Comparison of temporal to pulmonary artery temperature in febrile patients

As a routine part of clinical care, temperature measurement is a key indicator of illness. With the criterion standard of temperature measurement from the pulmonary artery catheter thermistor (PAT), which insertion of PAT carries significant risk to the patient, a noninvasive method that is accurate and precise is needed.

The purpose of this study was to measure the precision and accuracy of 2 commonly used methods of collecting body temperature: PAT considered the criterion standard and the temporal artery thermometer (TAT) in those patients with a temperature greater than 100.4°F.

This is a repeated-measures design with each patient with a PAT in the intensive care unit acting as their own control to investigate the difference in PAT readings and readings from TAT in the core mode. Accuracy and precision were analyzed.

There were 60 subjects, 41 males and 19 females, with mean age of 60.8 years, and 97% (n = 58) were post-cardiac surgery. There was a statistically significant difference between PAT and TAT (101.0°F [SD, 0.5°F] vs 100.5°F [SD, 0.8°F]; bias, -0.49°F; P < .001). Differences in temperature between the 2 methods were clinically significant (ie, >0.9°F different) in 15 of 60 cases (25%). No TAT measurements were 0.9 F greater than the corresponding PAT measurement (0%; 95% confidence interval, 0%-6%).

These data demonstrate the accuracy of TAT when compared with PAT in those with temperatures of 100.4°F or greater. This study demonstrates that TAT set to core mode is accurate with a 0.5°F lower temperature than PAT. There was 25% in variability in precision of TAT.