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

AIMS AND OBJECTIVES: To assess the capability of infrared ear thermometry accurately to predict rectal temperature in older patients. BACKGROUND: Infrared ear thermometry is now commonly used for predicting body temperature in older patients. However, ear thermometry has been insufficiently evaluated in geriatric patients. DESIGN: Prospective, convenience sample, unblinded study. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. RELEVANCE TO CLINICAL PRACTICE: Proper technique (measuring in both ears) and optimal instrumentation (model of ear thermometer) are essential for accuracy.

Skin tensile properties revisited during ageing. Where now, where next?

Skin and its subcutaneous layer represent a complex composite of tissues, whose mechanical characteristics depend upon the mutual interdependence of their constituent parts. The molecular and microanatomical structures of skin allow it to meet normal mechanical demands. They also determine the orientation both of Langer's lines and of relaxed skin tension lines. Ageing, photodamage, hormones, drugs, cosmetic products and dermatological interventions may modify the skin's overall tensile properties. In turn, any variation in mechanical stresses and strains imposed upon the skin's connective tissue influences the metabolic activity and phenotypic expression of fibroblasts and dermal dendrocytes. The viscoelastic functions of ageing skin can be tested by altering the orientation and magnitude of imposed stresses and strains over time. Assessment can be made of various biomechanical properties of skin: tensile, torsional, acoustic shear wave, indentation, impact and elevation. Such objective biomechanical assessments may be applied to dermocosmetic interventions, so providing opportunity for progress in cosmetic dermatological science.