Validación del termómetro como factor determinante de la eficacia en la toma de temperatura por infección de COVID-19 / Validation of the thermometer as a determining factor in the effectiveness of temperature measuring in covid-19 infection

FUNDAMENTOS: La pandemia por COVID-19 ha alcanzado más de cinco millones de contagios y trescientos mil fallecidos en el mundo. Todos ellos precisan la evaluación de factores pronósticos; además de la edad avanzada, las comorbilidades o la respuesta inflamatoria, es también evidente la necesidad de evaluar la temperatura corporal para determinar el contagio, la exposición, especialmente en personas con diferentes factores de riesgo, y distintos patrones evolutivos para conocer su influencia sobre los desenlaces clínicos. MÉTODOS: Se realizó un estudio transversal de tomas de temperatura a 42 sujetos voluntarios, para valorar la fiabilidad en términos de concordancia entre dos termómetros utilizados en las tomas de temperatura corporal; se compararon las mediciones de 2 termómetros en las zonas frontal y oído en 2 salas (mayor y menor iluminación). Se compararon los intervalos de confianza y se calculó el coeficiente de Correlación Intraclase (CCI) para obtener las diferencias estadísticas, proporcionando unos límites de concordancia a partir del cálculo del intervalo de confianza para la diferencia de dos mediciones. RESULTADOS: Con un intervalo de confianza del 95 %, una p < 0,5 y en las condiciones medidas, y sobre la muestra de sujetos, observamos que la correlación de las mediciones no tiene diferencia estadística significativa, pero sí en los diferentes ambientes con mayor iluminación. CONCLUSIONES: La media de temperatura corporal (frontal) medida con el termómetro láser es mayor que la temperatura (frontal) medida con el termómetro Testo. Existe diferencia significativa en las mediciones realizadas en las 2 salas, siendo mayores en la sala con menor iluminación. Hay correlación en las mediciones de temperatura del mismo instrumento en la zona frontal y en oído. Los termómetros láser son más efectivos para detectar las variaciones en la temperatura corporal, y más asertivos para identificar uno de los síntomas más asociados a la infección por SARS-CoV-2

BACKGROUND: The COVID-19 pandemic has reached more than five million infections and three hundred thousand deaths worldwide, all of which require the assessment of prognostic factors; in addition to advanced age, comorbidities or the inflammatory response, is also evident the need to assess body temperature to determine contagion, exposure, especially in people with different risk factors, and different evolutionary patterns to know its influence on clinical outcomes. METHODS: A cross-sectional study of temperature measurements was performed on 42 volunteer subjects, to assess the reliability in terms of agreement between two thermometers used in body temperature measurements; the measurements of 2 thermometers in the frontal and ear areas were compared in 2 rooms (higher and lower lighting). Confidence intervals were compared and the Intraclass Correlation Coefficient (ICC) was calculated to obtain the statistical differences, providing limits of agreement from the calculation of the confidence interval for the difference of two measurements. RESULTS: With a 95 % confidence interval, a p <0.5 and under the measured conditions, and on our sample of subjects, we observe that the correlation of the measurements does not have significant statistical difference, but indeed in different environments with greater lighting. CONCLUSIONS: The average body temperature (front) measured with the laser thermometer is greater than the temperature (front) measured with the Testo thermometer. There is a significant difference in the measurements made in the 2 rooms, being greater in the room with less lighting. There is correlation in the temperature measurements of the same instrument in the frontal zone and in the ear. Laser thermometers are more effective in detecting variations in body temperature, and more assertive in identifying one of the symptoms most associated with SARS-CoV-2 infection

Comprehensive Analysis of Temperature in Hospitalized Patients.

BACKGROUND: Human body temperature is believed to be linked to clinical diagnoses. However, most of the available data stems from healthy individuals, with no large-scale studies addressing body temperature in the inpatient setting, which is the focus of our study. MATERIALS AND METHODS: This is a retrospective analysis of a total of 695,107 temperature readings from 16,245 patients hospitalized over a 1-year period at a tertiary medical center, ages 0-105 years, 50% female, with rectal, monotherm, axillary, oral, temporal and tympanic measurement sites. The average temperature (Tave) per patient and per measurement site was used in all calculations. Descriptive statistics, Student's t-test, and Pearson's correlation were used, where appropriate, with statistical significance set at P < 0.05. RESULTS: Tave from all measurement sites was 98.13 ± 0.48(SD)F(36.74 ± 0.27°C). Tave varied by the site of measurement, in decreasing order highest-to-lowest being rectal, monotherm, axillary, oral, temporal, and tympanic, all of which were higher than the available reported averages for healthy subjects. Tave decreased as patients' age increased. There was only slight and likely clinically insignificant difference between the sexes. There were differences in Tave between the intensive care units (ICUs), listed from highest-to-lowest: Neuro ICU, Pediatric ICU, Surgical ICU, Cardiac ICU and Medical ICU. However, there was no difference between all ICU and non-ICU patients. CONCLUSIONS: Our inpatient data demonstrate that previously identified body temperature trends among healthy subjects are preserved, to an extent, in the inpatient setting. To our knowledge, ours is the first study that evaluates the temperatures of all hospitalized patients at a large tertiary medical center.

Evaluating the use of a temperature sensor to monitor spectacle compliance in warm versus cold climates.

BACKGROUND: This study investigates the utility of a temperature sensor data logger to monitor spectacle compliance for future application in research and clinical settings. Specifically, the question of whether warm versus cold climates negatively impact accuracy of the sensor to monitor spectacle wear is investigated. METHODS: Fifty adults from Houston, Texas (summer) and 40 adults from Columbus, Ohio (winter) wore a thermosensor on their spectacles for one week while keeping wear-time logs. Temperatures during reported spectacle wear (ON) were compared to temperatures during non-wear (OFF) between sites. Two methods to approximate wear time were evaluated by percent error with respect to subject-reported wear time. Method 1 filtered temperatures, classifying the range of 28.4 to 35.2°C as wear. Method 2 utilised examiners interpreting temperature versus time plots. Separate analysis of periods of reported outdoor wear was performed to identify the percentage of time examiners correctly identified wear. RESULTS: Group mean ON temperatures did not differ between sites (p = 0.72), but group mean OFF temperatures were significantly warmer in Houston (Houston: 24.7 ± 2.0°C, Columbus: 20.3 ± 2.1°C; p < 0.0001). Median percent error of the filtering technique to approximate subject reported wear time was 4 per cent for Houston and -8 per cent for Columbus. Median percent error for examiner 1: Houston 1 per cent, Columbus 0 per cent; median percent error for examiner 2: Houston 3 per cent, Columbus 0 per cent. Houston outdoor wear was correctly identified 88 and 97 per cent of the time by the examiners versus 79 and 81 per cent for Columbus. CONCLUSION: Despite environmental temperature differences, measured temperatures during spectacle wear were similar across subjects and median percent error was less than 10 per cent for both wear time approximation methods. The device studied was effective for objectively monitoring spectacle wear in both warm and cold climates with the caveat that subjects spent the majority of time indoors.

A coupling system to predict the core and skin temperatures of human wearing protective clothing in hot environments.

The aim of this study is to predict the core and skin temperatures of human wearing protective clothing in hot environments using the coupling system. The coupling system consisted of a sweating manikin Newton controlled by a multi-node human thermal model, and responded dynamically to the thermal environment as human body. Validation of the coupling system results was conducted by comparison with the subject tests. Five healthy men wearing protective clothing were exposed to the thermal neutral and high temperature environments. The skin temperatures of seven body segments and the rectal temperatures were recorded continuously. The predictions of core temperatures made by the coupling system showed good agreement with the experimental data, with maximum difference of 0.19 °C and RMSD of 0.12 °C. The predicted mean skin temperatures fell outside of the 95% CI for most points, whereas the difference between the simulated results and measured data was no more than 1 °C which is acceptable. The coupling system predicted the local skin temperatures reasonably with the maximum local skin temperature of 1.30 °C. The coupling system has been validated and exhibited reasonable accuracy compared with the experimental results.

Ventricular Temperatures in Idiopathic Normal Pressure Hydrocephalus (iNPH) Measured with DWI-based MR Thermometry.

PURPOSE: The brain produces intense heat as a result of cerebral metabolism and cerebral blood flow, and the generated heat is removed mainly through circulation of the intracranial blood vessels and cerebrospinal fluid (CSF). Because magnetic resonance (MR) images are constructed from analysis of the spin of various molecules, the diffusion coefficient can be used as a parameter that reflects the temperature of water molecules. We used diffusion-weighted imaging (DWI)-based MR imaging to measure the temperature of the CSF around the lateral ventricles in patients with idiopathic normal pressure hydrocephalus (iNPH). METHODS: Our study included 33 cases of iNPH (Group N, mean age, 75.1 years) and 40 age-matched controls (Group C, mean age, 74.5 years). We calculated CSF temperature in the ventricular domain using the conversion formula to evaluate the feasibility of iNPH study. RESULTS: The mean temperatures were significantly higher in Group N (37.6°C ± 0.4°C) than Group C (36.7°C ± 0.5°C; P < 0.01). The cut-off value of 37.2°C (more than the mean + 2 standard deviations [SD] of the values in Group C) showed sensitivity of 72.4% and specificity of 77.5% for distinguishing the 2 groups. We confirmed improved CSF temperature in the lateral ventricles in all patients examined both before and after shunting. CONCLUSIONS: Elevated ventricular temperatures in patients with iNPH (Group N) may represent a disturbance in heat balance. Our results showed that thermometry using DWI-based MR imaging can help in the noninvasive and consistent evaluation of CSF temperature and may thus provide a useful supplementary brain biomarker for iNPH.

Adherence among Italian paediatricians to the Italian guidelines for the management of fever in children: a cross sectional survey.

BACKGROUND: Italian guidelines for the management of fever in children (IFG) have been published in 2009 and thereafter disseminated in all country. A survey was conducted before their publication and three years later to investigate their impact on knowledge and behaviors of paediatricians. METHODS: A questionnaire was administered to convenient samples of paediatricians in 2009 and in 2012, eliciting information about fever definition, methods of temperature measurement, and antipyretic use. Differences in responses between 2009 and 2012 and between paediatricians who were or were not aware of the IFG were evaluated. RESULTS: The responses rates were 74% (480/648) in 2009 and 69% (300/434) in 2012. In 2012 168/300 (56%) of participants were aware of the IFG. The proportion of paediatricians who correctly would never suggest the use of physical methods increased from 18.7% to 36.4% (P < 0.001). In 2009 11% of paediatricians declared that the use of antipyretic drugs depends on patient discomfort and did not use a temperature cut off. In 2012 this percentage reached 45.3% (P < 0.001). Alternate use of antipyretics decreased from 27.0% to 11.3% (P < 0.001). Use of rectal administration of antipyretics in absence of vomiting decreased from 43.8% in 2009 to 25.3% in 2012 (P < 0.001). In general, improvements were more striking in paediatricians who were aware of the IFG than in those who were not aware of them. CONCLUSIONS: Behaviours of Italian paediatricians improved over time. However, some wrong attitudes need to be further discouraged, including use of physical methods and misuse of rectal administration. Further strategy to disseminate the IFG could be needed.

An approach for the visualization of temperature distribution in tissues according to changes in ultrasonic backscattered energy.

Previous studies developed ultrasound temperature-imaging methods based on changes in backscattered energy (CBE) to monitor variations in temperature during hyperthermia. In conventional CBE imaging, tracking and compensation of the echo shift due to temperature increase need to be done. Moreover, the CBE image does not enable visualization of the temperature distribution in tissues during nonuniform heating, which limits its clinical application in guidance of tissue ablation treatment. In this study, we investigated a CBE imaging method based on the sliding window technique and the polynomial approximation of the integrated CBE (ICBEpa image) to overcome the difficulties of conventional CBE imaging. We conducted experiments with tissue samples of pork tenderloin ablated by microwave irradiation to validate the feasibility of the proposed method. During ablation, the raw backscattered signals were acquired using an ultrasound scanner for B-mode and ICBEpa imaging. The experimental results showed that the proposed ICBEpa image can visualize the temperature distribution in a tissue with a very good contrast. Moreover, tracking and compensation of the echo shift were not necessary when using the ICBEpa image to visualize the temperature profile. The experimental findings suggested that the ICBEpa image, a new CBE imaging method, has a great potential in CBE-based imaging of hyperthermia and other thermal therapies.