level the transducer to the phlebostatic axis and zero it, the same as an arterial line.
PEEP of 10 cmH₂O or more makes CVP and wedge overread true filling; note the PEEP with every reading.

Cardiac profiles by shock type

After Bootsma 2021; SVR follows from SVR = (MAP − CVP) × 80 ÷ CO. Mixed and late shock blur these patterns.
Shock	CI	CVP	Wedge	SVR	SvO₂
Hypovolemic	↓	↓	↓	↑	↓
Cardiogenic (LV)	↓	↑ or normal	↑	↑	↓
Obstructive (PE, tamponade)	↓	↑	↑ in tamponade, normal or low in PE	↑	↓
Distributive (septic, early)	↑ or normal	↓ or normal	↓ or normal	↓	↑ or normal

PA catheter complications

When	Complication
Insertion	Arrhythmias (usually brief), RBBB or complete heart block, pneumothorax, arterial puncture, air embolism
While in place	Line infection (mostly at the sheath), thrombosis, migration
Balloon	Pulmonary infarction from a persistent wedge; PA rupture (0.1–0.8%, often fatal); balloon rupture

PA rupture is more likely with older age, female sex, pulmonary hypertension, anticoagulation, hypothermia (a stiffer catheter) or a catheter advanced too far. Remove the catheter when its numbers no longer change care.

In depth

The one-page summary above is what the PDF prints. These sections go further.

PA catheter ports and lumens

The catheter is 110 cm with marks every 10 cm. Hub colors vary by maker; read the labels. What may infuse through each lumen is set by unit policy.
Port	Sits in	Used for
Distal	Pulmonary artery	PA and wedge pressure, mixed venous (SvO₂) samples
Proximal	Right atrium	CVP, ScvO₂, thermodilution injectate
Balloon port	Balloon near the tip	Wedging with the syringe that comes with the catheter; 1.5 mL
Thermistor	Near the tip	Blood temperature and thermodilution cardiac output

Why the wedge reflects the left atrium (and when it does not)

With the balloon up, flow beyond the tip stops and a still column of blood links the catheter to the pulmonary veins and left atrium. That only works where pulmonary arterial and venous pressures exceed alveolar pressure (West zone 3). In zones 1 and 2 the catheter reads alveolar pressure. Low volume and high PEEP enlarge those zones.

Clues the tip is in the wrong zone: no clear a and v waves, or a wedge that swings widely with each breath.
Mitral regurgitation gives tall v waves on the wedge; read at the a wave, not the peak.
Overwedging (balloon against the vessel wall) gives a pressure that keeps rising, is not pulsatile or reads above PA diastolic.
Catheter whip gives sharp spikes at the start of systole on RV and PA traces; moving the catheter 1–2 cm may help.

Cardiac output and SvO₂ at the bedside

Bolus thermodilution injects cold fluid into the right atrium and the thermistor times its passage; continuous catheters warm the blood with a filament instead. Fast infusions through the sheath or proximal port, tricuspid regurgitation, intracardiac shunts and low injectate volume all disturb the reading. The continuous trend averages several minutes, so it lags behind sudden changes.

SvO₂ shows the balance between oxygen delivery and use. When it falls, check the four parts of delivery and demand: cardiac output, hemoglobin, arterial saturation and oxygen consumption (fever, shivering, pain, work of breathing).

Nursing care of a PA catheter

Watch the PA waveform continuously; a spontaneous wedge trace or an RV trace means migration.
Keep the balloon deflated and the syringe attached but empty, or follow your unit's lock-out practice.
Check the insertion depth at the sheath each shift and after moving the patient; compare with the post-insertion chest film.
Level and zero with position changes; read at end-expiration; trend numbers with the patient, not alone.
Sterile sheath and dressing care as for any central line; remove when it no longer guides therapy.

Exam pearls

Diastolic step-up from RV to PA is how you know the tip crossed the pulmonary valve.
Wedge is always lower than mean PA. High PA pressures with a normal wedge point to pre-capillary pulmonary hypertension; a high wedge points to the left heart.
Damped PA trace that looks like a wedge with the balloon down: migration, not a reading.
Hemoptysis after inflation: stop, call, bleeding side down.
Cardiogenic shock: low CI, high wedge, high SVR, low SvO₂. Septic shock: high or normal CI, low SVR, high SvO₂.

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Sources

Bootsma IT, Boerma EC, de Lange F, Scheeren TWL. The contemporary pulmonary artery catheter. Part 1: placement and waveform analysis. J Clin Monit Comput. 2022;36:5–15. Link
Bootsma IT, Boerma EC, de Lange F, Scheeren TWL. The contemporary pulmonary artery catheter. Part 2: measurements, limitations, and clinical applications. J Clin Monit Comput. 2022;36:17–31. Link
Nakamura Y, Saku K, Homma S, et al. Pulmonary artery rupture by pulmonary artery catheter in cardiac surgery: a case report and review of literature. Front Cardiovasc Med. 2025;12:1567723. Link
Saugel B, Kouz K, Meidert AS, Schulte-Uentrop L, Romagnoli S. How to measure blood pressure using an arterial catheter: a systematic 5-step approach. Crit Care. 2020;24:172. Link