Monitoring

1. Hemodynamic Monitoring
Dr. Mostafa El-Hamamsy MD
Consultant of Cardiac Anesthesia,
King Fahd Cardiac Center,
College of Medicine, King Saud University

3. Hemodynamic Monitoring
• Introductions
• Electrocardiography (ECG)
• Monitoring Coronary Perfusion
• Arterial Pressure Monitoring
• Cardiac Filling Pressures : Including:
1- Central Venous Pressure
2- Pulmonary Arterial Pressure
• Cardiac Output Monitoring
• Advanced techniques

4. Introductions
•Hemodynamic monitoring is
the intermittent or continuous
observation of physiological
cardiovascular parameters for
early detection of need for
therapeutic interventions

5. Hemodynamic Monitoring
• ASA (1905) Standards:

6. Hemodynamic Monitoring
• The American Society of Anesthesiologists
ASA (2011), the European Board of
Anaesthesiology EBA(2012), and the
Australian and New Zealand College of
Anaesthetists ANZCA (2013) have
published guidelines on standards of
clinical monitoring.
• Revised by The Association of
Anaesthetists of Great Britain & Ireland
(AAGBI), 2020.

7. Hemodynamic Monitoring
Standard Monitoring for
Cardiac Surgical Patients
• ECG
• Blood Pressure
• Pulse oximetry
• Capnometry
• Temperature
• Central venous pressure
• Urine output
• Intermittent arterial blood gas analysis

8. Hemodynamic Monitoring
• Extended Monitoring for Patients
Based on Case-Specific Factors
• Pulmonary artery catheter
• Cardiac Output Measurements
• TEE
• Bispectral index monitoring
• Cerebral oximetry

9. ECG
ECG & ST segment.
- Use of 5 lead ECG with ST-segment analysis in
patients at high risk may improve sensitivity for
myocardial ischemia detection.
- Myocardial ischemia occurs by at least a 1-mm
down sloping of the ST segment from baseline.
- Usually, lead II is monitored for inferior wall
ischemia (RT Coronary) and arrhythmias and
lead V5 for anterior wall ischemia (Lt Coronary)

10. Noninvasive BP
• Proper Fit of a Blood Pressure Cuff
• Width of cuff = 2/3 of upper arm
• Length of cuff encircles 80% arm
• Lower edge of cuff approximately 2.5 cm
above the antecubital space
10

11. Noninvasive BP
• Why A Properly Fitting Cuff?
• Too small causes false-high reading
• Too LARGE causes false-low reading
11

12. Indications for Arterial Blood Pressure
• Unable to obtain Non-invasive BP
• Unstable blood pressures
• Frequent ABGs or labs
• Frequent titration of vasoactive
drugs
12

13. Arterial line
• Advantages
– Easy setup
– Real time BP monitoring
– Beat to beat waveform display
– Allow regular sampling of blood for lab tests
• Disadvantages
– Invasive
– Risk of hematoma, distal ischemia, pseudo
aneurysm formation and infection

14. Arterial line
– Real time SBP, DBP, MAP
– Pulse pressure variation (PP)
• ΔPP (%) = 100 × (PPmax - PPmin)/([PPmax + PPmin]/2)
• >= 13% (in septic pts,) discriminate between fluid responder and non
responder (sensitivity 94%, specificity 96%)
Am J Respir Crit Care Med 2000, 162:134-138

15. 3- blood volume
1- Myocardial
contraction &
2- heart rate
4- Vasoactivity
4 factors that
affecting the
haemodynamic
conditions

16. Patient with hypotension
Hypovolemia
• Low CVP
• Low CI
• High SVRI
 Consider fluid
challenge
Cardiogenic
• High CVP
• Low CI
• High SVRI
 Consider
inotopic / IABP
Vasogenic
• Low CVP
• High CI
• Low SVRI
 Consider
vasopressor

17. Central Venous Catheter
• Central venous catheter Indications:
– Measurement of CVP, medications
( Inotropes & Vasopressors), TPN, and modified
form allow for transvenous pacing or dialysis.
* CVP:
• Normal values = 2 – 8 mm Hg
• Low CVP = hypovolemia or ↓ venous return
• High CVP = over hydration, ↑ venous return,
or right-sided heart failure

18. Central venous catheter
• Advantages
–Easy setup
–Good for medications infusion
• Disadvantages
–Cannot reflect actual RAP in most
situations
–Multiple complications
Infections, thrombosis, complications on
insertion, vascular trauma & pneumothorax.

19. Leveling and Zeroing
• Leveling
– Aligns transducer with catheter tip
– After patient, bed or transducer move
• Zeroing
– Performed before insertion & readings
• Level and zero transducer at the phlebostatic axis
19

20. Phlebostatic Axis
20
• Level of the atria 4th intercostal space, mid-axillary
line
• Phlebostatic axis with any position (dotted line)
(Edwards Lifesciences, n.d.)

21. Central Venous Pressure
• Techniques & Complications
• Internal Jugular Vein
• Subclavian Vein
• Basilic
• Femoral

22. Central Venous Pressure

23. Central Venous Pressure

24. Central Venous Pressure
Subclavian Vein
• Supraclavicular or Infraclavicular
approaches and has long been used for
central venous access.
• Cannulation of the subclavian vein is
associated with a higher incidence of
complications than the IJV approach,
especially pneumothorax.

25. Central Venous Pressure

26. Central Venous Pressure
•A good correlation has been
shown between the CVP and
left-sided filling pressures
during a change in volume
status in patients with coronary
artery disease and left
ventricular EF greater than 0.4.

27. Limitation of CVP
Systemic venoconstriction
Decrease right
ventricular
compliance
Obstruction of the
great veins
Tricuspid regurgitation
Mechanical
ventilation

28. Pulmonary Artery Catheter (PAC)
• Advantages
– Provide lot of important hemodynamic parameters
– Sampling site for SvO2
• Disadvantages
– Costly
– Invasive
– Multiple complications (e.g. arrhythmia,
catheter looping, balloon rupture, PA injury,
pulmonary infarction etc.)

29. Pulmonary Artery Catheter
*

30. Dr. Swan & Dr. Ganz (in 1970)

31. PAC Design
• (in 1970), Dr. Swan & Dr. Ganz
introduced a PA catheter that was
equipped with a small inflatable
balloon at its tip.
• This “balloon flotation” principle
allows a right-heart catheterization to
be performed at the bedside, without
fluoroscopic guidance.

32. Pulmonary artery catheter

33. Pulmonary Artery Catheter

34. Pulmonary Artery Catheter

35. Clinical applications of PAC
PAC hemodynamic parameters:
• Central venous pressure (CVP)
• Pulmonary arterial occlusion pressure (PAOP)
• Cardiac output (Thermodilution)
• Stroke volume (SV)
• R ventricle ejection fraction/ end diastolic volume
(RVEF / RVEDV)
• Systemic vascular resistance index (SVRI)
• Pulmonary vascular resistance index (PVRI)
• Oxygen delivery / uptake (DO2 / VO2)

36. Pulmonary artery catheter

37. CO Measurement
• Typically done with thermodilution
method
– A cold solution of fixed volume is injected and
a thermistor 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

38. CO Measurement
• Typically done with thermodilution method

39. Continuous Cardiac Output
• Newer generation catheter
TruCCOMS system
– Uses continuous cardiac output
measurements without need for bolusing
– Also provides continuous SvO2
measurements

40. TruCCOMS system

41. Area under curve is
inversely proportion to rate
of blood flow in PA ( = CO)

42. As CO increase, blood
flow over the heat
transfer device increase
and the device require
more power to keep the
temp. difference
Therefore, provide
continuous CO data

43. TruCCOMS system
• Advantage
– Continuous CO monitoring
– Provision of important hemodynamic
parameter as PAC
• Disadvantage
– Invasive
– Costly
– Complications associated with PAC use

44. Mixed Venous Saturation SvO2
• Measured in pulmonary artery blood
• Marker of the balance between whole body O2
delivery (DO2) and O2 consumption (VO2)
• VO2 = DO2 x (SaO2 – SvO2)
• In fact, DO2 determinate by CO, Hb and SaO2.
Therefore, SvO2 affected by
– CO
– Hb
– Arterial oxygen saturation
– Tissue oxygen consumption

45. Mixed Venous Saturation SvO2
• Normal SvO2 70-75%
Decreased SvO2
• increased consumption
• pain, hyperthermia
• decreased delivery
• low CO
• anemia
• hypoxia
Increased SvO2
• Increased delivery
• high CO
• hyperbaric O2
• Low consumption
• sedation
• paralysis
• cyanide toxicity

46. Indications for PAP monitoring
• Shock of all types
• Assessment of cardiovascular
function and response to therapy
• Assessment of pulmonary status
• Perioperative monitoring

47. Contraindications for PAC
• 1. Absolute contraindications
• A. Tricuspid or pulmonic valvular stenosis.
• B. Right atrial or RV masses (eg, tumor, clot).
• C. Tetralogy of Fallot.
• 2. Relative contraindications
• A. Severe dysrhythmias:
• WPW syndrome, and Epstein's malformation
(because of possible tachyarrhythmias).
• B. Coagulopathy.
• C. Newly inserted pacemaker wires.

48. Pulmonary Artery Catheter
- Routine use of PAC is not recommended even in
patients going for elevated-risk procedures.
- ASA concludes that the appropriateness of PAC
use depends on the combination of risks
associated with the patient, the operation, and
the setting.
- However, it may be considered in severe cardiac
conditions which cannot be corrected prior to
surgery and require strict hemodynamic
monitoring

49. Pulmonary artery catheter
- (Shah 2005):
Systematic review of 8 trials (2667 patients)
- In all trials All-cause mortality
PAC: 92/1389 (6.6%)
No PAC: 101/1318 (7.7%)
****************
- One trial showed ↑ risk pulmonary embolus
PAC: 8/997 (0.8%)
No PAC: 0/997 (0%)
p=0.004

50. Pulmonary artery catheter
- Canadian Cardiovascular Society (CCS)
CCS 2016 Guideline:
We recommend against using pulmonary
artery catheters in patients undergoing
noncardiac surgery
Strong recommendation,
moderate-quality evidence

51. Hemodynamic Monitoring
• Introductions
• Electrocardiography (ECG)
• Monitoring Coronary Perfusion (ST)
• Arterial Pressure Monitoring
• Cardiac Filling Pressures : Including:
1- Central Venous Pressure
2- Pulmonary Arterial Pressure
• Cardiac Output Monitoring
• Advanced techniques

52. Cardiac Output Monitoring
CARDIAC OUTPUT
• Indications
Patients who benefit from measurements of
pulmonary artery pressure also benefit from
determination of CO (Cardiac Study)
In fact, to use the information available from
PACs most effectively, cardiac output must be
obtained.

53. Cardiac Output Monitoring
TECHNIQUES & COMPLICATIONS
• FICK PRINCIPLE
• DYE DILUTION
• THERMODILUTION
• ULTRASONOGRAPHY
• RECENT TECHNIQUES: - PULSE CONTOR ANALYSIS
-THORACIC BIOIMPEDANCE

54. Cardiac Output Monitoring
Fick
principle
Indicator
dilution
Thermo
dilution
Doppler and echo
Pulse contor analysis
Bioimpedance

55. • The development of Stewart’s indicator-
dilution method at, 1897.
.
•The introduction (PAC) at ,1970 .
•Adolf Fick described the technique for
measuring cardiac output , at July 9, 1870
Historical Perspective

56. Cardiac Output Monitoring
FICK PRINCIPLE
• The amount of oxygen consumed by an
individual ( VO2) = the difference between
arterial and venous (a–v) oxygen content (C)
(CaO2 and CvO2) multiplied by cardiac output
(CO): VO2 = [CaO2 – CvO2] x CO
• Therefore

57. Fick Method
• CO = VO2 / [CaO2 – CvO2]
• SaO2 and SvO2 measured by ABG
•CO = VO2 / [SaO2 – SvO2] x Hgb x 1.34 x 10
• VO2 is usually considered fixed in SPT (B.M. Rate)
• Can use 3.5 mL/kg or 125 mL/m2
•So, to calculate CO using Fick principle you only need:
1- Weight & Height → BSA in meter square (m2)
2- Haemoglobin Conc gm/dl → x 10 → gm/L
2- ABG
3- VBG (mixed venous sample through CV line RA Line)
• If metabolic rate is abnormal e.g. Hyperthermia, the
calculation may be incorrect.

58. Dye Dilution
• If indocyanine green dye is injected through a
central venous catheter, its appearance in the
systemic arterial circulation can be measured
by analyzing arterial samples with an
appropriate detector, e.g.a densitometer for
indocyanine green.
• The area under the resulting dye indicator
curve is related to cardiac output. However,
dye-dilution technique, introduces the
problems of indicator recirculation, and
repeated arterial blood sampling.

59. Thermodilution
• Injection of a quantity (10 mL) of cooled saline
into the right atrium changes the temperature
of blood in contact with the thermistor at the
tip of the PAC.
• The degree of change is inversely
proportionate to cardiac output: Temperature
change is minimal if there is a high blood flow
but pronounced if flow is low. Plotting the
temperature change as a function of time
produces a thermodilution curve.

60. Transthoracic echo (TTE)
• Assessment of cardiac & valvular
structures , ejection fraction and
cardiac output based on 2D and
doppler flow technique
• Echo doppler ultrasound measure
blood flow velocity in heart and great
vessels

62. Transthoracic echo (TTE)
• Advantages
– Fast to perform
– Non invasive
– Can assess valvular structure and myocardial
function
– No added equipment needed
• Disadvantages
– Difficult to get good view (esp. whose on
ventilator / obese)
– Cannot provide continuous monitoring

63. Transesophageal echo (TEE)
• Better view and more accurate than
TTE
• CO assessment by doppler flow
technique as mentioned before
• Time consuming and require a high
level of operator skills and knowledge

64. TEE
• TEE assesses left ventricular filling (end-diastolic
volume and end-systolic volume), ejection
fraction, wall motion abnormalities, and
contractility.
• Pulsed Doppler is a related technology that can
be used to measure the velocity of aortic blood
flow. Combined with TEE, which determines the
aortic cross-sectional area, this technique can
measure stroke volume and cardiac output.

65. Esophageal aortic doppler US
• Doppler assessment of
descending aortic flow
• CO determinate by measuring
aortic blood flow and aortic CSA
• Assuming a constant partition
between caudal and cephalic
blood supply areas
• CSA obtain either from
nomograms or by M-mode US
• Probe is smaller than that for
TEE
• correlate well with CO
measured by thermodilution
Crit Care Med 1998 Dec;26(12):2066-72
Decending
aorta

66. Normovolemia

67. Esophageal Doppler measure COP
by:
Cross
sectional
area of
the aorta
Blood
flow
velocity

68. Esophageal aortic doppler US
• Advantages
– Easy placement, minimal training needed (12 cases)
– provide continuous, real-time monitoring
– Low incidence of iatrogenic complications
– Minimal infective risk
• Disadvantages
– High cost
– Poor tolerance at awake patient, so for those
intubated
– Probe displacement can occur during prolonged
monitoring and patient’s turning
– High inter observer variability when measuring
changes in SV in response to fluid challenges

70. Minimally Invasive Techniques
(Pulse Contour Analysis)
Pulse Contour Analysis System Categories
I - Requiring An Indicator For Calibration.
1- PICCO saline , 2 - LIDCO lithium
II - Requiring: 1- Preload Patient Data.
2- Arterial Impedance Estimation
- The FloTrac/Vigileo™system

71. Pulse contour analysis (PCA)
• PCA involves the use of an arterial catheter with
a pressure transducer, which can measure
pressure on a beat-to-beat basis
• Because vascular impedance varies between
patients, it had to be measured using another
modality to initially calibrate the PCA system
• The calibration method usually employed was
arterial thermodilution.

72. Pulse contour analysis (PCA)
• Arterial pressure waveform determinate
by interaction of stroke volume and SVR

73. CO Measurement
• Typically done with thermodilution method

74. Pulse contour analysis
• Advantages
– Almost continuous data of CO / SV / SV variation
– Provide information of preload and Extravascular
Lung Water EVLW
• Disadvantages
– Minimal invasive
– Optimal arterial pulse signal required
•Arrhythmia
•Damping
•Use of IABP

75. Pulse Contour Analysis System Categories
I - Requiring An Indicator For Calibration.
1- The PiCCO™ system

76. PiCCO...
...Simple – Safe – Speedy - Specific
PiCCO-Technology
PiCCO plus Standalone Monitor

77. PiCCO-Technology
• The PiCCO-Technology uses any
standard CV-line and a thermistor-
tipped arterial PiCCO-catheter
instead of the standard arterial line.

78. The PiCCO Technology uses :
1- Standard CV-line.
2- Thermistor-tipped arterial PiCCO catheter
(PULSIOCATH) instead of the standard arterial line.
The PiCCO-Technology

79. CV
A
B
F
R
PiCCO Catheter
Central venous line (CV)
PULSIOCATH thermodilution catheter
with lumen for arterial pressure measurement
Axillary: 4F (1,4mm) 8cm
Brachial: 4F (1,4mm) 22cm
Femoral: 3-5F (0,9-1,7mm) 7-20cm
Radial: 4F (1,4mm) 50cm

80. Discrepancies among central and peripheral blood
pressures may be large in this situation and give
false low COP:
After cardiopulmonary
bypass.
During reperfusion after a
liver transplant .
Septic shock treated with
high dose vasoprisors.

82. What is the PiCCO-Technology?
Pulse Contour Analysis
PULSIOCATH
CALIBRATIO
N
Transpulmonary Thermodilution injection
t
T
P
t
The PiCCO-Technology is a unique combination of 2 techniques
for advanced hemodynamic and volumetric management
without the necessity of a right heart catheter in most patients:

83. Parameters measured with the PiCCO-Technology
•Pulse Contour Parameters
•Pulse Contour Cardiac Output PCCO
• Arterial Blood Pressure AP
• Heart Rate HR
• Stroke Volume SV
• Stroke Volume Variation SVV
• Pulse Pressure Variation PPV
• Systemic Vascular Resistance SVR
• Index of Left Ventricular Contractility dPmx*
Thermodilution Parameters
• Cardiac Output CO
• Global End-Diastolic Volume GEDV
• Intrathoracic Blood Volume ITBV
• Extravascular Lung Water EVLW*
• Pulmonary Vascular Permeability Index PVPI*
• Cardiac Function Index CFI
• Global Ejection Fraction GEF

84. Pulse Contour Analysis - Principle
t [s]
P [mm Hg]
Area under
pressure curve
Shape of
pressure curve
PCCO = cal • HR •


Systole
P(t)
SVR
+ C(p) •
dP
dt
( ) dt
Aortic
compliance
Heart
rate
Patient-specific calibration factor
(determined by thermodilution)

85. SVmax
SVmin
SVmean
SVmax – SVmin
SVV =
SVmean
Stroke Volume Variation: Calculation
Stroke Volume Variation (SVV) represents the variation of stroke
volume (SV) over the ventilatory cycle.
SVV is...
... measured over last 30s window
… only applicable in controlled mechanically ventilated
patients with regular heart rhythm

86. Pulse Pressure Variation: Calculation
PPmax – PPmin
PPV =
PPmean
PPmax
PPmean
PPmin
Pulse pressure variation (PPV) represents the variation of
the pulse pressure over the ventilatory cycle.
PPV is...
…measured over last 30s window
…only applicable in controlled mechanically
ventilated patients with regular beat rhythm

87. SVV and PPV – Clinical Studies
Berkenstadt et al, Anesth Analg 92: 984-989, 2001
Sensitivity
Specificity
Central Venous Pressure (CVP) can
not predict whether volume load
leads to an increase in stroke
volume or not.
- - - CVP
__ SVV
1
0,2
0,4
0,6
0,8
1
0,5
0
0
SVV and PPV are excellent predictors of volume responsiveness.

88. What is the current situation?.………..……..………….Cardiac Output!
What is the preload?.……………….....…Global End-Diastolic Volume!
Will volume increase CO?....………...……….Stroke Volume Variation!
What is the afterload?……………..…..Systemic Vascular Resistance!
Are the lungs still dry?...…….……...…..….Extravascular Lung Water!*
Clinical application
CO GEDV SVV SVR
EVLW*

89. Bolus
Injection
Lungs
PiCCO Catheter
e.g. in femoral
artery
Transpulmonary
thermodilution measurement
only requires central venous
injection of a cold
(< 8°C) or room-tempered
(< 24°C) saline bolus…
A. Thermodilution parameters
Left Heart
Right Heart
RA PBV
EVLW*
LA LV
EVLW*
RV

90. Tb
injection
t
Transpulmonary thermodilution: Cardiac
Output
CO Calculation:
 Area under the
Thermodilution Curve
After central venous injection of the indicator, the thermistor at
the tip of the arterial catheter measures the downstream
temperature changes.
Cardiac output is calculated by analysis of the thermodilution
curve using a modified Stewart-Hamilton algorithm:

91. RAEDV
Thermodilution curve
measured with arterial
catheter
CV Bolus Injection
LAEDV LVEDV
RVEDV
Right Heart Left
Heart
Lungs
After injection, the indicator passes the following intrathoracic
compartments:
The intrathoracic compartments can be considered as a series of “mixing
chambers” for the distribution of the injected indicator (intrathoracic thermal
volume).
ITTV
PTV
The largest mixing chamber in this series are the lungs, here the indicator (cold)
has its largest distribution volume (largest thermal volume).
Transpulmonary thermodilution: Volumetric parameters 2

92. Pulmonary Vascular Permeability Index
Pulmonary Vascular Permeability Index (PVPI*) is the ratio of
Extravascular Lung Water (EVLW*) to pulmonary blood volume
(PBV). It allows to identify the type of pulmonary edema.
Pulmonarv Blood
Volume
Hydrostatic
pulmonary edema
Permeability
pulmonary edema
PVPI
*
=
PBV
EVLW*
normal
elevated
elevated

PVPI* =
PBV
EVLW*
elevated
elevated
normal
PVPI*
=
PBV
EVLW*
normal
normal
normal


PBV
PBV
PBV Normal Lung
Extra Vascular
Lung Water

93. Relevance of EVLW- Management
101 patients with pulmonary edema were randomized to a pulmonary artery catheter
(PAC) management group in whom fluid management decisions were guided by PCWP
measurements and to an Extravascular Lung Water (EVLW*) management group using a
protocol based on the bedside measurement of EVLW *.ICU days and ventilator-days
were significantly shorter in patients of the EVLW* group.
Mitchell et al, Am Rev Resp Dis 145: 990-998, 1992
22 days 15 days
9 days 7 days
* *
Ventilation days ICU days
n=101
EVLW* group
PAC group
EVLW* group
PAC group

94. Extravascular Lung Water, EVLW* has shown to have a clear
correlation to severity of ARDS, length of ventilation days, ICU-
Stay and Mortality and is superior to assessment of lung edema
by chest x-ray and clearly indicates fluid overload
Mortality as function of ELWI* in 373
critically ill ICU patients
Sakka et al , Chest 2002

95. Pulse Contour Analysis System Categories
I - Requiring An Indicator For Calibration.
2- The LiDCO™ plus &
LiDCO™ rapid systems

97. LiDCO system

98. The LiDCO™ plus system
• Combines pulse contour analysis with lithium
indicator dilution calibration system for continuous SV
and SVV monitoring.
• Reliability of the lithium calibration system may be
negatively affected by high peak doses of muscle
relaxants, which cross-react with the lithium sensor.
• SO the lithium calibration must be performed before
or 30 minutes after the administration of a muscle
relaxant.

99. Pulse Contour Analysis System Categories
II - Requiring: 1- Preload Patient Data.
2- Arterial Impedance Estimation
The FloTrac/Vigileo™system

100. The FloTrac/Vigileo™system
• FloTrac is an arterial transducer that connected
to the arterial line.
• Vigileo is a standard monitor measuring CO
through Pulse Contour Analysis (As PICCO)

102. Comparison Between Pulse Contour
Analysis Systems
PICCO
System
LIDCO
system
FLO Track
system
Advantage 1-Broad range of
hemodynamic
Parameters.
2-More Accurate
during
hemodynamic
instability.
1-Minimally invasive
2-More accurate
during hemodynamic
instability
1-Minimally invasive
2-Easy to use.
3-Operator
independent.
Disadvantage More invasive Require lithium 1-Inaccurate especially
in: vasoplegic patients.
2-Does not accurately
track changes in SV.

103. The FloTrac/Vigileo™system
Hypotension Prediction Index (HPI)
using the artificial intelligence

104. Non Invasive Techniques
Non invasive Systems:
1 - Partial CO2 rebreathing & Fick principle.
2 - The Clear Sight System
3 - Thoracic Bioimpedance & Electrical cardiometry
4 - Endotracheal CO measurement (ECOM).

105. Non Invasive Techniques
Non invasive Systems:
1- Partial CO2 rebreathing &
application of Fick principle.

106. Partial CO2 rebreathing & application of
Fick principle
• Fick principle is used for CO measurement
• CO = VO2 / (CaO2 – CvO2)
= VCO2 / (CvCO2 – CaCO2)
• Based on the assumption that blood flow
through the pulmonary circulation kept
constant and absence of shunt
• Proportional to change of CO2 elimination
divided by change of ETCO2 resulting from a
brief rebreathing period
• The change was measured by NICO sensor

108. S = slope of CO2 dissociation curve
assume that the mixed venous co2
concentration (Cvco2) remains
unchanged between baseline and
rebreathing conditions

109. Partial CO2 rebreathing & application of
Fick principle
• Advantages
– Non invasive
• Disadvantages
– Only for those mechanically ventilated patient
– Not continuous monitoring
– Variation of ventilation mood and presence of lung
diseased significantly affect the CO reading

110. Non invasive Systems:
Non invasive Systems:
2- The Clear Sight System

112. EV1000
monitor
EV1000
pump
unit
Pressure
controller
Finger
cuff
Heart
sensor The clear
sight system
consists of

115. The Clear Sight System
• Use finger cuff technology.
• A combination of noninvasive technology with
decision support.
• Its hemodynamic parameters are:
 Stroke Volume (SV).
 Stroke Volume Variation (SVV).
 Cardiac Output (CO).
 Systemic Vascular Resistance (SVR).
 continuous Blood Pressure (cBP).

117. Validation
• the clinical data demonstrate that the Nexfin
technology Blood Pressure is more accurate
than a traditional upper arm BP cuff when
compared to invasive measurements in patients
undergoing general surgery.
• Cardiac Output has been validated against
several reference methods including pulmonary
thermodilution transpulmonary thermodilution,9
trans-esophageal/ thoracic echo-Doppler and inert
gas rebreathing. Percentage errors range from
23% to 39%, which is comparable to more
invasive methods.

118. • Larger errors have been reported, but these
occurred in critically ill patients where
compromised flow to the finger may affect the
cc Nexfin technology performance.
• Beyond the ability to measure absolute Cardiac
Output values, several studies have shown that
the cc Nexfin technology is able to reliably
track changes in Cardiac Output.

119. Non invasive Systems:
Non invasive Systems:
3 - Thoracic Bioimpedance &
Electrical Cardiometry

120. Thoracic Bioimpedance
Changes in thoracic volume cause changes in
thoracic resistance (bioimpedance). ‫الحيوية‬ ‫المقاومة‬
• If changes in thoracic bioimpedance are
measured following ventricular contraction,
SV can be continuously determined.
• This noninvasive technique requires four pairs
of ECG electrodes to inject microcurrents and
to sense bioimpedance on both sides of the
chest.

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

122. Thoracic Bioimpedance

123. Thoracic Bioimpedance
• Thoracic electrical bioimpedance, a form of
plethysmography, when small electrical
signals are transmitted through the
thorax, the current travels along
Ascending Aorta, which is the most
conductive area.
• Changes in bioimpedance, resulting from
the pulsatile changes in the volume of
Ascending Aorta, are inversely
proportional to the stroke volume.

124. Thoracic Bioimpedance
• Advantage
–Non invasive
• Disadvantage
–Reliability in critically ill patients
still not very clear

125. Thoracic Bioimpedance
• Some report same clinical accuracy as
thermodilution technique
Crit Care Med 22: 1907-1912
Chest 111: 333-337
Crit Care Med 14: 933-935
• Other report poor agreement in those
hemodynamically unstable and post cardiac
surgery
Crit Care Med 21:1139-1142
Crit Care Med 23: 1667-1673
• Newly generation EB device using upgraded
computer technology and refined algorithms to
calculate CO and get better results
Curr Opin Cardio 19:229-237
Int Care Med 32:2053-2058

126. 3- Electrical Cardiometry or
Velocimetry (EV)
• A non-invasive method based on the
Electrical Velocimetry (EV)
• Measures Stroke Volume (SV), &
Cardiac Output (CO)
• Trademarked by Cardiotronic.
• U.S. FDA approved for use on adults,
children, and neonates.

127. 3- Electrical Cardiometry

128. Electrical Velocimetry (EV)
• EV is based on the fact that the
conductivity of the blood in the
aorta changes during the cardiac
cycle.
• EV was developed by Dr. Bernstein
and Dr. Osypka in 2001, as a new
model for interperating the
bioimpedance signals of the thorax.

129. Electrical Velocimetry (EV)
Random orientation Alignment of RBCs
AV CLOSED AV OPENING
The change from random orientation to alignment of
RBCs upon opening of aortic valve generates a
characteristic steep ↑ of conductivity (corresponding to
a steep ↓ of impedance) – beat to beat.

130. How Electrical Velocimetry (EV) work ?
- 4 ECG electrodes:
- 2 attached to the left
side of the neck &
- 2 attached at the
lower thorax.

131. Cardiotronic & ICG
• The Similarity:
Both methods measure thoracic electrical bio-
impedance (TEB).
• The Difference :
• ICG: electrical signals are transmitted through
the thorax, the current travels along Ascending
Aorta, which is the most conductive area.
• Cardiotronic: based on the fact that the
conductivity of the blood in the aorta changes
during the cardiac cycle.
.

132. Non invasive Systems:
Non invasive Systems:
4- Endotracheal CO
Measurement (ECOM).

133. Endotracheal COP measurement
(ECOM)
• Minimally invasive, accurate, reliable,
continuous, safe and real time.
• Using a principle of bioimpedance.
• Using standard endotracheal tube.
• ECOM system record low current
delivered to the endotracheal mucosa
produced by electrode on the
endotracheal tube.

135. Endotracheal COP measurement
(ECOM)
• The proximity of the ascending aorta and trachea
allows the optimization of the current delivery and
signal recording
• ECOM consists of :
1. Monitor.
2. Endotracheal tube with 6 electrodes on the cuff
and source electrode on the shaft.
3. Cable.

137. To Sum Up Techniques:
I- Minimally Invasive (Pulse Contour Analysis):
1- PICCO saline ,
2 - LIDCO lithium
3- The FloTrac/Vigileo™system
II- Non invasive Systems:
1 - Partial CO2 rebreathing & Fick principle.
2 - The Clear Sight System
3 - Thoracic Bioimpedance & Electrical Cardiometry
4 - Endotracheal CO Measurement (ECOM).

138. In conclusion
• Hemodynamic monitoring enable early
detection of changes in patient’s
conditions
• New techniques provide less invasive &
reasonably good results
• Always correlate the readings / findings
with clinical pictures in order to provide
the best treatment options
(Goal directed therapy)

139. It is important to appreciate that
NO device can change patient
outcome unless its use is coupled
with an intervention that by itself
improved patient outcomes.
Goal directed therapy

140. Hemodynamic Monitoring