HEMODYNAMIC HEMODYNAMIC MONITORINGMONITORING

IRVAN SETIAWANIRVAN SETIAWAN

IntroductionIntroduction

Hemodynamic:Hemodynamic:– study of the motion of blood through the bodystudy of the motion of blood through the body– Measurement & interpretation of biological Measurement & interpretation of biological

systems that describe performance of the systems that describe performance of the cardiovascular systemcardiovascular system

Oxygen Delivery is the GoalOxygen Delivery is the Goal

Oxygen DeliveryOxygen Delivery DO2 = CO x CaO2 x 10DO2 = CO x CaO2 x 10 CO = HR x SV CO = HR x SV CaO2 = [1.34 x Hb x SaO2 ] + [0.003 x CaO2 = [1.34 x Hb x SaO2 ] + [0.003 x

PaO2]PaO2]

Oxygen ConsumptionOxygen Consumption CVO2 = [1.34 x Hb x SvO2 ] + [.003 x PVO2]CVO2 = [1.34 x Hb x SvO2 ] + [.003 x PVO2] VO2 = CO x 3(CaO2 –CvO2 ) x 10VO2 = CO x 3(CaO2 –CvO2 ) x 10

Methods of Hemodynamic MonitoringMethods of Hemodynamic Monitoring

Arterial Blood PressureArterial Blood Pressure– Non-invasiveNon-invasive– Direct arterial pressure measurementDirect arterial pressure measurement

Central Venous PressureCentral Venous Pressure The Pulmonary Artery CatheterThe Pulmonary Artery Catheter Cardiac Output MeasurementCardiac Output Measurement Tissue OxygenationTissue Oxygenation

Non-invasive Blood Pressure MonitoringNon-invasive Blood Pressure Monitoring

Limitations of Non-invasive Blood Limitations of Non-invasive Blood Pressure MonitoringPressure Monitoring

Cuff must be placed correctly and must be Cuff must be placed correctly and must be appropriately sizedappropriately sized– Auscultatory method is very inaccurate Auscultatory method is very inaccurate

Korotkoff sounds difficult to hearKorotkoff sounds difficult to hear– Significant underestimation in low-flow (i.e. Significant underestimation in low-flow (i.e.

shock) statesshock) states Oscillometric measurements also Oscillometric measurements also

commonly inaccurate (> 5 mm Hg off commonly inaccurate (> 5 mm Hg off directly recorded pressures)directly recorded pressures)

Direct Arterial Blood Pressure Direct Arterial Blood Pressure MeasurementMeasurement

Indications for Arterial CatheterizationIndications for Arterial Catheterization

Need for continuous blood pressure Need for continuous blood pressure measurementmeasurement– Hemodynamic instabilityHemodynamic instability– Vasopressor requirementVasopressor requirement– Respiratory failure Respiratory failure Frequent arterial blood Frequent arterial blood

gas assessmentsgas assessments Most common locations: radial, femoral, Most common locations: radial, femoral,

axillary, and dorsalis pedisaxillary, and dorsalis pedis

Complications of Arterial CatheterizationComplications of Arterial Catheterization

HemorrhageHemorrhage HematomaHematoma ThrombosisThrombosis Proximal or distal embolizationProximal or distal embolization PseudoaneurysmPseudoaneurysm InfectionInfection

Limitations of Arterial CatheterizationLimitations of Arterial Catheterization

Pressure does not accurately reflect flow Pressure does not accurately reflect flow when vascular impedance is abnormalwhen vascular impedance is abnormal

Systolic pressure amplificationSystolic pressure amplification– Mean pressure is more accurateMean pressure is more accurate

Recording artifactsRecording artifacts– UnderdampingUnderdamping– OverdampingOverdamping

Central Venous CatheterizationCentral Venous Catheterization

Central venous pressureCentral venous pressure– Right atrial (superior vena cava) pressureRight atrial (superior vena cava) pressure– Limited by respiratory variation and PEEPLimited by respiratory variation and PEEP

Central venous oxygen saturationCentral venous oxygen saturation– SCvO2SCvO2– Correlates with SMVO2 assuming stable Correlates with SMVO2 assuming stable

cardiac functioncardiac function– Goal-directed resuscitation in severe sepsis Goal-directed resuscitation in severe sepsis

and septic shock (Rivers, et al)and septic shock (Rivers, et al)

Central Venous CanulationCentral Venous Canulation

IndicationsIndications– Measure central venous pressureMeasure central venous pressure– Access for resuscitationAccess for resuscitation– Selected drug administrationSelected drug administration– Placement of pulmonary artery catheterPlacement of pulmonary artery catheter

ComplicationsComplications– Hematoma/vessel injury/blood lossHematoma/vessel injury/blood loss– Pneumothorax/hemothoraxPneumothorax/hemothorax– Cardiac arrhythmiasCardiac arrhythmias– InfectionInfection

LevelingLeveling

MeasurementMeasurement

Central Venous Pressure WaveformCentral Venous Pressure Waveform

The Pulmonary Artery CatheterThe Pulmonary Artery Catheter

HJC Swan and Santa Monica Bay sailboats (NEJM HJC Swan and Santa Monica Bay sailboats (NEJM 1970)1970)

Widespread use in critically ill patientsWidespread use in critically ill patients– Remains controversialRemains controversial– Lack of prospective, randomized trialsLack of prospective, randomized trials– PAC data are only as good as the clinicians’ PAC data are only as good as the clinicians’

interpretation and applicationinterpretation and application Measures CVP, PAP, PAOP, Cardiac Index and Measures CVP, PAP, PAOP, Cardiac Index and

SVO2SVO2 Approximately 1 million PACs placed annuallyApproximately 1 million PACs placed annually

Pulmonary Artery CatheterPulmonary Artery Catheter

Pulmonary Artery Catheter InsertionPulmonary Artery Catheter Insertion

Normal Hemodynamic ValuesNormal Hemodynamic Values

Pulse OximetryPulse Oximetry

Estimates HbOEstimates HbO22 as SpO as SpO22

HR displayed shoud be = pulse rateHR displayed shoud be = pulse rate

Oximeter sensorsOximeter sensors

Source of ErrorSource of Error

Physiologic/anatomicalPhysiologic/anatomical

– Vasoconstriction/poor perfusionVasoconstriction/poor perfusion

– Abnormal hemoglobinAbnormal hemoglobin

– Skin pigmentationSkin pigmentation ExternalExternal

– Motion of sensorMotion of sensor

– Extraneous lightExtraneous light

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