Study on the Repeatability of Cardiac Output Measurements Dependence of Temperature of Injectate

This study has been completed.
Information provided by:
Norwegian University of Science and Technology Identifier:
First received: April 23, 2007
Last updated: May 28, 2008
Last verified: May 2008

This study tests the reliability of thermodilution cardiac output measurements with pulmonary artery catheters in immediate connection with heart surgery. In accordance with our clinical practice, thermal indicator injections are synchronized with respiration. The impact on measurement repeatability of spontaneous vs artificial ventilation and the effect of the injectate temperature is tested.

The study hypothesis is that when injections are synchronized with the respiration, only three injections at room temperature are needed to be within 5 % of the "true" cardiac output in mechanically ventilated patients.

Condition Intervention Phase
Thermodilution, Cardiac Output
Device: Pulmonary artery catheter
Phase 0

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: The Impact of Temperature of the Injectate on the Precision (Repeatability) of Cardiac Output Measurements Synchronized With the Respiration (the Temperature Study)

Further study details as provided by Norwegian University of Science and Technology:

Enrollment: 40
Study Start Date: November 2006
Study Completion Date: June 2007
Intervention Details:
    Device: Pulmonary artery catheter
    Four series of cardiac output measurements, each series consists of eight measurements using cold and eight measurements using tepid injectate. Randomized order of temperature at first series and crossover design.
    Other Name: Baxter
Detailed Description:

Bolus thermodilution cardiac output measurements by means of a pulmonary artery catheter have been a mainstay of monitoring critically ill patients for more than thirty years. Recent studies have questioned wether the traditional practice of averaging measurements from tree room temperature thermal indicator injections give sufficient precision.

This study tests the number of indicator injections necessary to be within 5 % of the "true" cardiac output (taken as the average of 16 injections) when the injection is synchronized with the respiration. The reliability of the thermodilution measurements are tested A) in sedated, artificially ventilated cardiac surgical patients and B) in the same patients when postoperatively awake and spontaneously breathing. We further compare the use of room temperature and iced thermal indicator injections.

The study hypothesis is that when injections are synchronized with the respiration, only three injections at room temperature are needed to achieve the desired precision in mechanically ventilated patients.

Only patients receiving a pulmonary artery catheter according our institution standard procedure of care will be included.


Ages Eligible for Study:   18 Years to 85 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Elective patients for cardiac surgery

Inclusion Criteria:

  • Cardiac surgical patients who receive a pulmonary artery catheter according to the institution clinical criteria -

Exclusion Criteria:

  • Acute cardiac surgery
  • Preoperative arrythmias
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Please refer to this study by its identifier: NCT00464750

St Olav University Hospital
Trondheim, Norway
Sponsors and Collaborators
Norwegian University of Science and Technology
Principal Investigator: Idar Kirkeby-Garstad, MD, Ph D St Olav University Hospital, Trondheim, Norway
  More Information

Responsible Party: Asbjorn Karevold, Head of Department, Dept of Cardiothoracic surgery, St Olav Univ Hospital, Trondheim, Norway Identifier: NCT00464750     History of Changes
Other Study ID Numbers: 4.2006.1012 / NSD15499
Study First Received: April 23, 2007
Last Updated: May 28, 2008
Health Authority: Norway: Norwegian Social Science Data Services processed this record on November 27, 2015