pa catheter in cardiac surgery patients for better monitoring of hemodynamics

1. The Pulmonary Artery
Catheter
Dr Soumi Das

3. History
• 1929- Dr. Warner
Forssman proven that
right heart
catheterization is
possible in humans
• 1964- Dr. Bradley
introduced small
diagnostic catheter
• 1970- Balloon Flotation
Catheter by Doctor
H.J.C Swan and William
Ganz

4. Pulmonary artery catheter – various parts

5. SPECIFICATIONS OF P.A CATHETER
 Introducer with side port (acts as a rapid infuser)
 7.5 French 110cm long PVC yellow catheter with balloon
surrounding tip containing lumen in end
 Syringe (plunger withdraws only to 1.5ml)
 Sliding locking device
 Markings designating distance from tip (each broad mark
represents 10cm)
 Connectors to monitor
 Sterile sheath
 4 Ports:
 Distal most for measurment of PAWP.
 30 cm from 1st Proximally for measuring CVP
 Port for balloon inflation.
 Thermister for temperature and cardiac output
measurement

6. Edward’s Life Science VIP Thermodilution Catheter
PA Distal
Proximal Injectate
RA infusion port
Thermistor port
Balloon inflation
port
The standard catheter is 7.5 FR and 110 cm long. Maximal balloon volume 1.5cc
Markings at 10 cm intervals

7. Pulmonary Artery Catheter

8. Indications for pulmonary artery
catheter placement

9.  There is no universally accepted indication as right heart (pulmonary
artery, PA) catheterization has not been shown to improve outcomes
 However it is useful in the following diagnostic and therapeutic
applications:
◦ Diagnostic
 Differentiation of various etiologies of shock and pulmonary
edema
 Evaluation of pulmonary hypertension
 Differentiation of pericardial tamponade from constrictive
pericarditis and restrictive cardiomyopathy
 Diagnosis of left to right intracardiac shunts
◦ Therapeutic
 Guide to fluid management and hemodynamic monitoring of
patients after surgery, complicated myocardial infarction, patients
in shock, heart failure, etc.
Indications
1Sandham JD et al. A randomized, controlled trial of the use of pulmonary-artery catheters in high-risk surgical patients. N Engl J Med

10. The most recent recommendations governing the use
of PACs are the American Society of
Anesthesiologists practice guidelines published
in 2003.
 Surgical patients undergoing procedures associated
with a high risk of complications from hemodynamic
changes (e.g., cardiac surgery).
 Patients with advanced cardiopulmonary diseases
that would place them at increased risk for adverse
perioperative events.
http://www.asahq.org/publicationsAnd-
Services/pulm_artery.pdf

11. Technique of insertion

12. Inserting the catheter
 The pulmonary artery (PA) catheter can be inserted either under
fluoroscopic guidance (preferred) or under the guidance of the
pressure wave forms
 Fluoroscopic guidance is recommended in patients with markedly
enlarged RA or RV, severe tricuspid regurgitation, or in those with left
bundle branch block
 A PA catheter with the balloon inflated is designed to be flow-directed
and will follow the direction of blood flow (right atrium to pulmonary
arteries)
 The catheter should be advanced to the vena cava/RA junction, the
approximate distance (as measured on the PA catheter) from the site
insertion is below

13. Guidelines for PA catheter Placement.
From I.J.V PUNCTURE
SITE
DISTANCE IN cm
RT ATRIUM 20 TO 25
RT VENTRICLE 30 TO 35
PULMONARY ARTERY 40 TO 45
WEDGE SITE 45 TO 50

14. Pulmonary artery catheter insertion

15. Pulmonary Artery Catheterization

16. Pulmonary artery catheter as seen on chest x-ray

17. Complications

18. Complications
1>Those related to establishment of central venous access
Accidental puncture of adjacent arteries
Bleeding
Neuropathy
Air embolism
Pneumothorax
2>Those related to Pulmonary artery catheterization
Dysrhythmias
–Premature ventricular and atrial contractions
–Ventricular tachycardia or fibrillation
Right Bundle Branch Block (RBBB)
–In patients with preexisting LBBB, can lead to complete
heart block.
Minor increase in tricuspid regurgitation

19. 3>Those related to Pulmonary catheter residence
Thromboembolism
Mechanical, catheter knots
Pulmonary Infarction
Infection, endocarditis
Endocardial damage, cardiac valve injury
Pulmonary Artery Rupture
Complications (..cont.)

20. Specific information obtained

21. Hemodynamic Parameters - Measured

22.  Central Venous Pressure (CVP)
◦ recorded from proximal port of PAC in the superior vena cava or right
atrium
◦ CVP = RAP
◦ CVP = right ventricular end diastolic pressure (RVEDP) when no
obstruction exists between atrium and ventricle
 Pulmonary Artery Pressure (PAP)
◦ measured at the tip of the PAC with balloon deflated
◦ reflects RV function, pulmonary vascular resistance and LA filling
pressures
 Pulmonary Capillary Wedge Pressure (PCWP)
◦ recorded from the tip of the PAC catheter with the balloon inflated
◦ PCWP = LAP = LVEDP (when no obstruction exists between atrium and
ventricle)
 Cardiac Output (CO)
◦ Calculated using the thermodilution technique
◦ thermistor at the distal end of PAC records change in temperature of
blood flowing in the pulmonary artery when the blood temperature is
reduced by injecting a volume of cold fluid through PAC into the RA.

23. Measured Normal values of cardiac pressures (mmHg) obtained from a
pulmonary artery catheter in a spontaneously breathing patient.
Mean Range
Right atrium 4 3–6
Right ventricle:
systolic 25 20–30
diastolic 4 2–8
Pulmonary artery:
systolic 25 20–30
diastolic 10 5–15
mean 15 10–20
Pulmonary artery wedge pressure 10 5–14

24. Central Venous Pressure/PCWP Waveform
Components
WAVEFORM PHASE OF
CARDIAC CYCLE
MECHANICAL EVENTS
a wave End diastole Atrial contraction
c wave Early systole
Isovolumic ventricular
contraction, tricuspid motion
toward the right atrium
v wave Late systole Systolic filling of the atrium
x descent Mid systole
Atrial relaxation, descent of the
base, systolic collapse
y descent Early diastole
Early ventricular filling, diastolic
collapse

25. The Pulmonary capillary wedge pressure

26. Catheter tip looks “through” the pulmonary circulation to “see”
the left atrial pressure.
•PCWP indirectly measures left atrial pressure
.
• PCWP reflects left atrial pressure and hence the left ventricular
end diastolic pressure as long as ventricular compliance is
normal or unchanging

27. Conditions resulting in discrepancies between PCWP and
LVEDP
PCWP > LVEDP
• Positive-pressure ventilation
• Positive end-expiratory pressure
• Increased intrathoracic pressure
• Non–West lung zone III pulmonary artery catheter placement
• Chronic obstructive pulmonary disease
• Increased pulmonary vascular resistance
• Left atrial myxoma
• Mitral valve disease (e.g., stenosis, regurgitation)
PCWP < LVEDP
• Noncompliant left ventricle (e.g., ischemia, hypertrophy)
• Aortic regurgitation (premature closure of the mitral valve)

28. 0 10
0
20
0
30
0
40
0
50
0
60
0
70
0
80
0
0
3
0
6
0
9
0
12
0
Atrial
Systole
Ventricular Systole Ventricular Diastole
EKG
Time (msec)

Pressur
e (mm
Hg)
P
QRS
Complex
T
P
Aorta
Dicrotic
Notch
Left Ventricular
Pressure
a
c
v
x
y
Left Atrial
Pressure
Cardiac Cycle
Left Sided
Pressures

29. 0 10
0
20
0
30
0
40
0
50
0
60
0
70
0
80
0
0
1
5
30
Atrial
Systole
Ventricular Systole Ventricular Diastole
EKG
Time (msec)

Pressur
e (mm
Hg)
P
QRS
Complex
T
P
PA Pressure
Dicrotic
Notch
Right Ventricular
Pressure
a
c
v
x
y
Right Atrial
Pressure
Cardiac Cycle
Right Sided
Pressures

30. Pulmonary Artery Pressure
Measurement Alert 30
Used with permission of PACEP Collaborative

31. Pulmonary Artery Pressure
Measurement Alert 31
Used with permission of PACEP Collaborative

32. Pulmonary Artery Pressure
Measurement Alert 32
Used with permission of PACEP Collaborative

33. Pressure Wave Interpretations
Wave pattern Mechanism Condition
Cannon ‘a’ wave AV dissociation Complete heart block,
ventricular tachycardia,
AVNRT
Tall ‘a’ wave Increased atrial
pressure
Mitral or tricuspid stenosis
No ‘a’ wave Loss of atrial kick Atrial fibrillation
Tall ‘v’ wave Increased volume
during ventricular
systole
Mitral or tricuspid
insufficiency, VSD
Loss of ‘y’ descent Equalization of
diastolic pressures
Cardiac tamponade
Exaggerated ‘y’
descent
Rapid diastolic filling Constrictive pericarditis
RA/ PCWP
AVNRT = Atrioventricular Nodal Reentry Tachycardia; VSD = Ventricular
Septal Defect

34. Hemodynamic Parameters - Derived

35.  Cardiac Index (CI) = CO/BSA
 Stroke Volume Index (SVI) = CI/HR
 Systemic Vascular Resistance (SVR)
◦ reflects impedance of the systemic vascular tree
◦ SVR = 80 x (MAP – CVP) / CO
 Pulmonary Vascular Resistance (PVR)
◦ reflects impedance of pulmonary circuit
◦ PVR = 80 x (PAM – PCWP) / CO
 Left ventricular stroke work index (LVSWI)
= (MAP – PCWP) x SVI x 0.136
 Right ventricular stroke work index (RVSWI)
= (PAM – CVP) x SVI x 0.136

36. Derived haemodynamic parameters:
Formula Normal Values
Cardiac index
CI = CO/BSA
2.8–4.2 L/min/m2
Stroke volume
SV = CO*1000/HR
50–110 mL (per beat)
Stroke index
SI = SV/BSA
30–65 mL/beat/m2
Left ventricular stroke work index
LVSWI = 1.36*(MAP − PCWP)*SI/100
45–60 gram-meters/m2
Right ventricular stroke work index
RVSWI = 1.36*(MPAP − CVP)*SI/100
5–10 gram-meters/m2
Systemic vascular resistance
SVR = (MAP − CVP)*80/CO
900–1400 dynes.sec.cm-5
E
14-2

37. Systemic vascular resistance index
SVRI = (MAP − CVP)*80/CI
1500-2400dynes.sec.cm-5/m2
Pulmonary vascular resistance
PVR = (MPAP − PCWP)*80/CO
150–250 dynes.sec.cm-5
Pulmonary vascular resistance index
PVRI = (MPAP − PCWP)*80/CI
250–400 dynes.sec.cm-5/m2
Derived haemodynamic parameters:
Formula Normal value

38. Oxygen Transport Parameters

39.  Oxygen Delivery (DO2)
◦ Rate of oxygen delivery in arterial blood
DO2 = CI x 13.4 x Hgb x SaO2
 Oxygen uptake (VO2)
◦ Rate of oxygen taken up from the systemic microcirculation
VO2 = CI x 13.4 x Hgb x (SaO2 - SVO2)
 Mixed Venous Oxygen Saturation (SVO2)
◦ Oxygen saturation in pulmonary artery blood
◦ Used to detect impaired tissue oxygenation.
It is a rough measure of CO
 MVO2 >80  High CO (shunt, sepsis, etc.)
 MVO2 65-80  Normal CO
 MVO2 <65  Low CO

40. Determination of cardiac output by thermistor
incorporated pulmonary artery catheter

41.  Thermodilution technique
 Known amount of solution (usually saline) is injected into the
proximal port (right atrium) and mixes and cools the blood which
is recorded by a thermistor located at the distal end of the
catheter
 CO is inversely proportional to the area under the curve
 Not reliable in patients with severe tricuspid or pulmonic valve
regurgitation. Results in lower peak and a prolonged washout
phase due to re-circulation resulting in underestimation of CO
 Not reliable in patients with intra-cardiac shunts. Overestimates
CO
 Normal CO = 4 - 8L/min
 Normal cardiac index (cardiac output indexed to body surface
area) = 2.5 - 4.0 L/min/m2

42. Continous cardiac output
• A 10 cm thermal filament is inserted into the catheter at the
level of the right ventricle.
•The surface temperature of the filament is always below
44°C.
•A crosscorrelation based on the input sequence and the
downstream signal measured by the thermistor is performed.
•The heat signal is processed over time and the classical
thermodilution curve is rebuilt.
•CO is determined using a modified Stewart–Hamilton
equation.
•The CO value is an average over a 3 min period (minimum)
and not a beat-to-beat measurement.

43. Special purpose pulmonary artery
catheters
•Pacing pulmonary artery catheters
•Mixed venous oxygen saturation catheters

44. Contraindications
Absolute contraindications
•Right sided endocarditis
•Mechanical tricuspid or pulmonic valve prosthesis
•Thrombus or tumour in right heart chamber
•Uncooperative patient
•Terminal illness for which aggressive management is considered
futile
Relative contraindications
•Profound coagulopathy (INR>2 or platelet count<20000 to 50000)
•Bioprosthetic tricuspid or pulmonic valve prosthesis
•Newly implanted pacemaker or defibrillator
•Left bundle branch block
•Pneumothorax/haemothorax in contralateral lung

45. Further read
•Manual of Cardiovascular Medicine – Ed. Griffin
•The ICU Book – Paul Marino
•The ASA Task Force on Pulmonary Artery Catheterization
updated practice guidelines for pulmonary artery
catheterization published in 2003 available at
http://www.asahq.org/publicationsAnd- Services/pulm_artery.pdf

46. ??

47. Abnormal Pulmonary Artery
and Wedge Pressure
Waveforms
 Artifactual pressure peaks and
troughs in the pulmonary artery
pressure (PAP) waveform caused by
catheter motion.
 when the balloon is overinflated and
occludes the lumen orifice. This
phenomenon is termed overwedging
and is usually caused by distal
catheter migration and eccentric
balloon inflation, which forces the
catheter tip against the vessel wall

48. PATHOLOGICAL CHANGES IN
PCWP WAVE FORMS
1. Severe mitral regurgitation.
A tall systolic v wave is inscribed in the pulmonary
artery wedge pressure (PAWP) trace and also
distorts the pulmonary artery pressure (PAP) trace,
thereby giving it a bifid appearance.
mean PAWP exceeds left ventricular end-diastolic
pressure in this condition.
V wave height is an indicator of the severity of
mitral regurgitation

49. 2.MITRAL STENOSIS.
 Mean pulmonary artery wedge
pressure (PAWP) is increased
(35 mm Hg)
 The diastolic y descent is
markedly attenuated.
 A waves are not seen in the PAWP
or CVP traces because of atrial
fibrillation

50. 3.Myocardial ischemia
 Pulmonary artery pressure (PAP) is
relatively normal
 Mean pulmonary artery wedge
pressure (PAWP) is only slightly
elevated (15 mm Hg).
 PAWP morphology is markedly
abnormal, with tall a waves (21 mm
Hg) resulting from the diastolic
dysfunction seen in this condition.

51. Constriction vs. Restriction
Parameter Constrictive Pericarditis Restrictive Cardiomyopathy
LVEDP-RVEDP, mm HG ≤ 5 > 5
RV Systolic, mm Hg ≤ 50 > 50
RVEDP/RVSP, mm Hg ≥ 0.33 < 0.3
RV/LV interdependence Discordance Concordance
Pressures Elevated with equalization of diastolic
pressures
Elevated with equalization of
diastolic pressures
RV/LV pressure waveform Dip and plateau (Square root sign) Dip and plateau (Square root sign)
RA pressure waveform Prominent y descent Prominent y descent
PCWP/LV respiratory
gradient
≥ 5 <5
 Hemodynamic parameters that help differentiate constrictive pericarditis
versus restrictive cardiomyopathy
LVEDP = Left Ventricular End Diastolic Pressure; PCWP = Pulmonary Capillary Wedge Pressure; RA = Right Atrial; RVEDP = Right Ventricular End
Diastolic Pressure; RVSP = Right Ventricular Systolic Pressure.

52. 4.Pericardial constriction.
 This condition causes elevation
and equalization of diastolic filling
pressure in the pulmonary artery
pressure (PAP), pulmonary artery
wedge pressure (PAWP), and
central venous pressure (CVP)
traces.
 The CVP waveform reveals tall a
and v waves with steep x and y
descents and a mid-diastolic
plateau wave or h wave.

53. 5.CARDIAC TEMPONADE.
 Like pericardial constriction, cardiac tamponade impairs
cardiac filling, but in the case of tamponade, a
compressive pericardial fluid collection produces this
effect. This fluid collection results in a marked increase in
CVP and reduced diastolic volume, stroke volume, and
cardiac output. Despite many similar hemodynamic
features, tamponade and constriction may be
distinguished by the different CVP waveforms seen in
these two conditions. In tamponade, the venous pressure
waveform appears more monophasic and is dominated by
the systolic x pressure descent. The diastolic y pressure
descent is attenuated or absent because early diastolic
flow from the right atrium to the right ventricle is impaired
by the surrounding compressive pericardial fluid collection

54. Referencing the “zeroing”
stopcock to Phlebostatic Axis
The phlebostatic axis is the approximate level of the left atrium. It is located
midway between the anterior-posterior chest wall at the 4th intercostal space.
The patient need not be flat, but must be supine.