CLINICAL STUDIES
Infrared Tympanic Thermometry for Neonatal Temperature Assessment

https://doi.org/10.1111/j.1552-6909.1994.tb01955.xGet rights and content

Objective

To investigate the accuracy and precision of infrared tympanic thermometer use with neonates by comparing with axillary and rectal measurements. Design: Descriptive, comparative study.

Setting

Newborn nursery of a tertiary‐level perinatal center.

Subjects

Thirty‐four full‐term newborns.

Instruments

Infrared thermometers were used to collect tympanic temperatures. An electronic thermometer was used to collect axillary and rectal temperatures.

Results

There was no significant difference between tympanic and axillary temperatures. The range of variation (95% CI) was ± 0.7–.9°C. The mean difference between tympanic and rectal measurements was 0.4°C. The range of variation was ± 0.7–0.75°C. Right ear measurements produced the best approximation of axillary temperature, and protected ear measurements produced the best approximation of rectal temperature. The protected ear was 0.2–0.3°C higher than the exposed ear.

Conclusions

There was more variation between tympanic versus axillary and tympanic versus rectal measurements than between axillary and rectal measurements. Tympanic thermometry may be useful for rapid screening of neonatal temperature, but its usefulness for monitoring unstable neonates remains in question.

Section snippets

Methods

A descriptive and comparative design was used to address the aims of the study. Accuracy, defined as equivalence to a standard, was assessed by comparing ear with axillary and rectal temperature readings. Precision was defined as repeatability of same ear measurements and reproducibility of opposite ear measurements. The effect of neonatal position was investigated by comparing temperature readings obtained in the ear lying against the crib mattress (protected ear) with readings in the ear

Assessing Precision With Infrared Tympanic Thermometers

Using repeated measures analysis of variance, there were no significant differences within repeated same ear temperature readings or between left and right ear readings taken with the professional and consumer models. Because the three readings in each ear were taken sequentially in a short period of time, it was assumed that these readings measured the same temperature. Mean absolute differences, maximum differences, and percent of differences exceeding 0.2°C were calculated (see Table 1), as

Discussion

Although tympanic and axillary mean temperatures were remarkably similar and not statistically different, correlations between readings were low and supported prior results with full-term and preterm infants (Weiss, 1991). Low correlations may have been the result of limited range of temperatures in this homogeneous sample of neonates and site or operator-related measurement error. Tympanic, axillary, and rectal sites reflect different physiologic processes that may result in varying degrees of

Limitations

Several limitations should be considered when interpreting the results of this study. Subjects were not randomly selected, the order of temperature recordings was not randomly assigned, and the data collector was not blinded to the temperature recordings. There was no attempt to control for environmental variables such as room temperature, amount of clothing and swaddling blankets, or the infant’s activity level. Ages of the neonates at the first temperature recordings varied.

This study

Nursing Implications

If tympanic measurement is to be used in the assessment of temperature with neonates, clinicians will need to learn normal values for tympanic measurement, to understand the relationship of tympanic temperature to temperature readings obtained at other sites, and to recognize the degree of variation possible with this and other methods of temperature measurement. The variation in tympanic readings, when compared to axillary and rectal recordings, may not be acceptable for assessment of

REFERENCES (15)

  • B.K. Muma et al.

    Comparison of rectal, axillary, and tympanic membrane temperatures in infants and small children

    Annals of Emergency Medicine

    (1991)
  • M. Benzinger et al.

    Tympanic clinical temperature

    National Bureau of Standards Fifth Symposium on Temperature

    (1972)
  • Bland, J. M., & Altman, D. G. (1986). Statistical methods for assessing agreement between two methods of clinical...
  • J.M. Chamberlain et al.

    Comparison of tympanic thermometer to rectal and oral thermometers in a pediatric emergency department

    Clinical Pediatrics

    (1991)
  • J.L. Engstrom

    Assessment of reliability of physical measures

    Research in Nursing and Health

    (1988)
  • C.L. Freed et al.

    Lack of agreement of tympanic membrane temperature assessments with conventional methods in a private practice setting

    Pediatrics

    (1992)
  • K.J. Johnson et al.

    Infrared thermometry of newborn infants

    Pediatrics

    (1991)
There are more references available in the full text version of this article.

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