Background: There is uncertainty about the accuracy of peripheral thermometers in measuring temperatures within the febrile physiological range.
Objective: To determine the accuracy of peripheral thermometers in detecting febrile core temperatures among critically ill patients, and, if required, to determine a standard conversion equation to improve accuracy.
Methods: A systematic search of MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and PubMed was undertaken to identify clinical trials comparing peripheral thermometry in critically ill adult patients with core temperatures > 37.5°C. Our prespecified plan was to perform a meta-analysis of the clinical accuracy of mean peripheral thermometer temperature difference from core temperature and calculation of limits of agreement.
Results: Systematic review identified three studies that compared infrared tympanic, rectal or oral thermometer readings with pulmonary artery catheter core temperature readings among critically ill adults with fever. Studies were heterogeneous and all failed to report appropriate measurements of variation for the estimates of clinical accuracy, which prevented meta-analysis and limited interpretation of the results. Mean differences were within ± 0.2°C in five of seven tympanic thermometer/mode/ temperature combinations and in the one oral thermometer studied. All of three rectal thermometer/temperature combinations studied reported mean differences outside this range.
Conclusion: The identified studies suggest that in critically ill patients, tympanic and oral thermometry provide, on average, accurate measures of core temperatures within the febrile range and can be recommended for this purpose. Further studies with appropriate statistical methods are required to assess the accuracy of peripheral thermometers among critically ill patients with fever.