Pulse contour cardiac output, PiCCO - Intensive Care ...

INTENISVE CARE SERVICE 

NURSING POLICY& PROCEDURES 

NAME OF POLICY: PULSE CONTOUR CARDIAC OUTPUT (PiCCO) 

GOAL: TO EVALUATE CARDIOPULMONARY AND CIRCULATORY 

VARIABLES 

Introduction: 

The PULSION PiCCO is indicated in patients where cardiovascular volume status monitoring is 

necessary. Cardiac output is determined both continuously through arterial pulse contour 

analysis and intermittently through transpulmonary thermodilution technique. In addition, the 

PiCCO measures heart rate, systolic and diastolic pressure and derives mean arterial pressure. 

Analysis of the thermodilution curve in terms of mean transit time (MTt) and downslope time 

(Dst) is used for determination of intra- and extravascular fluid volumes. If patient weight and 

height are entered the PiCCO presents the derived parameters indexed to body surface area 

(BSA). 

Equipment: 

• PV2015L20 PULSIOCATH arterial line 5Fx20cm 

• PV8115 Pulsion pressure transducer with PV4046 inline injectate sensor housing 

• M1012A#C10 C.O. Module with PiCCO capability 

• M1643A Cardiac Output cable 

• M1006B Pressure module with PMK 206 white Utah pressure cable 

• PC80102 Pulsion Inline Injectate Temperature Cable 

• 20ml Syringe 

• 500ml bag 5%Dextrose 

Pre Procedure: 

• Inform patient and significant others if applicable 

• Adhere to universal precautions 

• Insert 500mls preloaded heparin bag, into pressure bag, spike bag with transducer kit, inflate 

to 300mmHg and prime the line, ensuring air bubbles are evacuated 

• Align transducer to phlebostatic axis (4 th intercostal space mid axilla line) 

• ‘zero’ transducer to atmospheric air 

Post Procedure: 

• Secure arterial line appropriately 

• Connect to patient 

© ROYAL PRINCE ALFRED HOSPITAL INTENSIVE CARE SERVICE

Connecting the patient: 

PiCCO 

• Check that the C.O. module Option C10 is inserted into the rack. 

• Make sure that the patient’s height and weight have been entered into the haemodynamic 

calculation menu. 

• Plug the C.O. interface cable into the C.O. module 

• Attach the inline injectate sensor housing (PV4046) to the CVP lumen on central line (if 

CVC being inserted follow CVC policy) and attach inline injectate temperature cable 

(PULSION PC80102) between the housing and the cardiac output interface cable (M1643A) 

• Attach the blood temperature cable of the CO interface cable (M1643A) to the 

PULSIOCATH arterial line thermistor 

• Attach the PULSION pressure transducer (PV8115) to the PULSIOCATH arterial line 

• Attach the Pressure transducer cable (PMK-206) to the pressure transducer module 

(M1006B) 


Setup the monitor: 

• Enter the Setup CO menu by pressing CO on touch screen 

The method = Transpulmonary 

The injectate temperature probe = M1646 (PV4046) 

Enter CCO 

The Source of CCO = same as the name of the transducer connected to the 

PiCCO arterial line. Must be ABP not ART. 

Enter Cardiac output 

The catheter constant = 342 or whatever is on the catheter packet 

The volume of injectate = 20mls 

If any of the above items need changing select the item on the menu in the 

setup CO window and change to the appropriate setting. 

Performing Cardiac Output: 

• Select Cardiac Output 

• In the first C.O. measurement Task Window. A message “…Ready for new measurement” 

will appear on the screen. 

• Press Start C.O. and wait for the message “…Stable baseline inject now!” to appear on the 

screen. 

• Inject the 20mls of room temperature injectate as quickly as possible and in a smooth 

constant motion 

• At the end of the measurement the thermodilution curve, cardiac output, ITBVI and EVLWI 

indexed values 

• After waiting for one minute a message will appear “ready for new measurement” repeat 

steps 3 – 5 

• Continue to repeat this procedure until you have completed all the measurements you want to 

perform. If 2 thermodilution curves result in values within 10% of each other then further 

curves are unnecessary. You can perform a maximum of 6 measurements before editing 

(select which curves should be used for the averaging calculation). 

• Select which curve you want to edit. 

• Select Accept Reject. The curves you have selected will be green and the curves rejected 

red. If there is a question mark before the value it means the result may not be accurate. 

• Manual selection of the individual thermodilution curves enables the user to edit the final 

C.O. measurement. An average is calculated for the undeleted measurements and stored 

when Save CO and calibrate CCO is pressed. The average of multiple thermodilution 

measurements should be used for therapy decisions. Averages are also calculated for the 

EVLW, ITBV and CFI. The averaged C.O. data is then used to calibrate Continuous Cardiac 

Output (CCO). 

• If the message “high ETVI, more indicator required” appears cold fluid will need to be used. 

The cold fluid must be

Contraindication: 

• Patients receiving intra-aortic balloon counter pulsation (IABP) cannot be monitored with the 

PiCCO 

Nursing Responsibilities: 

• A measurement should be performed at least 8 th hourly to calibrate the PCCO and more 

frequently if there is a marked change in haemodynamics 

• Other nursing responsibilities see Arterial Line and CVC policies. 

Removal of Arterial Line: 

• See Arterial Line policy. 

• Consider the use of a ‘Femstop’ due to femoral vessel. 

• 

Parameters: 

The following parameters can be derived by transpulmonary thermodilution: 

Arterial 

Thermodilution 

Absolute 

Parameters 

Indexed 

Parameters 

Parameter Abbr. Unit Abbr. Unit 

Cardiac output, arterial C.O.a l/min CIa l/min/m 2 

Cardiac function index CFI 1/min 

Global end diastolic volume GEDV ml 

lntrathoracic blood volume ITBV mI ITBVI mI/m 2 

Extravascular lung water 

EVLW ml EVLW I ml/kg 

After initial calibration the following parameters can continuously derived by pulse contour 

analysis: 

Pulse Contour 

Absolute 

Parameters 

Indexed 

Parameters 

Parameter Abbr. Unit Abbr. Unit 

Pulse contour cardiac output PCCO l/min PCCI l/min/ 

m 2 

Systolic arterial blood pressure APsys mmHg 

Diastolic arterial blood pressure APdia mmHg 

Mean arterial blood pressure MAP mmHg ITBVI mI/m 2 

Heart rate HR 1/min 

Stroke volume SV ml SVI ml/m 2 

Stroke volume variation SVV % 

Systemic vascular resistance SVR dyn/sec/cm -5 

SVRI dyn/se 

c/cm – 

Index of left ventricular contractility DP/dtmax mmHg/s 

© ROYAL PRINCE ALFRED HOSPITAL INTENSIVE CARE SERVICE 

5 /m 2

INTERMITTENT VOLUMETRIC THERMODILUTION 

Cardiac Output (CO) is generally determined using the Stewart-Hamilton method. To 

accomplish thermodilution determination, a known volume of cold (at least 10°C lower than 

blood temperature) solution is injected intravenously as fast as possible. The recorded 

downstream temperature change is dependent on the flow and on the volume through which the 

cold indicator has passed. As a result, a thermodilution curve can be constructed. The PiCCO 

detects the indicator in the arterial system (preferably the femoral artery). The transpulmonary 

thermodilution curves are much longer and flatter than the respective pulmonary artery 

thermodilution curves. Compared to pulmonary artery thermodilution, the arterial thermodilution 

measurement has minimal ventilatory variations. 

Methods: 

The cardiopulmonary system represents a series of different mixing chambers for an indicator 

which has been injected central venously. 


Principles of Volume Calculation: 

Specific volumes can be calculated by multiplying the cardiac output (C.O.a) by characteristic 

transit times determined through the indicator dilution curves. 

For this the PiCCO calculates the mean transit time (MTt) and the exponential downslope time 

(Dst) of the thermodilution curve. 

MTt Volume: 

The result of the product of C.O. and MTt is the volume through which the relevant indicator has 

travelled. ie. the complete volume between the site of injection and the site of detection. For the 

cold indicator this is the total intrathoracic thermal volume (ITTV) which is composed of the 

global end-diastolic volume (GEDV), pulmonary blood volume (PBV), and extravascular lung 

water (EVLW). 

ITTV = CO x MTtTDa 

DSt Volume: 

The result of the product of CO and DSt is the largest individual mixing volume in a series of 

indicator dilution mixing chambers. For the cold indicator this is the pulmonary thermal volume 

(PTV) which is composed of PBV and EVLW. 

PTV = CO x DStTDa 


EVL 

RAED RVED LAED LVED 

PB 

EVL 

EVL 

PB 

EVL

Combination: 

By subtraction of PTV from ITTV one obtains a volume which represents the global enddiastolic 

volume. 

GEDV = ITTV - PTV 

Global end-diastolic volume is the sum of all end diastolic volumes of the atria and the 

ventricles. Thus, GEDV is equivalent to preload volume of the total heart. 

Traditionally central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) 

are used as indicators of cardiac preload. However, both CVP and PCWP are dependent on 

intravascular filling, intrathoracic pressure, vascular compliance and cardiac contractility. In 

contrast to pressures, GEDV represents cardiac preload volume. 

Intrathoracic Blood Volume (ITBV): 

ITBV = 1.25 x GEDV 

RAED RVED LAED LVED 

RAEDV RVEDV PBV 

LAEDV LVEDV 

Intrathoracic blood volume (ITBV) consists of the global end-diastolic volume (GEDV, is 

approximately 4/5 of ITBV) and the pulmonary blood volume (PBV). ITBV is calculated by 

GEDV x 1.25. 

Three volumes are found in the thorax, the intrathoracic blood volume, the intrathoracic gas 

volume and the extravascular lung water. Due to the limited expandability of the thorax, the 

volumes interact and change proportionally to each other. 

Lichtwarck-Aschoff et al. Were able to show that in intensive care patients on mechanical 

ventilation, ITBV reflects the status of the circulating blood volume. 


Extravascular Lung Water (EVLW): 

EVLW = ITTV - ITBV 

Arterial thermodilution results in the direct measurement of pulmonary thermal volume (PTV) 

and intrathoracic thermal volume (ITTV). From these values the extravascular lung water 

(EVLW) is assessable by the following: 

The water content in the lungs increases through left heart failure, pneumonia, ALI, and ARDS. 

Increased EVLW can occur through increased fluid transport to the interstitium, resulting from 

either high intravascular filtration pressure (left heart failure, volume overload) or an increased 

pulmonary vascular permeability for plasma proteins, which drag water along with them, 

corresponding to their colloid osmotic pressure. 

Relationship between intrathoracic blood volume and extravascular lung 

water: 

As it is known that the level of EVLW is related to patient outcome any measures to reduce 

EVLW are most likely to shorten ventilation days and stay in the ICU and reduce possible 

complications (pneumonia, pneumothorax, etc.). 

The hydrostatic component of increased EVLW can be reduced by volume restriction. In the 

lower diagram it is shown that below the normal range of ITBV one cannot reduce EVLW 

anymore. Therefore ITBV representing cardiac preload should not be driven below this level in 

order to avoid further reduction in cardiac output and hence oxygen supply to the body, as this 

would not result in a further reduction of extravascular lung water. 

Cardiac Function Index (CFI): 

Cardiac function index (CFI) is derived as the ratio of cardiac output divided by global enddiastolic 

volume. 

CFI = CI / GEDVI 


EVL 

EVL

Principle of Measurement: 

PULSE CONTOUR ANALYSIS 

During cardiac systole blood is ejected into the aorta. Simultaneously, blood flows out of the 

aorta into the peripheral vascular system. However, during the time of ejection, the sum of all 

blood flowing into the aorta is larger than the blood volume entering the peripheral vascular 

system. thus, the volume of the aorta increases. In the subsequent diastole, most of the remaining 

blood will empty into the peripheral vasculature. This behaviour is dependent on the ability of 

the aorta to expand and contract in response to ejected volumes. The volume change and 

subsequent pressure change is described as the compliance function of the aorta. 


The relationship between blood flow out of the aorta and pressure measured at the end of the 

aorta (femoral artery or other large artery) is determined by the compliance function. The 

compliance function can therefore be characterised by measuring blood pressure and blood flow 

(cardiac output) simultaneously. Transpulmonary thermodilution cardiac output (C.O.) 

determined simultaneously with continuous arterial pressure (AP) measurement is utilized to 

calibrate the pulse contour analysis to each individual patients aortic compliance function. 

For the continuous calculation of PCCO the PiCCO uses a calibration factor (cal) determined by 

the thermodilution cardiac output measurement and the heart rate (HR), as well as the integrated 

values for the area under the systolic part of the pressure curve (P(t)/SVR), the aortic compliance 

(C(p)) and the shape of the pressure curve, represented by change of pressure over change of 

time (dP/dT) 

Calibration of Pulse Contour Analysis: 

To derive the calibration factor ‘cal’ and the individual compliance function C(p) a reference 

transpulmonary thermodilution cardiac output is necessary. 

Pulse Contour Cardiac Output (PCCO): 

When the calibration factor ‘cal’ and the individual compliance function C(p) is determined, 

continuous cardiac output can be measured using the heart rate and the area under the aortic flow 

curve. Displayed PCCO is the mean value of the last 12 seconds. 


Arterial Blood Pressure (AP): 

Arterial blood pressure is one of the most important diagnostic parameters for patient 

management. The PiCCO measures the arterial pressure continuously using a special arterial 

thermodilution catheter with an additional pressure lumen. The arterial thermodilution and 

arterial pressure measurement can be done with the same catheter. The arterial pressure is 

registered by a pressure transducer. Displayed AP is the mean value over the last 12 seconds. 

Stroke Volume Variation (SVV): 

Stroke volume variation is presented as the change in stroke volume (in percent) calculated by 

the mean difference between highest and lowest stroke volume divided by a calculated mean 

stroke volume over the last 30 seconds. 

In mechanically ventilated patients, the SVV mainly depends on the intravascular volume of the 

patient. Big variations in stroke volume, induced by mechanical ventilation, is an indication of 

insufficient intravascular volume relative to the applied intrathoracic pressures. Thus, SVV 

allows a rough estimation of the vascular volume status. When high SVV is detected, it is 

recommended to perform a thermodilution measurement to quantify the volume status by 

measuring the ITBV. 

Systemic Vascular Resistance: 

The systemic vascular resistance is the quotient of driving pressure and cardiac output over the 

last 12 seconds. Here, the driving pressure represents the difference between mean arterial 

pressure (MAP) and central venous pressure (CVP). 

Complications: 

• See Arterial Line policy and CVC policy. 

SVR = (MAP - CVP) 

C.O.a 


x80

REFERENCES: 

Godje, O. Hoke, K. et al (2002) Reliability of a new algorithm for continuous cardiac output 

determination by pulse contour analysis during hemodynamic instability. Lippincott 

Williams and Wilkins. 

PULSION Medical Systems Operators Manual September 2000 

PULSION Pacific Information Package March 2000 

PULSION Medical Systems Rapid, less invasive continuous cardiac output, intrathoracic 

blood volume, and extravascular lung water monitoring. 

Occupational Health and Safety: Universal precautions taken in the preparation, administration of drug and 

disposal of equipment and sharps. 

Cross Referenced: RPAH Occ. Health & Safety Manual and Infection Control Manual 

NSW Infection Control Policy 98/99 

Written By: Cheryl Richards (CNE) February 2003. 

Authorised by: Richard Totaro (Intensivist) March 2003 

Revision due: March 2005

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