Brief concept about advanced hemodynamic monitoring Critical care medicine Icu Intensivisit

1. ADVANCED HEMODYNAMIC
MONITORING

2. • Goal – to target adequate organ perfusion and oxygen delivery
• Principles –
• Optimize preload
• Optimize MAP, Perfusion pressure
• Increase cardiac output
• Minimize oxygen demand

3. BASIC HEMODYNAMIC MONITORING
• CLINICAL SIGNS
• CAPILLARY REFILL TIME
• NONINVASIVE MONITORING
• LACTATE
• HOURLY URINE OUTPUT
• BASE EXCESS
• ECHOCARDIOGRAPHY
• INTRA ARTERIAL BLOOD PRESSURE ,CVP

4. PHASES OF FLUID RESUSCITATION
• RESCUE/RESUSCITATION
• OPTIMIZATION
• STABILIZATION
• DE-ESCALATION

5. PRELOAD
STATIC
PRESSURE
CVP
PAOP
VOLUME
GEDV
LVEDV
DYNAMIC
PPV
SPV
SVV
IVC/SVC COLLAPSIBITILY

6. CVP
• Central venous pressure
• Measured at the junction of the superior venacava and right atrium
• Indicates right atrial pressure;frequently used as an estimate of right
ventricular preload
• Patency
• Leveling
• Zeroing
• CVP should be taken at the end expiration
• Should be measured at the end of diastole

7. Factors increasing CVP levels
• Hypervolemia
• Forced exhalation
• Tension pneumothorax
• Heart failure
• Pleural effusion
• Decreased cardiac output
• Cardiac tamponade
• MV and PEEP
• PTN ,PE

8. • CVP readings must be correlated with clinical circumstances
• Difficult to predict fluid responsiveness with CVP
• Poor indicator of preload as influenced by several factors
• To assess preload responsiveness static indicators have minimal value

9. Arterial line
Basic principles
Pressure wave form of arterial pulse is transmitted via column of fluid
to pressure transducer where it is converted into an electrical signal
The electrical signal is then processed, amplified and converted to
visual display by a microprocessor
Patency
Levelling
zeroing

10. • Area under the curve – strokes volume
• Position of dicrotic notch – high afterload and low SVR when it is high
• Slope of upstroke – myocardial contractility

11. Damping
• Dissipation of stored energy
• Anything which takes energy out of the system resulting in
progressive diminution of amplitude of oscillations
• Under damped – high systoles, low diastoles
• Overdamped –low systoles,high diastoles

12. DAMPING EFFECT…
• PATIENT RELATED
• Overdamped -Aortic stenosis,vasodialation,cardiogenic
shock,sepsis,severe hypovolemia
• Underdamped – aortic
regurgitation,hypervolemia,atherosclerosis,vasospasm
• SYSTEM RELATED
• Overdamped –air bubbles,loose connections,embolism,low flush bag
pressure,kinked line,multiple stop cocks
• Under damped – stiff tubing,long tubing,increased vascular resistence

13. Square wave test

14. Dynamic estimates of preload
• Cyclic changes in arterial pulse pressure and systolic component
during mechanical ventilation are induced by complex interaction
between systemic venous returns,RV ejection,intrathoracic volume

15. Hierarchy of preload assessment
• PPV(Pulse Pressure variation)
• SPV(Systolic pressure variation)
• SVV(Stroke volume variation)
• CO(Cardiac out monitoring)
• IVC/SVC Assessment(Inferior Venacava/Superior Venacava)
• LVEDV(Left ventricular End Diastolic Variation)
• GEDV(Global End Diastolic Volume)
• CVP(Central venous pressure)
• PLRT(Passive Leg raising Test)
• EEOT(End expiratory occlusion test)

16. CARDIAC OUTPUT MONITORING
• Pulmonary artery catheter
• Intermittent Thermodilution techniques
• Thermal filament that provides continuous CO
• RAP,PAP,PAOP
• Stewart Hamilton equation

17. Pulmonary artery catheter

18. • Room temperature saline 10 ml
• Inject bolus within 4 seconds into proximal port
• Temperature changes sensed by PA thermistor
• 3 injections,results averaged

20. GEDV
• Difference between intrathoracic and pulmonary thermal values
• Extravascular lung water (EVLW)
• Intrathoracic thermal volume- intrathoracic blood volume
• 3-7 ml/kg

21. Heart lung interaction

22. PVV,SVV,SPV
• Using arterial pressure wave form analysis
• PiCCO(pulse index continuous cadiac output)
• LiDCO(lithium dilution cardiac output )
• Flotrac/Vigileo

25. PPV(PULSE PRESSURE VARIATION)

27. SPV(SYSTOLIC PRESSURE VARIATION)

28. SVV(STROKE VOLUME VARIATION)

29. LIMITATIONS
• Use of low tidal volume ventilation
• During spontaneous breathing
• Cardiac arrhythmias
• Low compliance of RS(<30 ml/cm H20)
• Right heart failure
• High frequency ventilation,high intra abdominal pressure,open chest

30. End expiratory occlusion test(EEOT)
• Abolishes increase in intrathoracic pressure, prevents drop in preload
during inspiration
• Allows increase in venous return,acting like a fluid challenge
• An increase in Cl>5% during EEOT with a sensitivity of 91% and
specificity of 100%
• Can be used in low TV,low compliance lung,arrythimias

32. PASSIVE LEG RAISING TEST
• Endogenous fluid challenge
• Set volume challenge
• Completively reversible
• Appropriate in spontaneously breathing patients,arrthymias
• Requires a real time CO assessment device to quantify the
hemodynamic response

34. Pitfalls of PLR
• Need for real time CO
• Raised ICP
• Post abdominal surgery
• Increased abdominal pressure

35. IVC ASSESSMENT

36. IVC Collapsibility index –diameter variability cut off value of more than 50 % identifies responders
IVC Distensibility index –variation threshold of 12% is used to identify fluid responders

38. SVC ASSESSMENT

39. • Superior vena caval collapsilbility of greater than 36% predicted an
increase in CO of at least 11% with 90 % sensitivity and 100%
specificity

40. EtCO2 -PLR
• Compared changes in EtCO2 with arterial pressure to reflect changes
in CO
• EtC02 increase > 5% predicted fluid responsiveness