Top

Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine

Published in:

Open Access 01-12-2015 | Original research

Influence of low ambient temperature on epitympanic temperature measurement: a prospective randomized clinical study

Authors: Giacomo Strapazzon, Emily Procter, Gabriel Putzer, Giovanni Avancini, Tomas Dal Cappello, Norbert Überbacher, Georg Hofer, Bernhard Rainer, Georg Rammlmair, Hermann Brugger

Published in: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine | Issue 1/2015

Abstract

Background

Epitympanic temperature (T_ty) measured with thermistor probes correlates with core body temperature (T_core), but the reliability of measurements at low ambient temperature is unknown. The aim of this study was to determine if commercially-available thermistor-based T_ty reflects T_core in low ambient temperature and if T_ty is influenced by insulation of the ear.

Methods

Thirty-one participants (two females) were exposed to room (23.2 ± 0.4 °C) and low (−18.7 ± 1.0 °C) ambient temperature for 10 min using a randomized cross-over design. T_ty was measured using an epitympanic probe (M1024233, GE Healthcare Finland Oy) and oesophageal temperature (T_es) with an oesophageal probe (M1024229, GE Healthcare Finland Oy) inserted into the lower third of the oesophagus. Ten participants wore ear protectors (Arton 2200, Emil Lux GmbH & Co. KG, Wermelskirchen, Switzerland) to insulate the ear from ambient air.

Results

During exposure to room temperature, mean T_ty increased from 33.4 ± 1.5 to 34.2 ± 0.8 °C without insulation of the ear and from 35.0 ± 0.8 to 35.5 ± 0.7 °C with insulation. During exposure to low ambient temperature, mean T_ty decreased from 32.4 ± 1.6 to 28.5 ± 2.0 °C without insulation and from 35.6 ± 0.6 to 35.2 ± 0.9 °C with insulation. The difference between T_ty and T_es at low ambient temperature was reduced by 82 % (from 7.2 to 1.3 °C) with insulation of the ear.

Conclusions

Epitympanic temperature measurements are influenced by ambient temperature and deviate from T_es at room and low ambient temperature. Insulating the ear with ear protectors markedly reduced the difference between T_ty and T_es and improved the stability of measurements. The use of models to correct T_ty may be possible, but results should be validated in larger studies.

Strapazzon G, Procter E, Paal P, Brugger H. Pre-hospital core temperature measurement in accidental and therapeutic hypothermia. High Alt Med Biol. 2014;15(2):104–11.CrossRefPubMed

Benzinger TH. On physical heat regulation and the sense of temperature in man. Proc Natl Acad Sci U S A. 1959;45(4):645–59.PubMedCentralCrossRefPubMed

Brinnel H, Cabanac M. Tympanic temperature is a core temperature in humans. J Therm Biol. 1989;14(1):47–53.CrossRef

Mariak Z, White MD, Lyson T, Lewko J. Tympanic temperature reflects intracranial temperature changes in humans. Pflugers Arch. 2003;446(2):279–84.PubMed

Walpoth BH, Galdikas J, Leupi F, Muehlemann W, Schlaepfer P, Althaus U. Assessment of hypothermia with a new “tympanic” thermometer. J Clin Monit. 1994;10(2):91–6.CrossRefPubMed

Shin J, Kim J, Song K, Kwak Y. Core temperature measurement in therapeutic hypothermia according to different phases: comparison of bladder, rectal, and tympanic versus pulmonary artery methods. Resuscitation. 2013;84(6):810–17.CrossRefPubMed

Brown DJ, Brugger H, Boyd J, Paal P. Accidental hypothermia. N Engl J Med. 2012;367(20):1930–38.CrossRefPubMed

Brugger H, Durrer B, Elsensohn F, Paal P, Strapazzon G, Winterberger E, et al. Resuscitation of avalanche victims: evidence-based guidelines of the international commission for mountain emergency medicine (ICAR MEDCOM): intended for physicians and other advanced life support personnel. Resuscitation. 2013;84(5):539–46.CrossRefPubMed

Oberhammer R, Beikircher W, Hörmann C, Lorenz I, Pycha R, Adler-Kastner L, et al. Full recovery of an avalanche victim with profound hypothermia and prolonged cardiac arrest treated by extracorporeal re-warming. Resuscitation. 2008;76(3):474–80.CrossRefPubMed

10.

Koppenberg J, Brugger H, Esslinger A, Albrecht R. Life-saving air supported avalanche mission at night in high alpine terrain. Anaesthesist. 2012;61(10):892–900.CrossRefPubMed

11.

Strapazzon G, Nardin M, Zanon P, Kaufmann M, Kritzinger M, Brugger H. Respiratory failure and spontaneous hypoglycemia during noninvasive rewarming from 24.7 degrees C (76.5 degrees F) core body temperature after prolonged avalanche burial. Ann Emerg Med. 2012;60(2):193–96.CrossRefPubMed

12.

Keatinge WR, Sloan RE. Deep body temperature from aural canal with servo-controlled heating to outer ear. J Appl Physiol. 1975;38(5):919–21.PubMed

13.

Teunissen LP, de Haan A, de Koning JJ, Clairbois HE, Daanen HA. Limitations of temperature measurement in the aural canal with an ear mould integrated sensor. Physiol Meas. 2011;32(9):1403–16.CrossRefPubMed

14.

Livingstone SD, Grayson J, Frim J, Allen CL, Limmer RE. Effect of cold exposure on various sites of core temperature measurements. J Appl Physiol Respir Environ Exerc Physiol. 1983;54(4):1025–31.PubMed

15.

Hu EW, Wakamatsu BK, Smith DD. Emergency procedures. In: Roppolo L, Davis D, Kelly S, Rosen P, editors. Emergency medicine handbook; critical concepts for clinical practice. Edinburgh: Elsevier Mosby; 2007. p. 1223–75.

16.

Lin LI. A concordance correlation coefficient to evaluate reproducibility. Biometrics. 1989;45(1):255–68.CrossRefPubMed

17.

Procter E, Strapazzon G, Rilk C, Überbacher N, Brugger H. Temperature gradient in the inner ear canal and implications for epitympanic temperature measurement. High Alt Med Biol. 2014;15:A-281.

18.

Cooper KE, Cranston WI, Snell ES. Temperature in the external auditory meatus as an index of central temperature changes. J Appl Physiol. 1964;19:1032–35.PubMed

19.

Pasquier M, Zurron N, Weith B, Turini P, Dami F, Carron PN, et al. Deep accidental hypothermia with core temperature below 24 °C presenting with vital signs. High Alt Med Biol. 2013;15(1):58–63.CrossRef

Title: Influence of low ambient temperature on epitympanic temperature measurement: a prospective randomized clinical study
Authors: Giacomo Strapazzon
Emily Procter
Gabriel Putzer
Giovanni Avancini
Tomas Dal Cappello
Norbert Überbacher
Georg Hofer
Bernhard Rainer
Georg Rammlmair
Hermann Brugger
Publication date: 01-12-2015
Publisher: BioMed Central
Published in: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine / Issue 1/2015
Electronic ISSN: 1757-7241
DOI: https://doi.org/10.1186/s13049-015-0172-5

Keynote webinar | Spotlight on medication adherence

Springer Medicine

Influence of low ambient temperature on epitympanic temperature measurement: a prospective randomized clinical study

Abstract

Background

Methods

Results

Conclusions

Keynote webinar | Spotlight on medication adherence

Springer Medicine

Abstract

Background

Methods

Results

Conclusions

Please log in to get access to this content

Other articles of this Issue 1/2015

The formation and design of the TRIAGE study - baseline data on 6005 consecutive patients admitted to hospital from the emergency department

Prehospital intravenous epinephrine may boost survival of patients with traumatic cardiac arrest: a retrospective cohort study

Risk factors for wound complications of closed calcaneal fractures after surgery: a systematic review and meta-analysis

Retrospective evaluation of prehospital triage, presentation, interventions and outcome in paediatric drowning managed by a physician staffed helicopter emergency medical service

Maxillofacial fractures and craniocerebral injuries – stress propagation from face to neurocranium in a finite element analysis

Short-term outcome and differences between rural and urban trauma patients treated by mobile intensive care units in Northern Finland: a retrospective analysis