Nurses should not rely on the accuracy of thermometers used in the mouth, ear or under the arm, suggests a new Canadian study.
Researchers reviewed data from 75 studies comparing peripheral thermometers that can be used orally, in the ear or under the arm with central thermometers used rectally or at other intravascular sites.
“Peripheral thermometers do not have clinically acceptable accuracy”
Body temperature is a key measure used to screen, diagnose and monitor patients.
Yet the findings, published in the journal Annals of Internal Medicine, suggest peripheral thermometers are not that accurate.
Sensitivity for detecting fever was low at just 64%, although good quality data was not available for all types of thermometer.
When it came it came to detecting fever or hypothermia, peripheral thermometers could be between one and two degrees out, researchers found.
“Peripheral thermometers do not have clinically acceptable accuracy and should not be used when accurate measurement of body temperature will influence clinical decisions,” the authors said.
When an accurate temperature reading is key, they suggested using rectal thermometers in most circumstances – although bladder thermometers could be used for patients with a bladder catheter.
Where central thermometers cannot be used, they said the best alternative was to use electronic oral thermometers for adults only, or tympanic membrane thermometers for children and adults with thermometers calibrated before use.