Should we replace the mercury in glass thermometer with the tympanic thermometer

Objective:  The tympanic thermometer is very popular and has been recently introduced to the hospitals of the Hospital Authority of Hong Kong. However, disagreement between the tympanic thermometer and the traditional mercury in glass thermometer is quite frequent. We attempt to explore the feasibility of using the tympanic thermometer in surgical patients and analyse if this thermometer is mature enough to replace the mercury in glass thermometer. Method:  Fifty consecutive febrile and afebrile patients admitted into the surgical ward of a regional hospital were enrolled. Temperature was recorded by both thermometers. Mean differences and averages of the recordings were analysed. Results:  A mean difference of 0.018 ± 0.54°C was found between the readings of the two thermometers in afebrile patients. Clinically, this translates to a difference of 0.54°C above or below the oral temperature. For febrile patients the mean difference was 0.24 ± 0.53°C. Thus, this translates to a difference of 0.67°C above or below the oral temperature. Conclusions:  There was almost 1°C discrepancy between the tympanic thermometer and the mercury in glass thermometer. Whether this will affect clinical management is not known. Further clinical study is required. We do not recommend the replacement of the traditional mercury in glass thermometer by the tympanic thermometer.