Swan Gantz Catherter
and the Meaning of its
Readings
Justin Chandler
Surgical Critical Care Fellow

The Pulmonary Artery Catheter and
Its History

The Pulmonary Artery Catheter and
Its History
 Cardiac catheterization dates back to Claude
Bernard
 used it on animal models
 Clinical application begins with Werner
Forssmann in the 1930s
 inserted a catheter into his own forearm, guided it
fluoroscopically into his right atrium, and took an X-
ray picture of it

The Pulmonary Artery Catheter and
Its History
 The pulmonary artery catheter
introducted in 1972
 Frequently referred to as a Swan-
Ganz catheter, in honor of its
inventors Jeremy Swan and
William Ganz, from Cedars-Sinai
Medical Center
 The “sail” or balloon tip was a
modification of the simple portex
tubing method developed by
Ronald Bradley
 Ganz added the thermistor

Indications
 Diagnostic indications:
 Shock states
 Differentiation of high vs low
pressure pulmonary edema
 Primary pulmonary
hypertension
 Valvular disease
 Intracardiac shunts
 Cardiac tamponade
 Pulmonary embolus
 Monitoring and management
of complicated acute
myocardial infarction
 Assessing hemodynamic
response to therapies
 Management of multiorgan
failure
 Severe burns
 Hemodynamic instability after
cardiac surgery
 Assessment of response to
treatment in patients with
primary pulmonary
hypertension
 Therapeutic indications:
 Aspiration of air emboli

Placement
 Place an introducer
 R IJ > L SC > R SC > L IJ
 Femoral is an option
 Hand ports off to RN, inspect and have RN flush
catheter
 if CCO, leave tip in the holder to calibrate
 Place swandom on catheter
 Insert about 15cm and the inflate balloon
 Slowly and steadily advance catheter watching the
waveforms
 NB When wedged, not the volume required

Placement

Typical Cather Insertion Landmarks
Anatomic Structure Distance
Right atrium 20 to 25 cm
Right ventricle 30 to 35 cm
Pulmonary artery 40 to 45 cm
Pulmonary capillary wedge 45 to 55 cm

Conformation

Zones of West

Insertion tips
 Turn CVP off!
 Once in the RV  advance to PA quickly to
avoid coiling, ventricular arrhythmia.
 Difficulty getting into PA
 Valsava
 Calciun iv
 HOB up

Basics to Remember
 Hemodynamic variables should not be
interpreted in isolation
 Integration of variables with the clinical situation
increases the accuracy of assessment
 Trends are generally more useful than isolated
variables at a single point in time

What does a PAC tell us?
 Direct measurements
 CVP
 PA (systolic and
diasotolic)
 PAOP (wedge)
 SvO2 (mixed)
 Calculated data
 Stroke volume (SV/SVI)
 Cardiac output (CO/CI)
 Vascular resistance (SVR,PVR)
 Oxygen delivery
 Extended calculations
 CCO
 Stroke work
 End diastolic volume, EF

Variables of Hemodynamics
Variable Assessment
Stroke volume/index Pump performance
Cardiac output/index Blood flow
CVP/RAP R heart filling pressure
PAOP/Wedge L heart filling pressure
SvO2 Tissue oxygenation

Normal Values
Variable Value
Stroke volume (SVI) 50-100 mL/beat (25-45)
Cardiac output (CI) 4-8 L/min(2.5-4.0)
CVP/RAP 2-6 mmHg
PAOP/Wedge 8-12 mmHg
SvO2 0.60 – 0.75

Additional Values
Variable Value
SVR (SVRI) 900-1300 (1900-2400)dynes
sec/cm5
PVR 40-150 dynes sec/cm5
MAP 70-110 mmHg

Equations to Remember
 CO = SV x HR or SV = CO / HR
 SV = EDV – ESV or EDV x EF
 C = ΔV/ΔP
 SVR = (MAP – CVP) x 80 / CO
 LSW = (MAP – LVEDP) x SV x 0.0136
To convert to index: divide by BSA
BSA = [Ht + Wt-60]/100 (in cm & kg)

Cardiac Output
 Major determinate of oxygenation delivery to
tissue
 Abnormalities are viewed in the context of
SV/SI and SvO2
 Remember: a normal CO/CI may be associated
with a low SV/SI in the presence of tachycardia

Factors Affecting CO
 Physiologic
 Dysrhythmias
 Septal defects
 Tricuspid regurg
 Respirations
 Technical
 Bolusing technique
 Themistor malfunction
 Factors not affecting
CO:
 Iced vs room temp
 NSS vs D5
 Pt elevation (<45o)
 5 cc vs 10 cc

CO Measurement
 Typically done with thermodilution method
 A cold solution of fixed volume is injected and a
thermsitor measures the change in temperature
 The area under the curve is integrated to calculate
the CO
 The waveform should be examined to determine if
the technique was good
 If the accuracy is in doubt, the Fick method may
be used

CO Waveforms

Fick Method
 CO = VO2 / [CaO2 – CvO2] * 10
 SaO2 and SvO2 often substituted
 CO = VO2 / [SaO2 – SvO2] * Hgb * 1.34* 10
 VO2 is not usually measured
 Can use 3.5 mL/kg or 125 mL/m2
 If metabolic rate is abnormal, the calculation may be
incorrect

Stroke volume
 If low
 Inadequate volume (hypovolemia)
 Impaired ventricular contraction
(ischemia/infarction)
 Increased SVR (drugs)
 Valve dysfunction (MVR)
 If high
 Low vascular resistance (sepsis, drugs)

CVP
 Reflects R heart diastolic function and volume
status
 60-70% of blood volume is in venous system
 Abnormalities are viewed in the context of
SV/SI
 If high (>6) implies right ventricular dysfunction,
especially if SV is low
 If low (< 2) implies hypovolemia especially if SV is
low

CVP
 High
 Hypervolemia
 RV failure
 Tricupid stenois/regurg
 Cardiac tamponade
 Cardiac pericarditis
 Pulm HTN
 Chronic LV failure
 Low
 Hypovolemia
 Venodiliation

PAOP
 Reflects left ventricular end
diastolic volume
 Assumes a static column
of blood from ventricle to
catheter during diastole and
consistent compliance
 Abnormalities are viewed in
the context of SV/SI
 If high (>18) implies left
ventricular dysfunction,
especially if SV is low
 If low (< 8) implies
hypovolemia especially if SV is
low

PAOP
 High
 Hypervolemia
 LV failure
 Cardiac tamponade
 Cardiac pericarditis
 Mitral stenosis/regurg
 Atrial myxoma
 Pulmonary diseases
 Low
 Hypovolemia
 Aortic regurg
 Elevated LVEDP
(>25mmHg) with
decreased compliance

PAOP
 Conditions in Which PAD Does Not Equal
PAOP (1 – 4 mm Hg)
 Increased PVR
 Pulmonary hypertension
 Cor pulmonale
 Pulmonary embolus
 Eisenmenger’s syndrome

Filling Pressures
 If low, but other parameters are normal may
only require observation
 If CO/CI are also low, treatment may be warranted
 If SvO2 and/or SV/SI are also low treatment is
needed
 Pulmonary congestion also warrants treatment

SvO2
 Reflects the balance between oxygen delivery
and utilization
 The larger the abnormality, the greater the risk
of hypoxemia
 Remember: a normal or high SvO2 may
represent a threat to tissue oxygenation

SvO2
 A low SvO2 usually warrants investigation
 Evaluate:
 SV/SI
 May require treatment, even if CVP/PAOP are normal
 Hb/Hct
 SaO2 (>90%)
 Reasons for oxygen consumption to be elevated
 Abnormally high SvO2 may be indicative of a
septal defect

Continuous Cardiac Output
 Newer generation catheter
 Uses continuous cardiac output measurements
without need for bolusing
 Allows for right heart “volumetric” data
 RVEDV, RVEF, and RVSV
 RVSW and RVSWI
 Also provides continuous SvO2 measurements

Additional Reference Numbers
(R)EDV (SV/EF) 100-160 ml
(R)EDVI 60-100 ml/m2
ESV (EDV-SV) 50-100 ml
ESVI 30-60 ml/m2 (*)
LVSWI 45-75 gm-m/m2/beat
RVSWI 5-10 gm-m/m2/beat

Waveform Analysis
 Changes in pressure waveforms are due to:
 Blood entering or leaving a chamber
 Changes in wall tension (contraction/relaxation)
 Are always preceded by electrical stimulation
 Waveforms are also affected by changes in
intrathoracic pressure (present as rhythmic
changes)

The Waves

The Waves - CVP/RA
 The a wave occurs with atrial contraction
 It occurs after the P wave in the PR-interval
 The c wave occurs with closure of the tricuspid valve
 It occurs at the end of the QRS (RST junction)
 The v wave occurs with filling of the atria with the tricupid valve closed
 Occurs after the T wave
 The mean of the a wave is the CVP

The Waves - RV
 Has a sharp, rapid upstroke and a rapid down stroke
 Falls to near zero

The Waves - PA
 Characteristics
 Rapid up stroke and
down stroke
 Dicrotic notch (closure of
pulmonic valve)
 Smooth runoff
 End systolic wave occurs
after the T wave
 End diastolic occurs
after the QRS

The Waves - PAOP
 Characteristics
 May contain 3 waves
 a atrial contraction
 Found after the QRS
 c closure of mitral valve
(often absent)
 v filling of atria with mitral
valve closed
 Found well after the T
 Mean PAOP
 Average the a wave

a Wave Differential
 Large
 Tricuspid or mitral regurg
 Decreased ventricular
compliance
 Loss of A-V synchrony
 Junctional rhythms
 Tachycardia (>130)
 Absent
 A-fib
 Junctional rhythms
 Paced rhythms
 Ventricular rhythms

v Wave Differential
 Large
 Tricuspid or mitral regurg
 Noncompliant atrium
 Ventricular
ischemia/failure
 Absent
 V-fib
 Asystole
 PEA

Diagnosis by Waveform
 Mitral insuffiency
 Prominent v wave
 Proximity of v and a
waves
 Returns to a more normal
configuration after
afterload reduction

Diagnosis by Waveform
 VSD
 Presents with increased
SvO2
 Note the delay in the v
wave
 May respond to afterload
reducers

Diagnosis by Waveform
 Cardiac Tamponade
 As with constrictive
pericarditis, there is
equalization of diastolic
pressures
 Note the loss of the y
descent in cardiac
tamponade

Diagnosis by Waveform
 Constrictive pericarditis
 Note the equalization of
the diastolic pressures
 Unlike tamponade, there
is an exaggeration of the y
descent due to a more
rigid pericardium

Points to remember
 Intrathoracic pressure during inhalation and
exhalation cause pressures in the heart to vary
 Therefore all pressures should be measured at end-
expiration when intrathoracic pressure is closest to
zero

Points to Remember
 Limitations in hemodynamic monitoring
 Ventricular filling pressures do not always accurately reflect ventricular
filling volume
 The pressure-volume relationship depends upon ventricular compliance
 If compliance changes, the pressure-volume relationship changes
 The PAOP is normally slightly (1-5 mm Hg) less than the PAD pressure
 This relationship stills exists with pulm hypertension due to LV failure
 However, with an ↑ PVR or tachycardia (>125 bpm) this relationship may
breakdown and the PAD becomes significantly higher than the PAOP
 The PAOP may not equal LVEDP when
 there is high alveolar pressures
 when the catheter tip is above the left atrium
 severe hypovolemia
 tachycardia (130 bpm)
 in mitral stenosis.

Points to remember
 Calculated variables (e.g. SVR, PVR & SV/SI)
are limited in value due to assumptions made in
their calculations

Complications
 Air embolism
 S&S: hypoxemia, cyanosis, hypotension/syncope, “machinery
murmur”, elevated CVP, arrest
 Tx: place in left lateral trendelenburg, FiO2 of 100%, attempt
aspiration of air, CPR
 Arrhythmias
 Prevention: keep balloon inflated, minimize insertion time
 Tx: removal of catheter, ACLS
 Heart blocks
 Typically RBBB occurs, so avoid PACs in LBBB
 Tx: transvenous/transcutaneous pacers, PACs with pacer

Complications
 Knotting
 Prevention: minimize insertion time, avoid pushing agaist
resistance, verify RA to RV transition
 Tx: check CXR, attempt to unknot
 Pulmonary artery rupture
 S&S: hypoxemia, hemoptysis, circ collapse
 Prevention: withdraw PAC if spontaneously wedges or
wedges with < 1.25 cc of air
 Tx: stop anti-coagulation, affected side down, selective
bronchial intubation, PEEP, surgical repair (CPB or ECMO)

Complications
 Pulmonary infarction
 Prevention
 Avoid distal positioning of catheter
 Check CXR
 Monitor PA EDP instead of PAOP
 Pull back if spontaneous wedge occurs
 Limit air in cuff (pull back if < 1.25 cc)
 Tx
 CXR
 Check cath position, deflate and withdraw
 Observe

Complications
 Infection
 Prevention!
 Aseptic technique
 Dead-end caps
 Sterile sleeve (swandom)
 Minimize entry into system
 Avoid glucose containing fluid
 Avoid over changing of tubing, etc (72-96 hr)
 Remove catheter ASAP
 Thrombus
 Prevention – continuous flush +/- heparin
 Tx – lytic agent ; remove catheter

Emerging Technology
 Devices exist that use arterial pressure waveform to
continuously measure cardiac output
 Variations of the arterial pressure are proportional to stroke
volume
 Several studies demonstrate that SVV has a high sensitivity
and specificity in determining if a patient will respond
(increasing SV) when given volume (“preload
responsiveness”)
 Limitations
 Only used in mechanically ventilated pts
 Wildly inaccurate when arrhythmias are present

Emerging Technology
 Impedance Cardiography (ICG)
 Converts changes in thoracic
impedance to changes in volume
over time
 ICG offers noninvasive, continuous,
beat-by-beat measurements of:
 Stroke Volume/Index (SV/SVI)
 Cardiac Output/Index (CO/CI)
 Systemic Vascular Resistance/Index
(SVR/SVRI)
 Velocity Index (VI)
 Thoracic Fluid Content (TFC)
 Systolic Time Ratio (STR)
 Left Ventricular Ejection Time (LVET)
 Pre-Ejection Period (PEP)
 Left Cardiac Work/Index
(LCW/LCWI)
 Heart Rate

In a Nutshell
 Right heart failure
 Low CI, high PVR
 Left heart failure
 High PAOP, low CI, high
SVR
 Tamponade
 High PAOP, low CI,
CVP ≈ POAP
 Hypotension
 Hypovolemia
 Low CVP, PAOP, CI
 High SVR
 Cardiogenic
 High CVP,PAOP, SVR
 Low CI
 Sepsis
 Low CVP, PAOP, SVR
 High CI

References
 Pulmonary Artery Catheter Education Project
 http://www.pacep.org
 Chatterjee, The Swan-Ganz Catheters: Past, Present, and Future: A Viewpoint.
Circulation 2009;119;147-152
 Edwards Scientific
 http://ht.edwards.com/presentationvideos/powerpoint/strokevolumevariation/s
trokevolumevariation.pdf

Question #1
 Which one of the following statements is
most correct?
A) A CVP <2 mmHg usually reflects
hypovolemia if the SVI is>45 mL/beat/M2
B) A CVP >6 mmHg usually reflects RV failure
if the SVI is <25 mL/beat/M2
C) A PAOP >18 mmHg usually reflects LV
failure if the SVI is >45 mL/beat/M2
D) A PAOP <8 mmHg usually reflects
hypovolemia if the SVI is >25 mL/beat/M2

Answer #1
 Which one of the following statements is
most correct?
A) A CVP <2 mmHg usually reflects
hypovolemia if the SVI is>45 mL/beat/M2
B) A CVP >6 mmHg usually reflects RV failure
if the SVI is <25 mL/beat/M2
C) A PAOP >18 mmHg usually reflects LV
failure if the SVI is >45 mL/beat/M2
D) A PAOP <8 mmHg usually reflects
hypovolemia if the SVI is >25 mL/beat/M2

Question #2
 Identify the condition most consistent with
the following hemodynamic profile:
SvO2 ... 0.50 ... PAOP ... 21 mmHg
CI ... 2.2 L/min/M2 ...CVP/RA ... 4 mmHg
SVI ... 23 ml/beat M2 ... HR ... 98
A) Hypovolemia
B) Hypervolemia
C) LV dysfunction/failure
D) Bilateral ventricular failure

Answer #2
 Identify the condition most consistent with
the following hemodynamic profile:
SvO2 ... 0.50 ... PAOP ... 21 mmHg
CI ... 2.2 L/min/M2 ...CVP/RA ... 4 mmHg
SVI ... 23 ml/beat M2 ... HR ... 98
A) Hypovolemia
B) Hypervolemia
C) LV dysfunction/failure
D) Bilateral ventricular failure

Question #3
 Identify the condition most consistent with
the following hemodynamic profile: SvO2 ...
0.47 ... PAOP ... 4 mm Hg
CI ... 2.0 L/min/M2 ... CVP/RA ... 2 mm
Hg
SVI ... 19 ml/beat/M2 ... HR ... 111
A) Hypovolemia
B) Hypervolemia
C) LV dysfunction/failure
D) Bilateral ventricular failure

Answer #3
 Identify the condition most consistent with
the following hemodynamic profile: SvO2 ...
0.47 ... PAOP ... 4 mm Hg
CI ... 2.0 L/min/M2 ... CVP/RA ... 2 mm
Hg
SVI ... 19 ml/beat/M2 ... HR ... 111
A) Hypovolemia
B) Hypervolemia
C) LV dysfunction/failure
D) Bilateral ventricular failure

Question #4
 Which of the combined set of hemodynamic values is of
greatest concern?
A) CO = 6.9 L/min; CI = 3.8 L/min/M2 SV = 63 mL/beat;
SVI = 34 mL/beat/M2 BP = 102/52 mm Hg SvO2 = 0.83
 B) CO = 4.3 L/min; CI = 2.5 L/min/M2 SV = 43 mL/beat;
SVI = 25 mL/beat/M2 BP = 94/62 mm Hg SvO2 = 0.64
 C) CO = 6.3 L/min; CI = 3.7 L/min/M2 SV = 64 mL/beat;
SVI = 37 mL/beat/M2 BP = 90/56 mm Hg SvO2 = 0.75
 D) CO = 3.8 L/min; CI =2.3 L/min/M2 SV = 73 mL/beat; SVI
= 43 mL/beat/M2 BP = 100/58 mm Hg SvO2 = 0.72

Answer #4
 Which of the combined set of hemodynamic values is of
greatest concern?
A) CO = 6.9 L/min; CI = 3.8 L/min/M2 SV = 63 mL/beat;
SVI = 34 mL/beat/M2 BP = 102/52 mm Hg SvO2 = 0.83
 B) CO = 4.3 L/min; CI = 2.5 L/min/M2 SV = 43 mL/beat;
SVI = 25 mL/beat/M2 BP = 94/62 mm Hg SvO2 = 0.64
 C) CO = 6.3 L/min; CI = 3.7 L/min/M2 SV = 64 mL/beat;
SVI = 37 mL/beat/M2 BP = 90/56 mm Hg SvO2 = 0.75
 D) CO = 3.8 L/min; CI =2.3 L/min/M2 SV = 73 mL/beat; SVI
= 43 mL/beat/M2 BP = 100/58 mm Hg SvO2 = 0.72

Question #5
 Immediate treatment of pulmonary artery
rupture may include all of the following
except:
A) Discontinuation of anticoagulation
B) Placing patient in lateral position with
unaffected side down.
C) Selective bronchial intubation
D) PEEP

Answer #5
 Immediate treatment of pulmonary artery
rupture may include all of the following
except:
A) Discontinuation of anticoagulation
B) Placing patient in lateral position with
unaffected side down.
C) Selective bronchial intubation
D) PEEP
 E) Hire a lawyer