Download Cardiac Output monitoring

Cardiac Output
Monitoring
Monica Morosan
Typical value
 End diastolic volume (EDV)120 ml (65–- 240 ml)
 End systolic volume (ESV)50 ml(16 - –
143 ml)
 Stroke volume (SV)70 ml (55 - 100 ml)
 Stroke volume index (33-47 ml/m2/beat)
 Ejection Fraction (Ef)58% (55 to 70%)
 Cardiac output (CO)4.9 L/minute (4.0 - 8.0 L/min)
 Cardiac index CI (2.6-4.2)L/min/m2
 SVR=80x(MAP-CVP)/CO (800-1200dynes/sec/cm5)
 SVRI (1970-2390dynes/sec/cm5/m2)
Cardiac output monitoring
Invasive
PA catheter
 Non invasive
TOE, Echo
Oesophageal Doppler
Transthoracic impedance
Arterial pulse contour analysis (PiCCO)
Arterial pulse power analysis (LiDCO)

Fick principle or indicator
dilution technique
PA catheter
PA catheter
Measures:
 Intracardiac pressures
 PA pressures
 Cardiac output
 Oxygen saturation
Indications:
 IHD, Cardiogenic shock
 RV failure
 Septic shock
 ARDS
 Periop: high risk
cardiac surgery or
neurosurgery
Contraindications:
 Tricuspid or pulm valve
mechanical prosthesis
 Right heart mass
(Tumour or thrombus)
 Tricuspid or pulmonary
endocarditis
PAOP (PCWP) significance
Estimates
 Left sided preload
 Left ventricular end diastolic pressure
 Extravascular lung water
 Miocardial O2 consumption
Thermodilution: Stewart
Hamilton equation
Oesophageal Doppler
Oesophageal Doppler
Measures:
Blood flow velocity in
the descending aorta
CO=VTIxCSAxHR
Parameters:
CO, SV, FTc, PV (peak
velocity), HR
CO: 86% agreement
between measured CO
with Doppler vs PAC
Normovolaemia Hypovolaemia
LiDCO
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Lithium indicator dilution
Continous, real time pulse power analysis rather than pulse
contour
Assumption than pulse power has a linear relationship with
flow, uses an algorithm to det CO
Minimally invasive
Safe
 Uses the CVP catheter
and A line
 Injectate 0.15-0.3 mmol
Lithium Chloride
Contraindications
-If already on Lithium
-Muscle relaxant drugs
-Weight less then 40 kg
-First 3 months pregnancy
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PiCCO
Pulse contour analysis
with intermittent
thermodilution
measurement
Good agreement with
PAC
Thermistor tipped A line
Relies on good A line
trace ( arrythmias, AoR,
Ao baloon, SVR up):
innaacuracies
PiCCO

Pulse contour analysis:
-Continuous pulse contour cardiac
analysis (PCCO)
-Arterial blood pressure (AP)
-Heart rate (HR)
-Stroke volume (SV)
-Stroke volume variation (SVV)
-Systemic vascular resistance
(SVR)
-Index of left ventricular
contractility

Intermittent
thermodilution:

Transpulmonary cardiac output
(CO)
Intrathoracic blood volume
(ITBV)
Extravascular lung water
(EVLW)
Cardiac function index (CFI)
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Impedance plethysmography
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2 sets circular wire electrodes around chest and
neck
Current passed between outer two( high frec, low
magnitude), with measurement of potential
difference between the inner two
Maximal rate of change of impedance occurs with
peak Ao flow
Movement, arrythmias and diathermy: innacuracies
More evidence in haemodynamically unstable
Thoracic bioreactance NICOM
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Modification of impedance technology
To improve the signal to noise ratio
Phase shift in voltage across thorax
4 electrodes across thorax
CO for L and R side and then averages
Also averages over 60s
Penaz technique
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Continous pulse contour analysis of NIBP ( also
known as vascular unloading technique)
Finger cuff applies pressure
Infrared light assesses the light absorbtion (artery
diameter)
Alters the pressure in the cuff to keep the diameter
constant (this pressure=BP)
Trace compared to oscillometric derived systolic and
diastolic values
Limitations: oedema or hypeperfusion, low CO, low
SVR
Others
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Pulse wave transit time: continous, derived
from ECG, sats probe trace and Art pressure
Radial artery tonometry
ECHO: LVEF, IVC collapsibility index
All might have a place in low/intermediate risk
patients, non-invasive haemodyn
optimisation, ED department and diagnostic
procedures