Comparison of Temporal to Pulmonary Artery Temperature Measurement in Patients With Fever
Condition: Fever
MeSH terms: Fever
Study type: Observational

Summary: 
      Assessment and evaluation of body temperature is an important sign of health and disease.
      Inferior thermometry increases the risk of morbidity and mortality, and increases health care
      cost by delaying the diagnosis and treatment of fever-related disease. The gold standard for
      measuring core body temperature is the pulmonary artery thermistor (PAT). The measurement of
      the PAT requires the insertion of the invasive pulmonary artery catheter, a high risk
      procedure.

      An innovative thermometry technology, the temporal artery thermometer (TAT), has been
      introduced into the clinical arena as a potential non-invasive proxy for the PAT. The TAT
      reduces the risk and cost of pulmonary artery catheter insertion by non-invasively measuring
      core blood temperature by measuring temperature over the skin of the temporal artery.

      Research to demonstrate the precision and accuracy of the TAT in normothermic patients has
      been published, but little to no data is available in those with temperatures greater than
      100.4oF. The purpose of this study is to measure the precision and accuracy of 2standard of
      care temperature methods: the thermistor from the PAT, considered the gold standard, and the
      TAT as measured in those patients with a PAT temperature greater than 100.4oF.
    

Detailed description: 
      The results from previous studies agree that direct comparisons of the PAT and TAT are
      clinically comparable in the normal temperature range in adults. This was defined as a
      clinical significance difference of less than ±.5ºC (.9ºF. In the one study that assessed
      subjects with fevers (temperatures greater than 37.8oC (100.0oF) with some methodological
      criticism, compared the TAT to PAT in adults (n=15). There were poor correlations (r=0.3)
      among the adult measurements with a difference of 1.3+0.6o C. Eighty-nine percent of the TAT
      measurements were different than the PAT by more that ±.5ºC.

      With only one study that focused in those who had a PAT outside the normal temperature range
      to evaluate accuracy and precision, there is a need for further research to assess the
      accuracy and precision of the TAT for detection of hyperthermia. A new onset of temperature
      equal to or above 100.4oF is defined as a fever and a temperature of 100.9oF is considered a
      reasonable trigger for a clinical assessment according to the Society of Critical Care
      Medicine in their fever guidelines for adults. Researchers synthesizing the literature on the
      TAT and other noninvasive temperature measurements, indicate that noninvasive temperature
      measurements are accurate for normal temperatures but may fail to detect hyperthermia and
      hypothermia, depending on the thermometer used. The authors concluded that the TAT is
      clinically comparable to the PAT in only the normal temperature range.

      A repeated measures design will be used to describe the accuracy and precision of 2
      temperature measurements, the PAT and the TAT. Study subjects will act as their own control
      in order to investigate the difference in PAT readings and the TAT readings in both the core
      and oral mode. The PAT will also be compared to the TAT reading taken by the clinical staff.
    

Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        ICU patients
      
Keywords: Temporal artery thermometer; Pulmonary artery thermistor