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

Comparison of two non-invasive body temperature measurement methods for the detection of febrile neutropenia in children with cancer

BACKGROUND

This study was conducted to compare the accuracy of two noninvasive thermometers (axillary and infrared non-contact forehead thermometer) in measuring core temperature compared to the gold standard oral thermometer in the detection of fever in pediatric cancer patients with febrile neutropenia.

METHODS

The study was conducted with a single group of 42 children with febrile neutropenia between 23 December 2020 and 25 January 2023 in the pediatric hematology and oncology clinic of a training and research hospital, which provides a specialized environment for both medical education and advanced scientific research in the field of pediatric hematology and oncology. The participants' body temperature was measured with an oral, axillary, and non-contact infrared forehead thermometer immediately after admission to the clinic and at 5 and 10 min after admission. The inter-rater agreement for each method and inter-method agreement between axillary and non-contact infrared temperature readings and oral readings were analyzed for each time point using intraclass correlation coefficients (ICC).

RESULTS

The children in the study had a mean age of 11.62 ± 3.00 years and 28 (66.7%) were boys, 19 (45.2%) were younger children (5-10 years of age), and 23 (54.8%) were adolescents (11-16 years of age). In the analysis of agreement between the thermometers at admission and at 5 and 10 min after admission in children with febrile neutropenia, the highest agreement was between the oral and axillary thermometers (ICC: 0.584, 0.835, 0.536, respectively) and the lowest agreement was between the oral and non-contact infrared thermometers (ICC: 0.219, 0.022, 0.473, respectively).

CONCLUSION

Compared to orally measured body temperature, axillary temperature readings showed better agreement than non-contact infrared temperature readings from the forehead in pediatric patients with febrile neutropenia.

PRACTICE IMPLICATIONS

The research findings may guide nurses and families caring for pediatric patients with febrile neutropenia and should contribute to the prevention of false findings of fever and the reduction of its adverse consequences.

Mitigating machine learning bias between high income and low-middle income countries for enhanced model fairness and generalizability

Collaborative efforts in artificial intelligence (AI) are increasingly common between high-income countries (HICs) and low- to middle-income countries (LMICs). Given the resource limitations often encountered by LMICs, collaboration becomes crucial for pooling resources, expertise, and knowledge. Despite the apparent advantages, ensuring the fairness and equity of these collaborative models is essential, especially considering the distinct differences between LMIC and HIC hospitals. In this study, we show that collaborative AI approaches can lead to divergent performance outcomes across HIC and LMIC settings, particularly in the presence of data imbalances. Through a real-world COVID-19 screening case study, we demonstrate that implementing algorithmic-level bias mitigation methods significantly improves outcome fairness between HIC and LMIC sites while maintaining high diagnostic sensitivity. We compare our results against previous benchmarks, utilizing datasets from four independent United Kingdom Hospitals and one Vietnamese hospital, representing HIC and LMIC settings, respectively.

A Comparative Study of Forehead Temperature and Core Body Temperature under Varying Ambient Temperature Conditions

When the ambient temperature, in which a person is situated, fluctuates, the body's surface temperature will alter proportionally. However, the body's core temperature will remain relatively steady. Consequently, using body surface temperature to characterize the core body temperature of the human body in varied situations is still highly inaccurate. This research aims to investigate and establish the link between human body surface temperature and core body temperature in a variety of ambient conditions, as well as the associated conversion curves.

METHODS

Plan an experiment to measure temperature over a thousand times in order to get the corresponding data for human forehead, axillary, and oral temperatures at varying ambient temperatures (14-32 °C). Utilize the axillary and oral temperatures as the core body temperature standards or the control group to investigate the new approach's accuracy, sensitivity, and specificity for detecting fever/non-fever conditions and the forehead temperature as the experimental group. Analyze the statistical connection, data correlation, and agreement between the forehead temperature and the core body temperature.

RESULTS

A total of 1080 tests measuring body temperature were conducted on healthy adults. The average axillary temperature was (36.7 ± 0.41) °C, the average oral temperature was (36.7 ± 0.33) °C, and the average forehead temperature was (36.2 ± 0.30) °C as a result of the shift in ambient temperature. The forehead temperature was 0.5 °C lower than the average of the axillary and oral temperatures. The Pearson correlation coefficient between axillary and oral temperatures was 0.41 (95% CI, 0.28-0.52), between axillary and forehead temperatures was 0.07 (95% CI, -0.07-0.22), and between oral and forehead temperatures was 0.26 (95% CI, 0.11-0.39). The mean differences between the axillary temperature and the oral temperature, the oral temperature and the forehead temperature, and the axillary temperature and the forehead temperature were -0.08 °C, 0.49 °C, and 0.42 °C, respectively, according to a Bland-Altman analysis. Finally, the regression analysis revealed that there was a linear association between the axillary temperature and the forehead temperature, as well as the oral temperature and the forehead temperature due to the change in ambient temperature.

CONCLUSION

The changes in ambient temperature have a substantial impact on the temperature of the forehead. There are significant differences between the forehead and axillary temperatures, as well as the forehead and oral temperatures, when the ambient temperature is low. As the ambient temperature rises, the forehead temperature tends to progressively converge with the axillary and oral temperatures. In clinical or daily applications, it is not advised to utilize the forehead temperature derived from an uncorrected infrared thermometer as the foundation for a body temperature screening in public venues such as hospital outpatient clinics, shopping malls, airports, and train stations.

Assessment of Alternative Body Points for Temperature Screening As Precautionary Screening During the Pandemic Using Infrared Thermometry

BACKGROUND

The recent coronavirus disease 2019 (COVID-19) pandemic, which swept across the globe in a short period, demonstrated that disease transmission management is a critical step in preventing an outbreak, as is good viral infectious disease screening. Infrared thermography (IRT) has long been considered ideal for screening body temperatures during pandemics.

METHODS

Single-centre cross-sectional study with 159 participants. Using infrared thermometry, participants were subjected to temperature measurement twice daily on various sites. This was compared to oral temperature.

RESULTS

The findings of the study revealed that infrared thermometry could be utilised as a proxy approach for screening by both individuals and medical professionals when employed at the glabella, cubits, or axillae.

CONCLUSION

 Temperature screening is implied as a prophylactic method during pandemics. Owing to contact limitations, oral thermometry cannot be used for mass screening during the pandemic. Infrared thermometry is a noncontact method of temperature screening that can readily be applied for mass temperature screening in congested venues such as airports, shopping malls, places of public convenience, and other similar locations.

Clinical accuracy and agreement between tympanic and forehead body temperature measurements for screening of patients with COVID-19

AIM

To investigate the accuracy, reliability and agreement between infrared forehead thermometers versus infrared tympanic thermometers temperature, a cross-sectional study was conducted in April 2020.

METHODS

The forehead and tympanic temperatures of 615 subjects were measured simultaneously in three exposed SARS-COV-2 groups at one hospital in Iran, during April 2020. These comparisons were evaluated by Bland-Altman Plot, repeatability, Passing-Bablok regression and Lin's concordance correlation coefficient. The receiver operating characteristic (ROC) analysis was done to describe the discrimination accuracy of a diagnostic test. The study adhered to STROBE checklist for cross-sectional studies.

RESULTS

A Bland-Altman plot indicated that the limits of agreement between the forehead and tympanic temperature were -0.259 to +0.19°C. Passing-Bablok regression analysis illustrated that the infrared forehead was not linearly related to tympanic temperatures (reference method), with a slope estimate that was significantly different from 1.00. The infrared forehead thermometer showed poor precision and lower accuracy than the tympanic. The forehead temperature readings had 60.0% sensitivity and 44.4% specificity (p > .05) to predict disease.

CONCLUSION

According to the results of study, there is no evidence that the assessment of temperature by infrared forehead thermometer could discriminate between the two groups (positive and negative).

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.

Evaluating the interchangeability of infrared and digital devices with the traditional mercury thermometer in hospitalized pediatric patients: an observational study

Gradual replacement of the mercury thermometers with alternative devices is ongoing around the world in a bid to protect human health and the environment from the adverse effects of mercury. However, to reduce the risks of misdiagnosis, unnecessary treatments, and omission of care in pediatric populations, more evidence on the reliability of alternative thermometers is needed. The aim of this comparative observational study was to detect any differences in temperature measurements between the use of the axillary mercury thermometer and the alternative techniques. Temperature values in degree Celsius (°C) were measured in a group of Albanian children aged up to 14 years using mercury and digital axillary thermometers, as well as forehead and tympanic infrared thermometers. The digital axillary device, compared with the mercury one, showed no clinically significant difference in the mean values (− 0.04 ± 0.29 °C) and the narrowest 95% level of agreement (+ 0.53 °C to − 0.62 °C) in the paired comparisons. For cut-off point of 37.5 °C, the digital axillary thermometer showed the highest levels of sensitivity (72.5%) and specificity (99.1%) in detecting fever. This study indicates that the digital axillary thermometer may be the better option since it adequately balances accuracy, safety, and children’s comfort.

Clinical accuracy of non-contact forehead infrared thermometer and infrared tympanic thermometer in postoperative adult patients: A comparative study

Core temperature monitoring is important for the assessment and prevention of possible postoperative complications. The aim of the present study was to examine the agreement between the core temperature values and the forehead, tympanic membrane and axillary values in postoperative adult patients in clinical practice. The study measured the core temperature of 65 patients undergoing scheduled abdominal surgery using SpotOn™ and compared these with those obtained using non-contact forehead infrared, infrared tympanic and axillary thermometers. Correlation and Bland-Altman analyses were conducted for these comparisons. All temperatures were recorded at 4h intervals after postoperative arrival to the ward. Forehead temperature recordings showed a good correlation with the core temperature with excellent accuracy and was comparable to the tympanic temperature. Both forehead and tympanic thermometers can rapidly and effectively measure the core temperature during early postoperative period. Considering patients' safety, non-contact forehead infrared thermometers may be useful for postoperative monitoring.

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.

Reliability of Body Temperature Measurements Obtained with Contactless Infrared Point Thermometers Commonly Used during the COVID-19 Pandemic

During the COVID-19 pandemic, there has been a significant increase in the use of non-contact infrared devices for screening the body temperatures of people at the entrances of hospitals, airports, train stations, churches, schools, shops, sports centres, offices, and public places in general. The strong correlation between a high body temperature and SARS-CoV-2 infection has motivated the governments of several countries to restrict access to public indoor places simply based on a person’s body temperature. Negating/allowing entrance to a public place can have a strong impact on people. For example, a cancer patient could be refused access to a cancer centre because of an incorrect high temperature measurement. On the other hand, underestimating an individual’s body temperature may allow infected patients to enter indoor public places where it is much easier for the virus to spread to other people. Accordingly, during the COVID-19 pandemic, the reliability of body temperature measurements has become fundamental. In particular, a debated issue is the reliability of remote temperature measurements, especially when these are aimed at identifying in a quick and reliable way infected subjects. Working distance, body–device angle, and light conditions and many other metrological and subjective issues significantly affect the data acquired via common contactless infrared point thermometers, making the acquisition of reliable measurements at the entrance to public places a challenging task. The main objective of this work is to sensitize the community to the typical incorrect uses of infrared point thermometers, as well as the resulting drifts in measurements of body temperature. Using several commercial contactless infrared point thermometers, we performed four different experiments to simulate common scenarios in a triage emergency room. In the first experiment, we acquired several measurements for each thermometer without measuring the working distance or angle of inclination to show that, for some instruments, the values obtained can differ by 1 °C. In the second and third experiments, we analysed the impacts of the working distance and angle of inclination of the thermometers, respectively, to prove that only a few cm/degrees can cause drifts higher than 1 °C. Finally, in the fourth experiment, we showed that the light in the environment can also cause changes in temperature up to 0.5 °C. Ultimately, in this study, we quantitatively demonstrated that the working distance, angle of inclination, and light conditions can strongly impact temperature measurements, which could invalidate the screening results.

Comparative accuracy testing of non-contact infrared thermometers and temporal artery thermometers in an adult hospital setting

Background

NCIT are non-invasive devices for fever screening in children. However, evidence of their accuracy for fever screening in adults is lacking. This study aimed to compare the accuracy of non-contact infrared thermometers (NCIT) with temporal artery thermometers (TAT) in an adult hospital.

Methods

A prospective observational study was conducted on a convenience sample of non-infectious inpatients in 2 Australian hospitals. NCIT and TAT devices were used to collect body temperature recordings. Participant characteristics included age, gender, skin color, highest temperature, and antipyretic medications recorded in last 24-hour.

Results

In 265 patients, a mean difference of ± 0.26°C was recorded between the NCIT (36.64°C) and the reference TAT (36.90°C) temperature devices. Bland-Altman analysis showed that NCIT and TAT temperatures were closely aligned at temperatures <37.5°C, but not at temperatures >37.5°C. NCIT had low sensitivity (16.13%) at temperatures ≥37.5°C. An AUROC score of 0.67 (SD 0.05) demonstrated poor accuracy of the NCIT device at temperatures ≥37.5°C.

Conclusion

This is the first study to compare accuracy of NCIT thermometers to TAT in adult patients. Although mass fever screening is currently underway using NCIT, these results indicate that the NCIT may not be the most accurate device for fever mass screening during a pandemic.

Use of non-contact infrared thermometers in rehabilitation patients: a randomized controlled study

Objective

In this randomized controlled study, we aimed to determine whether non-contact infrared thermometers (NCITs) are more time-efficient and create less patient distress than mercury axillary thermometers (MATs) and infrared tympanic thermometers (ITTs).

Methods

Forty-five rehabilitation inpatients were randomly assigned to one of three groups (NCIT, MAT, and ITT). Time required to measure body temperature with an NCIT, MAT, and ITT was recorded. We examined associations between time required to take patients’ temperature and measuring device used. Patient distress experienced during temperature measurement using the three thermometers was recorded.

Results

A significantly longer average time was required to measure temperatures using the MAT (mean 43.17, standard deviation [SD] 8.39) than the ITT (mean 13.74, SD 1.63) and NCIT (mean 12.13, SD 1.18). The thermometer used influenced the time required to measure body temperature (t = 33.99). There were significant differences among groups (NCIT vs. ITT, NCIT vs. MAT, and ITT vs. MAT) regarding patient distress among the different thermometers. Most distress arose owing to needing help from others, sleep disruption, and boredom.

Conclusion

The NCIT has clinically relevant advantages over the ITT and MAT in measuring body temperature among rehabilitation patients, including saving nurses’ time and avoiding unnecessary patient distress.

Clinical trial registration number (http://www.chictr.org.cn): ChiCTR1800019756.

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.

Evaluation of a wearable wireless device with artificial intelligence, iThermonitor WT705, for continuous temperature monitoring for patients in surgical wards: a prospective comparative study

OBJECTIVES

To evaluate a new-generation, non-invasive, wireless axillary thermometer with artificial intelligence, iThermonitor (WT705, Raiing Medical, Beijing, China), and to ascertain its feasibility for perioperative continuous body temperature monitoring in surgical patients.

SETTING

Departments of Biliary Surgery and Operating Room and the post-anaesthesia care unit of a university teaching hospital in Chengdu, China.

PARTICIPANTS

A total of 526 adult surgical patients were consecutively enrolled.

DESIGN

This was a prospective observational study. Axillary temperatures were continuously recorded with iThermonitor throughout the whole perioperative period. The temperatures of the contralateral armpit were measured with mercury thermometers at 8:00, 12:00, 16:00 and 20:00 every day and were used as references.

OUTCOME MEASURES

The outcomes were the accuracy and precision of the temperatures measured with iThermonitor, the validity to detect fever and the feasibility of continuous wear. Pairs of temperatures were evaluated with Student's t-test, Pearson's correlation and repeated-measures Bland-Altman plot.

RESULTS

A total of 3621 pairs of body temperatures were obtained. The temperatures measured with iThermonitor agreed with those measured with the mercury thermometers overall, with a mean difference of 0.03°C±0.35°C and a moderate correlation (r=0.755, p<0.001). The 95% limits of agreement (LoA) ranged from -0.63°C to 0.73°C, with 5.11% of the differences outside the 95% LoA. The intraclass correlation coefficient was 0.753. Continuous temperature monitoring captured more fevers than intermittent observation (117/526 vs 91/526, p<0.001), detected fever up to 4.35 hours earlier, and captured a higher peak temperature (0.29°C±0.27°C, 95% CI: 0.26-0.31). All subjects felt that wearing iThermonitor was more or less comfortable and did not affect their daily activities.

CONCLUSIONS

iThermonitor is promising for continuous remote temperature monitoring in surgical patients. However, further developments are still needed to improve the precision of this device, especially for temperature detection in underweight patients and those with lower body temperature.

TRIAL REGISTRATION NUMBER

ChiCTR1900024549; Results (registered on 5 July 2019).

Return to school in the COVID-19 era: considerations for temperature measurement

COVID-19 pandemics required a reorganisation of social spaces to prevent the spread of the virus. Due to the common presence of fever in the symptomatic patients, temperature measurement is one of the most common screening protocols. Indeed, regulations in many countries require temperature measurements before entering shops, workplaces, and public buildings. Due to the necessity of providing rapid non-contact and non-invasive protocols to measure body temperature, infra-red thermometry is mostly used. Many countries are now facing the need to organise the return to school and universities in the COVID-19 era, which require solutions to prevent the risk of contagion between students and/or teachers and technical/administrative staff. This paper highlights and discusses some of the strengths and limitations of infra-red cameras, including the site of measurements and the influence of the environment, and recommends to be careful to consider such measurements as a single "safety rule" for a good return to normality.

Development of a skin temperature map for dermatomes in individuals with spinal cord injury: a cross-sectional study

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

The aim of this study was to map the skin temperature (Tsk) of individuals with SCI and compare able-bodied individuals, and among the groups to demonstrate the effects of differences in the levels of injury (paraplegia and tetraplegia with high and low injuries).

SETTING

Outpatient clinic, Brazil.

METHODS

Individuals with tetraplegia (n = 20), paraplegia (n = 21), and able-bodied (n = 11) individuals were recruited. A noncontact infrared thermometer (IRT) was used to measure three times the Tsk at the forehead, and at the C2 to S2 dermatomes. Core body temperature was measured at the axilla using the IRT and three other clinical thermometers.

RESULTS

Autonomic regulation is impaired by the injury. A Tsk map was constructed for the three groups. Significant differences in the Tsk of dermatomes were observed when comparing individuals with SCI and the able-bodied at the following dermatomes: C3, C7, T2, T3, T8, T9, L1, L2, L4, and S2. When comparing individuals with tetraplegia and able-bodied individuals, the dermatomes that showed significant differences were C5, C6, C8, T1, T10, L3, and S1. Dermatomes C5-C7, and T5 showed significant differences between individuals with tetraplegia and those with paraplegia. For L5 and S1 in paraplegia significant differences were found when comparing high with low injury.

CONCLUSION

A Tsk map on dermatomes in individuals with SCI was implemented, and showed a significant difference between able-bodied. As temperature is a parameter for analyzing autonomic function, the study could benefit rehabilitation by providing baseline values when constructing clinical protocols.

Ingestible sensors correlate closely with peripheral temperature measurements in febrile patients

BACKGROUNDS

Reliable non-invasive methods for measuring body temperature are essential for the diagnosis and monitoring of infectious disease.

METHODS

This study used Intraclass Correlation Coefficients (ICC) and the Bland- Altman plot to analyse the agreement between temperature measurements using an ingestible capsule sensor, a skin sensor and two non-invasive peripheral temperature measurements (axillary and infrared non-contact), collected from a population of febrile patient admitted for infectious disease.

RESULTS

Of the 77 febrile patients screened, 26 patients were enrolled. The ICC between axillary temperature measurements (Taxi) vs. non-contact measurements (Tno-c) were 0.34 [-0.18; 0.63], 0.87 [0.55; 0.94] between Taxi vs. ingestible capsule measurements (Tcap) and 0.12 [-0.09; 0.37] between Taxi vs. Tetac. The mean difference between Taxi vs Tno-c was -1.18 °C with limits of agreement (LoA) from -2.96 to 0.58 °C. The mean difference between Taxi vs Tcap was 0.48 °C, with LoA from -0.60 to 1.56 °C. The mean difference between Taxi vs Tetac was -4.23 °C with LoA from -7.22 to -1.23 °C.

CONCLUSIONS

Ingestible capsule measurements are reliable enough to adequately estimate the core body temperature in clinical practice. Its non-invasiveness, and the real-time remote control offer new opportunities for future research into fever during infectious diseases.

Evaluation of Noninvasive Thermometers in an Endoscopy Setting

The measurement of body temperature is an important aspect of assessment prior to invasive procedures. The purpose of the study was to determine the level of agreement between temporal artery, noncontact infrared, and disposable oral electronic thermometers to a clinical reference device (nondisposable oral electronic thermometer) in outpatients prior to an endoscopic procedure. A descriptive, method-comparison study design was used to compare 3 noninvasive thermometers with a clinical reference device. Four noninvasive temperatures were measured with 3 test devices (temporal artery with ear tap; temporal artery without ear tap; disposable oral electronic; and noncontact infrared), followed by measurement with the clinical reference device (nondisposable, oral electronic). Differences (bias) and limits of agreement (±1.96 SD) were calculated for the test devices and graphed using Bland-Altman method. Clinically acceptable levels of agreement were set at a bias of 0.54 °F or less and precision of 0.90 °F or less. A total of 25 endoscopy patients (N = 14 female; N = 11 male) were studied, with temperatures ranging from 97.5 to 98.9, averaging 98.1 ± 0.3 °F. All thermometers, with the exception of the noncontact infrared (0.66 °F), had acceptable ranges for use in clinical practices. Findings from this study support the use of both temporal artery and disposable oral electronic thermometers in afebrile outpatients but not the noncontact infrared thermometer.

Impact of Hypothermic Stress During Special Operations Training of Chilean Military Forces

Introduction

The Chilean Army considers processes that can optimize physical capacities for responding to the impact of situations and given stressors. The study of the effect of hypothermia as a stressor agent (HSA) and its relationship with cardiovascular, hematological, anthropometric, endocrine, and immunological parameters has not been fully addressed experimentally in military populations.

Objective

To identify the endocrine, hematological, cardiovascular, and immunological changes caused by HSA and to associate these variables with body composition and physical fitness in the military special operation courses of the Chilean Army.

Materials and Methods

Forty-two male subjects were exposed to remain in cold water (10.6 °C) in the context of regular military operations training, the longest time of exposure was determined by individual volitional limits. The measurements were taken in pre-hypothermia conditions, then 2 d later under acute hypothermia condition, and finally during the course period of lesser physical and psychological stressors where the baseline measurements were taken. The statistical analysis consisted of testing normality of the distribution through the Shapiro-Wilk test, assessing the equality of variances through the Levene test, and variance analysis by applying the ANOVA test (analysis of variance). The Bonferroni test was used for multiple comparison correction and the Pearson test for correlations between two variables. The level of significance was of p < 0.05.

Results

The main finding of this study is that HSA has a significant impact at the cardiovascular level and produces an increment in the cell population of the immune and hematologic systems. Significant hormonal changes were observed: ACTH (r = 0.50, p < 0.002), cortisol (r = 0.32, p < 0.03), free testosterone (r = 0.13, p < 0.002), total testosterone r = 0.31, p < 0.002), and anthropometrics (r = -0.51, p < 0.05). However, there is no significant correlation between physical fitness and HAS.

Conclusions

All subjects experienced hypothermia stress elicited by immersion in cold water. This was evidenced by the decrease in core temperature as well as cardiovascular, endocrine, anthropometric, and immunological changes. Individual differences exist between subjects and their resistance to hypothermia in cold water. These differences are not explained by the physical fitness profile but rather respond to a greater body adiposity index and minor changes in the adrenocorticotropic hormone and cortisol hormone. An acute hypothermia stress condition also affects the anabolic/catabolic environment. Finally, HSA produces an increase in the cell population of the immune system. The authors believe that this study allows to standardize HSA exposure times during regular military operations training by identifying the physiological impacts under this extreme environment. At present, the availability of intra-abdominal temperature measurement apparatus with capsule thermometers raises the interest of corroborating the findings of the current study through the use of such measuring devices. Likewise, an interesting line of research for the future would be to compare the HSA against a psychological evaluation with the purpose of identifying the stress management mechanisms among subjects of these characteristics and include heart rate variability measurements as an indicator of sympathetic stress.

Axillary and Tympanic Temperature Measurement in Children and Normal Values for Ages

AIM

The aim of the study was define the normal values of tympanic and axillary body temperature in healthy children.

METHODS

This observational cross-sectional study was performed in healthy children aged 0 to 17 years who visited the ambulatory general pediatric of Istanbul Medical Faculty.

RESULTS

Of 1364 children, 651 (47.7%) were girls and 713 were boys, the mean (SD, range) age was 72.5 (53.6, 1-204) months. The mean (SD) axillary body temperature was 36.04°C (0.46°C; minimum, 35.0°C; maximum, 37.6°C). The 95th and 99th percentiles were 36.8°C and 37.0°C, respectively. The mean (SD) tympanic body temperature was 36.91°C (0.46°C; minimum, 35.15°C; maximum, 37.9°C). The 95th and 99th percentiles were 37.6°C and 37.8°C, respectively. There were statistically significant differences between sexes for only tympanic body temperatures. Both axillary and tympanic body temperatures were statistically higher in 0 to 2 months compared with other age groups. For this age group, the 99th percentile was 37.5°C for axillary and 37.85°C for tympanic temperature.

CONCLUSIONS

Axillary and tympanic body temperatures should be considered as fever when they are more than 37.0°C and 37.8°C, respectively. For 0 to 2 months, fever is 37.5°C and 37.85°C in axillary and tympanic temperatures, respectively.

Comparison of non-contact infrared thermometry and rectal thermometry in cats

OBJECTIVES

Body temperature is commonly used for assessing health and identifying infectious diseases in cats. Rectal thermometry, the most commonly used method, is stressful, invasive and time consuming. Non-contact infrared thermometry (NIRT) has been used with mixed success to measure temperature in humans and other species. The purpose of this study was to determine if NIRT measurements were comparable to rectal temperature measurements or, if not highly correlated, could at least identify cats in the hypothermic or hyperthermic range in need of further evaluation.

METHODS

From a total of six NIRT devices and 15 anatomic sites, three devices and three sites (pinna, gingiva and perineum) with the highest correlation to rectal temperature were selected for further study. Measurements were made in 188 adult cats housed indoors at animal shelters, veterinary clinics and private homes across a wide range of body temperatures and compared with rectal temperatures.

RESULTS

Bland-Altman analysis revealed poor agreement between NIRT and rectal thermometry. The mean NIRT measurements ranged from 0.7-1.3°C below the mean rectal measurements, but the effect was not consistent; NIRT measurements tended to exceed rectal measurements in hypothermic cats and fall below rectal measurements in normothermic and hyperthermic cats.

CONCLUSIONS AND RELEVANCE

The accuracy of temperature measurements using NIRT devices is not reliable for clinical use in cats.

Anticholinergic premedication-induced fever in paediatric ambulatory ketamine anaesthesia

Objective

A randomized, double-blind, prospective study to evaluate the effect of anticholinergic drugs on thermoregulation in paediatric patients undergoing ambulatory anaesthesia with ketamine.

Methods

Patients were randomized to receive either 0.005 mg/kg glycopyrrolate or the equivalent volume of normal saline (placebo) at 30 min before ketamine anaesthesia. Body temperature was measured tympanically at baseline and at 0, 30, 60 and 90 min postoperatively. The quantity of saliva prodiced during surgery and incidence of fever were recorded.

Results

Body temperature was significantly higher in the glycopyrrolate group (n = 42) than the placebo group (n = 42) at 30, 60 and 90 min after surgery, and higher than baseline at 0, 30, 60 and 90 min after surgery. In the placebo group, body temperature was significantly higher than baseline at 0 and 30 min after surgery. Saliva secretion was significantly lower in the glycopyrrolate group than the placebo group.

Conclusion

Routine premedication with adjunctive anticholinergics should not be considered in paediatric patients receiving ketamine sedation due to the increased risk of fever.

Trial registration number, Clinicaltrials.gov: NCT02430272

Performance of a non-contact infrared thermometer in healthy newborns

OBJECTIVE

To evaluate the performance of a non-contact infrared thermometer (NCIT) in comparison with digital axillary thermometer (DAT) and infrared tympanic thermometers (ITT) in a population of healthy at term and preterm newborns nursed in incubators.

SETTING

1 level III maternity hospital, and its intensive neonatal care unit.

PARTICIPANTS

119 healthy at term newborns and 70 preterm newborns nursed in incubators were consecutively enrolled. Exclusion criteria were unstable/critical conditions, polymalformative congenital syndromes and severe congenital syndromes.

INTERVENTIONS

Body temperature readings were prospectively collected. Each participant underwent bilateral axillary temperature measurement with DAT, bilateral tympanic measurement with ITT and mid-forehead temperature measurements using NCIT.

PRIMARY OUTCOME MEASURES

Degree of agreement between methods was evaluated by the Bland and Altman method.

RESULTS

714 measurements in 119 healthy at term newborns and 420 measurements in 70 preterm newborns nursed in incubators were performed. Clinical reproducibility of NCIT was 0.0455 °C for infants in incubators and 0.0861 °C for infants outside an incubator. Bias was 0.029 °C for infants in incubators and <0.0001 °C for infants outside an incubator. Zero outliers were recorded. The mean difference between methods was good both for newborns at term (0.12 °C for NCIT vs DAT and 0.02 °C for NCIT vs ITT) and preterm newborns in incubators (0.10 °C for NCIT vs DAT and 0.14 °C for NCIT vs ITT). Limits of agreement were 0.99 to -0.75 and 0.78 to -0.75 in at term newborns and were particularly satisfactory in preterm newborns in incubators (95% CI: 0.48 to -0.27 and 0.68 to -0.40).

CONCLUSIONS

Our results with Bland and Altman analysis demonstrate that NCIT is a very promising tool, especially in preterm newborns nursed in incubators.

TRIAL REGISTRATION

The study was approved by the Careggi University Hospital Ethics Committee (07/2011).

Infrared cameras are potential traceable "fixed points" for future thermometry studies

The National physical laboratory (NPL) requires "fixed points" whose temperatures have been established by the International Temperature Scale of 1990 (ITS 90) be used for device calibration. In practice, "near" blackbody radiators together with the standard platinum resistance thermometer is accepted as a standard. The aim of this study was to report the correlation and limits of agreement (LOA) of the thermal infrared camera and non-contact infrared temporal thermometer against each other and the "near" blackbody radiator. Temperature readings from an infrared thermography camera (FLIR T650sc) and a non-contact infrared temporal thermometer (Hubdic FS-700) were compared to a near blackbody (Hyperion R blackbody model 982) at 0.5 °C increments between 20-40 °C. At each increment, blackbody cavity temperature was confirmed with the platinum resistance thermometer. Measurements were taken initially with the thermal infrared camera followed by the infrared thermometer, with each device mounted in turn on a stand at a fixed distance of 20 cm and 5 cm from the blackbody aperture, respectively. The platinum thermometer under-estimated the blackbody temperature by 0.015 °C (95% LOA: -0.08 °C to 0.05 °C), in contrast to the thermal infrared camera and infrared thermometer which over-estimated the blackbody temperature by 0.16 °C (95% LOA: 0.03 °C to 0.28 °C) and 0.75 °C (95% LOA: -0.30 °C to 1.79 °C), respectively. Infrared thermometer over-estimates thermal infrared camera measurements by 0.6 °C (95% LOA: -0.46 °C to 1.65 °C). In conclusion, the thermal infrared camera is a potential temperature reference "fixed point" that could substitute mercury thermometers. However, further repeatability and reproducibility studies will be required with different models of thermal infrared cameras.