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Haemodynamic Monitoring. Theory and Practice. Haemodynamic Monitoring. Physiological Background Monitoring Optimising the Cardiac Output Measuring Preload Introduction to PiCCO Technology Practical Approach Fields of Application Limitations. Physiological Background.
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Haemodynamic Monitoring Theory and Practice
Haemodynamic Monitoring Physiological Background Monitoring Optimising the Cardiac Output Measuring Preload Introduction to PiCCO Technology Practical Approach Fields of Application Limitations
Physiological Background Task of the circulatory system Pflüger 1872: ”The cardio-respiratory system fulfils the physiological task of ensuring cellular oxygen supply” Goal Reached? Yes OK Assessment of oxygen supply and demand What is the problem? Diagnosis No Therapy Uni Bonn
Physiological Background Processes contributing to cellular oxygen supply Aim: Optimal Tissue Oxygenation Direct Control Indirect Pulmonary gas exchange Macrocirculation Microcirculation Cell function Volume Catecholamines Oxygen Utilisation Cells / Mitochondria Oxygen Absorption Lungs Oxygen Transportation Blood Oxygen Delivery Tissues Oxygen carriers Ventilation
Physiological Backgound Organ specific differences in oxygen extraction SxO2 in % Oxygen delivery must always be greater than consumption! modified from: Reinhart K in: Lewis, Pfeiffer (eds): Practical Applications of Fiberoptics in Critical Care Monitoring, Springer Verlag Berlin - Heidelberg - NewYork 1990, pp 11-23
Physiological Background Dependency of Oxygen Demand on delivery Behaviour of oxygen consumption and the oxygen extraction rate with decreasing oxygen supply Oxygen consumption Oxygen extraction rate DO2-independent area DO2- dependent area Decreasing Oxygen Supply DO2: Oxygen Delivery
Physiological Background Determinants of Oxygen Delivery and Consumption Central role of the mixed venous oxygen saturation CO SaO2 Delivery DO2: DO2 = CO x Hb x 1.34 x SaO2 Hb CO: Cardiac Output Hb: Haemoglobin SaO2: Arterial Oxygen Saturation SvO2: Mixed Venous Oxygen Saturation DO2: Oxygen Delivery VO2: Oxygen Consumption
Physiological Background Determinants of Oxygen Delivery and Consumption Central role of mixed central venous oxygen saturation CO SaO2 Delivery DO2: DO2 = CO x Hb x 1.34 x SaO2 Consumption VO2: VO2 = CO x Hb x 1.34 x (SaO2 - SvO2) Hb S(c)vO2 SvO2 Mixed Venous Saturation SvO2 CO: Cardiac Output Hb: Haemoglobin SaO2: Arterial Oxygen Saturation SvO2: Mixed Venous Oxygen Saturation DO2: Oxygen Delivery VO2: Oxygen Consumption
Physiological Background Oxygen delivery and its influencing factors DO2 = CaO2 x CO = Hb x 1.34 x SaO2 x CO Transfusion • Transfusion CO: Cardiac Output Hb: Haemoglobin SaO2: Arterial Oxygen Saturation CaO2: Arterial Oxygen Content
Physiological Background Oxygen delivery and its influencing factors DO2 = CaO2 x CO = Hb x 1.34 x SaO2 x CO Ventilation • Transfusion • Ventilation CO: Cardiac Output Hb: Haemoglobin SaO2: Arterial Oxygen Saturation CaO2: Arterial Oxygen Content
Physiological Background Oxygen delivery and its influencing factors DO2 = CaO2 x CO = Hb x 1.34 x SaO2 x CO Volume Catecholamines • Transfusion • Ventilation • Volume • Catecholamines CO: Cardiac Output Hb: Haemoglobin SaO2: Arterial Oxygen Saturation CaO2: Arterial Oxygen Content
Physiological Background Assessment of Oxygen Delivery Supply DO2 = CO x Hb x 1.34 x SaO2 SaO2 CO, Hb Oxygen Absorption Lungs Oxygen Transport Blood Oxygen Delivery Tissues Oxygen Utilization Cells / Mitochondria CO: Cardiac Output; Hb: Hemoglobin; SaO2: Arterial Oxygen Saturation
Physiological Background Assessment of Oxygen Delivery Supply Monitoring the CO, SaO2 and Hb is essential! SaO2 CO, Hb Oxygen Absorption Lungs Oxygen Transport Blood Oxygen Delivery Tissues Oxygen Utilization Cells / Mitochondria CO: Cardiac Output; Hb: Haemoglobin; SaO2: Arterial Oxygen Saturation
Physiological Background Assessment of Oxygen Delivery Supply Monitoring the CO, SaO2 and Hb is essential! SaO2 CO, Hb Oxygen Absorption Lungs Oxygen Transport Blood Oxygen Utilization Cells / Mitochondria Oxygen Delivery Tissues SvO2 VO2 = CO x Hb x 1.34 x (SaO2 – SvO2) Consumption CO: Cardiac Output; Hb: Haemoglobin; SaO2: Arterial Oxygen Saturation
Physiological Background Assessment of Oxygen Delivery Supply Monitoring CO, SaO2 and Hb is essential SaO2 CO, Hb Oxygen Absorption Lungs Oxygen Transport Blood Oxygen Delivery Tissues Oxygen Utilization Cells / Mitochondria SvO2 Monitoring the CO, SaO2 and Hb does not give information re O2-consumption! Consumption CO: Cardiac Output; Hb: Haemoglobin; SaO2: Arterial Oxygen Saturation
Physiological Background Balance of Oxygen Delivery and Consumption The adequacy of CO and SvO2 is affected by many factors Older Age Body weight /height Current Medical History Previous Medical History General Factors Microcirculation Disturbances Volume status Tissue Oxygen Supply Oxygenation / Hb level Situational Factors
Physiological Background Extended Haemodynamic Monitoring Monitoring Optimisation O2 supply O2 consumption Therapy
Physiological Background Summary and Key Points • The purpose of the circulation is cellular oxygenation • For an optimal oxygen supply at the cellular level the macro and micro-circulation as well as the pulmonary gas exchange have to be in optimal balance • Next to CO, Hb and SaO2 is SvO2 which plays a central role in the assessment of oxygen supply and consumption • No single parameter provides enough information for a full assessment of oxygen supply to the tissues.
Haemodynamic Monitoring Physiological Background Monitoring Optimizing the Cardiac Output Measuring Preload Introduction to PiCCO Technology Practical Approach Fields of Application Limitations
Monitoring Monitoring the Vital Parameters Respiration Rate Temperature
Monitoring Monitoring the Vital Parameters Respiration Rate ECG Temperature •Heart Rate •Rhythm
Monitoring Monitoring the Vital Parameters Respiration Rate Blood Pressure (NiBP) Temperature • no correlation with CO • no correlation with oxygen delivery ECG
Monitoring Monitoring the Vital Parameters MAP mmHg The Mean Arterial Pressure does not correlate with Oxygen Delivery! 150 120 90 60 n= 1232 DO2 ml*m-2*min-1 100 300 500 700 30 MAP: Mean Arterial Pressure, DO2: Oxygen Delivery Reinhart K in: Lewis, Pfeiffer (eds): Practical Applications of Fiberoptics in Critical Care Monitoring, Springer Verlag Berlin - Heidelberg - NewYork 1990, pp 11-23
Monitoring Monitoring the Vital Parameters Respiration Rate Blood Pressure (NiBP) Temperature • No correlation with CO • No correlation with oxygen delivery • No correlation with volume status ECG
Monitoring Monitoring the Vital Parameters 80% of blood volume is found in the venous blood vessels, only 20% in the arterial blood vessels!
Monitoring Monitoring the Vital Parameters Respiration Rate Blood Pressure (NiBP) • • No correlation with CO • • No correlation with oxygen delivery • • No correlation with volume status • No evidence of what is the ‘right’ perfusion pressure Temperature ECG
Monitoring Standard Monitoring Respiration Rate Oxygen Saturation Temperature •No information re the O2 transport capacity • No information re the O2 utilisation in the tissues ECG NIBP
Monitoring Standard Monitoring Respiration Rate Temperature ECG NIBP Oxygen Saturation Urine Production Blood Circulation (clinical assessment)
Monitoring Advanced Monitoring The standard parameters do not give enough information in unstable patients. What other parameters do I need?
Monitoring Advanced Monitoring Invasive Blood Pressure (IBP) •Continuous blood pressure recording • Arterial blood extraction possible • Limitations as with NiBP
Monitoring Advanced Monitoring Arterial BGA IBP Information re: •Pulmonary Gas exchange •Acid Base Balance No information re oxygen supply at the cellular level
Monitoring Advanced Monitoring IBP Lactate Marker for global metabolic situation Significant limitations due to: •Liver metabolism •Reperfusion effects Arterial BGA
Monitoring Advanced Monitoring IBP CVP • central venous blood gas analysis possible • When low: hypovolaemia probable • When high: hypovolaemia not excluded • Not a reliable parameter for volume status Arterial BGA Lactate
Monitoring Advanced Monitoring IBP ScvO2 •Good correlation with SvO2 (oxygen consumption) • Surrogate parameter for oxygen extraction • Information on the oxygen consumption situation • When compared to SvO2 less invasive (no pulmonary artery catheter required) Arterial BGA Lactate CVP
Monitoring Monitoring of the central venous oxygen saturation The ScvO2 correlates well with the SvO2! ScvO2 (%) SvO2 90 90 85 80 80 70 75 60 70 n = 29 r = 0.866 ScvO2 = 0.616 x SvO2 + 35.35 50 65 r = 0.945 40 60 30 30 40 50 60 70 80 90 40 50 60 70 80 90 ScvO2 SvO2 (%) Reinhart K et al: Intensive Care Med 60, 1572-1578, 2004; Ladakis C et al: Respiration 68, 279-285, 2000
A low ScvO2 is a marker for increased global oxygen extraction! 7.0 6.0 7.0 4.0 3.0 r= -0.664 n= 1191 avDO2= 12.7 -0.12*ScvO2 2.0 1.0 0 ScvO2 % Monitoring Monitoring of the central venous oxygen saturation avDO2 ml/dl 30 40 50 60 70 80 90 100 avDO2: arterial-venous oxygen content difference, ScvO2: central venous oxygen saturation Reinhart K in: Lewis, Pfeiffer (eds): Practical Applications of Fiberoptics in Critical Care Monitoring, Springer Verlag Berlin - Heidelberg - NewYork 1990, pp 11-23
Monitoring Monitoring of the central venous oxygen saturation avDO2 ml/dl 7.0 CO SaO2 6.0 Delivery DO2: DO2 = CO x Hb x 1.34 x SaO2 Consumption VO2: VO2 = CO x Hb x 1.34 x (SaO2 - S(c)vO2) 7.0 Hb 4.0 Mixed / Central Venous Saturation S(c)vO2 3.0 r= -0.664 n= 1191 avDO2= 12,7 -0.12*ScvO2 2.0 1.0 0 ScvO2 % 30 40 50 60 70 80 90 100 avDO2: arterial-venous oxygen content difference, ScvO2: central venous oxygen saturation Reinhart K in: Lewis, Pfeiffer (eds): Practical Applications of Fiberoptics in Critical Care Monitoring, Springer Verlag Berlin - Heidelberg - NewYork 1990, pp 11-23
Monitoring Monitoring of the central venous oxygen saturation Early goal-directed therapy Rivers E et al. New Engl J Med 2001;345:1368-77 O2- Therapy and Sedation Intubation + Ventilation Central Venous Catheter Invasive Blood Pressure Monitoring Cardiovascular Stabilisation Mortality < 8 mmHg Volume therapy CVP 8-12 mmHg < 65 mmHg Vasopressors MAP Hospital 60 days 65 mmHg < 70% Blood transfusion to Haematocrit 30% < 70% ScVO2 ScVO2 Inotropes >70% 70% yes Therapy maintenance, regular reviews no Goal achieved?
Monitoring Monitoring of the ScvO2 – Clinical Relevance Significance of the ScvO2 for therapy guidance 39
Monitoring Monitoring of the ScvO2 – Clinical Relevance Early monitoring of ScvO2 is crucial for fast and effective hemodynamic management! 40
Monitoring Monitoring ScvO2 – therapeutic consequences in the example of sepsis Pt unstable ScvO2 < 70% Volume bolus (when absence of contraindications) ScvO2 < 70% ScvO2 > 70% or < 80% Continuous ScvO2 monitoring – CeVOX Advanced Monitoring - PiCCO Re - evaluation Volume / Catecholamine Erythrocytes 41
Monitoring Monitoring ScvO2 – Limitations Tissue hypoxia despite ”normal“ or high ScvO2? SxO2 in % ? Microcirculation disturbances in SIRS / Sepsis modified from: Reinhart K in: Lewis, Pfeiffer (eds): Practical Applications of Fiberoptics in Critical Care Monitoring, Springer Verlag Berlin - Heidelberg - NewYork 1990, pp 11-23 42
Monitoring Monitoring ScvO2 – therapeutic consequences in the example of sepsis Tissue hypoxia despite „normal“ or high ScvO2? ScvO2 Pt unstable ScvO2 <70% ScvO2 > 80% Volume administration (when absence of contraindications) ScvO2 >70% but < 80% ScvO2 <70% ? Re- evaluation Advanced Monitoring cont. ScvO2 monitoring Volume / Catecholamine / Erythrocytes
Monitoring Monitoring ScvO2 – therapeutic consequences in the example of sepsis Tissue hypoxia despite ”normal“ or high ScvO2? Pt unstable ScvO2 > 80% Volume bolus (when absence of contraindications) ScvO2 > 80% ScvO2 <80% but > 70% Microcirculation? Organ perfusion? Re-evaluation Further information needed Macro-haemodynamics (PiCCO) Liver function (PDR – ICG) Renal function Neurological assessment 44
Monitoring Summary and Key Points • Standard monitoring does not give information re the volume status or the adequacy of oxygen delivery and consumption. • The CVP is not a valid parameter to measure volume status • The measurement of central venous oxygen saturation gives important information re global oxygenation balance and oxygen extraction • Measuring the central venous oxygenation can reveal when more advanced monitoring is indicated 45
Haemodynamic Monitoring Physiological Background Monitoring Optimising the Cardiac Output Measuring Preload Introduction to PiCCO Technology Practical Approach Fields of Application Limitations
Optimisation of CO Monitoring – what is the point? The haemodynamic instability is identified. What can be done for the patient (sepsis example)? Aim? Optimisation of CO 1. Step: Volume Management Recommendation of the SSC How can you optimise CO? 47
Optimisation of CO Monitoring – what is the point? Optimisation of CO Preload Contractility Afterload Chronotropy Frank-Starling mechanism 48
Optimisation of CO Preload, CO and Frank-Starling Mechanism SV V SV SV V Normal contractility SV V volume responsive target area volume overloaded Preload 49
SV V SV V Optimisation of CO Preload, CO and Frank-Starling Mechanism SV Normal contractility Poor contractility volume responsive target area volume overloaded Preload 50