cardiac output monitoring monica morosan. typical value end diastolic volume (edv)120 ml (65 - 240...

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 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

PiCCO

Pulse contour analysis with intermittent thermodilution measurement

Good agreement with PAC

Thermistor tipped A lineRelies 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)

Impedance plethysmography

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

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 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

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