Digital Tympanic Membrane Temperature versus Digital Axillary Temperature: Comparative Study among Neonates

Abstract

Neonatal hypothermia continues to be a significant issue in the developing countries and there remains considerable controversy regarding the most appropriate thermometer and the best anatomical site for temperature measurement. In this diagnostic study, the prime objective was to find which thermometry practice could be proved effective for assessment of temperature in neonates. For this, the authors evaluated the agreement between tympanic thermometry measurements, digital axillary thermometry measurements and skin probe thermometry in neonates and evaluated the diagnostic utility of digital axillary and digital tympanic thermometers in making decisions for the assessment of hypothermia. They also measured the nursing time associated with both thermometry methods. The study was conducted from December 2012 to February 2013. The setting was a rural tertiary care institution. Neonates of gestational age 32 weeks and above, admitted in the nursery under constant skin temperature monitoring (gold standard) were recorded with their axillary temperature using a digital axillary thermometer and tympanic temperature using an infrared tympanic membrane thermometer. The temperatures were recorded three times a day and consecutively for three days of a particular neonate and all observations were recorded in the temperature recording sheet. Significant agreement between the tympanic thermometry measurements and digital axillary thermometry in comparison to skin probe thermometry was found. Diagnostic utility of digital tympanic thermometer and significantly less nursing time associated with tympanic thermometry was found. Statistical analysis showed positive correlation and good agreement (−0.273 to 0.264) between digital tympanic thermometry and skin probe thermometry in comparison to digital axillary and skin probe thermometry (−0.654 to 0.349) which showed a poor agreement. Digital tympanic thermometer was found to have high sensitivity (90.5%), specificity (92.9%), and positive predictive value (84.1%) than digital axillary thermometry with a sensitivity (88.6%) and specificity (82.4%) which was comparatively low. In addition to this, mean nursing time associated with digital tympanic thermometry was significantly less than the digital axillary thermometry. The agreement between digital tympanic thermometer and skin probe thermometry was good, with digital tympanic thermometry having high sensitivity, specificity and positive predictive values which makes a good diagnostic utility of the tool, especially in detecting cases of hypothermia. Nursing time associated with digital tympanic thermometry was found significantly less. Tympanic thermometer seems to be quick and fast in giving temperature results in comparison to digital axillary temperature.