Accuracy of Non-invasive Temperature Measurement in Deep Hypothermia

Study Overview
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Brief Summary
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In pre-hospital care, there are few non-invasive thermometers that are proved both robust and accurate. The aim of this study is to investigate the accuracy of a certain ear-canal based thermometer on patients undergoing thoracic surgery in deep hypothermia.

Detailed Description
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The study is a prospective cohort study on patients undergoing elective thoracic surgery in deep hypothermia. The goal is to assess the accuracy of non-invasive temperature devices compared to a gold standard representing core temperature. At the study hospital, Oslo University Hospital Rikshospitalet, patients undergoing thoracic surgery will already have several routes of temperature monitoring as part of standard procedure. Before cardiopulmonary bypass bladder temperature is normally used as a reference for core temperature. After cardiopulmonary bypass is established, temperature is monitored directly in the circulating blood, hence reflecting core temperature. For measuring the epitympanic temperature we will use the Metraux Epitympanic Thermometer (Walpoth, Galdikas et al. 1994), a nasopharyngeal temperature probe (Mon-a-Therm, General Purpose Temperature Probe 12Fr/Ch, Covidien) and a new transcutaneous device (SpotOn 3M). The temperature will be measured in degrees Celsius. The first reading will be noted just after induction of anaesthesia and compared to the bladder temperature. After cardiopulmonary bypass (CPB) is established and therapeutic hypothermia is induced, the values for both non-invasive and blood temperature will be recorded every minute. After reaching the target temperature according to the blood temperature, we will continue recording the non-invasive temperature until relative similarity is established. The process will be repeated during re-warming.

Official Title
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Accuracy of Non-invasive Temperature Measurement in Deep Hypothermia; a Prospective Cohort Study

Conditions
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Hypothermia

Intervention / Treatment
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* Device: Non-invasive temperature in hypothermia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult >18 years Elektive cardiac surgery in deep hypothermia No pathology in ear canal on otoscopy Exclusion Criteria: Pathology in ear canal non-consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Non-invasive temperature in hypothermia<br>Adult patients undergoing elective thoracic surgery in deep hypothermia | Device: Non-invasive temperature in hypothermia<br>* accuracy of non-invasive temperature measurement in deep hypothermia compared to core temperature<br>* Other names: metraux epitympanic, nasopharyngeal, 3M spotOn;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Temperature in degrees celsius | The temperature reading from the epitympanic thermometer will be recorded every two minutes during deep hypothermia and compared to the temperature measured in the cardiopulmonary bypass circuit. | The patients will be followed during the induced per-operative hypothermia, an expected average of 1,5 hours. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hypothermia, Temperature, epitympanic, pre-hospital