Temperature tympanic

In clinical settings core temperature measurements, including pulmonary artery and esophagus measurements, are often required. In 1959 Benzinger [1] first proposed the human tympanic membrane as the ideal site for core temperature measurements. The tympanic membrane is ideal, because it is located near the carotid artery and shares its blood supply with the hypothalamus, which controls body temperature. First temperature measurements in the ear were performed with thermistor sensors in direct contact with the tympanic membrane. The invasiveness of this method limited its use mainly to anaesthetized patients. 

The first clinical IRET used thermopile sensors to achieve non-contact temperature measurement in the ear. In 1991 a tympanic thermometer for home use was first introduced to the consumer market (Thermoscan HM 1). It utilized a pyroelectric sensor which requires the use of a suitable mechanical shutter or chopper mechanism, since it is only sensitive to temperature changes [3]. The main advantage of the pyroelectric sensor unit was its lower cost. However, prices for thermo-... 

How the temperature is measured (i.e., brain vs arterial, venous, tympanic, bladder, or rectal temperature) is also critical, as the core temperature is usually 0.3-1.1°C lower than brain temperature (51). However, it is important to consider that these values may be different in patients with acute cerebral ischemia or trauma. 

Christensen H. and Boysen G. (2002) Acceptable agreement between tympanic and rectal temperature in acute stroke patients. Int. J. Clin. Pract. 56, 82-84. 

Rectal temperature is the most accurate at about 37°C. However this is not usually practical and thus oral or underarm temperatures are often taken. There are electronic tympanic devices available which take the temperature from the ear. These read in both centigrade (°C) and Fahrenheit (°F) and are placed in the ear for a few seconds (depending on device) and produce a good level of accuracy if used correctly. These are commonly used in hospitals and can be bought over the counter. Also available over the counter are disposable temperature strips these are popular as they are easy to use but relatively inaccurate. 

Cold otic drops cause pain when they eome in eontaet with the tympanic membrane. Therefore, otie solutions should be allowed to warm to room temperature before being administered. 

Immediately check the rectal or tympanic temperature and cool the patient rapidly (see p 22) if the temperature is above 40°C (104°F). The most rapid and reliably effective method of temperature control is neuromuscular paralysis with pancuronium, 0.1 mg/kg IV (p 472) or another nondepolarizing neuromuscular blocker. Caution If paralysis is used, the patient must be intubated and ventilated in addition, monitor the electroencephalogram (EEG) for continued brain seizure activity because peripheral muscular hyperactivity is no longer visible. 

D. Treatment. Sometimes the patient can be calmed with reassuring words and reduction of noise, light, and physical stimulation. It this is not quickly effective, rapidly gain control of the patient to determine the rectal or tympanic temperature and begin rapid cooling and other treatment if needed. 

IV. Diagnosis is based on a history of use and the presence of signs of sympathetic stimulation. Diagnosis of hyperthermia requires a high level of suspicion and use of a thermometer that accurately measures core temperature (rectal, tympanic membrane, or esophageal probe),... 

Martha SL, Forsberg C, Wahren LK. Normal oral, rectal, tympanic and axillary body temperature in adult men and women a systematic bterature review. Scand J Caring Sci 2002 16(2) 122. 

Matsukawa, T., Ozaki, M., Hanagata, K., Iwashita H., Miyaji, T., and Kumazawa, T., 1996, A Comparison of Four Infrared Tympanic Thermometers with Tympanic Membrane Temperatures Measured by Thermocouples, Can. J. Anaesth., 43(12) 1224-1228. 

Shibasaki, M., Kondo, N., Tominaga, H., Aoki, K., Hasegawa, E., Idota, Y., and Moriwaki, T., 1998, Continuous Measurement of Tympanic Temperature with a New Infrared Method Using an Optical Fiber, J. Applied Physiology, 85(3) 921-926. 

Another problem is intolerance of core temperature sensors by the wearer. Oral temperature is not very accurate and reliable for core temperature assessments. Rectal probes provide more accurate readings, but are less tolerable. A more acceptable sensor is a tympanic sensor. It has a thermistor bead or small thermocouple placed in the ear canal against or very near the eardrum and held in place by a custom-molded ear plug. Tympanic temperature closely follows changes in core temperature. The preferred readout display is a digital one. 

Invasive methods for direct measurement of deep brain temperature can not be easily justified for ethical reasons. Correlations between deep brain temperature and surrogate measures such as tympanic membrane, nasopharyngeal, esophageal or rectal temperatures are uncertain, particularly... 

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