1) The document discusses the history and uses of pulmonary artery catheters, which can be used to measure hemodynamic variables invasively. 2) Pulmonary artery catheters are inserted through the internal jugular or subclavian vein and the balloon is inflated in the pulmonary artery to measure variables like pulmonary capillary wedge pressure. 3) Pulmonary capillary wedge pressure is considered the "holy grail" as it approximates left ventricular preload and end-diastolic pressure, but can be affected by factors like mitral stenosis or high positive end-expiratory pressure. 4) Pulmonary artery catheters allow classification of shock as cardiogenic, distributive, obstructive

1. ‘Maximally Invasive’
Hemodynamic Monitoring
Dr. Souvik Maitra
Associate Professor
Department of Anaesthesiology, Pain Medicine & Critical Care
All India Institute of Medical Sciences, New Delhi

2. Hemodynamic Monitoring Devices: Spectrum
Invasive Minimally invasive Non- invasive

3. PA Catheter: History
• 1929- Frossmann
• 1944- Cournad & Richards
• 1956- Forssmann, Cournand and Richards - Nobel Prize in
Medicine
• 1970- Swan & Ganz
• 1972- Thermistor added in PAC for CO monitoring

4. PA Catheter:
Design

5. PA Catheter:
Design

6. PAC: Insertion Technique
• Initial steps- same as CVC insertion
• Insert an introducer sheath
• PAC inserted through the sheath- with pressure transducer
attached
• Inflate the balloon when in RA

7. PAC: Insertion Technique

8. How to Confirm Position?
• Characteristic PAWP waveforms
• Lateral CXR- tip below the LA
• AP CXR- tip within 2-3cm of hilum
• Significant respiratory variation of PCWP- z1 or z2
• Effect of PEEP> 50%- z1 or z2

9. PAC: Measured Variables
• CVP/ RA Pressure
• RVESP & RVEDP
• PA pressure (systolic/ diastolic/ mean)
• PCWP
• Cardiac output (thermodilution)
• SmVO2

10. PAC: Calculated Variables
• All flows indexed to BSA
• SVR= (MAP- RAP)/CO*80
• PVR= (mPAP- PCWP)/CO*80
• SV= CO/HR
• O2 ER= DO2/VO2 ~ (SaO2- SvO2)/SaO2

11. CVP/RA Pressure
• CVP≠ 𝑉𝑜𝑙𝑢𝑚𝑒 𝑠𝑡𝑎𝑡𝑢𝑠
• Trend of CVP≠ 𝑉𝑜𝑙𝑢𝑚𝑒 𝑠𝑡𝑎𝑡𝑢𝑠
• CVP>12mmHg- predicts AKI in critically ill patients
• CVP/PCWP> 0.63- predicts mortality in AHF
Highly dependent
upon venous tone (or
mSFP)

12. PCWP: ‘The Holy Grail’
PCWP ≈ LVEDP= LV preload
PC – PLA = Flow * Resistance
In wedge position,
Flow=0

13. PCWP: Physiological Relevance
PCWP≅ 𝐿𝐴𝑃 ≅ 𝐿𝑉𝐸𝐷𝑃 ≅ 𝐿𝑉𝐸𝐷𝑉
LV Preload
Crit Care Med. 2004;32:691-9

14. When PCWP> LVEDP?
• Zone 1 or 2 placement (PADP<PCWP in z. 1 & z.2)
• Incomplete occlusion- reflects PA pressure (check for oxygen
saturation)
• Postcapillary PH
• Mitral stenosis (falsely elevated)
• High PEEP
• High alveolar pressure

15. When LVEDP> PCWP?
• Non- compliant LV
Myocardial ischemia
Diastolic dysfunction
LVH
• Early MV closure
AR

16. PAC: Thermodilution CO measurement
CO= V(Tb-Ti)/area under △temp- time
curve

17. tdCO Measurement: Source of Error
• Timing of injection
• Volume & temperature of the injectate
• Low CO state
• Intra-cardiac shunt
• Tricuspid regurgitation

18. Classification of Shock
CVP PCWP SVR CO
Cardiogenic
Distributive
Obstructive
Hypovolemic

19. Classification of Cardiogenic Shock
CVP PCWP SVR PVR CO
LV Failure Variable
RV Failure
PASP #-
(RVMI) (RVMI)
Cardiac
Tamponade$
$CVP= PCWP
# PASP is higher in chronic conditions

20. When to use
PAC?
• Sepsis & ARDS? NO!
• High risk non- cardiac surgery? NO!
• Postcardiac surgery? May be in significant RV
dysfunction/ with IABP
• Acute heart failure? May be in ‘refractory’ cases
• Patients with MCS? May be to uncover RV
dysfunction

21. Indications of PAC in HF

22. Resuscitation in Septic Shock: Role of SmVO2
• SmVO2 ~ 70% - considered ‘normal’
• Denotes ‘balance’ between oxygen supply & demand
• In sepsis- oxygen utilization is supply dependent
• PAC- continuous SmVO2 depicted
• Used as a ‘therapeutic target’ in major surgery
• SmVO2<60% or > 77%- predicts poor outcome in sepsis

23. SmVO2- Pitfalls!
• SmVO2 and CO- NOT linear
• Lactate clearance- better prognostic marker
• ScVO2- reasonable alternative, unless hemodynamically unstable

24. Complications of PA Catheter
• All possible complications of CVC insertion
• Arrythmia, bradycardia & CHB
• Malposition
• Myocardial injury
• PA rupture
• Pulmonary embolism

25. Thanks for your attention!
Reach me at souvikmaitra@live.com