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

ImportanceAccurate 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. ObjectivesWe compared the accuracy and precision of a novel non-invasive Zero-Heat-Flux Thermometer (SpotOn (TM)) to a standard invasive esophageal probe in a cohort of patients undergoing TTM post-cardiac arrest. Design, Setting, and ParticipantsWe 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 (TM) probe was applied on each patient's forehead, while an esophageal temperature probe was inserted, and both temperature readings were recorded at 1-min intervals for the duration of TTM. Main outcomes and MeasuresWe compared the SpotOn (TM) and esophageal monitors using the Bland-Altman analysis and the Pearson correlation, with accuracy set as a primary outcome. Secondary outcomes included precision and correlation. Bias exceeding 0.1 degrees C and limits of agreement exceeding 0.5 degrees C were considered clinically important. ResultsSixteen (80%) of patients had complete data used in the final analysis. The median (interquartile range) duration of recording was 38 (12-56) h. Compared to the esophageal probe, SpotOn (TM) had a bias of 0.06 +/- 0.45 degrees C and 95% limits of agreement of -0.83 to 0.95 degrees C. The Pearson correlation coefficient was 0.97 (95% confidence interval 0.9663-0.9678), with a two-tailed p < 0.0001. Conclusion and RelevanceThe SpotOn (TM) is an accurate method that may enable non-invasive monitoring of core body temperature during TTM, although its precision is slightly worse than the predefined 0.5 degrees C when compared to invasive esophageal probe.