1. Haemodynamic Monitoring Theory and Practice

2. 2 Haemodynamic Monitoring A.Physiological Background B.Monitoring C.Optimising the Cardiac Output D.Measuring Preload E.Introduction to PiCCO Technology F.Practical Approach G.Fields of Application H.Limitations

3. 3 Task of the circulatory system Pflüger 1872: ”The cardio-respiratory system fulfils the physiological task of ensuring cellular oxygen supply” Physiological Background Uni Bonn Goal Reached? Assessment of oxygen supply and demand OK No Yes What is the problem? Diagnosis Therapy

4. 4 Physiological Background Processes contributing to cellular oxygen supply Aim: Optimal Tissue Oxygenation Pulmonary gas exchange Macrocirculation MicrocirculationCell function Direct ControlIndirect Oxygen Absorption Lungs Oxygen Transportation Blood Oxygen Delivery Tissues Oxygen Utilisation Cells / Mitochondria Volume Catecholamines Oxygen carriersVentilation

5. 5 Organ specific differences in oxygen extraction Physiological Backgound Oxygen delivery must always be greater than consumption! SxO 2 in % 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

6. 6 Physiological Background Dependency of Oxygen Demand on delivery Behaviour of oxygen consumption and the oxygen extraction rate with decreasing oxygen supply Oxygen consumption DO 2 -independent area DO 2 - dependent area Oxygen extraction rate Decreasing Oxygen Supply DO 2 : Oxygen Delivery

7. 7 Central role of the mixed venous oxygen saturation Physiological Background Determinants of Oxygen Delivery and Consumption Delivery DO 2 : DO 2 = CO x Hb x 1.34 x SaO 2 CO: Cardiac Output Hb: Haemoglobin SaO 2 : Arterial Oxygen Saturation SvO 2 : Mixed Venous Oxygen Saturation DO 2 : Oxygen Delivery VO 2 : Oxygen Consumption SaO 2 CO Hb

8. 8 Central role of mixed central venous oxygen saturation Physiological Background Determinants of Oxygen Delivery and Consumption SaO 2 S(c)vO 2 Consumption VO 2 : VO 2 = CO x Hb x 1.34 x (SaO 2 - SvO 2 ) Delivery DO 2 : DO 2 = CO x Hb x 1.34 x SaO 2 CO Hb Mixed Venous Saturation SvO 2 SvO 2 CO: Cardiac Output Hb: Haemoglobin SaO 2 : Arterial Oxygen Saturation SvO 2 : Mixed Venous Oxygen Saturation DO 2 : Oxygen Delivery VO 2 : Oxygen Consumption

9. 9 Oxygen delivery and its influencing factors Physiological Background DO 2 = CaO 2 x CO = Hb x 1.34 x SaO 2 x CO Transfusion CO: Cardiac Output Hb: Haemoglobin SaO 2 : Arterial Oxygen Saturation CaO 2 : Arterial Oxygen Content

10. 10 Oxygen delivery and its influencing factors Physiological Background DO 2 = CaO 2 x CO = Hb x 1.34 x SaO 2 x CO Ventilation Transfusion Ventilation CO: Cardiac Output Hb: Haemoglobin SaO 2 : Arterial Oxygen Saturation CaO 2 : Arterial Oxygen Content

11. 11 Oxygen delivery and its influencing factors Physiological Background DO 2 = CaO 2 x CO = Hb x 1.34 x SaO 2 x CO Volume Catecholamines Transfusion Ventilation Volume Catecholamines CO: Cardiac Output Hb: Haemoglobin SaO 2 : Arterial Oxygen Saturation CaO 2 : Arterial Oxygen Content

12. 12 Assessment of Oxygen Delivery Physiological Background CO: Cardiac Output; Hb: Hemoglobin; SaO 2 : Arterial Oxygen Saturation CO, HbSaO 2 DO 2 = CO x Hb x 1.34 x SaO 2 Oxygen Absorption Lungs Oxygen Transport Blood Oxygen Delivery Tissues Oxygen Utilization Cells / Mitochondria Supply

13. 13 Assessment of Oxygen Delivery Physiological Background CO, HbSaO 2 Monitoring the CO, SaO 2 and Hb is essential! Oxygen Absorption Lungs Oxygen Delivery Tissues Oxygen Utilization Cells / Mitochondria Oxygen Transport Blood CO: Cardiac Output; Hb: Haemoglobin; SaO 2 : Arterial Oxygen Saturation Supply

14. 14 Assessment of Oxygen Delivery Physiological Background SvO 2 SaO 2 CO, Hb Monitoring the CO, SaO 2 and Hb is essential! VO 2 = CO x Hb x 1.34 x (SaO 2 – SvO 2 ) Oxygen Utilization Cells / Mitochondria Oxygen Absorption Lungs Oxygen Transport Blood Oxygen Delivery Tissues CO: Cardiac Output; Hb: Haemoglobin; SaO 2 : Arterial Oxygen Saturation Supply Consumption

15. 15 Assessment of Oxygen Delivery Physiological Background SvO 2 SaO 2 CO, Hb Monitoring CO, SaO 2 and Hb is essential Monitoring the CO, SaO 2 and Hb does not give information re O 2 -consumption! Oxygen Utilization Cells / Mitochondria Oxygen Absorption Lungs Oxygen Transport Blood Oxygen Delivery Tissues CO: Cardiac Output; Hb: Haemoglobin; SaO 2 : Arterial Oxygen Saturation Supply Consumption

16. 16 Situational Factors Balance of Oxygen Delivery and Consumption The adequacy of CO and SvO 2 is affected by many factors Microcirculation Disturbances Volume status Tissue Oxygen Supply Oxygenation / Hb level Older Age Body weight /height Current Medical History Previous Medical History Physiological Background General Factors

17. 17 Physiological Background Extended Haemodynamic Monitoring Therapy Optimisation O 2 supply O 2 consumption Monitoring

18. 18 Summary and Key Points Physiological Background 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 SaO 2 is SvO 2 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.