Efeito da termometria na prevenção de úlceras de pé diabético: revisão sistemática com metanálise / Effect of thermometry on the prevention of diabetic foot ulcers: a systematic review with meta-analysis* / Efecto de la termometría en la prevención de las úlceras del pie diabético: revisión sistemática con metaanálisis

Resumo Objetivo: analisar o efeito da termometria podálica cutânea em pessoas com diabetes mellitus, comparado com prevenção padrão de úlceras podálicas adotada nesses pacientes. Método: revisão sistemática com metanálise. Protocolo registrado na PROSPERO (CRD42020202686). Foram seguidas as recomendações do Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Busca realizada nas fontes de dados: SCOPUS, Web of Science, MEDLINE via PubMed, MEDLINE via EBSCO, MEDLINE via Biblioteca Virtual em Saúde, Embase, CINAHL, Cochrane Library, LILACS via Biblioteca Virtual em Saúde, Google Scholar, Biblioteca Digital Brasileira de Teses e Dissertações, Catálogo de Teses & Dissertações-Capes, Open Grey e ProQuest Dissertations and Theses. O risco de viés foi avaliado pela Cochrane Collaboration Risk of Bias Tool (RoB 2), a metanálise no software Review Manager 5.4 e a Certeza da evidência no sistema Grading of Recommendations Assessment, Development and Evaluation. Resultados: dos 670 registros, cinco artigos eram elegíveis. A metanálise foi calculada para o desfecho prevenção da incidência de úlceras de pé diabético, com sumarização de efeito (RR 0,53; IC95% 0,29, 0,96; p=0,02), com certeza da evidência moderada. Conclusão: a termometria mostrou efeito protetor na incidência de úlceras de pé diabético, se comparada ao cuidado podálico padrão.

Abstract Objective: to analyze the effect of cutaneous foot thermometry in people with Diabetes Mellitus, compared with the standard prevention of foot ulcers adopted in these patients. Method: a systematic review with meta-analysis. Protocol registered with PROSPERO (CRD42020202686). The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were followed. The search was performed in the following data sources: SCOPUS, Web of Science, MEDLINE via PubMed, MEDLINE via EBSCO, MEDLINE via Biblioteca Virtual em Saúde, Embase, CINAHL, Cochrane Library, LILACS via Biblioteca Virtual em Saúde, Google Scholar, Biblioteca Digital Brasileira de Teses e Dissertações, Catálogo de Teses & Dissertações-Capes, Open Grey and ProQuest Dissertations and Theses. The risk of bias was assessed by the Cochrane Collaboration Risk of Bias Tool (RoB 2), the meta-analysis was performed in the Review Manager 5.4 software and the Certainty of evidence in the Grading of Recommendations Assessment, Development and Evaluation system. Results: of the 670 records, five articles were eligible. The meta-analysis was calculated for the prevention of the incidence of diabetic foot ulcers outcome, with effect summarization (RR 0.53; 95%CI 0.29-0.96; p=0.02), with certainty of moderate evidence. Conclusion: thermometry showed a protective effect on the incidence of diabetic foot ulcers when compared to standard foot care.

Resumen Objetivo: analizar el efecto de la termometría cutánea del pie en personas con diabetes mellitus, en comparación con la prevención estándar de las úlceras del pie adoptada en estos pacientes. Método: revisión sistemática con metaanálisis. Protocolo registrado en PROSPERO (CRD42020202686). Se siguieron las recomendaciones de Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). La búsqueda se realizó en las fuentes de datos: SCOPUS, Web of Science, MEDLINE a través de PubMed, MEDLINE a través de EBSCO, MEDLINE a través de la Biblioteca Virtual en Salud, Embase, CINAHL, Cochrane Library, LILACS a través de la Biblioteca Virtual en Salud, Google Scholar, Biblioteca Digital Brasileña de Tesis y Disertaciones, Catálogo de Tesis y Disertaciones-Capes, Open Grey y ProQuest Dissertations and Theses. El riesgo de sesgo se evaluó mediante la Cochrane Collaboration Risk of Bias Tool (RoB 2), el metaanálisis se realizó con el software Review Manager 5.4 y la certeza de la evidencia se evaluó mediante el sistema Grading of Recommendations Assessment, Development and Evaluation. Resultados: de los 670 registros, cinco artículos fueron elegibles. El metaanálisis se calculó para el resultado prevención de la incidencia de úlceras del pie diabético, con sumarización del efecto (RR 0,53; IC95% 0,29, 0,96; p=0,02), con certeza de evidencia moderada. Conclusión: la termometría mostró un efecto protector sobre la incidencia de úlceras del pie diabético en comparación con el cuidado estándar del pie.

Asociación entre la termografía por infrarrojo, parámetros antropométricos y gasto energético de reposo en hombres / Association between infrared thermography, anthropometry parameters and rest energy expenditure in men

RESUMEN: Es reconocido que un incremento de la grasa corporal subcutánea es capaz de alterar el patrón de liberación de calor a través de la piel. Sin embargo, la asociación con otras variables antropométricas y la influencia del gasto energético en reposo (GER), han sido escasamente abordadas. Este estudio determinó la relación de la temperatura de la piel con variables antropométricas, peso corporal y GER de hombres adultos sanos. Participaron en el estudio un total de 24 varones sanos de 33,9±8,7 años de edad, 85,8±9,7 kg de peso corporal, 172,5±6,1 cm de estatura y 28,9±3,4 kg/m2 de índice de masa corporal (IMC). Se realizaron evaluaciones antropométricas, de termografía por infrarrojo y del GER por calorimetría indirecta, con analizador de gases. La temperatura promedio de los 6-pliegues, y las individuales (toracoabdominales, supra-espinal y abdominal), tuvieron correlaciones negativas con el IMC, perímetro de cintura, índice cintura cadera, índice cintura estatura, y la sumatoria de 6 pliegues; todos con p<0,05. Además, la temperatura del pliegue supraespinal tuvo una correlación negativa con el porcentaje de masa adiposa (MA%), r=0,47(p=0,0194). La MA% y el IMC tuvieron correlaciones negativas con el GER, con r=-0,59 (p=0,002) y r=-0,53 (p=0,006), respectivamente. El promedio de temperatura de los 6-pliegues presentó una correlación positiva con el GER (r=0,44; p=0,02). La composición corporal causa una modificación en los patrones de termografía superficial local, sin afectar la relación entre el promedio de la temperatura superficial total con el GER, pudiendo éste ser un factor predictor.

SUMMARY: It is known that an increase in the subcutaneous body fat can alter the pattern of heat release through the skin. However, the relationship with other anthropometric variables and the influence of the Resting Energy Expenditure (REE) have scarcely been addressed. To determine the relationship of skin temperature with different anthropometric variables, body weight, and the REE of healthy adult males. The participants were a total of 24 healthy males of 33.9±8.7 years-old, 85.8±9.7 kg of body mass, 172.5±6.1 cm of height, and 28.9±3.4 kg/m2 of body mass index (BMI). Anthropometric, infrared thermography, and indirect calorimetry REE assessments were performed with gas analyzer. The six skinfolds average temperature, as well as the individual skinfolds (thoracoabdominal, supraspinal, and abdominal), had negative correlations with the BMI, waist circumference, waist- hip ratio, waist-to-height ratio, and the sum of the six skinfolds, all with p<0.05. In addition, the temperature of the supraspinal fold had a negative correlation with the percentage of fat mass (MA%), r=0.47 (p=0.0194). MA% and BMI had negative correlations with REE, with r=-0.59 (p=0.002) and r=-0.53 (p=0.006), respectively. The six-skinfolds average temperature presented a positive correlation with the REE (r=0.44; p=0.02). Body composition changes cause a modification in the local surface thermography patterns without affecting the relationship between the average total body surface temperature with the REE; therefore, this could act as a predictive factor.

Métodos de termometria não invasiva em comparação oa método de aferição da temperatura de cateter de artéria pulmonar: um estudo de medidas repetidas / Comparison of noninvasive methods of thermometry and the pulmonary artery, temperature method: a repeated measures study

A aferição da temperatura corporal é uma ferramenta essencial no cuidado de pacientes críticos. Para a identificação da temperatura corporal é necessário o uso de um termômetro preciso e ágil. Quando técnicas invasivas não estão sendo utilizadas, a equipe de enfermagem depende de termômetros não invasivos. Atualmente, na literatura, não há um consenso sobre a acurácia e precisão de métodos como as temperaturas oral, axilar, de membrana timpânica ou de artéria temporal. Ademais evidências acerca dos fatores que podem alterar a confiabilidade desses métodos são escassas. Por isso estudos clínicos devem ser realizados com esses métodos para respaldar o uso dessas técnicas na prática. Objetivo: Comparar a acurácia e precisão de métodos de termometria não invasivas (artéria temporal, membrana timpânica, oral e axilar) em comparação a temperatura de artéria pulmonar. Método: Foram realizados uma revisão sistemática e metanálise e um estudo clínico de medidas repetidas. A metanálise foi realizada com dados de 41 artigos pesquisados na literatura. Os dados do estudo clínico foram coletados em duas Unidades de Terapia Intensiva na cidade de Belo Horizonte. Foram incluídos pacientes adultos em uso do cateter de artéria pulmonar. As cinco temperaturas foram aferidas três vezes de cada paciente. Para análise dos dados foi realizada análise descritiva, gráficos de Bland-Altman e análises de regressão. Resultados: A acurácia e precisão das temperaturas na metanálise foram; temperatura axilar, -0,35 e 0,06; temperatura oral, -0,21 e 0,08; temperatura de membrana timpânica, -0,05 e 0,05; e temperatura de artéria temporal, -0,22 e 0,26. A acurácia e precisão após análise dos dados do estudo clínico foram, respectivamente: temperatura axilar, -0,42 e 0,59; temperatura oral, -0,30 e 0,37; temperatura de membrana timpânica, -0,21 e 0,44; e temperatura de artéria temporal, -0,25 e 0,61. Conclusão: Os termômetros não invasivos mostraram uma boa acurácia e precisão em relação a temperatura de artéria pulmonar, entretanto em pacientes com alterações da temperatura os termômetros não invasivos tornam-se pouco acurados.(AU)

The identification of body temperature is an essential tool in critical care nursing. The use of a reliable and agile thermometer is necessary to identify the real body temperature. When available, invasive thermometer are indicated for its precision. Although, when not available, the nursing staff must rely in noninvasive thermometers. Nowadays, in the literature, there isn´t a consensus about the reliability of noninvasive temperature techniques, such as axillary, oral, tympanic membrane and temporal artery. Furthermore, there is a lack of knowledge about factors that alters the reliability of those thermometers. Clinical studies must be developed to back these techniques in nursing care. Aim: Compare the accuracy and precision of noninvasive techniques (axillary, oral, tympanic membrane and temporal artery) with the pulmonary artery temperature. Methods: An Systematic review/Metanalysis and a Cross-sectional Repeated measure clinical study were developed. The Metanalysis used data from 41 published articles. The data for the clinical study were collected in two intensive care units of two hospitals in Belo Horizonte. Patients with pulmonary artery catheter were included. The five temperatures were measured three times in each patient. Descriptive analyses were made, Bland-Altmann graphics were plotted and a four regression models were developed. Results: The accuracy and precision identified in the Metanalysis were: axillary, -0,35 and 0,06; oral, -0,21 and 0,08; tympanic membrane, -0,05 and 0,05; and temporal artery, -0,22 and 0,26. The accuracy and precision of the noninvasive thermometers and the pulmonary artery temperature identified in the clinical study were: axillary -0,42 and 0,59; oral -0,30 and 0,37; tympanic membrane -0,21 and 0,44; and temporal artery -0,25 and 0,61. Conclusion: The noninvasive thermometers showed a good accuracy and precision when compared with the pulmonary temperature, However, in non-normothermic patients the reliability of the thermometers is poor.(AU)

Videothermometry to evaluate metabolic activity in real time during pneumectomy in rats

Abstract Purpose: To evaluate, in rats, the open field videothermometry in real time while performing left pneumonectomy for early diagnosis of cardiopulmonary changes. Methods: Twelve non-specific pathogen-free Wistar rats were randomly allocated into two groups; pneumectomy group (GP) and sham surgery group (GS). Mean arterial pressure, videothermometry in real time, of the right lung, and histopathological analysis of the remaining lung were evaluated in all animals. Results: Videothermometry in real time allowed identification of temperature variance of right lung after pneumectomy, indicating a significant decrease in temperature during evaluation. There was a statistical difference between M0 and M1, M1 and M2 and M0 and M2 (p<0.004) in GS, and significant difference between M0 and M1, M1 and M2, and M2 and M0 with p<0.0001 in GP. Conclusions: Left pneumonectomy in rats shows initial histopathological changes after 60 minutes of its completion, indicating a possible compensation beginning. The open-field videothermometry in real time proved to be efficient identifying the temperature changes of the remaining lung.

Thermometry and interpretation of body temperature

This article reviews the historical development and up-to-date state of thermometric technologies for measuring human body temperature (BT) from two aspects: measurement methodology and signifi cance interpretation. Since the fi rst systematic and comprehensive study on BT and its relation to human diseases was conducted by Wunderlich in the late 19th century, BT has served as one of the most fundamental vital signs for clinical diagnosis and daily healthcare. The physiological implication of BT set point and thermoregulatory mechanisms are briefl y outlined. Infl uential determinants of BT measurement are investigated thoroughly. Three types of BT measurement, i.e., core body temperature, surface body temperature and basal body temperature, are categorized according to its measurement position and activity level. With the comparison of temperature measurement in industrial fi elds, specialties in technological and biological aspects in BT measurement are mentioned. Methodologies used in BT measurement are grouped into instrumental methods and mathematical methods. Instrumental methods utilize results of BT measurements directly from temperature-sensitive transducers and electronic instrumentations by the combination of actual and predictive measurement, invasive and noninvasive measurement. Mathematical methods use several numerical models, such as multiple regression model, autoregressive model, thermoregulatory mechanism-based model and the Kalman fi lter-based method to estimate BT indirectly from some relevant vital signs and environmental factors. Thermometry modalities are summarized on the dichotomies into invasive and noninvasive, contact and noncontact, direct and indirect, free and restrained, 1-D and n-D. Comprehensive interpretation of BT has an equal importance as the measurement of BT. Two modes to apply BT are classifi ed into real-time applications and long-term applications. With rapid advancement in IoT infrastructure, big data analytics and AI platforms, prospects for future development in thermometry and interpretation of BT are discussed.

T1-Based MR Temperature Monitoring with RF Field Change Correction at 7.0T

PURPOSE: The objective of this study is to determine the effect of physical changes on MR temperature imaging at 7.0T and to examine proton-resonance-frequency related changes of MR phase images and T1 related changes of MR magnitude images, which are obtained for MR thermometry at various magnetic field strengths. MATERIALS AND METHODS: An MR-compatible capacitive-coupled radio-frequency hyperthermia system was implemented for heating a phantom and swine muscle tissue, which can be used for both 7.0T and 3.0T MRI. To determine the effect of flip angle correction on T1-based MR thermometry, proton resonance frequency, apparent T1, actual flip angle, and T1 images were obtained. For this purpose, three types of imaging sequences are used, namely, T1-weighted fast field echo with variable flip angle method, dual repetition time method, and variable flip angle method with radio-frequency field nonuniformity correction. RESULTS: Signal-to-noise ratio of the proton resonance frequency shift-based temperature images obtained at 7.0T was five-fold higher than that at 3.0T. The T1 value increases with increasing temperature at both 3.0T and 7.0T. However, temperature measurement using apparent T1-based MR thermometry results in bias and error because B1 varies with temperature. After correcting for the effect of B1 changes, our experimental results confirmed that the calculated T1 increases with increasing temperature both at 3.0T and 7.0T. CONCLUSION: This study suggests that the temperature-induced flip angle variations need to be considered for accurate temperature measurements in T1-based MR thermometry.

Magnetic Resonance-Guided Focused Ultrasound in Neurosurgery: Taking Lessons from the Past to Inform the Future

Magnetic resonance-guided focused ultrasound (MRgFUS) is a new emerging neurosurgical procedure applied in a wide range of clinical fields. It can generate high-intensity energy at the focal zone in deep body areas without requiring incision of soft tissues. Although the effectiveness of the focused ultrasound technique had not been recognized because of the skull being a main barrier in the transmission of acoustic energy, the development of hemispheric distribution of ultrasound transducer phased arrays has solved this issue and enabled the performance of true transcranial procedures. Advanced imaging technologies such as magnetic resonance thermometry could enhance the safety of MRgFUS. The current clinical applications of MRgFUS in neurosurgery involve stereotactic ablative treatments for patients with essential tremor, Parkinson's disease, obsessive-compulsive disorder, major depressive disorder, or neuropathic pain. Other potential treatment candidates being examined in ongoing clinical trials include brain tumors, Alzheimer's disease, and epilepsy, based on MRgFUS abilities of thermal ablation and opening the blood-brain barrier. With the development of ultrasound technology to overcome the limitations, MRgFUS is gradually expanding the therapeutic field for intractable neurological disorders and serving as a trail for a promising future in noninvasive and safe neurosurgical care.

Tympanic and temporal thermometry in hypothermia assessment for adult in intraoperative abdominal surgery / Termometría timpánica y temporal en la evaluación de hipotermia en el trans-operatorio de cirugía abdominal / Termometria timpânica e temporal na avaliação da hipotermia no intraoperatório de cirurgia abdominal em adultos

ABSTRACT Objective: to analyze the association between sociodemographic, clinical, operative and environmental characteristics with hypothermia events, measured intraoperatively by tympanic and temporal thermometers in adult patients undergoing elective abdominal surgery with visceral exposure. Method: prospective quantitative, correlational, observational study. Data were collected by means of structured instrument containing the variables: age, Body Mass Index; American Society of Anesthesiologists class; type of anesthesia; time of surgery; tympanic and temporal temperature; temperature and relative humidity of the surgical room. Temperatures were assessed by methods of tympanic and temporal measurement in 63 patients. The data analysis sought an association between hypothermia and patient characteristics, type of anesthesia, surgical environment, according to the method of measurement and surgical time. Results: Among the 63 patients, 15 (23.8%) had hypothermia. Of the total (n=15; 100%) number of hypothermic patients, 13 (80%) had mild hypothermia. Moderate hypothermia was identified only by temporal thermometry in three (20%) patients. Severe hypothermia was not identified, and in two (13.3%) patients the hypothermia was identified only by temporal thermometry. Hypothermia had a statistically significant association only with age (p=0.0027) and sex (p=0.015), when measuring tympanic temperature. Conclusion: Only sex and age showed correlation with hypothermia during surgery measured by tympanic thermometry; no variable influenced hypothermia measured by temporal thermometry.

RESUMEN Objetivo: analizar la asociación entre las características sociodemográficas, clínicas, operatorias y ambientales con la ocurrencia de hipotermia medida por medio de termómetros timpánicos y temporales, en pacientes adultos en el trans-operatorio sometidos a cirugías abdominales electivas con exposición visceral. Métodos: estudio observacional, prospectivo, cuantitativo, correlacional. Los datos fueron recolectados mediante instrumento estructurado conteniendo las variables: edad; índice de massa corporal; classificación American Society of Anesthesiologists; tipo de anestesia; tiempo de la cirugía; temperatura timpánica y temporal; temperatura y humedad relativa a la sala quirúrgica. Fueron medidas las temperaturas por los métodos de afección timpánico y temporal en 63 pacientes. En el análisis de los datos se buscó la asociación de la hipotermia con las características de los pacientes, del tipo de anestesia, del ambiente quirúrgico segundo el método de afección y del tiempo quirúrgico. Resultado: de los 63 pacientes, 15 (23,8%) presentaron hipotermia. Del total (n=15; 100%) de pacientes hipotérmicos, 13 (80%) presentaron hipotermia leve. La hipotermia moderada fue identificada apenas por la termometría temporal, en tres (20%) pacientes. No hubo hipotermia grave y en dos (13,3%) pacientes a la hipotermia ocurrió apenas en la medida de la termometría temporal. En la relación de las variables, identificación que la hipotermia tuvo asociación estadísticamente significante solamente con la edad (p=0,0027) y el sexo (p=0,015), en la afección de la temperatura timpánica. Conclusión: apenas el sexo y la edad interfirieron en la hipotermia en el trans-operatorio por la termometría timpánica y ninguna variable influenció por la termometría temporal.

RESUMO Objetivo: analisar a associação entre características sociodemográficas, clínicas, operatórias e ambientais com a ocorrência de hipotermia medida por meio de termômetros timpânico e temporal, em pacientes adultos, no intraoperatório, submetidos à cirurgias abdominais eletivas com exposição visceral. Método: estudo observacional prospectivo, quantitativo, correlacional. Os dados foram coletados mediante instrumento estruturado contendo as variáveis: idade; Índice de Massa Corporal; classificação da American Society of Anesthesiologists; tipo de anestesia; tempo da cirurgia; temperatura timpânica e temporal; temperatura e umidade relativa da sala cirúrgica. Foram mensuradas as temperaturas pelos métodos de aferição timpânico e temporal em 63 pacientes. Na análise dos dados buscou-se associação da hipotermia com as características dos pacientes, do tipo de anestesia, do ambiente cirúrgico segundo o método de aferição e do tempo cirúrgico. Resultados: dos 63 pacientes, 15 (23,8%) apresentaram hipotermia. Do total (n=15; 100%) de pacientes hipotérmicos, 13 (80%) tiveram hipotermia leve. A hipotermia moderada foi identificada apenas pela termometria temporal, em três (20%) pacientes. Não houve hipotermia grave e em dois (13,3%) pacientes a hipotermia ocorreu apenas na medida da termometria temporal. Na relação das variáveis, identificou-se que a hipotermia teve associação estatisticamente significante somente com a idade (p=0,0027) e o sexo (p=0,015), na aferição da temperatura timpânica. Conclusão: apenas o sexo e a idade interferiram na hipotermia no intraoperatório pela termometria timpânica e nenhuma variável influenciou na hipotermia pela termometria temporal.

Body surface infrared thermometry in patients with central venous cateter-related infections / Termometria infravermelha da superfície corporal em pacientes com infecção relacionada a cateter venoso central

Objective To evaluate if body surface temperature close to the central venous catheter insertion area is different when patients develop catheter-related bloodstream infections.Methods Observational cross-sectional study. Using a non-contact infrared thermometer, 3 consecutive measurements of body surface temperature were collected from 39 patients with central venous catheter on the following sites: nearby the catheter insertion area or totally implantable catheter reservoir, the equivalent contralateral region (without catheter), and forehead of the same subject.Results A total of 323 observations were collected. Respectively, both in male and female patients, disregarding the occurrence of infection, the mean temperature on the catheter area minus that on the contralateral region (mean ± standard deviation: -0.3±0.6°C versus-0.2±0.5ºC; p=0.36), and the mean temperature on the catheter area minus that on the forehead (mean ± standard deviation: -0.2±0.5°C versus-0.1±0.5ºC; p=0.3) resulted in negative values. Moreover, in infected patients, higher values were obtained on the catheter area (95%CI: 36.6-37.5ºC versus 36.3-36.5ºC; p<0.01) and by temperature subtractions: catheter area minus contralateral region (95%CI: -0.17 - +0.33ºC versus -0.33 - -0.20ºC; p=0.02) and catheter area minus forehead (95%CI: -0.02 - +0.55ºC versus-0.22 - -0.10ºC; p<0.01).Conclusion Using a non-contact infrared thermometer, patients with catheter-related bloodstream infections had higher temperature values both around catheter insertion area and in the subtraction of the temperatures on the contralateral and forehead regions from those on the catheter area.

Objetivo Avaliar se a temperatura da superfície corporal nas proximidades da área de inserção do cateter venoso central é diferente quando os pacientes desenvolvem infecções da corrente sanguínea relacionadas ao cateter.Métodos Estudo transversal observacional. Usando um termômetro infravermelho sem contato, 3 medições consecutivas de temperatura da superfície corporal foram coletadas de 39 pacientes com cateter venoso central nos seguintes locais: nas proximidades da área de inserção do cateter ou do reservatório do cateter totalmente implantável, na região contralateral equivalente (sem cateter), e na fronte do mesmo paciente.Resultados Um total de 323 observações foram coletadas. Respectivamente nos pacientes do sexo masculino e feminino, desconsiderando a ocorrência de infecção, a temperatura média na área do cateter menos a da região contralateral (média ± desvio padrão: -0,3±0,6°C versus -0,2±0,5°C; p=0,36) e a da área do cateter menos a da fronte (média ± desvio padrão: -0,2±0,5°Cversus -0,1±0,5°C; p=0,3) resultaram em valores negativos. Além disso, em pacientes infectados, foram obtidos valores mais elevados na área do cateter (IC95%: 36,6-37,5ºC versus36,3-36,5ºC; p<0,01) e nas subtrações de temperaturas: área do cateter menos região contralateral (IC95%: -0,17 - +0,33°C versus-0,33 - -0,20°C; p=0,02) e a área do cateter menos fronte (IC95%:-0,02 - +0,55°C versus -0,22 - -0,10ºC; p<0,01).Conclusão Utilizando um termômetro infravermelho sem contato, os pacientes com infecções da corrente sanguínea associadas ao cateter apresentaram valores de temperatura mais elevados, tanto ao redor da área de inserção do cateter e na subtração das temperaturas das regiões contralateral e fronte, em relação àquelas da área do cateter.

In vivo verification of regional hyperthermia in the liver

PURPOSE: We performed invasive thermometry to verify the elevation of local temperature in the liver during hyperthermia. MATERIALS AND METHODS: Three 40-kg pigs were used for the experiments. Under general anesthesia with ultrasonography guidance, two glass fiber-optic sensors were placed in the liver, and one was placed in the peritoneal cavity in front of the liver. Another sensor was placed on the skin surface to assess superficial cooling. Six sessions of hyperthermia were delivered using the Celsius TCS electro-hyperthermia system. The energy delivered was increased from 240 kJ to 507 kJ during the 60-minute sessions. The inter-session cooling periods were at least 30 minutes. The temperature was recorded every 5 minutes by the four sensors during hyperthermia, and the increased temperatures recorded during the consecutive sessions were analyzed. RESULTS: As the animals were anesthetized, the baseline temperature at the start of each session decreased by 1.3degrees C to 2.8degrees C (median, 2.1degrees C). The mean increases in temperature measured by the intrahepatic sensors were 2.42degrees C (95% confidence interval [CI], 1.70-3.13) and 2.67degrees C (95% CI, 2.05-3.28) during the fifth and sixth sessions, respectively. The corresponding values for the intraperitoneal sensor were 2.10degrees C (95% CI, 0.71-3.49) and 2.87degrees C (1.13-4.43), respectively. Conversely, the skin temperature was not increased but rather decreased according to application of the cooling system. CONCLUSION: We observed mean 2.67degrees C and 2.87degrees C increases in temperature at the liver and peritoneal cavity, respectively, during hyperthermia. In vivo real-time thermometry is useful for directly measuring internal temperature during hyperthermia.

Preliminary Study on the MR Temperature Mapping using Center Array-Sequencing Phase Unwrapping Algorithm

PURPOSE: To investigate the feasibility and accuracy of Proton Resonance Frequency (PRF) shift based magnetic resonance (MR) temperature mapping utilizing the selfdeveloped center array-sequencing phase unwrapping (PU) method for non-invasive temperature monitoring. MATERIALS AND METHODS: The computer simulation was done on the PU algorithm for performance evaluation before further application to MR thermometry. The MR experiments were conducted in two approaches namely PU experiment, and temperature mapping experiment based on the PU technique with all the image postprocessing implemented in MATLAB. A 1.5T MR scanner employing a knee coil with T2* GRE (Gradient Recalled Echo) pulse sequence were used throughout the experiments. Various subjects such as water phantom, orange, and agarose gel phantom were used for the assessment of the self-developed PU algorithm. The MR temperature mapping experiment was initially attempted on the agarose gel phantom only with the application of a custom-made thermoregulating water pump as the heating source. Heat was generated to the phantom via hot water circulation whilst temperature variation was observed with T-type thermocouple. The PU program was implemented on the reconstructed wrapped phase images prior to map the temperature distribution of subjects. As the temperature change is directly proportional to the phase difference map, the absolute temperature could be estimated from the summation of the computed temperature difference with the measured ambient temperature of subjects. RESULTS: The PU technique successfully recovered and removed the phase wrapping artifacts on MR phase images with various subjects by producing a smooth and continuous phase map thus producing a more reliable temperature map. CONCLUSION: This work presented a rapid, and robust self-developed center arraysequencing PU algorithm feasible for the application of MR temperature mapping according to the PRF phase shift property.

Development of Multichannel On-line Thermometry System / 영남의대학술지

BACKGROUND: Measurement of body temperature is an important parameter inpatient management in many clinical condition. Failure to reach minimal acceptable and has necessitated the application of additional therapy. The authors developed a new, simple, accurate thermometry system, which could be used to undertake precise temperature measurement for various clinical conditions. MATERIALS AND METHODS: A new thermometry system using a specially designed temperature detecting and display system was developed. This system contains a temperature detecting sensor(LM 35CZ), which enables multiple serual checking of heat, data collection and processing computer, and 3-dimensional display system. It provides realtime volumetric visualization of temperature of a defined volume and stores and prints the data. RESULTS: With this system, temperature can be measured at multiple interesting sites simultaneously , demonstrated as a 3-dimensional temperature distribution and stored. In well-controlled, systematic experiments a significant correlation has been observed between standard temperature using this system at carious measuring points. CONCLUSION: This thermonetry system is a real-time measurement system, which can demonstrate 3-dimensional heat distribution in experimental phantom and human body and can be used for diagnosing abnormal conditions. In addition, this system reduces the nursing staff work load, providing them more time for long term care to patients.

Effects of Radiofrequency Induced local Hyperthermia on Normal Canine Liver / 대한치료방사선과학회지

In order to assess the effects of radiofrequency-induced local hyperthermia on the normal liver, histopathologic findings and biochemical changes after localized hyperthemia in canine liver were studied. Hyperthermia was externally administered using the Thermotron RF-8 (Yamamoto Vinyter Co., Japan; Capacitive type heating machine) with parallel opposed electrodes. Thirteen dogs were used and allocated into one control group (N=3) and two treatment groups according to the treatment temperature. GroupI(N=5) was heated with 42.5+/-0.5degree C for 30 minutes, and GroupII(N=5) was heated with 45+/-0.5degree C for 15-30 minutes. Samples of liver tissue were obtained through a needle biopsy immediately afterhyperthermia and 7, 14 and 28 days after treatment and examined for SGOT, SGPT and alkaline phosphatase. Although SGOT and SGPT were elevated after hyperthermia in both groups (three of five in each group), there was no liver cell necrosis or hyperthermia related mortality in GroupI. A hydropic swelling of hepatocytes was prominent histologic finding. Hyperthermia with 45degree C for 30 minutes was fatal and showed extensive liver cell necrosis. In conclusion, liver damage day heat of 42.5+/-0.5degree C for 30 minutes is reversible, and liver damage by heat of 45+/-0.5degree C for 30 minutes can be fatal or irreversible. However, these results cannot be applied directly to human trial. Therefore, in order to apply hyperthermic treatment on human liver tumor safely, close observation of temperature with proper thermometry is mandatory. Hyperthermic treatment should be confined to the tumor area while sparing a normal liver as much as possible.

Thermometry in Hyperthermia induced by Ultrasound A Phantom study / 대한치료방사선과학회지

No abstract available.