Can the SpotOn™ Zero-Heat-Flux-Thermometry Sensor Accurately Measure Core Temperature in Children?
Condition: Hypothermia; Anesthesia; Hypothermia Following Anesthesia; Children
MeSH terms: Hypothermia
Study type: Interventional

Summary: 
      The present study aims to assess the accuracy of the SpotOn™ Zero-heat-flux-thermometry
      sensor in measuring core temperature in the paediatric population in the perioperative
      period.
    

Detailed description: 
      Temperature regulation in the perioperative period is of primordial importance in paediatric
      population - a particularly sensitive group for thermal variations.

      In fact, infants lose a significantly high percentage of their core heat from skin
      perspiration in comparison to adults (where it approximates roughly 10%). This percentage can
      go up to 20% in premature infants and relates to the fact that cutaneous heat loss is "grosso
      modo" proportional to body surface area.

      This higher thermal vulnerability is aggravated during the perioperative period, where body
      exposure to the cold operating room environment is increased, and where anaesthetic
      interventions impair the compensatory mechanisms to the extent of being unable to
      sufficiently increase heat production to compensate for hypothermia.

      An alternative thermometry method called Zero-heat-flux was developed in the 1970's in an
      attempt to compensate for the limitations of pure skin temperature, while maintaining its
      practical character. It is based on the principle that the temperature 1-2 cm below skin
      surface reasonably approximates core temperature. In order to measure it, it uses 4-layered
      probe, with the following inside-out structure: patient temperature thermistor, insulating
      foam layer, heating (flex) circuit, and insulating foam. A servo-controlled system actively
      warms the probe circuit to the point where, theoretically, temperature equilibrium is
      achieved between the skin and deeper structures and there is zero heat transfer to the
      surrounding areas. This concept is commonly exemplified as the creation of a vertical
      isothermal tunnel between the skin surface and lower dermal layers. Assuming a good tissue
      perfusion, dermal temperature will reasonably approximate core temperature.

      Although a systematic adult population validation is on its way, no data on the paediatric
      patients exists.

      Considering the practical and non-invasive character of this skin surface probe, as well as
      the abovementioned thermal sensitivity concerns on the paediatric population, it seems that,
      should the probe indeed prove to be accurate in this age range, it can definitely contribute
      to the improvement of the perioperative temperature management in children.
    

Intervention name(s): Thermometry
Intervention type(s): Device
Intervention description(s): Within the same patient comparison of 2 thermometry methods: SpotOn skin sensor versus oesophageal temperature probe
Allocation: Non-Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Other
Keywords: Thermometry; SpotOn