European Society for Computing and Technologyin Anesthesia and Intensive Care 2010

Non-invasive pulse contour cardiac output by Nexfin technology

Johannes J. van Lieshout, Wilbert A. Wesselink, Berend E. WesterhofSpecial Medical Care, Dpt Internal Medicine

Laboratory for Clinical Cardiovascular Physiology, Center for Heart Failure Research

Academic Medical Center Amsterdam

Casus

Casus

• Continuous Finger Arterial Pressure

• From Finger Pressure to Flow

Non-invasive pulse contour cardiac output - Outline

Clinical standard

9/00 JJvL05/06 JJvL

late 1970s: Non-Invasive Blood pressure Device (NIBD)

9/00 JJvL05/06 JJvL

Pressure as Function of Location in Arterial Tree

Nichols & O’Rourke 2005

Finger pressure

Portapres

Finometer

NexFin

Diameter of an artery under a finger cuff is kept constant (clamped) in spite of changes in arterial pressure during each heart beat

Blood Pressure - Volume Clamp

Diameter of an artery under a finger cuff is kept constant (clamped) in spite of changes in arterial pressure during each heart beat

Detection of arterial diameter by an infra-red plethysmograph built in the finger cuff

Blood Pressure - Volume Clamp

Diameter of an artery under a finger cuff is kept constant (clamped) in spite of changes in arterial pressure during each heart beat

Detection of arterial diameter by an infra-red plethysmograph built in the finger cuff

Changes in diameter opposed by a fast pressure servo controller that changes finger cuff pressure

Blood Pressure - Volume Clamp

Bogert LW, Van Lieshout JJ. Exp Physiol 2005;90(4):437-46

Blood Pressure - Volume Clamp

Diameter of an artery under a finger cuff is kept constant (clamped) in spite of changes in arterial pressure during each heart beat

Detection of arterial diameter by an infra-red plethysmograph built in the finger cuff

Changes in diameter opposed by a fast pressure servo controller that changes finger cuff pressure

Expert system (Physiocal ) defines and maintains the correct diameter at which the finger artery is clamped

Bogert LWJ et al. Anaesthesia, 2010

Martina J et al. Revision

Martina J et al. Revision

Martina J et al. Revision

• Continuous Finger Arterial Pressure

• From Finger Pressure to Flow

Non-invasive pulse contour cardiac output - Outline

Windkessel model 1-3

The 3 element Windkessel model is used to determine the afterload (Zin) of the heart for every beat

Windkessel model 2-3

Windkessel model 3-3

Nexfin CO-Trek

age

gender

height

weight

Z0

Cw

stroke volume

cardiac output

heart rate

RpPressure

MAP

Zin

05/06 JJvL

Harms MPM, Wesseling KH, Pott F, Jenstrup M, Van Goudoever J, Secher NH, Van Lieshout JJ. Clin Sci 1999 Jellema WT, Wesseling KH, Groeneveld AB, Stoutenbeek CP, Thijs LG, Van Lieshout JJ. Anesthesiology 1999

Nissen P, Van Lieshout JJ, Novovic S, Bundgaard-Nielsen M, Secher NH. Liver Transplantation 2009

Bogert LW, Wesseling KH, Schraa O, Van Lieshout EJ, De Mol BA, Van GJ, Westerhof BE, Van Lieshout JJ. Anaesthesia 2010

• Continuous Finger Arterial Pressure

• From Finger Pressure to Flow

Non-invasive pulse contour cardiac output - Outline

Continuous Cardiac Output

Tissue Perfusion & Oxygenation

Perspective