Tympanic, infrared skin, and temporal artery scan thermometers compared with rectal measurement in children: a real-life assessment

Clinical accuracy of infrared temperature measurement devices: a comparison against non-invasive core-body temperature

During the coronavirus 2019 (COVID-19) pandemic, the implementation of non-contact infrared thermometry (NCIT) became an increasingly popular method of screening body temperature. However, data on the accuracy of these devices and the standardisation of their use are limited. In the current study, the body temperature of non-febrile volunteers was measured using infrared (IR) thermography, IR tympanic thermometry and IR gun thermometry at different facial feature locations and distances and compared with SpotOn core-body temperature. Poor agreement was found between all IR devices and SpotOn measurements (intra-class correlation coefficient <0.8). Bland-Alman analysis showed the narrowest limits of agreement with the IR gun at 3 cm from the forehead (bias = 0.19°C, limits of agreement (LOA): -0.58°C to 0.97°C) and widest with the IR gun at the nose (bias = 1.40°C, LOA: -1.15°C to 3.94°C). Thus, our findings challenge the established use of IR thermometry devices within hospital settings without adequate standard operating procedures to reduce operator error.

Are all thermometers equal? A study of three infrared thermometers to detect fever in an African outpatient clinic

Infrared thermometry has certain advantages over traditional oral thermometry including quick, non-invasive administration and an absence of required consumables. This study compared the performance of tympanic, temporal artery and forehead contactless thermometers with traditional oral electronic thermometer as the reference in measuring temperature in outpatients in a Nigerian secondary care hospital. A convenience sample of 100 male and 100 female adult patients (Mean age = 38.46 years, SD = 16.33 years) were recruited from a secondary care hospital in Kano, Nigeria. Temperature measurements were taken from each patient using the tympanic, temporal artery and contactless thermometers and oral electronic thermometer. Data was analyzed to assess bias and limits using scatterplots and Bland-Altman charts while sensitivity analysis was done using ROC curves. The tympanic and temporal artery thermometers systematically gave higher temperature readings compared to the oral electronic thermometer. The contactless thermometer gave lower readings compared to the oral electronic thermometer. The temporal artery thermometer had the highest sensitivity (88%) and specificity (88%) among the three infrared thermometers. The contactless thermometer showed a low sensitivity of 13% to detect fever greater than 38 °C. Our study shows that replacing oral thermometers with infrared thermometers must be done with caution despite the associated convenience and cost savings.

Regression model for predicting core body temperature in infrared thermal mass screening

With fever being one of the most prominent symptoms of COVID-19, the implementation of fever screening has become commonplace around the world to help mitigate the spread of the virus. Non-contact methods of temperature screening, such as infrared (IR) forehead thermometers and thermal cameras, benefit by minimizing infection risk. However, the IR temperature measurements may not be reliably correlated with actual core body temperatures. This study proposed a trained model prediction using IR-measured facial feature temperatures to predict core body temperatures comparable to an FDA-approved product. The reference core body temperatures were measured by a commercially available temperature monitoring system. Optimal inputs and training models were selected by the correlation between predicted and reference core body temperature. Five regression models were tested during the study. The linear regression model showed the lowest minimum-root-mean-square error (RSME) compared with reference temperatures. The temple and nose region of interest (ROI) were identified as optimal inputs. This study suggests that IR temperature data could provide comparatively accurate core body temperature prediction for rapid mass screening of potential COVID cases using the linear regression model. Using linear regression modeling, the non-contact temperature measurement could be comparable to the SpotOn system with a mean SD of ± 0.285 °C and MAE of 0.240 °C.

Non-contact infrared thermometers compared with current approaches in primary care for children aged 5 years and under: a method comparison study

BACKGROUND

Current options for temperature measurement in children presenting to primary care include either electronic axillary or infrared tympanic thermometers. Non-contact infrared thermometers could reduce both the distress of the child and the risk of cross-infection.

OBJECTIVES

The objective of this study was to compare the use of non-contact thermometers with the use of electronic axillary and infrared tympanic thermometers in children presenting to primary care.

DESIGN

Method comparison study with a nested qualitative study.

SETTING

Primary care in Oxfordshire.

PARTICIPANTS

Children aged ≤ 5 years attending with an acute illness.

INTERVENTIONS

Two types of non-contact infrared thermometers [i.e. Thermofocus (Tecnimed, Varese, Italy) and Firhealth (Firhealth, Shenzhen, China)] were compared with an electronic axillary thermometer and an infrared tympanic thermometer.

MAIN OUTCOME MEASURES

The primary outcome was agreement between the Thermofocus non-contact infrared thermometer and the axillary thermometer. Secondary outcomes included agreement between all other sets of thermometers, diagnostic accuracy for detecting fever, parental and child ratings of acceptability and discomfort, and themes arising from our qualitative interviews with parents.

RESULTS

A total of 401 children (203 boys) were recruited, with a median age of 1.6 years (interquartile range 0.79-3.38 years). The readings of the Thermofocus non-contact infrared thermometer differed from those of the axillary thermometer by -0.14 °C (95% confidence interval -0.21 to -0.06 °C) on average with the lower limit of agreement being -1.57 °C (95% confidence interval -1.69 to -1.44 °C) and the upper limit being 1.29 °C (95% confidence interval 1.16 to 1.42 °C). The readings of the Firhealth non-contact infrared thermometer differed from those of the axillary thermometer by -0.16 °C (95% confidence interval -0.23 to -0.09 °C) on average, with the lower limit of agreement being -1.54 °C (95% confidence interval -1.66 to -1.41 °C) and the upper limit being 1.22 °C (95% confidence interval 1.10 to 1.34 °C). The difference between the first and second readings of the Thermofocus was -0.04 °C (95% confidence interval -0.07 to -0.01 °C); the lower limit was -0.56 °C (95% confidence interval -0.60 to -0.51 °C) and the upper limit was 0.47 °C (95% confidence interval 0.43 to 0.52 °C). The difference between the first and second readings of the Firhealth thermometer was 0.01 °C (95% confidence interval -0.02 to 0.04 °C); the lower limit was -0.60 °C (95% confidence interval -0.65 to -0.54 °C) and the upper limit was 0.61 °C (95% confidence interval 0.56 to 0.67 °C). Sensitivity and specificity for the Thermofocus non-contact infrared thermometer were 66.7% (95% confidence interval 38.4% to 88.2%) and 98.0% (95% confidence interval 96.0% to 99.2%), respectively. For the Firhealth non-contact infrared thermometer, sensitivity was 12.5% (95% confidence interval 1.6% to 38.3%) and specificity was 99.4% (95% confidence interval 98.0% to 99.9%). The majority of parents found all methods to be acceptable, although discomfort ratings were highest for the axillary thermometer. The non-contact thermometers required fewer readings than the comparator thermometers.

LIMITATIONS

A method comparison study does not compare new methods against a reference standard, which in this case would be central thermometry requiring the placement of a central line, which is not feasible or acceptable in primary care. Electronic axillary and infrared tympanic thermometers have been found to have moderate agreement themselves with central temperature measurements.

CONCLUSIONS

The 95% limits of agreement are > 1 °C for both non-contact infrared thermometers compared with electronic axillary and infrared tympanic thermometers, which could affect clinical decision-making. Sensitivity for fever was low to moderate for both non-contact thermometers.

FUTURE WORK

Better methods for peripheral temperature measurement that agree well with central thermometry are needed.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN15413321.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 53. See the NIHR Journals Library website for further project information.

Proper use of noncontact infrared thermometry for temperature screening during COVID-19

Among the myriad of challenges healthcare institutions face in dealing with coronavirus disease 2019 (COVID–19), screening for the detection of febrile persons entering facilities remains problematic, particularly when paired with CDC and WHO spatial distancing guidance. Aggressive source control measures during the outbreak of COVID-19 has led to re-purposed use of noncontact infrared thermometry (NCIT) for temperature screening. This study was commissioned to establish the efficacy of this technology for temperature screening by healthcare facilities. We conducted a prospective, observational, single-center study in a level II trauma center at the onset of the COVID-19 outbreak to assess (i) method agreement between NCIT and temporal artery reference temperature, (ii) diagnostic accuracy of NCIT in detecting referent temperature \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge 100.0\,^{\circ }{\mathrm{F}}$$\end{document}≥100.0∘F and ensuing test sensitivity and specificity and (iii) technical limitations of this technology. Of 51 healthy, non-febrile, healthcare workers surveyed, the mean temporal artery temperature was \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$98.4\,^{\circ }{\mathrm{F}}$$\end{document}98.4∘F (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$95\%$$\end{document}95% confidence interval (CI) = \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$[98.2,98.6]\,^{\circ }{\mathrm{F}}$$\end{document}[98.2,98.6]∘F). Mean NCIT temperatures measured from \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${1}\,{\mathrm{ft}}$$\end{document}1ft, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${3}\,{\mathrm{ft}}$$\end{document}3ft, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${6}\,{\mathrm{ft}}$$\end{document}6ft distances were \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$92.2\,^{\circ }{\mathrm{F}}$$\end{document}92.2∘F\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(95\%\ {\text {CI}}=[91.8\ 92.67]\,^{\circ }{\mathrm{F}})$$\end{document}(95%CI=[91.892.67]∘F), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$91.3\,^{\circ }{\mathrm{F}}$$\end{document}91.3∘F\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(95\%\ {\text {CI}}=[90.8\ 91.8]\,^{\circ }{\mathrm{F}})$$\end{document}(95%CI=[90.891.8]∘F), and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$89.6\,^{\circ }{\mathrm{F}}$$\end{document}89.6∘F\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(95\%\ {\text {CI}}=[89.2 \ 90.1]\,^{\circ }{\mathrm{F}})$$\end{document}(95%CI=[89.290.1]∘F), respectively. From statistical analysis, the only method in sufficient agreement with the reference standard was NCIT at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${1}\,{\mathrm{ft}}$$\end{document}1ft. This demonstrated that the device offset (mean temperature difference) between these methods was \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-6.15\,^{\circ }{\mathrm{F}}$$\end{document}-6.15∘F (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$95\%\ {\text {CI}}=[-6.56,-5.74]\,^{\circ }{\mathrm{F}}$$\end{document}95%CI=[-6.56,-5.74]∘F) with 95% of measurement differences within \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-8.99\,^{\circ }{\mathrm{F}}$$\end{document}-8.99∘F (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$95\%\ {\text {CI}}=[-9.69,-8.29]\,^{\circ }{\mathrm{F}}$$\end{document}95%CI=[-9.69,-8.29]∘F) and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-3.31\,^{\circ }{\mathrm{F}}$$\end{document}-3.31∘F (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$95\%\ {\text {CI}}= [-4.00,-2.61]\,^{\circ }{\mathrm{F}}$$\end{document}95%CI=[-4.00,-2.61]∘F). By setting the NCIT screening threshold to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$93.5\,^{\circ }{\mathrm{F}}$$\end{document}93.5∘F at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${1}\,{\mathrm{ft}}$$\end{document}1ft, we achieve diagnostic accuracy with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$70.9\%$$\end{document}70.9% test sensitivity and specificity for temperature detection \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge 100.0\,^{\circ }{\mathrm{F}}$$\end{document}≥100.0∘F by reference standard. In comparison, reducing this screening criterion to the lower limit of the device-specific offset, such as \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$91.1\,^{\circ }{\mathrm{F}}$$\end{document}91.1∘F, produces a highly sensitive screening test at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$98.2\%$$\end{document}98.2%, which may be favorable in high-risk pandemic disease. For future consideration, an infrared device with a higher distance-to-spot size ratio approaching 50:1 would theoretically produce similar results at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${6}\,{\mathrm{ft}}$$\end{document}6ft, in accordance with CDC and WHO spatial distancing guidelines.

The diagnostic accuracy of digital, infrared and mercury-in-glass thermometers in measuring body temperature: a systematic review and network meta-analysis

Not much is known about how accurate and reproducible different thermometers are at diagnosing patients with suspected fever. The study aims at evaluating which peripheral thermometers are more accurate and reproducible. We searched Medline, Embase, Scopus, WOS, CENTRAL, and Cinahl to perform: (1) diagnostic accuracy meta-analysis (MA) using rectal mercury-in-glass or digital thermometry as reference, and bivariate models for pooling; (2) network MA to estimate differences in mean temperature between devices; (3) Bland-Altman method to estimate 95% coefficient of reproducibility. PROSPERO registration: CRD42020174996. We included 46 studies enrolling more than 12,000 patients. Using 38 °C (100.4 ℉) as cut-off temperature, temporal infrared thermometry had a sensitivity of 0.76 (95% confidence interval, 0.65, 0.84; low certainty) and specificity of 0.96 (0.92, 0.98; moderate certainty); tympanic infrared thermometry had a sensitivity of 0.77 (0.60,  0.88; low certainty) and specificity of 0.98 (0.95, 0.99; moderate certainty). For all the other index devices, it was not possible to pool the estimates. Compared to the rectal mercury-in-glass thermometer, mean temperature differences were not statistically different from zero for temporal or tympanic infrared thermometry; the median coefficient of reproducibility ranged between 0.53 °C [0.95 ℉] for infrared temporal and 1.2 °C [2.16 ℉] for axillary digital thermometry. Several peripheral thermometers proved specific, but not sensitive for diagnosing fever with rectal thermometry as a reference standard, meaning that finding a temperature below 38 °C does not rule out fever. Fixed differences between temperatures together with random error means facing differences between measurements in the order of 2 °C [4.5 ℉]. This study informs practitioners of the limitations associated with different thermometers; peripheral ones are specific but not sensitive.

Diagnostic accuracy of non-contact infrared thermometers and thermal scanners: a systematic review and meta-analysis

Infrared thermal screening, via the use of handheld non-contact infrared thermometers (NCITs) and thermal scanners, has been widely implemented all over the world. We performed a systematic review and meta-analysis to investigate its diagnostic accuracy for the detection of fever. We searched PubMed, Embase, the Cochrane Library, medRxiv, bioRxiv, ClinicalTrials.gov, COVID-19 Open Research Dataset, COVID-19 research database, Epistemonikos, EPPI-Centre, World Health Organization International Clinical Trials Registry Platform, Scopus and Web of Science databases for studies where a non-contact infrared device was used to detect fever against a reference standard of conventional thermometers. Forest plots and Hierarchical Summary Receiver Operating Characteristics curves were used to describe the pooled summary estimates of sensitivity, specificity and diagnostic odds ratio. From a total of 1063 results, 30 studies were included in the qualitative synthesis, of which 19 were included in the meta-analysis. The pooled sensitivity and specificity were 0.808 (95%CI 0.656-0.903) and 0.920 (95%CI 0.769-0.975), respectively, for the NCITs (using forehead as the site of measurement), and 0.818 (95%CI 0.758-0.866) and 0.923 (95%CI 0.823-0.969), respectively, for thermal scanners. The sensitivity of NCITs increased on use of rectal temperature as the reference. The sensitivity of thermal scanners decreased in a disease outbreak/pandemic setting. Changes approaching statistical significance were also observed on the exclusion of neonates from the analysis. Thermal screening had a low positive predictive value, especially at the initial stage of an outbreak, whereas the negative predictive value (NPV) continued to be high even at later stages. Thermal screening has reasonable diagnostic accuracy in the detection of fever, although it may vary with changes in subject characteristics, setting, index test and the reference standard used. Thermal screening has a good NPV even during a pandemic. The policymakers must take into consideration the factors surrounding the screening strategy while forming ad-hoc guidelines.

Diagnostic test accuracy of new generation tympanic thermometry in children under different cutoffs: a systematic review and meta-analysis

Background

The infrared tympanic thermometer (IRTT) is a popular method for temperature screening in children, but it has been debated for the low accuracy and reproducibility compared with other measurements. This study was aimed to identify and quantify studies reporting the diagnostic accuracy of the new generation IRTT in children and to compare the sensitivity and specificity of IRTT under different cutoffs and give the optimal cutoff.

Methods

Articles were derived from a systematic search in PubMed, Web of Science Core Collection, and Embase, and were assessed for internal validity by the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). The figure of risk of bias was created by Review Manager 5.3 and data were synthesized by MetaDisc 1.4.

Results

Twelve diagnostic studies, involving 4639 pediatric patients, were included. The cut-offs varied from 37.0 °C to 38.0 °C among these studies. The cut-off 37.8 °C was with the highest sROC AUC (0.97) and Youden Index (0.83) and was deemed to be the optimal cutoff.

Conclusion

The optimal cutoff for infrared tympanic thermometers is 37.8 °C. New Generation Tympanic Thermometry is with high diagnostic accuracy in pediatric patients and can be an alternative for fever screening in children.

Thermoregulation: A journey from physiology to computational models and the intensive care unit

Thermoregulation plays a vital role in homeostasis. Many species of animals as well as humans have evolved various physiological mechanisms for body temperature control, which are characteristically flexible and enable a fine-tuned spatial and temporal regulation of body temperature in different environmental conditions and circumstances. Human beings normally maintain a core body temperature at around 37°C, and maintenance of this relatively high temperature is critical for survival. Therefore, principles of thermoregulatory control have also important clinical implications. Infections can cause the body temperature to rise internally and several diseases can cause a dysfunction of thermoregulatory mechanisms. Moreover, the utilization of thermotherapies in treating various diseases has been known for thousands of years with a recent resurgence of interest. An increasing amount of research suggests that targeted temperature management is of paramount importance to patient outcomes in certain clinical scenarios. We provide a concise summary of the basic concepts of thermoregulation. Emphasis is given to the principles of thermoregulation in humans in basic pathological states and to targeted temperature management strategies in the clinical environment, with special attention on therapeutic hypothermia in postcardiac arrest patients. Finally, the discussion is focused on the potential offered by computational thermophysiological models for predicting thermal responses of patients in various clinical circumstances, for proposing new perspectives in the design of novel thermal therapies, and to optimize targeted temperature management strategies. This article is categorized under: Cardiovascular Diseases > Cardiovascular Diseases>Computational Models Cardiovascular Diseases > Cardiovascular Diseases>Environmental Factors Cardiovascular Diseases > Cardiovascular Diseases>Biomedical Engineering.

Fever Incidence Is Much Lower in the Morning than the Evening: Boston and US National Triage Data

INTRODUCTION

In this observational study, we evaluated time-of-day variation in the incidence of fever that is seen at triage. The observed incidence of fever could change greatly over the day because body temperatures generally rise and fall in a daily cycle, yet fever is identified using a temperature threshold that is unchanging, such as ≥38.0° Celsius (C) (≥100.4° Fahrenheit [F]).

METHODS

We analyzed 93,225 triage temperature measurements from a Boston emergency department (ED) (2009-2012) and 264,617 triage temperature measurements from the National Hospital Ambulatory Medical Care Survey (NHAMCS, 2002-2010), making this the largest study of body temperature since the mid-1800s. Boston data were investigated exploratorily, while NHAMCS was used to corroborate Boston findings and check whether they generalized. NHAMCS results are nationally representative of United States EDs. Analyses focused on adults.

RESULTS

In the Boston ED, the proportion of patients with triage temperatures in the fever range (≥38.0°C, ≥100.4°F) increased 2.5-fold from morning to evening (7:00-8:59 PM vs 7:00-8:59 AM: risk ratio [RR] 2.5, 95% confidence interval [CI], 2.0-3.3). Similar time-of-day changes were observed when investigating alternative definitions of fever: temperatures ≥39.0°C (≥102.2°F) and ≥40.0°C (≥104.0°F) increased 2.4- and 3.6-fold from morning to evening (7:00-8:59 PM vs 7:00-8:59 AM: RRs [95% CIs] 2.4 [1.5-4.3] and 3.6 [1.5-17.7], respectively). Analyses of adult NHAMCS patients provided confirmation, showing mostly similar increases for the same fever definitions and times of day (RRs [95% CIs] 1.8 [1.6-2.1], 1.9 [1.4-2.5], and 2.8 [0.8-9.3], respectively), including after adjusting for 12 potential confounders using multivariable regression (adjusted RRs [95% CIs] 1.8 [1.5-2.1], 1.8 [1.3-2.4], and 2.7 [0.8-9.2], respectively), in age-group analyses (18-64 vs 65+ years), and in several sensitivity analyses. The patterns observed for fever mirror the circadian rhythm of body temperature, which reaches its highest and lowest points at similar times.

CONCLUSION

Fever incidence is lower at morning triages than at evening triages. High fevers are especially rare at morning triage and may warrant special consideration for this reason. Studies should examine whether fever-causing diseases are missed or underappreciated during mornings, especially for sepsis cases and during screenings for infectious disease outbreaks. The daily cycling of fever incidence may result from the circadian rhythm.

Evaluating the Interchangeability of Forehead, Tympanic, and Axillary Thermometers in Italian Paediatric Clinical Settings: Results of a Multicentre Observational Study

PURPOSE

This study was conducted to investigate the interchangeability of infrared forehead, digital axillary, and infrared tympanic thermometers while identifying the most reliable non-invasive body temperature measurement method in paediatric settings.

DESIGN AND METHODS

A multicentre observational study was conducted enrolling all children less than or equal to 14 years of age requiring a temperature measurement and after obtaining their parent's informed consent. Socio-demographic characteristics and temperature values in Celsius (°C) were simultaneously collected using forehead, axillary, and tympanic thermometers.

RESULTS

A total of 433 children were enrolled, 57.5% were male and the mean age was 5.3 ± 3.9 years. The average value of tympanic temperature (37.05 °C) was higher than forehead (36.87 °C) and axillary (36.8 °C). The mean difference between axillary and forehead temperatures (-0.06 °C) was not statistically significant (p = 0.158). Comparing the measurements of each type of thermometer with the overall average of the three measurements recorded as the virtual gold standard, Bland Altman analysis highlighted tympanic with narrower 95% limits of agreement (+0.96 °C to -0.68 °C). The tympanic thermometer also had the highest percentage (81.6%) of differences falling within the maximum clinically acceptable difference (±0.5 °C).

CONCLUSIONS

Differences between paired measurements of the three investigated devices demonstrated the devices are not interchangeable. Measurements using the tympanic thermometer more closely resembled the reference temperature indicating its preferential use in paediatric clinical practice.

PRACTICE IMPLICATIONS

To safely and consistently measure body temperature, nurses should not assume peripheral thermometers are interchangeable. It is essential to clinically validate all temperature values with clinical observations.

Non-contact infrared versus axillary and tympanic thermometers in children attending primary care: a mixed-methods study of accuracy and acceptability

BACKGROUND

Guidelines recommend measuring temperature in children presenting with fever using electronic axillary or tympanic thermometers. Non-contact thermometry offers advantages, yet has not been tested against recommended methods in primary care.

AIM

To compare two different non-contact infrared thermometers (NCITs) to axillary and tympanic thermometers in children aged ≤5 years visiting their GP with an acute illness.

DESIGN AND SETTING

Method comparison study with nested qualitative component.

METHOD

Temperature measurements were taken with electronic axillary (Welch Allyn SureTemp®), electronic tympanic (Braun Thermoscan®), NCIT Thermofocus® 0800, and NCIT Firhealth Forehead. Parents rated acceptability and discomfort. Qualitative interviews explored parents' experiences of the thermometers.

RESULTS

In total, 401 children were recruited (median age 1.6 years, 50.62% male). Mean difference between the Thermofocus NCIT and axillary thermometer was -0.14°C (95% confidence interval [CI] = -0.21 to -0.06°C); lower limit of agreement was -1.57°C (95% CI = -1.69 to -1.44°C) and upper limit 1.29°C (95% CI = 1.16 to 1.42°C). A second NCIT (Firhealth) had similar levels of agreement; however, the limits of agreement between tympanic and axillary thermometers were also wide. Parents expressed a preference for the practicality and comfort of NCITs, and were mostly negative about their child's experience of axillary thermometers. But there was willingness to adopt whichever device was medically recommended.

CONCLUSION

In a primary care paediatric population, temperature measurements with NCITs varied by >1°C compared with axillary and tympanic approaches. But there was also poor agreement between tympanic and axillary thermometers. Since clinical guidelines often rely on specific fever thresholds, clinicians should interpret peripheral thermometer readings with caution and in the context of a holistic assessment of the child.

Comparing alternatives to canine rectal thermometry at the axillary, auricular and ocular locations

Body temperature is an important component in the diagnosis and treatment of disease in canines. The rectal temperature remains the standard of obtaining temperature within the clinical setting, but there are many drawbacks with this method, including time, access, animal stress, and safety concerns. Interest in using infrared thermometry in canines to obtain body temperature has grown as animal scientists and veterinarians search for non-invasive and non-contact methods and locations of obtaining canine temperatures. Here, we review evidence on axillary, auricular, and ocular region canine thermometry and the degree to which measurements in these locations are representative of rectal temperature values. Instrumentation refinement and development, as well as morphologic differences, play an important role in the potential correlation between the rectal temperature and these other locations. These caveats have yet to be fully addressed in the literature, limiting the options for those seeking alternatives to rectal thermometry.

An investigation into the effects of acupuncture on radial pressure pulse waves in patients with low back pain: A protocol for a quasi-experimental study

Introduction

The characteristics of radial pressure pulse waves (RPPW) provide an essential diagnostic technique in Traditional Chinese Medicine (TCM). The purpose of this research is to develop a study protocol that integrates the concept of TCM and traditional acupuncture treatment with modern scientific tools utilizing a quasi-experimental design. We will investigate the effects of acupuncture on the RPPW in study participants with low back pain (LBP) using modern tools, including the pulse sphygmograph, the fingertip-to-floor test, the Faces Pain Scale-Revised, the Oswestry Disability Index, the Health Status Questionnaire, and the Constitution in Chinese Medicine Questionnaire.

Methods

We will attempt to recruit 80 eligible subjects with LBP based on our predefined inclusion and exclusion criteria. Acupuncture intervention will be performed bilaterally on Shenshu (BL23), Dachangshu (BL25) and Weizhong (BL40) for 20 min. Objective and subjective baseline assessments and outcome evaluations will be performed at a specific time before and after the intervention. This paper describes the methods of our original research approved by the China Medical University Hospital's Research Ethics Committee. Recruitment is in progress and data collection will continue until March 2019.

Conclusions

To our knowledge, this preliminary study is the first attempt to investigate the effects of acupuncture on the RPPW in LBP subjects using a pulse sphygmograph and other modern tools. The findings will also investigate the effectiveness of the selected acupuncture point combinations for LBP. We hope this preliminary study will provide a basic foundation for a large-scale research study that involves randomisation in the future.

A Survey About Fever Knowledge, Attitudes, and Practices Among Parents

A 21-question survey was conducted among parents attending 4 pediatric outpatient practices to assess their knowledge, perceptions, and attitudes about fever. One hundred and ninety-seven surveys were included. Most commonly the participating parent was the mother. Parents used mainly axillary thermometers to measure child's temperature and mentioned integers for their definition of fever, 100°F being the most frequent answer. Most parents would treat all fevers and would use alternating antipyretics. Parents had a generally negative perception of fever: only one third thought fever may have some benefit, and more than half thought there must be some risk. A positive perception of fever was associated with parental educational level but not with information by the pediatrician. There is much confusion about fever among our parents, a negative perception is prevalent, and parents seem to receive-or recall-little information from the pediatrician.

Temporal Artery Thermometry in Pediatric Patients: Systematic Review and Meta-Analysis

PROBLEM

Non-invasive thermometry methods have been used as substitutes for intra-corporeal ones in order to decrease patient discomfort and risk for complications, yet the evaluation of their performance is necessary. Our aim was to synthesize the evidence on the accuracy and precision of temporal artery (TA) thermometry, as well as on its sensitivity and specificity for fever detection.

ELIGIBILITY CRITERIA

This systematic review and meta-analysis included method-comparison studies, which compared TA temperature measurements with invasive thermometry ones, were published between 2000 and 2018, and were conducted on patients aged <18 years.

SAMPLE

Thirty articles were selected for inclusion in the final analysis after screening those identified by searches in CINAHL, PubMed, Web of Science, Cochrane Library, EMBASE and Scopus.

RESULTS

Quantitative synthesis indicated that pooled mean TA temperature was lower than core temperature by 0.01 °C (95% limits of agreement, -0.06 °C to 0.03 °C). Average summary sensitivity and specificity for fever detection were 0.72 (95% confidence interval, 0.66-0.79) and 0.91 (95% confidence interval, 0.86-0.93) respectively. Subgroup analysis indicated a trend toward larger temperature underestimation in febrile patients and in ages ≤4 years.

CONCLUSIONS

Despite its satisfactory accuracy, precision and specificity, TA thermometry has low sensitivity when used in pediatric patients, which does not allow satisfactory fever detection.

IMPLICATIONS

TA thermometry cannot be recommended for replacing rectal temperature measurement methods in children, due to its high proportion of false negative readings during screening for fever.

Confluent Retropharyngeal, Lateral Pharyngeal, and Peritonsilar MRSA Abscess in an Infant

Neck abscesses such as retropharyngeal, peritonsilar, and lateral pharyngeal are well described, typically cause a characteristic illness, and have a known epidemiology. We present a rare occurrence of case of confluent, mixed retropharyngeal, lateral pharyngeal, and peritonsilar abscess in a 9-month-old female infant. The symptoms at presentation were very mild and not expected in association with this extensive an abscess. The causative organism was methicillin-resistant Staphylococcus aureus.

Forehead or ear temperature measurement cannot replace rectal measurements, except for screening purposes

BACKGROUND

Measuring rectal temperature in children is the gold standard, but ear or forehead measures are less traumatic and faster. The quality of non-invasive devices has improved but concerns remain whether they are reliable enough to substitute rectal thermometers. The aim was to evaluate in a real-life children population whether the forehead or ear temperature measurements could be used in screening to detect fever and if the agreement with the rectal temperature for different age groups is acceptable for clinical use.

METHODS

Cross-sectional clinical study comparing temporal and tympanic temperatures to rectal temperature in 0-18-year-old children. The ear thermometer was a Pro 4000 Thermoscan, the temporal Exergen TAT. Rectal temperature ≥ 38.0 °C was defined as fever.

RESULTS

Among 995 children, 39% had a fever. The ear thermometer had a significantly greater ability to detect fever than the temporal thermometer (AUC 0.972; 95% CI: 0.963-0.981 versus AUC 0.931; 95% CI: 0.915-0.947, p < 0.0001). Both devices had the lowest sensitivity in the youngest and oldest children, and only the ear thermometer reached a sensitivity above 90% in the 0.5-5-year age group. The Bland-Altman analysis showed that the 95% limits of agreement for the temporal thermometer was between - 1.2 to + 1.5 °C and for the ear thermometer between - 0.97 to + 1.07 °C.

CONCLUSIONS

Based on a large sample of children, the temporal measurement of temperature is not currently recommendable, but with the technology used in this study the ear measurement proved useful for screening purposes, especially among children aged 6 months to 5 years. For the exact measurement of temperature, the rectal method is still recommended.

Association between Fever and Primary Tooth Eruption: A Systematic Review and Meta-analysis

Aim

To perform a systematic review and meta-analysis to establish if fever is associated with primary tooth eruption.

Materials and methods

Literature searches involved Pubmed, MEDLINE, Web of Science, Scopus and Cochrane. The potentially relevant studies had the full text analyzed. Only studies concerning fever during eruption period of primary tooth in humans were included. Papers in non-English language, and papers that included syndromic patients or patients with any disease were excluded. The meta-analyses were performed with Review Manager (version 5.3). Only studies that reported the results as dichotomous data were analyzed with Cochran-Mantel-Haenszel test in meta-analysis function of Review Manager 5.3. The fixed-effects model was used to evaluate the association between tooth eruption and fever.

Results

Search identified 83 potential studies. After exclusion of the duplicated studies, or were not related to the criteria of inclusion only 6 studies were selected for the systematic review. In the overall meta-analysis, no association was found [OR = 1.32 (0.88-1.96)] between fever and primary tooth eruption. However, in the subgroup analysis, when the method used to measure fever was the rectal temperature there was an association [OR = 2.82 (1.55-5.14)] between fever and primary tooth eruption.

Conclusion

There are few suitable studies in the literature regarding the association between primary tooth eruption and fever. However, our study found an association between fever and primary tooth eruption only when rectal temperature was performed

How to cite this article

Nemezio MA, De Oliveira KMH, Romualdo PC, Queiroz AM, Paula-e-Silva FWG, Silva RAB, Kuchler EC. Association between Fever and Primary Tooth Eruption: A Systematic Review and Meta-analysis. Int J Clin Pediatr Dent 2017;10(3):293-298.

Precision, Sensitivity and Patient Preference of Non-Invasive Thermometers in a Pediatric Surgical Acute Care Setting

PURPOSE

The purpose of the project was to compare the temporal artery thermometer (TAT) to the digital probe thermometer readings at axillary or oral sites, to determine the relative precision and sensitivity of the three methods of thermometry, to compare their readings to core temperature when feasible, and to survey patient and family thermometer preferences.

DESIGN & METHODS

A randomized crossover design in a 70-bed surgical unit over eight months. Two sets of temperature measurements were obtained for each patient: TAT, axillary, oral (depending on patient ability) and a bladder temperature representing core body temperature (when available). Each method was used twice on each patient, to examine within-method precision. Following measurement, patients or caregivers provided their thermometer preference. For younger/nonverbal patients, a professional observer recorded a disruption score. N=298 patients were enrolled RESULTS: TAT was more precise than oral and axillary thermometers (p<0.001 vs. axillary, p=0.001 vs. oral). TAT measurements were higher on average than axillary and oral, by 0.7°C and 0.6°C respectively (p<0.001). TAT's disruption score for younger patients was 0.6 points lower on average than axillary (p<0.001). 84% of patients and families who indicated a clear thermometry preference chose TAT. Only 3 patients had bladder-temperature devices, and therefore accuracy could not be analyzed.

CONCLUSIONS

TAT is more precise, more fever sensitive, less disruptive to younger children, and more preferred by patients and families.

PRACTICE IMPLICATIONS

TAT is an acceptable temperature measure that could be substituted for oral or axillary temperature in acute care pediatric settings.

Comparison of Temporal Artery Versus Rectal Temperature in Emergency Department Patients Who Are Unable to Participate in Oral Temperature Assessment

INTRODUCTION

In the emergency department, pediatric and geriatric patients who present with illnesses and are unable to participate in oral evaluation of temperature must undergo a rectal temperature (RT) assessment. This study asks if a temporal artery temperature (TAT) measure can supplant the RT measure.

METHODS

A convenience sample, using a within-subject design, was used to evaluate the efficacy of TAT compared with RT in patients ≤ 3 and ≥ 65 years of age, who were unable to participate in oral temperature assessments.

RESULTS

Instrument reliability of the TAT is adequate for both the pediatric and geriatric populations. An unadjusted TAT did not provide acceptable temperature measurements. We also found that adjusting a TAT reading by adding -17.22°C (1° F) rendered the TAT average (either mean or median) adequately similar to RT averages for research purposes for both pediatric and geriatric groups.

DISCUSSION

No influence was detected on the differences between RT and TAT due to age, sex, or emergency severity index (ESI) score in patients or due to profession, years of education, or years of experience in caregivers for either the pediatric or geriatric groups. Furthermore, the adjusted TAT reading could detect fever in individual patients adequately in both the pediatric and geriatric groups. However, the adjusted TAT readings were too frequently divergent from RT readings to be used to measure temperature in individual patients for both pediatric and geriatric groups.

Ideal Site for Skin Temperature Probe Placement on Infants in the NICU: A Review of Literature

BACKGROUND

Maintaining normothermia and prevention of hypothermia are critical determinants of morbidity and mortality in infants. Noninvasive monitoring of skin temperature using skin temperature probes (STPs) has been a practice in neonatal intensive care units (NICUs) for decades. Incubators and radiant warmers use feedback mechanisms from the STP readings to determine the heat output to maintain normothermia. Placing the STP on an ideal site on the infant's body is essential for optimum servo control of the temperature. More importantly, where is the ideal site for the STP placement? Clinical practice guidelines (CPGs) vary on information regarding the site and proper placement of the STPs. The literature is analyzed to identify evidence for the ideal STP placement on infants in NICUs.

PURPOSE

To review the literature for evidence for ideal placement for skin temperature probe placement on an infant.

SEARCH STRATEGY

OVID/MEDLINE, CINAHL, Cochrane databases, and CPGs were searched to identify research, literature reviews, and guidelines for ideal sites for STP placement. Twenty documents were reviewed.

RESULTS

Guidelines vary in suggested sites for STP placement. The majority of the studies compared temperature measurement between abdomen and axilla. Although a Cochrane review found abdominal skin as an ideal site, other studies did not find any difference between axially and abdominal skin temperature measurements.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Placing the STP on an ideal site is essential for accurate and safe monitoring of skin temperature in infants. NICU nurses are uniquely positioned to undertake research to identify the ideal site for STP placement to guide safe practice and impact optimal neonatal outcome.

Cost minimisation analysis of thermometry in two different hospital systems

INTRODUCTION

Temperature monitoring can be accomplished by various methods, including oral (OT), rectal (RT), axillary (AT), tympanic membrane (TMT) and temporal artery (TAT) thermometry, with varying amounts of cost incurred by healthcare systems.

METHODS

The potential thermometry cost savings in two hospital systems-University Hospital Centre Zagreb (UHCZ), which uses TMT (device Covidien Genius 2) and University of Michigan Hospitals (UMH), which relies on OT, RT and AT (device Welch Allyn suretemp plus 692)-were analysed to evaluate institution-wide TAT (device Exergen TAT-5000) implementation. Two scenarios were developed: scenario 1, comparing costs for a period of 1, 3 and 5 years; scenario 2, calculation of the number of measurements per device for TAT to be cost-effective.

RESULTS

At UHCZ, use of TAT would bring budget savings regardless of the number of devices per bed and the number of years observed. Savings would range from US$0.08 million (one device per bed, impact for 1 year) to US$1.8 million (one device per 10 beds, impact for 5 years). At UMH, use of TAT would lead to budget savings if one device per 10 beds were acquired, but only over a period of 3 or 5 years. Other TAT scenarios were associated with budget costs at UMH even after a period of 5 years.

CONCLUSIONS

Sensitivity analyses showed that the price of current consumables had the highest impact on the model in both hospital settings, with TAT up to 10 times cheaper in that regard over TMT at UHCZ, potentially leading to considerable budget savings within a year of hospital-wide implementation.

2016 Update of the Italian Pediatric Society Guidelines for Management of Fever in Children

OBJECTIVE

To review new scientific evidence to update the Italian guidelines for managing fever in children as drafted by the panel of the Italian Pediatric Society.

STUDY DESIGN

Relevant publications in English and Italian were identified through search of MEDLINE and the Cochrane Database of Systematic Reviews from May 2012 to November 2015.

RESULTS

Previous recommendations are substantially reaffirmed. Antipyretics should be administered with the purpose to control the child's discomfort. Antipyretics should be administered orally; rectal administration is discouraged except in the setting of vomiting. Combined use of paracetamol and ibuprofen is discouraged, considering risk and benefit. Antipyretics are not recommended preemptively to reduce the incidence of fever and local reactions in children undergoing vaccination, or in attempt to prevent febrile convulsions in children. Ibuprofen and paracetamol are not contraindicated in children who are febrile with asthma, with the exception of known cases of paracetamol- or nonsteroidal anti-inflammatory drug-induced asthma.

CONCLUSIONS

Recent medical literature leads to reaffirmation of previous recommendations for use of antipyretics in children who are febrile.

Intraoperative body temperature control: esophageal thermometer versus infrared tympanic thermometer

Abstract OBJECTIVE To verify the correlation between temperature measurements performed using an infrared tympanic thermometer and an esophageal thermometer during the intraoperative period. METHOD A longitudinal study of repeated measures was performed including subjects aged 18 years or older undergoing elective oncologic surgery of the digestive system, with anesthesia duration of at least 1 hour. Temperature measurements were performed simultaneously by a calibrated esophageal thermometer and by a calibrated infrared tympanic thermometer, with laboratory reading precision of ±0.2ºC. The operating room temperature remained between 19 and 21ºC. RESULTS The study included 51 patients, mostly men (51%), white (80.4%). All patients were kept warm by a forced-air heating system, for an average of 264.14 minutes (SD = 87.7). The two temperature measurements showed no different behavior over time (p = 0.2205), however, tympanic measurements were consistently 1.24°C lower (p<0.0001). CONCLUSION The tympanic thermometer presented reliable results but reflected lower temperatures than the esophageal thermometer.

Temperature measurements with a temporal scanner: systematic review and meta-analysis

OBJECTIVES

Systematic review and meta-analysis on the diagnostic accuracy of temporal artery thermometers (TAT).

DESIGN

Systematic review and meta-analysis. The index test consisted of temperature measurement with TAT. The reference test consisted of an estimation of core temperature.

PARTICIPANTS

Clinical patients as well as healthy participants, with or without fever.

INTERVENTIONS

Literature search in PubMed, Embase, Cinahl and Web of Science. Three reviewers selected articles for full-text reading after which a further selection was made. Risk of bias was assessed with QUADAS-2. Pooled difference and limits of agreement (LoA) were estimated with an inverse variance weighted approach. Subgroup and sensitivity analyses were performed. Sensitivity and specificity were estimated using hierarchical models. Quality of evidence was assessed according to the GRADE system.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was measurement accuracy expressed as mean difference ± 95% LoA. A secondary outcome was sensitivity and specificity to detect fever. If tympanic thermometers were assessed in the same population as TAT, these results were recorded as well.

RESULTS

37 articles comprising 5026 participants were selected. Pooled difference was -0.19 °C (95% LoA -1.16 to 0.77 °C), with moderate quality of evidence. Pooled sensitivity was 0.72 (95% CI 0.61 to 0.81) with a specificity of 0.94 (95% CI 0.87 to 0.97). The subgroup analysis revealed a trend towards underestimation of the temperature for febrile patients. There was a large heterogeneity among included studies with wide LoA which reduced the quality of evidence.

CONCLUSIONS

TAT is not sufficiently accurate to replace one of the reference methods such as rectal, bladder or more invasive temperature measurement methods. The results are, however, similar to those with tympanic thermometers, both in our meta-analysis and when compared with others. Thus, it seems that TAT could replace tympanic thermometers with the caveat that both methods are inaccurate.

TRIAL REGISTRATION NUMBER

CRD42014008832.

The Role of ADC-Based Thermometry in Measuring Brain Intraventricular Temperature in Children

BACKGROUND AND PURPOSE

To determine the feasibility of apparent diffusion coefficient (ADC)-based thermometry to assess intraventricular temperature in children.

METHODS

ADC maps were generated from diffusion tensor imaging data, which were acquired with diffusion gradients along 20 noncollinear directions using a b-value of 1000 s/mm(2) . The intraventricular temperature was calculated based on intraventricular ADC values and the mode method as previously reported. The calculated intraventricular temperature was validated with an estimated brain temperature based on temporal artery temperature measurements. We included 120 children in this study (49 females, 71 males, mean age 6.63 years), 15 consecutive children for each of the following age groups: 0-1, 1-2, 2-4, 4-6, 6-8, 8-10, 10-14, and 14-18 years. Forty-three children had a normal brain MRI and 77 children had an abnormal brain scan. Polynomial fitting to the temperature distribution and subsequent calculation of mode values was performed. A correlation coefficient and a coefficient of determination were calculated between ADC calculated temperatures and estimated brain temperatures. Linear regression analysis was performed to investigate the two temperature measures.

RESULTS

ADC-based intraventricular temperatures ranged between 31.5 and 39.6 °C, although estimated brain temperatures ranged between 36.3 and 38.1 °C. The difference between the temperatures is larger for children with more than 8,000 voxels within the lateral ventricles compared to children with less than 8,000 voxels. The correlation coefficient between ADC-based temperatures and the estimated brain temperatures is .1, the respective R(2) is .01 indicating that 1% of the changes in estimated brain temperatures are attributable to corresponding changes in ADC-based temperature measurements (P = .275).

CONCLUSIONS

ADC-based thermometry has limited application in the pediatric population mainly due to a small ventricular size.

Accuracy of peripheral thermometers for estimating temperature: a systematic review and meta-analysis

BACKGROUND

Body temperature is commonly used to screen patients for infectious diseases, establish diagnoses, monitor therapy, and guide management decisions.

PURPOSE

To determine the accuracy of peripheral thermometers for estimating core body temperature in adults and children.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL Plus from inception to July 2015.

STUDY SELECTION

Prospective studies comparing the accuracy of peripheral (tympanic membrane, temporal artery, axillary, or oral) thermometers with central (pulmonary artery catheter, urinary bladder, esophageal, or rectal) thermometers.

DATA EXTRACTION

2 reviewers extracted data on study characteristics, methods, and outcomes and assessed the quality of individual studies.

DATA SYNTHESIS

75 studies (8682 patients) were included. Most studies were at high or unclear risk of patient selection bias (74%) or index test bias (67%). Compared with central thermometers, peripheral thermometers had pooled 95% limits of agreement (random-effects meta-analysis) outside the predefined clinically acceptable range (± 0.5 °C), especially among patients with fever (-1.44 °C to 1.46 °C for adults; -1.49 °C to 0.43 °C for children) and hypothermia (-2.07 °C to 1.90 °C for adults; no data for children). For detection of fever (bivariate random-effects meta-analysis), sensitivity was low (64% [95% CI, 55% to 72%]; I2 = 95.7%; P < 0.001) but specificity was high (96% [CI, 93% to 97%]; I2 = 96.3%; P < 0.001). Only 1 study reported sensitivity and specificity for the detection of hypothermia.

LIMITATIONS

High-quality data for some temperature measurement techniques are limited. Pooled data are associated with interstudy heterogeneity that is not fully explained by stratified and metaregression analyses.

CONCLUSION

Peripheral thermometers do not have clinically acceptable accuracy and should not be used when accurate measurement of body temperature will influence clinical decisions.

PRIMARY FUNDING SOURCE

None.

Using axillary temperature to approximate rectal temperature in newborns

AIM

Various factors have been shown to potentially affect the difference between axillary and rectal temperature measurements in newborns. We aimed to explore their roles and, if possible, to construct a formula that explained the difference.

METHODS

The study was based on a consecutive sample of 175 infants, with a gestational age of 24-42 weeks, whose rectal and axillary temperatures were measured simultaneously at the neonatal unit at Skaraborg Hospital in Sweden. Data were analysed using multiple regressions.

RESULTS

Premature infants had a significantly smaller mean difference (0.33°C) between rectal and axillary temperatures than full-term infants (0.43°C). Significant associated factors for premature infants were chronological age (p = 0.025), time of day (p = 0.004) and axillary temperature (p < 0.001). For full-term infants, the only significant associated factor was axillary temperature (p = 0.015).

CONCLUSION

Although it is possible to construct a formula that estimates neonate rectal temperature based on axillary temperature with a slightly higher reliability than simply adding a fixed value like 0.4°C, such a formula would be too complex to apply in practice. Adding 0.3°C or 0.4°C to the measured axillary temperature for premature infants or full-term infants, respectively, yields acceptable approximations in most cases.

Heart rates in hospitalized children by age and body temperature

BACKGROUND AND OBJECTIVES

Heart rate (HR) is frequently used by clinicians in the hospital to assess a patient's severity of illness and make treatment decisions. We sought to develop percentiles that characterize the relationship of expected HR by age and body temperature in hospitalized children and to compare these percentiles with published references in both primary care and emergency department (ED) settings.

METHODS

Vital sign data were extracted from electronic health records of inpatients <18 years of age at 2 large freestanding children's hospitals from July 2011 to June 2012. We selected up to 10 HR-temperature measurement pairs from each admission. Measurements from 60% of patients were used to derive the percentile curves, with the remainder used for validation. We compared our upper percentiles with published references in primary care and ED settings.

RESULTS

We used 60,863 observations to derive the percentiles. Overall, an increase in body temperature of 1°C was associated with an increase of ∼ 10 beats per minute in HR, although there were variations across age and temperature ranges. For infants and young children, our upper percentiles were lower than in primary care and ED settings. For school-age children, our upper percentiles were higher.

CONCLUSIONS

We characterized expected HR by age and body temperature in hospitalized children. These percentiles differed from references in primary care and ED settings. Additional research is needed to evaluate the performance of these percentiles for the identification of children who would benefit from further evaluation or intervention for tachycardia.

Force protection in contingency operations: an evaluation of temperature monitoring in Sierra Leone

OBJECTIVES

The deployment of the UK-led Joint Inter-Agency Taskforce to Sierra Leone in September 2014 brought the era of contingency operations into focus. Daily health screening of such deployed personnel forms a key element of medical force protection. We have performed a service evaluation of an existing screening programme and detail the comparison of the two thermometers used in this role.

METHODS

Data from the existing screening programme were used to inform a sample size required to enable statistically and clinically significant differences to be detected between the two interchangeably used thermometer systems in use. A prospective service evaluation on these devices was then carried out over a 10-day period and the data analysed by parametric tools. 10 personnel had their temperature recorded by both devices at the same time by a single operator every day.

RESULTS

For the screened population, a mean temperature of 36.55°C and SD of 0.32°C was revealed. Powered to 80% with a two-tailed α of 0.05, the evaluation of the two thermometers revealed no significant difference between recordings taken with either device (p=0.115). The low SD meant that a pyrexial patient (>37.5°C) would require a recording over 3 SD from the population mean.

DISCUSSION

Evaluations of medical force protection will carry increasing consequence as the UK deploy on short notice operations to regions of considerable endemic threat. Presence of pyrexia is a key early indicator of illness affecting deployed personnel, and two different thermometer types are provided for this function. We have shown for the first time with statistical and clinical significance that the two thermometers used in contingency force protection are interchangeable. The narrow variance is reassuring and confirms that the chosen trigger (>37.5°C) would warrant further investigation in the pyrexial patient.

Accuracy of infrared tympanic thermometry used in the diagnosis of Fever in children: a systematic review and meta-analysis

BACKGROUND

Accurate determination and detection of fever is essential in the appropriate treatment of pediatric population. It is widely known that improper definitions of fever can cause grave and dangerous consequences in medical procedures. Infrared tympanic thermometry seems a relatively new and popular alternative for traditional measurement in the diagnosis of pediatric fever. However, its accuracy in the diagnosis of fever remains a major concern.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Ovid, Elsevier, Google Scholar, and Cochrane library.

STUDY SELECTION

Cross-sectional, prospective design.

DATA EXTRACTION

Two investigators independently assessed selected studies and extracted data. Disagreements were resolved by discussion with other reviewers.

RESULTS

A total of 25 articles were included in our meta-analysis. The summary estimates revealed that the pooled sensitivity was 0.70 (95% confidence interval [CI] = 0.68-0.72), pooled specificity was 0.86 (95% CI = 0.85-0.88), and pooled diagnostic odds ratio was 47.3 (95% CI = 29.76-75.18), for the diagnosis of fever using infrared tympanic thermometry. Additionally, the area under the summary receiver operating characteristic curve was 0.94, and Q* value was 0.87.

CONCLUSION

A total of 25 articles that encompassing 31 studies were analyzed. Based on our meta-analysis, accuracy of infrared tympanic thermometry in diagnosing fever is high. We can cautiously make conclusion that infrared tympanic thermometry should be widely used as fever of thermometer.