Comparison of cutaneous facial temperature using infrared thermography to standard temperature measurement in the critical care setting

Abstract

To assess the accuracy and precision of infrared cameras compared to traditional measures of temperature measurement in a temperature, humidity, and distance controlled intensive care unit (ICU) population. This was a prospective, observational methods comparison study in a single centre ICU in Metropolitan Melbourne, Australia. A convenience sample of 39 patients admitted to a single room equipped with two ceiling mounted thermal imaging cameras was assessed, comparing measured cutaneous facial temperature via thermal camera to clinical temperature standards. Uncorrected correlation of camera measurement to clinical standard in all cases was poor, with the maximum reported correlation 0.24 (Wide-angle Lens to Bladder temperature). Using the wide-angle lens, mean differences were - 11.1 °C (LoA - 14.68 to - 7.51), - 11.1 °C ( - 14.3 to - 7.9), and - 11.2 °C ( - 15.23 to - 7.19) for axillary, bladder, and oral comparisons respectively (Fig. 1a). With respect to the narrow-angle lens compared to the axillary, bladder and oral temperatures, mean differences were - 7.6 °C ( - 11.2 to - 4.0), - 7.5 °C ( - 12.1 to - 2.9), and - 7.9 °C ( - 11.6 to - 4.2) respectively. AUCs for the wide-angle lens and narrow-angle lens ranged from 0.53 to 0.70 and 0.59 to 0.79 respectively, with axillary temperature demonstrating the greatest values. Infrared thermography is a poor predictor of patient temperature as measured by existing clinical standards. It has a moderate ability to discriminate fever. It is unclear if this would be sensitive enough for infection screening purposes. Fig. 1 Bland-Altman plots for temperatures measured using clinical standards to infrared camera. a Wide-angle camera versus bladder temperature. b Narrow-angle camera versus bladder temperature.

Keywords: Fever screening; ICU; Infrared thermography; Temperature monitoring; Thermal cameras.