Accuracy of a Dual-Sensor Heat-Flux (DHF) Non-Invasive Core Temperature Sensor in Pediatric Patients Undergoing Surgery

Abstract

Accurate temperature measurement is crucial for the perioperative management of pediatric patients, and non-invasive thermometry is necessary when invasive methods are infeasible. A prospective observational study was conducted on 57 patients undergoing elective surgery. Temperatures were measured using a dual-sensor heat-flux (DHF) thermometer (Tcore™) and a rectal temperature probe (TRec), and the agreement between the two measurements was assessed. The DHF measurements showed a bias of +0.413 °C compared with those of the TRec. The limits of agreement were broader than the pre-defined ±0.5 °C range (-0.741 °C and +1.567 °C). Although the DHF sensors tended to overestimate the core temperature compared to the rectal measurements, an error grid analysis demonstrated that 95.81% of the DHF measurements would not have led to a wrong clinical decision, e.g., warming or cooling when not necessary. In conclusion, the low number of measurements that would have led to incorrect decisions suggests that the DHF sensor can be considered an option for continuous temperature measurement when more invasive methods are infeasible.

Keywords: anesthesia; hypothermia; pediatric; perioperative care; temperature management; temperature measurement.

Figure 1

Patient flow chart.

Figure 2

Bland–Altman Plot: This plot illustrates the agreement between the T_DHF and T_Rec measurements. The sizes of the data points correspond to the number of observations they represent. The central gray dashed line indicates 0 °C (no difference), while the additional gray dashed lines at ±0.5 °C represent predefined tolerated deviations. The blue line represents a linear trend, while the solid orange line represents the mean difference (bias) of 0.413 °C. The dashed orange lines indicate the limits of agreement at −0.741 °C and +1.567 °C.

Figure 3

Error grid analysis of DHF temperature (T_DHF) against rectal temperature (T_Rec). Zone A represents measurements within an acceptable range, Zone B represents measurements with deviations but without clinical impact, Zone C indicates measurements leading to incorrect clinical decisions, Zone D represents potential failures to detect severe hypothermia or hyperthermia and Zone E represents potential harmful treatment.