Evaluation of the noninvasive Temple Touch Pro temperature monitoring system compared with oesophageal temperature in paediatric anaesthesia (PETER PAN)

Abstract

BACKGROUND Monitoring peri-operative body temperature in children is currently mainly achieved through invasive devices. The Temple Touch Pro Temperature Monitoring System estimates core temperature noninvasively based on heat flux thermometry. OBJECTIVE To investigate the agreement of this noninvasive sensor against standard oesophageal core temperature. DESIGN A prospective observational study. SETTING University hospital recruiting between April and July 2021.PATIENTS One hundred children (32 girls) aged 6 years or younger scheduled for noncardiac surgery, resulting in 6766 data pairs. Exclusion criteria were contraindication for the insertion of an oesophageal temperature probe, and procedures in which one of the measurement methods would interfere with the surgical field.MAIN OUTCOME MEASURES Primary outcome was the agreement analysis by a Bland-Altman comparison with multiple measurements. Posthoc, we performed another agreement analysis after exclusion of a statistically determined equilibration time. Secondary outcomes were the temperature differences over time and subgroup analysis of hypothermic, normothermic and hyperthermic temperature ranges, age, sex and sensor's side by type III analysis of variance. Further, we correlated the sonographically determined depth of the artery with trueness. RESULTSThe mean difference was -0.078C (95% CI -0.15 to R0.05) with limits of agreement of -1.00 and R0.858C. After adjusting for an equilibration time of 13 min, the mean difference improved to -0.048C (95% CI -0.08 to R0.01) with limits of agreement of -0.68 and R0.608C. Concordance correlation coefficient was 0.83 (95% CI 0.82 to 0.84). Differences between the skin sensor and oesophageal reference increased over time by -0.058C per hour. Subgroup analysis showed no clinically relevant differences. Depth of artery negatively correlated with trueness by 0.038C per millimetre.CONCLUSIONS Although the Temple Touch Pro sensor showed acceptable accuracy after allowing for an equilibration time, it still needs further investigation for routine use in children. This particularly affects accuracy in hypothermic ranges, imprecise positioning and applicability in children with immature or vulnerable skin.

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

“…Zone A was defined as an area of a ±0.5 • C error on either side of the T Rec measurements. Measurement errors smaller than ±0.5 • C were considered clinically not relevant [7,31,36]. Zone B was the area where measurement errors would exceed 0.5 • C but not lead to wrong clinical decisions; e.g., if T Rec were 36.5 • C and T DHF showed a temperature of 37.4 • C, neither temperature would lead to active warming therapy or a diagnostic workup for infection.…”

“…Zone B was the area where measurement errors would exceed 0.5 • C but not lead to wrong clinical decisions; e.g., if T Rec were 36.5 • C and T DHF showed a temperature of 37.4 • C, neither temperature would lead to active warming therapy or a diagnostic workup for infection. In contrast, Zone C indicated errors that would lead to wrong clinical decisions and may harm a patient; e.g., if T Rec were 36.5 • C and T DHF showed 34.0 • C, the patient would receive active warming, although not indicated [31]. Region D was the points indicating a potentially dangerous failure to detect a need for treatment that could prevent hypothermia, defined as below 35.6 • C, or hyperthermia, defined as above 37.9 • C in T Rec but not in T DHF [27,31,37].…”

“…In contrast, Zone C indicated errors that would lead to wrong clinical decisions and may harm a patient; e.g., if T Rec were 36.5 • C and T DHF showed 34.0 • C, the patient would receive active warming, although not indicated [31]. Region D was the points indicating a potentially dangerous failure to detect a need for treatment that could prevent hypothermia, defined as below 35.6 • C, or hyperthermia, defined as above 37.9 • C in T Rec but not in T DHF [27,31,37]. Since the standard of care in this population is an underbody blanket and a room temperature of 26 • C, we assumed only temperatures below 35.6 • C or above 37.9 • C would lead to additional treatment [15].…”

“…A recent multicenter study showed no outcome difference between patients at 35.5 • C and at 37 • C; however, severe hypothermia below 35 • C needs to be avoided, and countermeasures should be taken before a patient reaches such a low core temperature [38]. Zone E was all points that would lead to the opposite of the correct treatment: for example, a T DHF of 35.3 • C and a T Rec of 38.4 • , meaning a patient that should have been cooled would receive additional warming, or vice versa [31].…”

“…The Temple Touch Pro™ and the 3M™ Bair Hugger™ temperature monitoring systems have been tested for pediatric patients [7,[29][30][31]; however, to date, no study exists of the use of Tcore thermometer technology in neonates and infants.…”