During the Orthognathic Surgery, the mechanisms that regulate the thermal homeostasis are deeply altered, secondary a depression of the hypothalamic function and alteration in the mechanisms of production and loss of heat.

As a result the organism is exposed to hyper or hypothermia and secondary organ disfunction.

The purpose of this work is to characterize the changes in the temperature of patients submitted to orthognatic surgery (OS).

Materials and methods: We studied 100 patients operated of OS anesthetized managed with general anesthesia based in halogenates and opioids. The temperature was measured using a rectal probe. We kept the OR temperature around 20 °C. We used simple statistics to analyze the results.

Results: There were many variations of temperature. 2 patients had a decrease superior to 1 °C. In the other hand, 8 had an increase superior to 1 °C. At the end of the case, 4 patients had more then 37.5 °C and 17 less than 36 °C.

25 patients required active manoeuvres to keep the temperature in an acceptable range. 19 were actively warmed, 5 cooled and one both.

There were no correlation between the duration of the intervention and the temperature change.

Conclusion: In OS the patients experience important and unpredictable changes in their corporal temperature with the consequent derangement of the function of organs and systems.

In these patients the temperature always must be monitorized and we need the means to manage adequately temperature deviations specially in the sense of a rise.

Conflict of interest: None declared.