Accuracy of Core Body Temperature Measurement Depending on Oesophageal Probe Tip Location

NCT06370676 | Completed

• 1 other identifier: ESO-TIP
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

Background An accurate measurement of the core body temperature (CBT) is of pivotal importance in the management of severely hypothermic patients. For instance, triage decisions for or against extracorporeal rewarming of hypothermic patients in cardiac arrest strongly depend on CBT. CBT measurement with an oesophageal probe is currently considered the gold standard in hypothermic patients with a secured airway in the prehospital setting, with the tip of the probe placed into the distal third of the oesophagus (i.e., posteriorly to the heart and distal to the tracheal bifurcation). However, the correct placement of the probe tip cannot be verified in the prehospital setting, and it is unknown how incorrect placement affects temperature readings. Hypothesis and aim The investigators hypothesise that an incorrect placement of the oesophageal temperature probe tip could lead to inaccurate measurements (i.e., temperature readings not reflecting the real CBT). Particularly, a tip location too high in the oesophagus in close proximity to the trachea could lead to falsely low temperature readings, especially when the patient is ventilated with cold air. The aim of the proposed study is to investigate the influence of oesophageal temperature probe tip location on CBT measurement. Methods Experimental, interventional study on 16 healthy volunteers. During the test oesophageal temperature is measured while participants are breathing ambient air first at 20°C (baseline) followed by cold (-20°C) ambient air in supine position for 20 minutes each test in an environmental simulator (terraXcube). Each participant repeats the 20-min test two times with the oesophageal temperature probe tip placed either in the lower third of the oesophagus (i.e., correct position) or too high in the oesophagus, i.e. behind the trachea.

Conditions

Emergencies; Hypothermia

Outcome Measures

Primary Outcomes (1)

• Difference in core body temperature between the two tip positions

  Difference in core body temperature between the two tip positions (i.e. in the lower third of the oesophagus (behind the left atrium) and in the middle third of the oesophagus (behind the trachea)

  20 minutes after cold air exposure

Study Arms (4)

Correctly placed oesophageal probe at +20 degrees celsius ambient temperature

ACTIVE COMPARATOR

Oesophageal probe tip located in the lower third of the oesophagus, i.e. behind the left atrium, +20°C ambient temperature, outside terraXcube

Diagnostic Test: Oesophageal temperature measurement

Oesophageal probe tip too high at +20 degrees celsius ambient temperature

EXPERIMENTAL

Oesophageal probe tip located too high the oesophagus, i.e. behind the trachea, 1-2 cm above the level of the tracheal bifurcation, +20°C ambient temperature, outside terraXcube

Diagnostic Test: Oesophageal temperature measurement

Correctly placed oesophageal probe at -20 degrees celsius ambient temperature

ACTIVE COMPARATOR

Oesophageal probe tip located in the lower third of the oesophagus, i.e. behind the left atrium, -20°C ambient temperature, inside terraXcube

Diagnostic Test: Oesophageal temperature measurement

Oesophageal probe tip too high at -20 degrees celsius ambient temperature

EXPERIMENTAL

Oesophageal probe tip located too high the oesophagus, i.e. behind the trachea, 1-2 cm above the level of the tracheal bifurcation, -20°C ambient temperature, inside terraXcube

Diagnostic Test: Oesophageal temperature measurement

Interventions

Oesophageal temperature measurement DIAGNOSTIC_TEST

Oesophageal temperature measurement

Correctly placed oesophageal probe at +20 degrees celsius ambient temperature; Correctly placed oesophageal probe at -20 degrees celsius ambient temperature; Oesophageal probe tip too high at +20 degrees celsius ambient temperature; Oesophageal probe tip too high at -20 degrees celsius ambient temperature

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Volunteers with an American Society of Anaesthesiologists (ASA) score ≤2.

You may not qualify if:

• ASA \>3
• Age \< 18 and age \>75
• Pregnant women
• No signed informed consent
• Signs and symptoms of an acute illness on the study day
• History of oesophageal and nasopharyngeal disorders
• Allergies to Local Anaesthetics (i.e. Lidocain).

Sponsors & Collaborators

• Institute of Mountain Emergency Medicine: lead

Study Sites (1)

TerraXCube

Bolzano, Italy

Location

MeSH Terms

Conditions

Emergencies; Hypothermia

Condition Hierarchy (Ancestors)

Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Body Temperature Changes; Signs and Symptoms

Study Officials

• Simon Rauch, MD, PhD

  Institute of Mountain Emergency Medicine, Eurac Research

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: The participant is blinded for the location of the oesophageal temperature probe tip.
• Purpose: DIAGNOSTIC
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 11, 2024
• First Posted: April 17, 2024
• Study Start: May 23, 2024
• Primary Completion: December 31, 2024
• Study Completion: December 31, 2024
• Last Updated: August 8, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

IT (1)