Book contents
- Frontmatter
- Contents
- Contributors
- Preface
- Foreword
- Abbreviations
- SECTION 1 Admission to Critical Care
- SECTION 2 General Considerations in Cardiothoracic Critical Care
- 8 Managing the airway
- 9 Tracheostomy
- 10 Venous access
- 11 Invasive haemodynamic monitoring
- 12 Pulmonary artery catheter
- 13 Minimally invasive methods of cardiac output and haemodynamic monitoring
- 14 Echocardiography and ultrasound
- 15 Central nervous system monitoring
- 16 Point of care testing
- 17 Importance of pharmacokinetics
- 18 Radiology
- SECTION 3 System Management in Cardiothoracic Critical Care
- SECTION 4 Procedure-Specific Care in Cardiothoracic Critical Care
- SECTION 5 Discharge and Follow-up From Cardiothoracic Critical Care
- SECTION 6 Structure and Organisation in Cardiothoracic Critical Care
- SECTION 7 Ethics, Legal Issues and Research in Cardiothoracic Critical Care
- Appendix Works Cited
- Index
13 - Minimally invasive methods of cardiac output and haemodynamic monitoring
from SECTION 2 - General Considerations in Cardiothoracic Critical Care
Published online by Cambridge University Press: 05 July 2014
- Frontmatter
- Contents
- Contributors
- Preface
- Foreword
- Abbreviations
- SECTION 1 Admission to Critical Care
- SECTION 2 General Considerations in Cardiothoracic Critical Care
- 8 Managing the airway
- 9 Tracheostomy
- 10 Venous access
- 11 Invasive haemodynamic monitoring
- 12 Pulmonary artery catheter
- 13 Minimally invasive methods of cardiac output and haemodynamic monitoring
- 14 Echocardiography and ultrasound
- 15 Central nervous system monitoring
- 16 Point of care testing
- 17 Importance of pharmacokinetics
- 18 Radiology
- SECTION 3 System Management in Cardiothoracic Critical Care
- SECTION 4 Procedure-Specific Care in Cardiothoracic Critical Care
- SECTION 5 Discharge and Follow-up From Cardiothoracic Critical Care
- SECTION 6 Structure and Organisation in Cardiothoracic Critical Care
- SECTION 7 Ethics, Legal Issues and Research in Cardiothoracic Critical Care
- Appendix Works Cited
- Index
Summary
Introduction
Minimally invasive haemodynamic monitoring devices are increasingly beingused in cardiac critical care. Their advantages include ease of set-up, continuous measurement of stroke volume (SV) and cardiac output (CO) and the ability to provide other haemodynamic data to assist circulatory management.
Arterial pressure monitors
LiDCO and PiCCO monitors use a modified form of the Fick principle to analyze the arterial pressure waveform and calculate specific data based on this. They both allow calculation of CO and preload responsiveness, a useful measure of intravascular volume.
Cardiac output
THE LIDCO
The LiDCO (Lithium Dilution Continuous Cardiac Output monitor) detects changes in the concentration of a fixed dose of lithium. Lithium is chosen because of its low toxicity and high signal-to-noise ratio. Lithium is injected via a central venous line and sensed via a radial or other systemic arterial line every time the monitor is calibrated. This allows measurement of CO using the Fick principle and calibrates the instrument for further readings. Calibration is recommended when the monitor is first connected to a patient, and then every 24 hours. This method uses a characteristic of the arterial pulse waveform known as the pulse power. Pulse power analysis makes use of the law of mass conservation, and assumes that within a fixed circulatory system, any acute changes in that system are due to changes in SV input.
- Type
- Chapter
- Information
- Core Topics in Cardiothoracic Critical Care , pp. 97 - 102Publisher: Cambridge University PressPrint publication year: 2008