LiDCO™plus Frequently Asked Questions & Features and Benefits

Introducing the Hemodynamic Monitor

  1. What is the science underlying the LiDCO™plus Hemodynamic Monitor?

    The plus Hemodynamic Monitor hosts the complementary LiDCO™ & PulseCO™ softwares and collectively provides a real time and comprehensive assessment of a patient's hemodynamic status.

    The LiDCO™ System is a bolus indicator dilution method of measuring cardiac output and calibrating the PulseCO software. A small dose of lithium chloride is injected via a central or peripheral venous line; the resulting arterial lithium concentration-time curve is recorded by withdrawing blood past a lithium sensor attached to the patient's existing arterial line. In terms of accuracy, clinical studies have demonstrated that the LiDCO™ System method is at least as accurate as thermodilution over a wide range of cardiac outputs and in patients with varying cardiac outputs.1,4-8 The dose of lithium marker needed (0.15 - 0.3 mmol for an average adult) is very small and has no known pharmacological effects.2,3

    The PulseCO™ System software calculates continuous beat-to-beat cardiac stroke volume, stroke volume variation & cardiac output by analysis of the arterial blood pressure trace following calibration with an indicator dilution cardiac output measurement. This system has been shown to be accurate and reliable in the peri-operative and ICU settings. It has also been shown that a check on the calibration is required only every 8 hours and that the software can track changes in cardiac output even in the presence of moderately damped arterial lines.10-14

  2. What are the primary indications for use of the LiDCO™plus Hemodynamic Monitor?

    The LiDCO™plus Hemodynamic Monitor is intended for monitoring continuous blood pressure and cardiac output in patients with pre- existing peripheral arterial line access. The system is safe, accurate and easy to use.10-14 In acute care settings, where information on real time hemodynamic changes are required, the LiDCO™plus Monitor can be set up in five to ten minutes by a trained nurse or doctor. It can be used on a conscious patient and used in pre-inter-and post-operative situations.

    The primary indications for use include: peri operative care of cardiac surgery and high risk surgical patients, acute heart failure, sepsis, drug intoxication, acute renal failure, severe hypovolemia, fluid shifts, complex circulatory situations & medical emergencies.

  3. What are the common secondary indications for its use?

    The LiDCO™plus Hemodynamic Monitor provides a rapid response 'Early Warning' of a significant change in the hemodynamic status. Thus in patients who are conventionally indicated for invasive arterial blood pressure monitoring, the device is intended as a more sensitive way of displaying continuous hemodynamic data. In addition to arterial blood pressure parameters and cardiac output, the LiDCO™plus Hemodynamic Monitor calculates a number of other parameters: Body Surface Area, Systolic Pressure Variation, Pulse Pressure Variation, Cardiac Index, Stroke Volume, Stroke Volume Index, Stroke Volume Variation, Systemic Vascular Resistance, Systemic Vascular Resistance Index. It has been shown that for fluid management the measurements of pulse pressure variation and stroke volume variation can be most useful in closed chest mechanically ventilated patients.15-37 These 'preload' measurements benefit from being dynamic, real time and available in a minimally invasive manner. One recent paper in Anaesthesia and Analgesia showed that "a SVV value of 9.5% or more, will predict an increase in the SV of at least 5% in response to a 100ml volume load, with a sensitivity of 79% and specificity of 93%." 22

  4. What are the efficacy data to support its use?

    The LiDCO™plus Hemodynamic Monitor has been shown to be accurate and reliable in various clinical settings.10-14 These studies include cardiac surgery patients undergoing bypass and off-pump procedures where cardiac output is rapidly changing and has ranged from 2.7 - 21.3 litres.13 Data has also been presented validating its use in the medical intensive care unit with patients having a variety of diagnoses and the cath lab.14,9 It is clear that this system provides no incremental risk to the patient and could reduce the requirement for more invasive monitoring in many risk patients.10-14

  5. Are there any appropriate outcome data available?

    There is a growing volume of evidence to suggest that optimising flow (cardiac output) and oxygen delivery (DO2) can lead to improved outcomes in terms of mortality and morbidity in suitable patients.38-41 The LiDCO™plus Hemodynamic Monitor allows the patients hemodynamics to be 'optimised' in a safe, accurate and timely manner. In particular the ability to use the product in a non-ventilated and conscious patient facilitates the implementation of peri operative optimisation protocols in high risk surgical patients.

  6. What are the costs of using the technology?

    In order to use the technology, a monitor (LiDCO™plus) and single patient use lithium dilution sensor and associated disposables are required. It is designed to work with any of the commonly used arterial catheter systems. The indicator dilution calibration method does not require the use of special catheters, introducer trays or a subsequent x-ray for catheter position verification. Savings can usually be realised against the costs associated with the use of more invasive continuous technologies.

  7. Are there any contraindications for the use of this technology?

    The LiDCO™plus Hemodynamic Monitor is suitable for patients who have arterial and venous catheters (peripheral or central) inserted and who require hemodynamic monitoring. Patients undergoing treatment with lithium salts, patients who are less than 40kg (88lb) in weight and patients in the first trimester of pregnancy are contraindicated for calibration with the lithium chloride indicator. Performance of the continuous waveform analysis PulseCO software may be compromised in patients with severe peripheral arterial vasoconstriction, those undergoing treatment with aortic balloon pumps and in the case of aortic valve regurgitation.

  8. What is the current status of this technology?

    The technology has FDA clearance and CE mark approval and has been actively marketed since July 2001 in the USA and UK. In continental Europe lithium approval (as an in vivo diagnostic) was received for Germany, Italy, Spain, Holland, Belgium and Austria in January 2003. The use of minimally invasive hemodynamic monitoring is receiving widespread acceptance in the market place with over 70 key institutions in the US and UK now routinely using the LiDCO™ technology.

LiDCO™plus FEATURE: Real Time
Real time beat-to-beat display of key hemodynamic parameters including: cardiac output, stroke volume, blood pressure, peripheral resistance, and oxygen delivery

BENEFIT:

  • Provides early warning of significant hemodynamic events
  • Shows comprehensive hemodynamic status of patient
  • Guides correct drug administration and shows hemodynamic response
  • Indicates relationship between linked hemodynamic variables
  • Facilitates the setting and achievement of patient specific hemodynamic targets

LiDCO™plus FEATURE: Power Based Waveform Analysis
The PulseCO™ Algorithm computes the heart beat period and stroke volume from the entire blood pressure waveform

BENEFIT:

  • Uncalibrated, provides an indication of direction of changes in preload, cardiac output and oxygen delivery
  • When calibrated, provides accurate measurement of both direction and magnitude of change in cardiac output and oxygen delivery
  • Only requires a calibration check every 8 hours

LiDCO™plus FEATURE: Minimally Invasive
LiDCO™plus uses existing arterial and peripheral / central venous access

BENEFIT:

  • No incremental risk to the patient 7,21
  • Applicable to a wide arterial line patient population 7,21
  • Can be used on ventilated or non ventilated patients, in the peri-operative or ICU setting 7,21
  • Nurse or clinician applicability 7,21

LiDCO™plus FEATURE: Accurate and Reliable Lithium Indicator Dilution Calibration
The LiDCO™ - Lithium Dilution Cardiac Output has been demonstrated to give an accurate and reliable measurement from a single injection

BENEFIT:

  • Only one injection required - time consuming repeated determinations are unnecessary 11-21
  • Accurate even in the intra-operative situation - lithium is unaffected by thermal noise from respiration, cooling or fluid(s) infusion 11-21
  • Results are consistent and reproducible between various users 11-21

LiDCO™plus FEATURE: Safe Lithium Chloride Indicator Dilution Technology
The injectate is an isotonic solution of lithium chloride

BENEFIT:

  • Uses existing central or peripheral venous and arterial catheters
  • The dose of lithium chloride needed has no known pharmacological effect

LiDCO™plus FEATURE: Provides Beat-to-Beat Oxygen Delivery

BENEFIT:

  • Provides early and immediate indication of global oxygen delivery status, as actual or indexed value
  • Allows for easy implementation of oxygen delivery based peri-operative and trauma optimisation protocols

LiDCO™plus FEATURE: Continuous Pre Load, After Load and Cardiac Output Monitoring

BENEFIT:

  • Optimises fluid administration through pre load parameters that indicate the likely response of the patient to volume
  • Quantifies stroke volume response to increased pre load
  • Indicates response in left ventricular contractility after inotrope administration

LiDCO™plus FEATURE: Provides Indexed Values

BENEFIT:

  • Indexed values help normalise hemodynamic parameters to patient requirements

LiDCO™plus FEATURE: Novel User Interfaces

BENEFIT:

  • The Chart Screen demonstrates the interrelationship between pressure, flow and resistance using indexed values and their variation from predetermined targeted normal values
  • Demonstrates the patient's hemodynamic picture
  • Visual (at a distance) displays
  • Facilitates the interpretation of data to aid therapeutic intervention
  • Facilitates appropriate action regarding the patient's hemodynamic status by nurses and doctors

LiDCO™plus FEATURE: Provides Volume Management Parameters
Volemia and preload management features of: Stroke Volume Variation, Pulse Pressure Variation, and Systolic Pressure Variation

BENEFIT:

  • Measurements are available in real-time 8-10
  • Available from pre-existing lines 8-10
  • Allows for effective beat-to-beat volume management 8-10
  • Guides volume based therapeutic intervention 8-10

LiDCO™plus FEATURE: Quick to Set Up and Use
Typically takes between 5 and 10 minutes to set-up and establish cardiac output with the lithium indicator dilution method

BENEFIT:

  • Quick, minimally invasive measure of cardiac output
  • Ideal for nurse-led management practice
  • Cost effective utilisation of resources

LiDCO™plus FEATURE: Records Patient Data

BENEFIT:

  • Ability to mark and record interventions and events for later reference
  • Ability to store data for each patient on an integrated zip drive for patient records and academic uses

LiDCO™plus FEATURE: PC Based Monitor Platform

BENEFIT:

  • Technology/software platform for future software measurements and displays
  • Easy to maintain and repair
  • Provides ability to upgrade software and remain current with new developments in hemodynamic monitoring and information management

References - Frequently Asked Questions

  1. Mason DJ, O'Grady M, Woods JP, McDonell W. (2001) Assessment of lithium dilution cardiac output as a technique for measurement of cardiac output in dogs. American Journal of Veterinary Research Aug; 62(8): 1255 - 1261.
  2. Hatfield C, McDonell W, Lemke D, Black W. (2001) Pharmacokinetics and toxic effects of lithium chloride after intravenous administration in conscious horses. American Journal of Veterinary Research Sep; 62(9): 1387-1392.
  3. Jonas, Linton, O'Brien, Band, Linton, Kelly, Burden, Chevalier, Thompson, Birch and Powell. (2001) The pharmacokinetics of intravenous lithium chloride in patients and normal volunteers. Journal of Trace and Microprobe Techniques. 19: 313-320.
  4. Mason DJ, O'Grady M, Woods JP, McDonell W. (2000) Assessment of lithium chloride dilution as a new measure of cardiac output in the dog as compared to thermodilution. Meeting of the American College of Veterinary Internal Medicine May 2000.
  5. Linton RA, Jonas MM, Tibby SM, Murdoch IA, O'Brien TK, Linton NW, Band DM. (2000) Cardiac output measured by lithium dilution and transpulmonary thermodilution in patients in a paediatric intensive care unit. Intensive Care Med. Oct; 26(10): 1507-11.
  6. Linton RA, Young LE, Marlin DJ, Blissett KJ, Brearley JC, Jonas MM, O'Brien TK, Linton NW, Band DM, Jones RS. (2000) Cardiac output measured by lithium dilution, thermodilution and transesophageal doppler echocardiography in anesthetized horses. American Journal of Veterinary Research Jul; 61(7): 731-7.
  7. Linton R, Band D, O'Brien T, Jonas MM & Leach R. (1997) Lithium dilution cardiac output measurement: A comparison with thermodilution. Critical Care Medicine; 25: 1796-1800.
  8. Kurita T, Morita K, Kato S, Kikura M, Horie M, Ikeda K. (1997) Comparison of the accuracy of the lithium dilution technique with the thermodilution technique for measurement of cardiac output. British Journal of Anaesthesia; 79: 770-775.
  9. Roberts PR, Allen S, Robinson S, Tanser SJ, Jonas MM, Morgan JM (2002) Use of lithium dilution assessment of cardiac output to optimise right/left ventricular activation in resynchronisation therapy. Presented at the 80th Anniversary British Cardiac Society Annual Scientific Conference. Harrogate.
  10. Pitman JA, Sum Ping JS, Sherwood MW, El-Moalem H, Mark JB (2002) Continuous cardiac output monitoring by arterial pressure waveform analysis: A 24-hour comparison with the lithium dilution indicator method. Presented at: The Society of Cardiovascular Anesthesiologists. New York.
  11. Aronson A, Heller L, Jayakar D, Jeevanandam V, Fisher M, Pfanzelter N, Babb P, Dupont F, Chaney M, Tung A. (2002) Continuous intraoperative cardiac output determination with arterial pulse wave analysis (PulseCO™) is valid and precise. Submitted to the Society of Cardiovascular Anesthesiologists Annual Meeting, May.
  12. T. Hamilton, MD, Lynne M. Huber, RN, and Michael E Jessen (2002) PulseCO - A less-invasive technique to monitor cardiac output from arterial pressure after cardiac surgery. Ann Thorac Surg 2002:74:S1408-12.
  13. Heller L B, Fisher M, Pfanzelter N, Jayakar D, Jeevanandam V, Aronson S. (2002) Continuous intraoperative cardiac output determination with arterial pulse wave analysis (PulseCO™) is valid and precise. Anesth. Analg; 93:SCA1-SCA112.
  14. Jonas M, Bruce R, Knight J, Kelly F, O'Brien T, Band D. (2001) Comparison of cardiac output measurements using a continuous arterial waveform analysis monitor (PulseCO) with an indicator dilution technique (LiDCO) in patients in intensive care. Accepted for presentation at the ICCM Sydney, October.
  15. Systolic pressure variation: A clinical application of respiratory-circulatory interaction. From; Atlas of Cardiovascular monitoring.
  16. Reuter et al. (2002) Optimizing fluid therapy in mechanically ventilated patients after cardiac surgery by on-line monitoring of left ventricular stroke variations. Comparison with aortic systolic pressure variations. Brit Jour Anaesth 88 (1) 124-126.
  17. Avila et al. (2002) Predicting hypovolemia during mechanical ventilation: A prospective, clinical trial of doppler variations of aorta and axillary arterial velocities to identify systolic pressure variation. Poster Presentation. American Society of Critical Care Anestheiologists, Anaesthesiology 97 (3) B17.
  18. Gunn and Pinsky. (2001) Implications of arterial pressure variation in patients in the intensive care unit. Critical Care 7: 212-217.
  19. Michard et al. (1999) Clinical use of respiratory changes in arterial pulse pressure to monitor the hemodynamic effects of PEEP. Critical Care Medicine 159: 935-939.
  20. Michard et al. (2000) Relation between respiratory changes in arterial pulse pressure and fluid responsiveness in septic patients with acute circulatory failure. Critical Care Medicine 162: 134-138.
  21. Michard & Teboul. (2000) Using heart-lung interactions to assess fluid responsiveness during mechanical ventilation. Crit Care 4: 282-289.
  22. Berkenstadt et al. (2001) Stroke volume variation as a predictor of fluid responsiveness in patients undergoing brain surgery. Anesth Analg 92: 984-989.
  23. Perel et al. (1987) Systolic blood pressure variation is a sensitive indicator of hypovolemia in ventilated dogs subjected to graded hemorrhage. Anesth 67: 498-502.
  24. Harrigan & Pinsky. (2001) Heart-lung interactions. Part 1: effects of lung volume and ventilation as exercise. Int Jour Inten Care Spring 2001: 6-13.
  25. Harrigan & Pinsky. (2001) Heart-lung interactions. Part 2: effects of intrathoracic pressure. Int Jour Inten Care Summer 2001: 99-108.
  26. Rooke et al. (1995) The effect of graded hemorrhage and intravascular volume replacement on systolic pressure variation in humans during mechanical and spontaneous ventilation. Anesth Analg 80: 925-932.
  27. Marik. (1993) The systolic blood pressure variation as an indicator of pulmonary capillary wedge pressure in ventilated patients. Anaes & Intens Care 21 (4) 405-408.
  28. Tavernier et al. (1998) Systolic pressure variation as a guide to fluid therapy in patients with sepsis-induced hypotension. Anesth 89 (6) 1309-1310 [Abstract].
  29. Pizov et al. (1996) Positive end-expiratory pressure-induced hemodynamic changes are reflected in the arterial pressure waveform. Crit Care Med 24 (8) 1381-7 [Abstract].
  30. Szold et al. (1989) The effect of tidal volume and intravascular volume state on systolic pressure variation in ventilated dogs. Inten Care Med 15 (6) 368-371 [Abstract].
  31. Baeaussier et al. (1995) Determinants of systolic pressure variation in patients ventilated after vascular surgery. J Cardioth Vasc Anesth 9 (5) 547-551 [Abstract].
  32. Pizov et al. (1990) The use of systolic pressure variation in hemodynamic monitoring during deliberate hypotension in spine surgery. J Clin Anesth 2 (2) 96-100 [Abstract].
  33. Perel et al. (1987) Systolic blood pressure variation is a sensitive indicator of hypovolemia in ventilated dogs subjected to graded hemorrhage. Anesth 67 (4) 498-502 [Abstract] See above.
  34. Weiss et al. (1999) Systolic pressure variation in hemodynamic monitoring after severe blast injury. J Clin Anesth 11 (2) 132-135 [Abstract].
  35. Ornstein et al. (1998) Systolic pressure variation predicts the response to acute blood loss. J Clin Anesth 10 (2) 137-140 [Abstract].
  36. Klingzing et al. Stroke volume variation as a predictor of fluid responsiveness for cardiac output in patients undergoing cardiac surgery. 173/M55 [Abstract].
  37. Reuter et al. Left ventricular stroke volume variations for functional preload monitoring after cardiac surgery in high risk patients. 93/M1 [Abstract].
  38. Kern & Shoemaker. (2002) Meta-analysis of hemodynamic optimisation in high-risk patients. Crit Care Med 30 (8) 1686-1692.
  39. Bennett. (2002) Goal-directed therapy is successful in the right patients. Editorial in Crit Care Med 30 (8) 1909-10.
  40. Rivers et al. (2001) Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med 345 (19) 1368-77.
  41. Singh and Manji. (2001) A survey of pre-operative optimisation of high-risk surgical patients undergoing major elective surgery. Anaesthesia 56:988-1002.

References - Features and Benefits

  1. Heller et al (2002) Continuous intraoperative cardiac output determination with arterial pulsewave analysis (PulseCO) is valid and precise. Anesth. Analg; 93 SCA7.
  2. Hamilton et al. PulseCO: accurate monitoring of cardiac output from the arterial waveform. Presented at 8th Ann. CTT meeting 2002.
  3. Jonas. Comparison of cardiac output measurements using a continuous arterial waveform analysis monitor (PulseCO) with an indicator dilution method (LiDCO) in patients in intensive care. Abstract: ICCM 2001 Sydney.
  4. Pitman et al. (2002) Continuous cardiac output monitoring by arterial pressure waveform analysis. A 24 hr comparison with the Lithium dilution indicator method. Presented at The Society of Cardiovascular Anaesthesia. New York.
  5. Jonas et al. (1999) A comparison of lithium dilution method cardiac output using central and antecubital venous injection of lithium chloride. J. of Clinical Monitoring and Computing 15:525-528.
  6. Gunn et al. (2001) Implications of arterial pressure variation in patients in the intensive care unit. Current Opinions in Critical Care; 7:212-217.
  7. Pinsky. Use of heart-lung interactions to diagnose cardiovascular alterations. Presented at 22nd Symp. on Intensive Care Medicine & Emergency Medicine. Brussels 2002.
  8. Perel. Assessment of volume responsiveness. Presented at 22nd Symp. on Intensive Care Medicine & Emergency Medicine. Brussels 2002.
  9. Linton et al. (1993) A new method of measuring cardiac output in man using lithium dilution. Br. J. Anaesth; 71: 262-266.
  10. Linton et al. Lithium dilution cardiac output measurement - a brief review. In: Ikeda et al. State of the art technology in anaesthsia & intensive care. Elsevier 1998: 61-66.
  11. Jonas et al. (2001) The pharmacokinetics of intravenous lithium chloride in patients and normal volunteers. J. Trace Elements Microprobe Technologies; 19:313-320.
  12. Linton et al. (2000) Cardiac output measured by lithium dilution, and transpulmonary thermodilution in paediatric intensive care. Intensive Care Med; 26:1507-1511.
  13. Linton et al. (2000) Cardiac output measured by lithium dilution ,thermodilution and transesophageal doppler echocardiography in anaesthesised horses Am. J. Vet Res; 61:731-737.
  14. Siddall et al. Comparison of clinical assessment of hemodynamic status with actual data obtained through a minimally invasive lithium dilution method. Presented at the 14th Ann. Inter. Respiratory Congress. San Antonio, Texas 2001.
  15. Garcia-Rodriquez et al. Abstract: Cardiac output measurements without pulmonary artery or central venous catheterisation: a clinical assessment of the of the lithium dilution method. Presented at the AUA meeting 2000.
  16. Mappes et al. Hemodynamic monitoring during cardiac surgery. The new LiDCO method. Presented at the Cardiothoracic Technology and Tech. Bal. Harbour. 2000.
  17. Kurita et al. (1999) Comparison of the accuracy of the lithium dilution technique with the thermodilution technique for measurement of cardiac output. Br. J. Anaesthesia; 79:770-775.
  18. Hatfield et al. (2001) Pharmacokinetics and toxic effects of lithium chloride after intravenous administration in conscious horses. AJVR; 62:9:1387-1392.
  19. Garcia-Rodriguez et al. (2002) Lithium dilution cardiac output measurement: a clinical assessment of central venous and peripheral venous indicator injection. Crit Care Med 2002 Vol. 30 No. 10: 2199-2204.

For full bibliography list please see www.lidco.com/html/clinical/bibliography.html