Best Practice for Measuring Body Temperature

Best Practice for Measuring Body Temperatures

Kim Carter, PhD, RN, NEA-BC - Senior Director Nursing Research

Purpose of Review

The purpose of this review was to examine the literature to identify best practice for non-invasive body temperature measurement for adult hospital inpatients, with a specific focus on axillary temperature.

Background

Core body temperature (CBT) reflects overall health and endurance. The gold standard location for measuring core body temperature is the pulmonary artery; however, accessing this location is invasive and risky15,21. The esophagus and rectum are also recognized as accurate, but with some risk, inconvenience, and are not practical for many situations21. Therefore, other measurement locations and devices, including contact-type (sublingual mouth, rectum, axillary, and base of urethra) and non-contact-type infrared (IRT) thermometers (tympanic and forehead) are options5. Forehead thermometry includes a thermistor probe, a liquid crystal strip, and an IR thermometer5. There are two types of infrared techniques for surface temperature: point estimation (tympanic IRT or forehead IRT) and IR thermal imaging5 .

What constitutes “normal” in core and peripheral temperature measurement further complicates the situation. Variations in core body temperatures between rectal (37.04 ͦ C) and urine (36.61 ͦC) are a result of a fundamental problem with how urine core body temperature was measured in the 1970s and 1980s22. Following an analysis of 36 articles reflecting 9227 measurement sites from 7636 subjects in a systematic review of papers published from 1935 to 2017, Geneva and colleagues defined “calculated ranges (mean + standard deviations) were 36.32-37.76 (rectal), 35.76-37.52 (tympanic), 35.61-37.61 (urine) 35.73-37.41 (oral), and 35.01-36.93 (axillary)” (p. 1). Many studies grapple with determining “normal” for each of the methods of measuring body temperature5 .

The complexity of body temperature measurement is also affected by a variety of influences. Normal oral adult temperature has decreased in Japan24 and in the U.S. at a rate of 0.03 ͦC per birth decade since 186023. Geneva, et al.’s findings22 are consistent with a normal body temperature lower than the currently accepted normothermia cutpoint of 36.8 ͦC, but not to a level of clinical impact. It is important to consider the patient’s age, blood pressure, pulse rate, time of day, and site of measurement when assessing body temperature22, 24. Compared to younger adults, healthy older adults have lower body temperatures (an average of 0.23 ͦC) due to slowing metabolism and decline in internal temperature regulation mechanisms, which is clinically important as people aged 60+ may not exhibit a temperature in the traditional fever range22 .

The ideal device for measuring core temperature in critical care patients would be continuous, noninvasive, and accurate18. This review followed the evidence-based practice review process outlined by the Ohio State University Fuld Institute to analyze and synthesize the current evidence related to thermometry options.

Approach

Search Process. The following data bases were searched: 1. HERO: “axillary temperature adult”, published since 2016, English 2. CINAHL: “body temperature” AND “axillary” OR “oral” AND “adult”, 2016, English 3. Google Scholar: “body temperature measurement”, English 4. TRIP: “temperature measurement” 5. Ancestry search yielded Singh, 2000; Jensen 2000

they were pediatric or did not compare temperature to a referent method. Further, papers were excluded if the focus of the work was to determine “normal” core and/or peripheral body temperature. The literature review in Chen, Chen, & Chen (2020)5 was used to further augment the synthesis table, citing their literature as secondary sources in this review.

Synthesis and Analysis Following the process from the Ohio State University Fuld Institute of EBP, analysis and synthesis tables were developed (Table 1).

Findings

The literature is relatively weak in identifying best practice for measuring body temperature peripherally. Studies are limited in sample size, design, and many do not compare the peripheral approach being studied to a core body temperature measurement. Systematic reviews and meta-analyses either did not use established meta-analytic methods or were narrow in scope to select populations15. Not all studies identified the specific device brand or device type (such as infrared or electronic) that was used.

No approach for measuring peripheral body temperature stands out as best practice from this review (See synthesis table on page 6).

Axillary: Of the 9 studies reported, 4 do not recommend use of the axilla, and 2 note use with caution. The Agency for Clinical Innovation (2014) identifies some support for the axillary approach1, and Pei (2018) found that axillary thermometry using the iThermonitor WT701 was suitable for clinical use with noncardiac surgical patients17 .

Infrared or electronic Tympanic: Of the 14 studies reported, 10 do not recommend use for fever detection. Mogensen (2018, as cited in Chen, Chen, & Chen, 20205) determined that IRT was adequate for screening. When compared to IR TA, IR tympanic was most accurate compared to nasopharyngeal. A combined screening approach is recommended with tympanic and oral12 and with IR forehead5 .

Oral: Of the 8 studies examining oral approaches, 3 did not support use3,10,15. Some support for oral thermometry was yielded by the Agency for Clinical Innovation1. The disposable oral electronic thermometer had some degree of support from studies4,7 and the Emergency Nurses Association (as noted by Hafizi, 20199). A combination approach for detection of fever between oral and tympanic was recommended by others12 .

Forehead: Of the 22 studies, infrared forehead temporal artery measurement was not recommended by 14 studies of contact-type, liquid crystalline strip, non-contact IRT, and the Exergen TAT-5000, especially with medications used for anesthesia1-5,8-9,11,14-16. The contact-type forehead with and without ear tap approach was supported by Blake (2019). Chen, Chen, & Chen (2020) recommended a combined screening with IR forehead and then confirmed with tympanic thermometry. Cautious use was suggested by Fitzwater (2019), Hafizi (2019), and Hsiao (2020, as cited in Chen et al, 20205) suggests two readings with using forehead thermometry. However, a summary of 7 studies between 1969 and 20025 found that contact type deep skin forehead thermometry was accurate and suitable for clinical use.

Other: The infrared wrist approach was not recommended5. The Zero Heat Flux was found to be comparable to rectal and bladder thermometry and recommended for medical, surgical and neurologically injured ICU patients18, but another did not recommend it6, based on findings from 2 studies. However, one study6 did not identify the product tested for zero heat flux in the 2 studies, while Schell-Chaple (2018)6 used the SpotOn thermometry system (3M Healthcare). It is possible that different brands were examined. The Vital-SCOPE thermopile contactless temperature sensor was found to be promising20. Jensen (2000) noted that the electronic rectal temperature compared

Table 1: Synthesis Table

most closely to rectal mercury10; although many new products have emerged in the 21 years since this paper was published.

References

1. Agency for Clinical Innovation. 2014. Temperature measurement for critically ill adults clinical practice guideline. https://www.aci.health.nsw.gov.au/__data/assets/pdf_file/0004/240178/ACI14_Temperature-1 -4.pdf

2. Aykanat, V., Broadbent, E., & Peyton, P. 2021. Reliability of alternative devices for postoperative patient temperature measurement: two prospective, observational studies. Anaesthesia, 76, 514-519. doi:10.1111/anae.15248

3. Bijur, P., Shah, P., & Esses, D. 2016. Temperature measurement in the adult emergency department: oral, tympanic membrane and temporal artery temperatures versus rectal temperature. Emergency Medicine Journal, 33, 843-847. Doi: 10.1136/ememed-2015-205122

4. Blake, S., Fries, K., Higginbotham, L., et al. 2019. Evaluation of noninvasive thermometers in an endoscopy setting. Gastroenterology Nursing, 42(2),123-131. DOI: 10.1097/SGA.0000000000000367.

5. Chen, H., Chen, A., & Chen, C. 2020. Investigation of the impact of infrared sensors on core body temperature monitoring by comparing measurement sites. Sensors, 20, doi: 10.3390/s20102885.

6. Cutili, S., See, E., Osawa, E., Ancona, P., Marshall, D., Eastwood, G., Glassford, N., & Bellomo, F. 2021. Accuracy of non-invasive body temperature measurement methods in adult patients admitted to the intensive care unit: A systematic review and meta-analysis. Critical Care and Resuscitation, 23(1), 6-13.

7. Fitzwater, J., Johnstone, C., Schippers, M., Cordoza, M., & Norman, B. 2019. A comparison of oral, axillary, and temporal artery temperature measuring devices in adult acute care. MEDSURG Nursing, 28(1), 35-41. NLM UID: 9300545

8. Gates, D, Horner, V., Bradley, L., Sheperd, T., John, O., & Higgins, M. 2018. Temperature Measurements: Comparison of different thermometer types for patients with cancer. Clinical Journal of Oncology

Nursing, 22(6), 611-617. Doi: 10.1188/18.CJON.611-617

9. Hafizi, D. & McCormack, S. 2019. Infrared tympanic thermometers for measurement of temperature in adults and children: clinical effectiveness, diagnostic accuracy, and guidelines. Ottawa: CADTH Rapid

Response Report, Apr.

10. Jensen, B., Jensen, F., Madsen, S., & Lossi, K. 2000. Accuracy of digital tympanic, oral, axillary, and rectal thermometers compared with standard rectal mercury thermometers. European Journal of Surgery, 166, 848-851. DOI: 10.1080/110241500447218

11. Kiekkas, P., Stefanopoulos, N., Bakalis, N., Kefaliakos, A., Karanikolas, M. 2016. Agreement of infrared temporal artery thermometry with other thermometry methods in adults: systematic review. Journal of

Clinical Nursing, 25, 894-905, doi: 10.1111/jocn.13117

12. Martin, D., Das, P., Friedman, M., & Rahman, M. 2019. Assessing performance of multiple methods for measurement of body temperature, Bangladesh. Poster Abstracts, Open Forum Infectious Diseases (OFID), 6, (Suppl 2). S614.

13. Marui, S., Misawa, A.,Tanaka, Y., & Nagashima, K. 2017. Assessment of axillary temperature for the evaluation of normal body temperature of healthy young adults at rest in a thermoneutral environment.

Journal of Physiological Anthropology, 36(18), doi: 10.1186/s40101-017-0133-y

References continued:

15. Niven, D., Gaudet, J., Laupland, K., Mrklas, K., Roberts, D., & Stelfox, H. 2015. Accuracy of peripheral thermometers for estimating temperature: A systematic review and meta-analysis. Annals of Internal Medicine, 163, 768-777. Doi: 10.7326/M15-1150

16. Paik, G., Henker, H., Sereika, S., Alexander, S., Piotrowski, K., Appel, N. Meng, L., Bircher, N., & Henker, R. 2019. Accuracy of temporal artery thermometry as an indicator of core body temperature in patients receiving general anesthesia. Journal of PeriAnesthesia Nursing, 34(2), 330-337.

17. Pei, L., Huang, Y., Mao, Guangmei, & Sessler, D. 2018. Axillary temperature, as recorded by the iThermonito WT701, well represents core temperature in adults having noncardiac surgery. Anesth Analg, 126, 833-838. DOI: 10.1213/ANE.0000000000002706

18. Schell-Chaple, H., Liu, K., Matthay, M., & Puntillo, K. 2918. Rectal and bladder temperatures vs forehead core temperatures measured with SpotOn Monitoring System. American Journal of Critical Care, 27(1), 43-50.

19. Singh, V., Sharma, A., Khandelwal, R., & Kothari, K. 2000. Variation of axillary temperature and its correlation with oral temperature. Journal of Association of Physicians in India, 48(9), 898-900. PMID: 11198790

20. Sun, G., Matsui, T., Watai, Y., Kim, S., Kirimoto, T., Suzuki, S., & Hakozaki, Y. 2018. Vital-SCOPE: design and evaluation of a smart vital sign monitor for simultaneous measurement of pulse rate, respiratory rate, and body temperature for patient monitoring. Journal of Sensors, 2018. Https:// doi.org/10.1155/2018/4371872

21. Yeoh, W., Lee, J., Gan, C., Liang, W., & Tan, K. 2017. Re-visiting the tympanic membrane vicinity as core body temperature measurement site. PLoS ONE, 12(4), e)174120. https://doi.org/10.1371/ journal.pone.0174120.

Other papers cited, but not included in analysis and synthesis:

Geneva, I., Cuzzo, B., Fazili, T., & Waleed, J. 2019. Normal body temperature: A systematic review. Open Forum Infectious Diseases, DOI: 10.1093/ofid/ofz032

Protsiv, M., Ley, C., Lankester, J., Hastie, T., & Parsonnet, J. 2020. Decreasing human body temperature in the United States since the Industrial Revolution. Elife, 9(e49555. DOI: https://doi.org/10.7554 eLife.49555.

Yoshihara, T., Zaitsu, M., Ito, K., et al. 2021. Statistical analysis of the axillary temperatures measured by a predictive electronic thermometer in healthy Japanese adults. International Journal of Environmental Research and Public Health, 18, 5096. doi.org/10.3390/ijerph18105096