AUTHOR=Fiorini Kyle , Tamasi Tanya , Dorie Justin , Hegazy Ahmed F. , Lee Ting-Yim , Slessarev Marat 

TITLE=Non-Invasive Monitoring of Core Body Temperature for Targeted Temperature Management in Post-Cardiac Arrest Care

JOURNAL=Frontiers in Medicine

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.810825

DOI=10.3389/fmed.2022.810825

ISSN=2296-858X

ABSTRACT=Importance: Accurate monitoring of core body temperature is integral to targeted temperature management (TTM) following cardiac arrest. However, there are no reliable non-invasive methods for monitoring temperature during TTM. 

Objectives: We compared the accuracy and precision of a novel non-invasive Zero-Heat Flux Thermometer (SpotOn) to a standard invasive esophageal probe in a cohort of patients undergoing TTM post cardiac arrest. 

Design, Setting and Participants: We prospectively enrolled 20 patients undergoing post-cardiac arrest care in the intensive care units at the London Health Sciences Centre in London, Canada. A SpotOn probe was applied on each patient’s forehead, while an esophageal temperature probe was inserted, and both temperature readings were recorded at 1-minute intervals for the duration of TTM.
Main Outcomes and Measures: We compared the SpotOn and esophageal monitors using Bland-Altman analysis and Pearson correlation, with accuracy set as a primary outcome. Secondary outcomes included precision and correlation. Bias exceeding 0.1°C and limits of agreement exceeding 0.5°C were considered clinically important.

Results: Sixteen (80%) of patients had complete data used in the final analysis. The median (interquartile range) duration of recording was 38 (12-56) hours. Compared to the esophageal probe, SpotOn had a bias of 0.06 ± 0.45ºC and 95% limits of agreement of -0.83 to 0.95 ºC. Pearson correlation coefficient was 0.97 (95% confidence interval 0.9663-0.9678), with a two-tailed p-value of <0.0001. 

Conclusion and Relevance: The SpotOn is an accurate method that may enable non-invasive monitoring of core body temperature during TTM, although its precision is slightly worse than the pre-defined 0.5°C when compared to invasive esophageal probe.