Infrared ear thermometry in drowning: not a good choice

Introduction

Hypothermia is a serious problem in many out-of-hospital emergencies [1], one of them being (near-)drowning. Hypothermia per se may threaten the patient, but it can also protect vital organs [1, 2]. Since severe hypothermia also impacts the decision where to bring the victim for further treatment [2], exact temperature measurement assumes crucial importance in this context. The purpose of this trial was to determine the reliability of the tympanic temperature measurement after immersion in water.

Materials and methods

The trial was approved by the ethics committee of the University of Ulm. In 28 volunteers aged 18–49 years sublingual (Fixotherm; Tradesell Europe, Eglharting, Germany) and tympanal (First Temp Genius; Sherwood Medical, Sulzbach, Germany) temperature measurements were taken before immersion in water, immediately after the 45 min of immersion, and 15 min after leaving the water. We measured the oral temperature once at each of these three time-points. During immersion the volunteers had to swim in a manner that provides a temporary submersion of the ears. The control group consisted of 11 volunteers who had to swim for the same time with their heads always above the water. The trial was performed in an indoor swimming pool at 28°C water temperature and 30°C air temperature.

Results

In both groups oral temperature time-dependently varied within only 0.4°C. Tympanic temperature was significantly lower after immersion compared with the baseline values in the 'submerged' group (Submerg) (33.7 vs 37.5°C, P < 0.001), while no such effect was observed in the control subjects (37.6 vs 37.5°C, P = 0.31). At baseline, oral temperature was lower than tympanic temperature in both groups (P < 0.001), while this relation was reversed after immersion. This reversed response was not detectable in the controls.

Conclusions

The data suggest that in emergencies like near-drowning, the use of infrared ear thermometry to measure body (core) temperature should be cautioned.

Figure 1

(abstract P299)