A comparison of oral, tympanic, and rectal temperature measurement in the elderly

The association between the degree of fever as measured in the emergency department and clinical outcomes of hospitalized adult patients

BACKGROUND

Fever is a physiologic response to a wide range of pathologies and one of the most common complaints and clinical signs in the emergency medicine department (ED). The association between fever magnitude and clinical outcomes has been evaluated in specific populations with inconsistent results.

OBJECTIVES

In this study we aimed to investigate the association between the degree of fever in the ED and clinical outcomes of hospitalized febrile adult patients.

METHODS

This was a retrospective single-center cohort study of all the patients with maximal body temperature (BT) ≥ 38.0 °C, as recorded during the ED evaluation, who were hospitalized between January 2015 and December 2020. Patients with heatstroke were excluded. The primary outcome was 30-day all-cause mortality and secondary outcomes were intensive care unit (ICU) admission and development of acute kidney injury (AKI).

RESULTS

Fever was recorded among 8.1% of patients evaluated in the ED. Elevated BT was associated with increased risk of hospital admission (70.3% vs. 49.4%, p < 0.001), 30-day mortality (12.3% vs. 2.6%, p < 0.001), ICU admission (5.7% vs. 2.8%, p < 0.001), and AKI 11.7% vs. 3.8%, p < 0.001). After exclusion of nine patients with heatstroke, 21,252 hospitalized febrile patients were included in the final analysis. BT > 39.7 °C was progressively associated with increased mortality (OR 1.64-2.22, 95% CI 1.16-2.81, p < 0.005) as compared to BT 38.0-38.1 °C. More AKI events were observed in patients with BT > 39.5 °C (OR 1.48-2.91, 95% CI 1.11-3.66, p < 0.007). Temperature between 39.2 and 39.5 °C was associated with lower mortality (OR 0.62-0.71, 95% CI 0.51-0.87, p < 0.001). In a multiple logistic regression analysis BT > 39.9 °C was independently associated with increased mortality and AKI. BT > 39.7 °C was progressively associated with an increased risk of ICU admission.

CONCLUSION

Among febrile patients admitted to the hospital, BT > 39.5 °C was associated with adverse clinical course, as compared to patients with lower-grade fever (38.0-38.1 °C). These patients should be flagged on arrival to the ED and likely warrant more aggressive evaluation and treatment.

Evaluation of commercial, wireless dermal thermometers for surrogate measurements of core temperature

Extensive research has been devoted to developing methods for assessing core body temperature, and to determine which method is most accurate. A number of wireless dermal thermometers for home use are presently available, but their relation to core body temperature and suitability for use in clinical research has hitherto not been assessed. The current study aimed to evaluate such thermometers by comparing them to the results of a rectal thermometer. Four wireless dermal thermometers for home use (FeverSmart, iThermonitor, Quest Temp Sitter, and Thermochron iButton) were applied to 15 patients during 24 h, and rectal temperature was measured at four occasions. Pearson correlation revealed moderate correlation for the Feversmart (r = 0.75), iThermonitor (r = 0.79), and Thermochron iButton (r = 0.71) systems. The Quest Temp Sitter system malfunctioned repeatedly, and the correlation (r = 0.29) for this method should therefore be assessed with caution. All dermal thermometers rendered lower average temperatures than Terumo c405 (Feversmart -0.70 ± 0.65 °C; iThermonitor -0.77 ± 0.53 °C, Quest Temp Sitter -1.18 ± 0.66 °C, and Thermochron iButton -0.87 ± 0.65 °C). Sensitivity of the dermal thermometers for detecting core temperatures ≥38.0 °C was low, ranging from 0.33 to 0.6, but improved to 0.60 to 0.80 after adjusting temperatures by the methods' average deviation from rectal temperature. The results from the dermal thermometers tested here showed an insufficient correlation to core temperature to be used for core temperature monitoring in clinical research and practice. Unfortunately, other options for non-invasive temperature measurements are few. The two thermometers with the least unsatisfactory performance profile in our evaluations were the Feversmart and iThermonitor systems.

Considerations for an Access-Centered Design of the Fever Thermometer in Low-Resource Settings: A Literature Review

Background

The lack of adequate information about fever in low-resource settings, its unreliable self-assessment, and poor diagnostic practices may result in delayed care and under-or-overdiagnosis of diseases such as malaria. The mismatches of existing fever thermometers in the context of use imply that the diagnostic tools and connected services need to be studied further to address the challenges of fever-related illnesses and their diagnostics.

Objective

This study aims to inform a product-service system approach to design a reliable and accessible fever thermometer and connected services, as well as contribute to the identification of innovative opportunities to improve health care in low-resource settings.

Methods

To determine what factors impede febrile people seeking health care to access adequate fever diagnostics, a literature search was conducted in Google Scholar and PubMed with relevant keywords. Next, these factors were combined with a patient journey model to design a new product-service system for fever diagnostics in low-resource settings.

Results

In total, 37 articles were reviewed. The five As framework was used to categorize the identified barriers. The results indicate that there is a poor distribution of reliable fever diagnostic practices among remote communities. This paper speaks to the global public health and design communities. Three complementary considerations are discussed that support the idea of a more holistic approach to the design of fever diagnostics: (1) understanding of the fever diagnostics patient journey, (2) identifying user groups of the thermometers in a specific health care system, and (3) assessing different needs and interests of the different users.

Conclusions

Access to basic, primary health care may be enhanced with better information and technology design made through the involvement of system users.

[Comparison of body temperatures in children measured using 3 different thermometers: tympanic, skin and digital axillary]

OBJECTIVE

To compare body temperature measurements using tympanic, skin and digital axillary thermometers.

METHOD

Hospitalized or outpatient children from the General Hospital Celaya, ISSSTE Hospital Clinic and General Hospital No. 4 IMSS, and the pediatric private service in Celaya, Guanajuato, from 1 day of life until 16 years old, were recruited over a one month period, after their parents signed the consent form. The order of each institution was selected by simple randomization. Body temperatures were measured in triplicate using tympanic, skin and digital axillary thermometers.

RESULTS

The sample consisted of 554 children. The Pearson r between the tympanic and digital axillary thermometers was 0.57 to 0.65, with a positive linear relationship (P<.05); between the skin and the digital axillary thermometers, it was between 0.47 and 0.52 with a positive linearrelationship (P<.05). The intra-observer Kappa for the tympanic thermometer was 0.86, and for the inter-observer was 0.77; for the skin thermometer it was 0.82 and 0.67, respectively, and for the digital axillary thermometer it was 0.86 for intra-observer reliability and 0.78 for inter -observer reliability.

CONCLUSION

Tympanic and axillary thermometers showed better precision in measuring the body temperature in children than skin thermometers.

Assessment of body temperature measurement options

Assessment of body temperature is important for decisions in nursing care, medical diagnosis, treatment and the need of laboratory tests. The definition of normal body temperature as 37°C was established in the middle of the 19th century. Since then the technical design and the accuracy of thermometers has been much improved. Knowledge of physical influence on the individual body temperature, such as thermoregulation and hormones, are still not taken into consideration in body temperature assessment. It is time for a change; the unadjusted mode should be used, without adjusting to another site and the same site of measurement should be used as far as possible. Peripheral sites, such as the axillary and the forehead site, are not recommended as an assessment of core body temperature in adults. Frail elderly individuals might have a low normal body temperature and therefore be at risk of being assessed as non-febrile. As the ear site is close to the hypothalamus and quickly responds to changes in the set point temperature, it is a preferable and recommendable site for measurement of body temperature.

Clinical accuracy of tympanic thermometer and noncontact infrared skin thermometer in pediatric practice: an alternative for axillary digital thermometer

INTRODUCTION

The aim of this study was to compare the body temperature measurements of infrared tympanic and forehead noncontact thermometers with the axillary digital thermometer.

METHODS

Randomly selected 50 pediatric patients who were hospitalized in Dr Behcet Uz Children's Training and Research Hospital, Pediatric Infectious Disease Unit, between March 2012 and September 2012 were included in the study. Body temperature measurements were performed using an axillary thermometer (Microlife MT 3001), a tympanic thermometer (Microlife Ear Thermometer IR 100), and a noncontact thermometer (ThermoFlash LX-26).

RESULTS

Fifty patients participated in this study. We performed 1639 temperature readings for every method. The average difference between the mean (SD) of both axillary and tympanic temperatures was -0.20°C (0.61°C) (95% confidence interval, -1.41°C to 1.00°C). The average difference between the mean (SD) of both axillary and forehead temperatures was -0.38 (0.55°C) (95% confidence interval, -1.47°C to 0.70°C). The Bland-Altman plot showed that most of the data points were tightly clustered around the zero line of the difference between the 2 temperature readings. With the use of the axillary method as the criterion standard, positive likelihood ratios were 17.9 and 16.5 and negative likelihood ratios were 0.2 and 0.4 for tympanic and forehead measurements, respectively.

DISCUSSION

The results demonstrated that the infrared tympanic thermometer could be a good option in the measurement of fever in the pediatric population. The noncontact infrared thermometer is very useful for the screening of fever in the pediatric population, but it must be used with caution because it has a high value of bias.

Emergency department rectal temperatures in over 10 years: A retrospective observational study

BACKGROUND

Fever in patients can provide an important clue to the etiology of a patient's symptoms. Non-invasive temperature sites (oral, axillary, temporal) may be insensitive due to a variety of factors. This has not been well studied in adult emergency department patients. To determine whether emergency department triage temperatures detected fever adequately when compared to a rectal temperature.

METHODS

A retrospective chart review was made of 27 130 adult patients in a high volume, urban emergency department over an eight-year period who received first a non-rectal triage temperature and then a subsequent rectal temperature.

RESULTS

The mean difference in temperatures between the initial temperature and the rectal temperature was 1.3 °F (P<0.001), with 25.9% of the patients having higher rectal temperatures ≥2 °F, and 5.0% having higher rectal temperatures ≥4 °F. The mean difference among the patients who received oral, axillary, and temporal temperatures was 1.2 °F (P<0.001), 1.8 °F (P<0.001), and 1.2 °F (P<0.001) respectively. About 18.1% of the patients were initially afebrile and found to be febrile by rectal temperature, with an average difference of 2.5 °F (P<0.001). These patients had a higher rate of admission (61.4%, P<0.005), and were more likely to be admitted to the hospital for a higher level of care, such as an intensive care unit, when compared with the full cohort (12.5% vs. 5.8%, P<0.005).

CONCLUSIONS

There are significant differences between rectal temperatures and non-invasive triage temperatures in this emergency department cohort. In almost one in five patients, fever was missed by triage temperature.

Oral and tympanic membrane temperatures are inaccurate to identify Fever in emergency department adults

Introduction

Identifying fever can influence management of the emergency department (ED) patient, including diagnostic testing, treatment, and disposition. We set out to determine how well oral and tympanic membrane (TM) temperatures compared with rectal measurements.

Methods

A convenience sample of consecutively adult ED patients had oral, TM, and rectal temperatures performed within several minutes of each other. Descriptive statistics, Bland–Altman agreement matrices with 95% confidence interval (CI), and measures of test performance, including sensitivity, specificity, predictive values, and interval likelihood ratios were performed.

Results

A total of 457 patients were enrolled with an average age of 64 years (standard deviation: 19 years). Mean temperatures were: oral (98.3°F), TM (99.6°F), and rectal (99.4°F). The mean difference in rectal and oral temperatures was 1.1°F, although there was considerable lack of agreement between oral and rectal temperatures, with the oral temperature as much as 2.91°F lower or 0.74°F higher than the rectal measurement (95% CI). Although the difference in mean temperature between right TM and rectal temperature was only 0.22°F, the right TM was lower than rectal by up to 1.61°F or greater by up to 2.05°F (95% CI). Test performance varied as the positive predictive value of the oral temperature was 97% and for tympanic temperature was 55% (relative to a rectal temperature of 100.4°F or higher). Comparative findings differed even at temperatures considered in the normal range; among patients with an oral temperature of 98.0 to 98.9, 38% (25/65) were found to have a rectal temperature of 100.4 or higher, while among patients with a TM of 98.0 to 98.9, only 7% (10/134) were found to have a rectal temperature of 100.4 or higher.

Conclusion

The oral and tympanic temperature readings are not equivalent to rectal thermometry readings. Oral thermometry frequently underestimates the temperature relative to rectal readings, and TM values can either under- or overestimate the rectal temperature. The clinician needs to be aware of the varying relationship between oral, TM, and rectal temperatures when interpreting readings.

Core body temperature in obesity

BACKGROUND

A lower core body temperature set point has been suggested to be a factor that could potentially predispose humans to develop obesity.

OBJECTIVE

We tested the hypothesis that obese individuals have lower core temperatures than those in normal-weight individuals.

DESIGN

In study 1, nonobese [body mass index (BMI; in kg/m(2)) <30] and obese (BMI ≥30) adults swallowed wireless core temperature-sensing capsules, and we measured core temperatures continuously for 24 h. In study 2, normal-weight (BMI of 18-25) and obese subjects swallowed temperature-sensing capsules to measure core temperatures continuously for ≥48 h and kept activity logs. We constructed daily, 24-h core temperature profiles for analysis.

RESULTS

Mean (±SE) daily core body temperature did not differ significantly between the 35 nonobese and 46 obese subjects (36.92 ± 0.03°C compared with 36.89 ± 0.03°C; P = 0.44). Core temperature 24-h profiles did not differ significantly between 11 normal-weight and 19 obese subjects (P = 0.274). Women had a mean core body temperature ≈0.23°C greater than that of men (36.99 ± 0.03°C compared with 36.76 ± 0.03°C; P < 0.0001).

CONCLUSIONS

Obesity is not generally associated with a reduced core body temperature. It may be necessary to study individuals with function-altering mutations in core temperature-regulating genes to determine whether differences in the core body temperature set point affect the regulation of human body weight. These trials were registered at clinicaltrials.gov as NCT00428987 and NCT00266500.

Normal body temperature and the effects of age, sex, ambient temperature and body mass index on normal oral temperature: a prospective, comparative study

BACKGROUND

Body temperature is an indicator of health status. However, thermoregulatory function is thought to decline with aging.

OBJECTIVES

To determine normal body temperature and the effects of age, sex, ambient temperature (AT), and body mass index (BMI) on normal oral temperatures (OTs).

DESIGN

A prospective four group comparative descriptive design was used to compare four cohorts: young adults in summer, older adults in summer, young adults in winter, and older adults in winter.

METHODS

The OT of 519 community dwelling older adults ages 65-95 and 540 younger adults ages 20-64 was compared. The OT was taken with an electronic thermometer between 8 a.m. and 10 a.m. during summer and winter in 2007 in Taipei, Taiwan.

RESULTS

There was no difference in mean OT between the <65 and > or =65 groups measured during winter. However, the mean OT of the <65 group was 0.11 degrees C lower than the > or =65 group measured in the summer. Subjects (> or =85 years) had a higher correlation coefficient (r=0.48) between OT and AT than those in the 65-74 year older group (r=0.31) and 75-84 year older group (r=0.23). Moreover this study found that the mean OT of older females was higher than that of older males in both winter and summer cohorts. Finally, multiple regression analysis results indicated AT and sex were predictors of OT while age and BMI were not a significant predictor of OT. These four factors together accounted for 9.4% of the variance in the overall sample (age 20-95), 12.8%, in those 65-95 and 28.2% for those, > or =85 years old.

CONCLUSIONS

These findings help to clarify discrepancies in the literature. The OT of those over age 65 and those 20-64 was lower than the accepted 37 degrees C norm. However, "older is colder" does not apply to all older adults. Our findings indicate AT and sex rather than age alone account for temperature variation in older adults with normal baseline temperature. Further investigation is needed to identify potential risk factors of impaired thermoregulation in older adults.

Hypothermia in the geriatric population

Hypothermia is common in the geriatric population and its significance perhaps under-recognized. Hypothermia is associated with substantial morbidity and fatality, but to some extent is preventable provided caregivers and providers of healthcare to older adults adopt preventive measures to lower its occurrence. Hypothermia occurs in both cold and warm settings; its pathogenesis involves alterations in the age-related physiology of thermoregulation, along with a variable combination of environmental factors, disease processes and medications, many of which are recognizable. Once diagnosed, treatment must be prompt and aggressive, and must consider several options for rewarming. Education of healthcare providers regarding early recognition of hypothermia and a better understanding of preventive and treatment measures will undoubtedly lower complications of hypothermia in affected elderly.

La mesure de la température en pratique pédiatrique quotidienne

The use of rectal mercury thermometer has long been the standard method for measurement of body temperature. The restriction of mercury use since 1996 has led to development of other devices. The liquid crystal strip thermometer held against the forehead has a low sensitivity. The single-use chemical thermometer measures oral temperature. Its accuracy must be evaluated. Infrared ear thermometers are routinely used because it is convenient and fast to use. However, numerous studies have shown that it does not show sufficient correlation with rectal temperature, leading to the risk to miss cases of true fever. Rectal temperature remains the gold standard in case of fever. Rectal temperature measurement with an electronic device is well correlated with the glass mercury standard. Galistan thermometer accuracy must be evaluated because of sterilization of the whole device, which is not the case for the electronic thermometer. A pediatric study is necessary to evaluate the performance of this device in comparison with the electronic thermometer.