Infrared Ear Thermometers Research Articles

Agreement of infrared ear temperature with nasopharyngeal temperature and diagnostic performance on hypothermia in general anesthetized patients.

Infrared ear thermometry is widely used in clinical practice due to its noninvasive, convenient, and quick sampling. However, its accuracy and feasibility in anesthetized patients have not yet been established. We conducted this cross-sectional study to evaluate the agreement between infrared ear temperature and nasopharyngeal temperature in general anesthetized patients and its performance in intraoperative hypothermia, defined as nasopharyngeal temperature <36°C. Adult female patients who underwent gynecological surgery under general anesthesia were enrolled in this study. Infrared ear temperature by Braun ThermoScan PRO 4000 (Braun GmbH, Kronberg, Germany) and nasopharyngeal temperature were measured simultaneously before, during, and after surgery. The agreement between the two temperatures was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. The diagnostic performance of the infrared ear thermometer for hypothermia was evaluated using receiver operating characteristic (ROC) curve analysis. Fifty-six patients with 168 pairs of simultaneous infrared ear and nasopharyngeal temperatures were included in this analysis. The mean infrared ear temperature was consistently higher than the nasopharyngeal temperature throughout surgery, but the differences were small (0.22, 0.13, and 0.06°C before, during, and after surgery, respectively). The ICC between the two temperatures before, during, and after surgery was 0.70, 0.75, and 0.80, respectively, and 93.5% of the differences fell within the 95% limits of agreement of ±0.5°C. An infrared ear thermometer had high diagnostic accuracy for hypothermia, with an area under the ROC curve of 0.95 (95% confidence interval [CI], 0.92-0.98). The cutoff of infrared ear temperature for hypothermia was 36.2°C with a sensitivity of 0.89 (95% CI, 0.71-0.98) and a specificity of 0.87 (95% CI, 0.81-0.92). The infrared ear temperature is in good agreement with the nasopharyngeal temperature in general anesthetized patients without hyperthermia and has high performance for detecting hypothermia. An infrared ear thermometer can be a diagnostic tool for intraoperative hypothermia.

Accurate Clinical Tympanic Thermometer Measurement System at NMISA

Infrared ear thermometers allow users to measure body temperature quickly and non-invasively by inserting a probe into the patient’s ear canal. The effectiveness of tympanic ear thermometers is dependent on how accurate their measurement is. This prompts the demand for accurate and reliable calibration of ear thermometers. Developing capability and providing traceability to the health care facilities in South Africa have become crucial, as there is no calibration laboratory that provides such a service. A standard ear-thermometer black-body source system that is traceable to ITS-90 temperature has been constructed and assembled at the NMISA temperature laboratory. The ITS-90-traceable measurement system developed has a measuring capability of 40 mK (k=2) to 70 mK (k=2) in the temperature range of 35.5 °C to 41.5 °C. At the human body temperature of 37 °C an uncertainty of 45 mK (k=2) is achieved.

Suitability of Different Thermometers for Measuring Body Core and Skin Temperatures in Suckling Piglets.

Simple SummaryAfter birth, piglets’ temperatures usually drop some degrees because of low ambient temperatures in the stable. Piglets have no ability to increase their body temperatures during their first days of life, which can cause health issues if piglets are not appropriately cared for. Monitoring temperatures can, therefore, contribute to reducing impaired wellbeing and unnecessary losses. The most common method for assessing core temperatures is measuring rectally with a digital thermometer. This, however, takes time and requires securing of the animal, which is stressful. Therefore, the aim of this study was to determine whether other thermometers or thermometric devices, such as an infrared camera, can deliver results similar to the digital thermometer. For the measurements in newborn piglets, infrared ear thermometers, infrared forehead thermometers, and infrared laser thermometers were used, as it was assumed that these would deliver results fast and cause little distress in piglets. The results were compared to rectally measured temperatures and it was found that the temperatures measured in-ear correspond to a great extent to rectal temperatures and show little variation between measurements, while the other used devices can only give a rough estimate of the actual core temperatures.Monitoring the temperature of piglets after birth is critical to ensure their well-being. Rectal temperature measurement is time-consuming, requires fixation of the animal and is stressful for piglets. This study aims to evaluate the effectiveness of infrared thermometry and thermography as compared to rectal temperatures. We investigated digital thermometers for rectal measurements, infrared ear thermometers, infrared forehead thermometers, infrared laser thermometers and an infrared camera during field trials with piglets aged 1–13 days. Temperatures differed between the left and right ear and ear base (p < 0.01), but not between temples. Three forehead and laser devices yielded different temperatures (p < 0.01). Temperatures assessed with a laser thermometer decreased with distance from the target (p < 0.01). The highest correlation observed was between the rectal and tympanic temperatures (r = 0.89; p < 0.01). For temperatures assessed with the camera, inner thigh and abdomen correlated most closely to core temperature (0.60 ≤ r ≤ 0.62; p < 0.01). Results indicate that infrared ear thermometry commonly used in humans is also suited for assessing temperature in piglets. The inner thigh and abdomen seem promising locations for estimating core temperature with an infrared camera, but this approach needs to be adapted to reduce time exposure and stress for the piglets to be used under practical conditions.

Temporal artery and non-contact infra-red thermometers: is there sufficient evidence to support their use in secondary care?

Abstract&#x0D; Background and Objective&#x0D; Accurate measurement of body temperature is a key part of patient observations and can influence important decisions regarding tests, diagnosis and treatment. For routine measurements in hospitals, non-invasive thermometers such as tympanic infra-red ear thermometers are very widely used even though non-invasive thermometers are not as accurate as core thermometry. However, there are known issues regarding the accuracy of these thermometers due to user errors including dirty probe covers and not straightening the ear canal. We were therefore keen to understand if there was evidence to support the use of alternative non-tympanic, non-invasive thermometer that could be easily and widely deployed across Nottingham University Hospitals NHS Trust.&#x0D; &#x0D; Material and Methods&#x0D; A search of the published literature via the NICE HDAS was undertaken to identify the evidence on the use of temporal artery (TAT) or non-contact infra-red forehead (NCIT) thermometers compared to a core body temperature thermometer in a clinical setting. The relevant literature was identified, appraised and summarised.&#x0D; &#x0D; Results&#x0D; 15 papers described the use of TAT but only 5 reported results that were considered within clinically acceptable limits of which 2 included febrile patients. Nine of the 10 studies where TAT was considered not to be within acceptable limits included febrile patients. For the NCIT, 3 studies were identified but only 1 reported results within acceptable limits and this did not include febrile patients.&#x0D; &#x0D; Conclusion&#x0D; A review of the literature for both TAT and NCIT has indicated that neither is currently suitable as a replacement for tympanic IR ear thermometers in clinical practice. In particular, the evidence suggests that they are not acceptable methods for detecting temperatures outside the normothermic range and do not detect fever accurately. In addition, the potential for user error with TAT is considered unacceptable.

PSII-9 Body core and skin temperatures in suckling piglets measured by infrared thermography and thermometry methods

Abstract Monitoring piglets’ temperatures after birth is crucial to prevent losses caused by hypothermia and ensure well-being. Rectal measuring, which is still considered the ‘gold standard’ for assessing core temperatures, takes time and requires fixation. Aim of this study was to evaluate the effectiveness of infrared thermography and thermometry in comparison to rectal temperatures. In one to seven days old piglets, rectal temperatures were measured with digital thermometers (DT) (Geratherm® GT-195-1) (n = 958), tympanic membrane temperatures with an infrared ear thermometer (IET) (ThermoScan® IRT6520) (n = 424), skin temperatures with infrared laser thermometers (ILT) (Eventek™ ET312) behind the ear (n = 671), an infrared camera (IC) (Optris® PI400) at six body locations (n≥488) or an infrared camera attachment (ICA) (FLIR ONE® for iOS) (n = 60). Devices’ reliability was tested. Correlations and differences (GLM) were estimated with SAS® 9.4. DT devices and repeated measurements showed no differences (n = 77). Repeated IET measurements at left and right ear were not different (n = 57). Temperatures decreased for ILT when measured from 10, 30, 50, and 100cm (P &amp;lt; 0.001; n = 360). Three ILT devices obtained different values (P &amp;lt; 0.001). At 10cm, means were different at left and right side (P &amp;lt; 0.001). For following results, the same device was used for all measurements (10cm, left). Highest correlations were found between DT and IET (r = 0.93; P &amp;lt; 0.001) and ILT (r = 0.81; P &amp;lt; 0.001). All infrared temperatures were lower (P &amp;lt; 0.001) than rectal temperatures (38.8°C), except IET (38.7°C). For IC, temperatures at inner thigh and lower abdomen correlated best with DT (0.59≤r≤0.62; P &amp;lt; 0.001). IET seems suited for assessing temperatures in piglets as it is reliable, with values comparable to DT. For IC, inner thigh and lower abdomen seem promising locations, but fixation is still required for both techniques. ILT is an option for estimating core temperatures at a short distance, but reliability needs to be considered.

COMPARISON OF BODY TEMPERATURE ACQUIRED VIA AURICULAR AND RECTAL METHODS IN FERRETS

Measuring body temperature in ferrets with rectal thermometers is often very stressful and potentially painful as it can damage the rectal mucosa. Recently, the veterinarians have used infrared ear thermometers since they record the temperature in a shorter time and are less invasive than the rectal equipment. This study compared several thermometers; two pediatric ear thermometers, a veterinary ear thermometer, a digital rectal thermometer, and a mercury-in-glass thermometer as a gold standard test for the body temperature of healthy ferrets (n = 27). The recording of auricular temperature in three study groups had a variation of approximately −1 °C compared to the one taken with rectal thermometers. According to this study, the measurement of temperature registered with auricular thermometers is not a precise method to obtain the body temperature and therefore does not replace the value obtained with rectal thermometers. They may not be used interchangeably in clinical practice. Nevertheless, because there were no significant differences (P > 0.05) among the values obtained with auricular thermometers, the recordings can be considered as accurate reference for auricular temperature in healthy ferrets.

Environmental Heat Stress Among Young Working Women: A Pilot Study

BackgroundHeat waves are increasing significantly in frequency and severity and threaten the health and income of outdoor workers. Pregnant women workers are particularly at risk due to their delicate physiological systems and accountabilities to future generations. Animal and human studies propose that elevated body temperatures during pregnancy can induce adverse pregnancy outcomes. ObjectiveTo measure the change in internal body temperature (Tcore) in young working women before, after, and during work (both outdoor and indoor) on hot humid days and relate threshold temperature to the upshot adverse effects of pregnancy (teratogenicity and related miscarriage). MethodsTympanic temperatures were measured using infrared ear thermometers and workplace temperatures were collected using Lascar Data Logger. Brief exploratory interviews were conducted to gather qualitative data, and content analysis was also carried out. FindingsBody temperatures were found elevated among outdoor women workers compared with that of indoor women workers. ConclusionsThe present study found that outdoor work during pregnancy in hot, humid days might increase body temperature up to levels that could induce fetal destruction or anomaly.

Comparison between tympanic temperature measurement with infrared ear thermometer and rectal temperature measurement with mercury clinical thermometer for children

Objective To explore the feasibility for application of infrared ear thermometer in body temperature measurement among children. Method Ear temperature and rectal temperature of 500 children patients at outpatient and emergency departments were measured and the difference between ear temperature and rectal temperature were compared with the self-control method. With 500 children patients were divided into the following groups: 0-1 year old group, > 1-2 years old group, > 2-3 years old group, > 3-7 years old group, the difference of these two measuring methods in these different age groups were compared. Results Average rectal temperature was (38.28±0.93) ℃, higher than average ear temperature (38.06±0.92) ℃ with statically significant difference (t =-12.711, P =0.000); 0-1 year old group, > 1-2 years old group, > 2-3 years old group, > 3-7 years old group, four age groups rectal temperature minus ear temperature difference results M(Q25, Q75) were as follows: 0.2(0.0, 0.5), 0.2 (0.1, 0.4) 0.2 (0.0,0.4) 0.2(0.0,0.4), which meant the difference between two temperature measurement methods in different age groups showed that the difference was not statistically significant (H=0.600, P =0.896); ear temperature and rectal temperature were linearly correlated (r=0.915, P =0.000); taking rectal temperature as Y and ear temperature as X, the regression equation was =3.080+0.925X; with rectal temperature of ≥38.0℃ as golden standard, the area in ROC curve of ear temperature was 0.97 and correct diagnosis index of ear temperature was highly correct. Therefore, as for whether a child is diagnosed as fever based on the ear temperature, it is recommended that the ear temperature be ≥37.8℃; the difference of fever incidence for rectal temperature method of 58.2% and fever incident for ear temperature method of 57.2% was determined as not statistically significant (χ2=0.102, P=0.749). Conclusions Infrared ear thermometer may be used for measuring children′s body temperature by replacing mercury rectal thermometer; however, ear temperature should be different from rectal temperature in terms of criteria for clinical judgment of fever. Key words: Children; Temperature measuring method; Infrared ear thermometer; Mercury clinical thermometer

Tympanic, Infrared Skin, and Temporal Artery Scan Thermometers Compared with Rectal Measurement in Children: A Real-Life Assessment

IntroductionBody temperature measurement in children is of clinical relevance. Although rectal measurement is the gold standard, less invasive tools have become available. We aimed to describe the accuracy of tympanic, infrared skin, or temporal artery scan thermometers compared with rectal measurement to reflect core temperature. MethodsRectal (Filac 3000; Covidien, Mechelen, Belgium), tympanic (AccuSystem Genius2 Typmanic Infrared Ear Thermometer, Covidien, Mechelen, Belgium), temporal artery scan (Exergen, Exergen Corp, Watertown, Massachusetts), and infrared (ThermoFlash Contactless Medical Electronic Thermometer, Visiomedlab, Paris, France) body temperature measurements were randomly performed and readings were collected once. Temperature readings were described as median and range, and observations were compared with rectal temperature readings (using Wilcoxon, Bland-Altman, sensitivity, and specificity tests). The child’s comfort was assessed by the child, parent, and nurse (using Likert scales) and ease of use was assessed by nurses (using visual analog scale). ResultsBased on observations in 294 (median age = 3.2 years, range = 0.02–17 years) children, the mean difference was 0.49°C (tympanic scan; P < 0.0001), 0.34°C (infrared skin scan; P < 0.0001), and 0°C (temporal artery scan; P = 0.9288), respectively, when compared with rectal temperature readings. Based on visual inspection of Bland-Altman plots, all tools overestimated the temperature at lower body temperature and underestimated the temperature at higher body temperature, resulting in a sensitivity of 22% to 41% and a specificity of 98% to 100% for rectal temperatures above 38°C. The Likert scale scores and the visual analog scale scores for rectal measurement were only slightly higher when compared with the other methods. ConclusionsAll noninvasive techniques underperformed compared with rectal measurement. The temporal artery scan deviations were smallest, but all noninvasive techniques overestimate lower temperatures and underestimate higher temperatures compared with rectal measurement. In our hands, temporal artery scan measurement seems to be second best, but not yet ideal.

Bilateral Comparison of Blackbodies for Clinical Infrared Ear Thermometers between NIMT and NMIJ

This article describes the results of the bilateral comparison of blackbodies for infrared ear thermometers (IRETs) between the National Institute of Metrology (Thailand), NIMT, and the National Metrology Institute of Japan (NMIJ). The purpose of this comparison was to ensure consistency of the national radiance temperature scales for IRETs maintained by NIMT and NMIJ. Results of the measurements indicate differences in radiance temperature within 10 mK with a maximum measurement uncertainty of 64 mK. The equivalence of the radiance temperature scales realized by both NIMT and NMIJ in the range of 35 \(^{\circ }\)C to 42 \(^{\circ }\)C for IRET calibration is indicated. The results of this bilateral comparison can be used in terms of quality assurance and validation of calibration.

A small-size transfer blackbody cavity for calibration of infrared ear thermometers

A small-size transfer blackbody cavity for calibration of infrared ear thermometers (IRETs) was developed and characterized at the Korea Research Institute of Standards and Science. This blackbody cavity consists of a reflector exposed to the air and a radiator with three-step curves immersed in a water-bath, and has an angularly uniform emissivity of higher than 0.9993. The radiance temperature of the blackbody cavity was measured with an IRET. We also calculated the effective emissivity by using the software STEEP322, considering the influence of the shape and temperature of the probe-tip of the IRET on the effective emissivity of the blackbody cavity. The measured and calculated radiance temperatures of the blackbody cavity were compared to those of the ASTM-type blackbody cavity and are in good agreement. Uncertainties (k = 1) of the blackbody cavity are estimated to be less than 44 mK in the temperature range 35–42 °C.

Temperature of Periimplant Tissues in Clinically Successful Implants: An Observational Clinical Study in Humans

The aim of this study was to evaluate periimplant tissue temperature in a successful implant. It has been shown that periimplant disease and mucositis are inflammatory diseases. As such, one of the main clinical signs is the change in temperature. We try to establish normal values of temperature with an easy to use appliance. Fifty-one individuals were enrolled in this study. Only 1 implant per patient was included. The implants were clinically and radiographically examined and diagnosed as clinical successful implants. An infrared ear thermometer was used to measure periimplant temperature (PIT) and the difference with the sublingual temperature (ΔT). These data were analyzed using the Student t test, analysis of variance, and cluster analysis. Statistically significant differences in PIT were observed between the second sextant and the fourth and fifth sextants. These differences were not significant on considering ΔT. In addition, for the clinically and radiographically successful implants, ΔT for all sextants showed a mean of 0.81 (CI, 0.57-1.04). We have found a difference in outcome between periimplant temperature and the temperature differential. PIT depends on the anatomical location, though ΔT is an independent measurement with a value of 0.81°C.

Comparison of Blackbodies for Calibration of Infrared Ear Thermometers

The article presents the results of the EURAMET Project No. 927 “Comparison of blackbodies for calibration of infrared ear thermometers (IRETs)”. The objective of the comparison was to determine the agreement of blackbodies used for the calibration of IRETs among European national laboratories. To verify the accuracy of an IRET, a suitable blackbody (BB) is needed. Such a blackbody related to the EN standard, designed for the calibration of ear thermometers and immersed in a stirred water bath, was provided for the comparison by the pilot laboratory. The pilot provided also the transfer IRET and organized the comparison.

基于MLX90615的红外耳温计设计

The design of infrared ear thermometer based on medical digital infrared sensor MLX90615 was presented. According to infrared temperature measurement principle,the design mainly consisted of digital infrared sensor,low power consuption CPU unit,LCD display and other external circuit. The CPU unit read infrared ray siginal collected by MLX90615 through I2C bus,converted the digital signal to corresponding temperature of ear cavity and showed in LCD display. The experiment showed that the resolution and accuracy of the design reached 0.02 ℃ and 0.1 ℃,and achieved the goal to measure ear cavity accurately and rapidly.

Measurement of body temperature in adult patients: Comparative study of accuracy, reliability and validity of different devices

Background and aims We compared a range of alternative devices with core body temperature measured at the pulmonary artery to identify the most valid and reliable instrument for measuring temperature in routine conditions in health services. Methods 201 patients from the intensive care unit of the Candelaria University Hospital, Canary Islands, admitted to hospital between April 2006 and July 2007. All patients (or their families) gave informed consent. Readings from gallium-in-glass, reactive strip and digital in axilla, infra-red ear and frontal thermometers were compared with the pulmonary artery core temperature simultaneously. External factors suspected of having an influence on the differences were explored. The cut-off point readings for each thermometer were fixed for the maximum negative predictive value in comparison with the core temperature. The validity, reliability, accuracy, external influence, the waste they generated, ease of use, speed, durability, security, comfort and cost of each thermometer was evaluated. An ad hoc overall valuation score was obtained from these parameters for each instrument. Results For an error of ±0.2 °C and concordance with respect to fever, the gallium-in-glass thermometer gave the best results. The largest area under the receiver operating characteristic (ROC) curve is obtained by the digital axillar thermometer with probe (0.988 ± 0.007). The minimum difference between readings was given by the infrared ear thermometer, in comparison with the core temperature (−0.1 ± 0.3 °C). Age, weight, level of conscience, male sex, environmental temperature and vaso-constrictor medication increases the difference in the readings and fever treatment reduces it, although this is not the same for all thermometers. The compact digital axillar thermometer and the digital thermometer with probe obtained the highest overall valuation score. Conclusion If we only evaluate the aspects of validity, reliability, accuracy and external influence, the best thermometer would be the gallium-in-glass after 12 min. The gallium-in-glass thermometer is less accurate after only 5 min in comparison with the reading taken after being placed for 12 min. If we add the evaluation of waste production, ease-of-use, speed, durability, security, patient comfort and costs, the thermometers that obtain the highest score are the compact digital and digital with probe in right axilla.

Comparison Measurements of Infrared Ear Thermometers Against Three Types of Blackbody Sources

Body temperature is a basic vital sign of the human body, and the use of infrared ear thermometers for medical diagnosis and health management on human bodies has been widespread nowadays. To gain credibility and confidence in the usage of IR ear thermometers, a standard blackbody source (BBS) with a calibration traceable to ITS-90 is necessitated. Three types of cavity-shaped blackbodies (designated BBC-A, BBC-E, and BBC-J) vertically immersed in a temperature-controlled stirred water bath were developed at the Center for Measurement Standards (CMS) as standard BBSs to calibrate and verify 14 commercial IR ear thermometers produced by six manufacturers. The basic structure of each cavity was designed based on the informative examples recommended in ASTM E-1965, EN 12470-5, and JIS T 4207 standards. The temperature of the blackbody cavity shall be represented by the water temperature near the bottom of the cavity that is measured using an immersed platinum resistance thermometer (PRT) for which the calibration is traceable to our national standard and with an uncertainty no greater than 0.03 °C (k = 2). The water bath was evaluated using the PRT to be stable within ±3.5 mK over 1 h and uniform within ±1.1 mK. Three types of BBSs were compared and analyzed utilizing two IR ear thermometers of 0.01 °C resolution as well as the statistical technique of analysis of variance (ANOVA). On the contrary, IR ear thermometers were tested and verified against three BBSs at three blackbody temperatures of 35.5 °C, 37 °C, and 41 °C. The analysis results of ANOVA showed that there is no significant temperature difference among three different structured blackbodies, and the average measured radiance temperature of three BBSs at 35.5 °C, 37 °C, and 41 °C were within 0.026 °C, 0.024 °C, and 0.027 °C of each other. Three among fourteen IR ear thermometers tested were outside of the 0.2 °C MPE (maximum permissible error) recommended by ASTM E-1965, EN 12470-5, or JIS T 4207 standards while BBC-A and BBC-E were used; however, four were outside of MPE requirement when BBC-J was used.

The effects of measurement site and ambient temperature on body temperature values in healthy older adults: A cross-sectional comparative study

Background Accurate baseline body temperature measurement is essential for assessment. Tympanic membrane temperature (TMT) measurement is popular, but there is no consensus on whether it is as accurate as oral temperature (OT) for use with the elderly at varying ambient temperature levels. Objectives To test agreement between TMT and OT measurement of body temperature among an elderly population; and to explore whether agreement between the two sites depends on ambient temperature. Design A cross-sectional comparison study. Methods Two samples of older community-dwelling adults were recruited from 17 community senior citizen centers in Taipei, Taiwan in winter ( n = 262) and summer ( n = 257) of 2007. TMT and OT were simultaneously measured by electronic infrared ear thermometer and electronic digital thermometer. Ambient temperatures measured by digital thermo-hygrometer of the data collection setting were recorded when body temperature was taken. Results In winter mean TMT was 36.64 °C (S.D. 0.37), and mean OT was 36.74 °C (S.D. 0.18). In summer, the mean TMT was 37.05 °C (S.D. 0.30) and mean OT was 36.85 °C (S.D. 0.22). The relationship between TMT and OT were r = 0.42 ( p < 0.001) in winter and r = 0.57 ( p < 0.001) in summer. The values of OT were used as standard to assess the accuracy of the measurement. The bias between TMT and OT was −0.10 °C (S.D. 0.34) and 95% limits of agreement were 0.57 and −0.77 °C in winter; and bias was 0.20 °C (S.D. 0.25) and 95% limits of agreement were 0.69 and −0.29 °C in summer. The findings of this study demonstrate that the TMT has high variability that may under or over estimate body temperatures. Conclusions There is a lack of agreement in body temperatures values between TMT and OT in community-dwelling elderly in both winter and summer. OT was more stable than TMT regardless of ambient temperature influences. Therefore, the oral cavity is preferable to the TM site for temperature measurement in alert elderly. The limitation of this study is that hospitalized patients who are most likely to need temperature measurement are not included in this study.

Reliability of infrared ear thermometry in the prediction of rectal temperature in older inpatients

To assess the capability of infrared ear thermometry accurately to predict rectal temperature in older patients. Infrared ear thermometry is now commonly used for predicting body temperature in older patients. However, ear thermometry has been insufficiently evaluated in geriatric patients. Prospective, convenience sample, unblinded study. All patients (or their guardians) gave informed consent. Patients hospitalised in a geriatric unit underwent sequential ear and rectal temperatures measurements using two different models of infrared ear thermometers (ThermoScan and Genius) and a rectal probe, respectively. After a brief otoscopic examination, ear temperatures were measured twice at both ears with each thermometer, the highest of four measurements being retained for analysis. The rectal temperature was the reference standard. Hundred patients (31 males), aged 81 (SD 7) years completed the study. The mean rectal temperature was 37.3 degrees C (SD 0.7) degrees C (range 36.3-40.7 degrees C). Eighteen patients were febrile (rectal temperature >or= 37.8 degrees C). The mean bias between rectal and ear temperatures as measured with the ThermoScan was -0.20 degrees C (SD 0.32) degrees C and the 95% limits of agreement were -0.83 degrees C and 0.42 degrees C (95% CI, -0.88-0.48 degrees C). Using the Genius, the corresponding figures were -0.56 degrees C (SD 0.39) degrees C, -1.32 degrees C and 0.20 degrees C (95% CI, -1.39-0.27 degrees C). After correction for bias, the ThermoScan predicted the level of fever with a maximum error of 0.7 degrees C (mean error 0.3 degrees C). Using the Genius, the maximum error and the mean error were 1.6 degrees C and 0.4 degrees C, respectively. Infrared ear thermometry can predict rectal temperature in normothermic and in febrile inpatients with an acceptable level of accuracy. However, the predictive accuracy depends on both operator technique and quality of instrumentation. Proper technique (measuring in both ears) and optimal instrumentation (model of ear thermometer) are essential for accuracy.

Body Temperature Change During Anesthesia for Electroconvulsive Therapy: Implications for Quality Incentives in Anesthesiology

The American Society of Anesthesiologists has announced that perioperative normothermia is a "Quality Incentive in Anesthesiology." We examined whether we could meet this quality incentive in a simple population: patients undergoing anesthesia for electroconvulsive therapy (ECT). We compared infrared-measured ear temperature before anesthesia to temperature upon delivery of patients to the postanesthesia care unit (PACU) after 101 consecutive brief anesthetics to facilitate ECT. For 35 procedures, the patients had an infrared ear thermometer temperature of <36 degrees C before anesthesia was administered, and 18 had a temperature of <36 degrees C after anesthesia when transferred to the PACU. For 30 anesthetics, the patients' temperature decreased during anesthesia, for 64 anesthetics it increased during anesthesia, and for 7 it did not change. Overall examination of the data demonstrated no correlation between preprocedure and postprocedure temperature. We conclude that there was no consistent change in temperature during anesthesia between our study patients when anesthesia was administered to facilitate ECT. If patients' tympanic temperatures were below 36 degrees C upon admission to the PACU, it would be incorrect to conclude that intraprocedural temperature management measures were substandard. Also, current methods of measuring temperature may be inadequate to ascertain if patients are hypothermic after surgery. As the avoidance of hypothermia is a meritorious goal, anesthesia departments need to ensure that their temperature monitoring equipment is adequate to ensure accurate measurement of postanesthetic temperature if this variable is to be used as a quality incentive.

Improving the reliability of temperature measurements taken with clinical infrared ear thermometers

Infrared ear thermometer was developed and rapidly spread in Japan in the late 1990's, but users began to question the reliability of the temperature readings. AIST developed a new national standard for the calibration and conformity assessment of new ear thermometers, and also designed and organized the traceability system, conducted technological verification, and improved reliability of measured temperature, to meet the demands of Japanese industry and consumers. An international comparison of national measurement standards among Germany, UK, and AIST was conducted and the equality of the standards was experimentally verified to maintain international reliability.