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Hypothermia and Circulatory Arrest During Surgery on the Ascending Aorta: A Comparison Between Two Cooling Methods

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified March 2012 by University of Aarhus.
Recruitment status was:  Recruiting
Aarhus University Hospital
Information provided by (Responsible Party):
University of Aarhus Identifier:
First received: January 7, 2011
Last updated: March 20, 2012
Last verified: March 2012

PURPOSE: To compare crash cooling versus gradient cooling methods for patients undergoing planned surgery on the ascending aorta in deep hypothermic circulatory arrest. To investigate the impact of hypothermia and circulatory arrest on the coagulation, stress-response, and cerebral outcome.

BACKGROUND: Cooling to 18 °C using extracorporeal circulation allows for circulatory arrest during surgery on the ascending aorta. Two different methods are used either lowering the temperature of the blood by 10 °C at a time, gradient cooling, or as cold as possible, crash cooling. The distribution of hypothermia is expected to be different for the two methods, the latter predominantly cooling the body core. The influence on the physiological response is expected to vary with the two methods. The surgical procedure and the cooling greatly elicit a stress response and the coagulation is profoundly influenced. There can be adverse effects on the neurological outcome due to the procedure. The two methods are considered equal, but have never been subjected to comparison. The surgery and circulatory changes can have a negative influence on the cerebral outcome .

METHODS: Twenty patients between 18 and 80 yrs randomized either to crash cooling or gradient cooling, ten patients in each group.. Patients with severe comorbidities or known coagulopathy are excluded. Anesthesia and operation as performed routinely in the department. The primary endpoint is duration of cooling, secondary endpoints include coagulation parameters (thromboelastography, clot stability), stress response parameters (adhesion molecule expression on endothelial cells, oxidative stress analysis, inflammatory markers), neuropsychological tests, MRI of the cerebrum, markers of cerebral ischemia, and ultrasound imaging of the great vessels for detection of air bubbles. Baseline values are obtained for all parameters.

Ascending Aorta Aneurism

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Hypothermia and Circulatory Arrest During Surgery on the Ascending Aorta: A Comparison Between Two Cooling Methods

Resource links provided by NLM:

Further study details as provided by University of Aarhus:

Primary Outcome Measures:
  • Duration of cooling [ Time Frame: intraoperatively ]

Secondary Outcome Measures:
  • MRI of cerebrum [ Time Frame: Baseline prior to surgery and 4 to 5 days postoperatively ]
    Standard perfusion-weighed Magnetic Resonance imaging of the cerebrum. The same investigator describes all images. No use of contrast agents.

  • Markers of neurological injury [ Time Frame: baseline, postoperative ]
    s-100b, Neuron specific enolase

  • neurological exam [ Time Frame: baseline, postoperative, after 4 months ]
  • cognitive test [ Time Frame: baseline, postoperative, after 4 months ]
  • markers of elevated inflammatory response [ Time Frame: perioperatively ]
  • Markers of oxidative stress [ Time Frame: perioperatively ]
  • Coagulation parameters [ Time Frame: perioperatively ]

Biospecimen Retention:   Samples With DNA
Bloodsamples serum plasma

Estimated Enrollment: 20
Study Start Date: March 2011
Estimated Study Completion Date: December 2012
Estimated Primary Completion Date: September 2012 (Final data collection date for primary outcome measure)
Gradient cooling group
Study group receiving gradient cooling during the procedure using extracorporeal circulation (ECC). The procedure is used routinely in the department and is not an experimental procedure. A maximum of 10 degrees celsius is allowed between the measured nasopharyngeal body temperature and the heater-cooler unit of the ECC-machine, when cooling or rewarming.
Crash cooling group
Study group receiving rapid cooling using extracorporeal circulation. The protocol for rapid cooling is using routinely in the department and is not an experimental procedure. When cooling, the investigators aim for maximal difference in temperature between the heater-cooler unit of the ECC-machine.


Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Tertiary care clinic. Patients eligible for planned ascending aorta aneurism repair under deep hypothermic circulatory arrest.

Inclusion Criteria:

  • Patients scheduled for surgery on the ascending aorta
  • Need for deep hypothermic circulatory arrest during the procedure

Exclusion Criteria:

  • Known coagulopathy
  • Ejection fraction less than 30 %
  • Severe psychiatric or neurological disease
  • Severe liver disease
  • Severely reduced lung function
  • Glomerular filtration rate less than 15 ml/min/1.73 m2
  Contacts and Locations
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Please refer to this study by its identifier: NCT01306734

Contact: Hans Kirkegaard, MD, Ph.D. +4589498852
Contact: Kristian K Andersen, MD +4521680494

Department of anesthesia and intensive care, Aarhus University Hospital, Skejby Recruiting
Aarhus, Aarhus N, Denmark, 8200
Contact: Kristian K Andersen, MD   
Principal Investigator: Hans Kirkegaard, MD, Ph.D.         
Sponsors and Collaborators
University of Aarhus
Aarhus University Hospital
  More Information

Responsible Party: University of Aarhus Identifier: NCT01306734     History of Changes
Other Study ID Numbers: HYPO-SKS-2011
Study First Received: January 7, 2011
Last Updated: March 20, 2012

Keywords provided by University of Aarhus:
Extracorporeal circulation
Deep Hypothermic Circulatory Arrest
aortic aneurism
neurological injury

Additional relevant MeSH terms:
Aortic Aneurysm
Vascular Diseases
Cardiovascular Diseases
Body Temperature Changes
Signs and Symptoms
Aortic Diseases processed this record on August 22, 2017