Temperature changes in paediatric patients undergoing Magnetic Resonance Imaging: A Red Cross War Memorial Children's Hospital experience

Abstract

Background: Magnetic resonance imaging (MRI) scanning places paediatric patients at risk of both hypothermia and hyperthermia. The aim of this study is to determine primarily if paediatric patients gain or lose heat during MRI scanning, and secondarily to examine potential risk factors for any such change. Methods: A prospective audit was conducted from February 2015 until April 2015 involving 200 children aged five days to 12 years. Tympanic temperatures were recorded pre- and post- MRI scan. Variables including age, height, weight, head circumference, area scanned, length of time in the scanning room and duration of scan were recorded. The type of anaesthetic management was decided by the anaesthetist and recorded. Results: Tympanic temperature decreased in 111 patients, with a loss of greater than 0.5°C in 29% of patients (n=58) and a range of decrease from 0.1°C to 1.9°C. Hypothermia, defined as a core temperature of less than 36°C for this study, occurred in 13.5% (n=27) patients. A total of 23 patients had no change in pre- and post-scan temperature, and 66 recorded a higher temperature post-scan. The range of gain in temperature was 0.1°C to 1.5°C, with 14.5% (n=29) of patients' temperatures increasing by 0.5°C or more. The mean pre-scan temperature was 36.603 °C ± 0.512°C (range: 35.5 - 38.70 °C) and the mean post-scan temperature was 36.442°C ± 0.615 (34.80-40.0 °C). Overall, the mean post scan temperature was 0.16°C (P<0.001) less than the pre-scan temperature. Linear regression analysis identified sedation and general anaesthesia as signficant risk factors for heat loss. Conclusion: Overall paediatric patients tend to have a minor decrease in temperature during MRI scanning. Individually, each paediatric patient may have an increase or decrease in temperature, or no change. A significant proportion of paediatric patients are at risk of hypothermia post MRI scan, and almost half are at risk of an increase or decrease in temperature of a minimum of 0.5°C. These factors are clinically significant and may be associated with adverse outcomes. For these reasons, temperature monitoring and active temperature management should be implemented during MRI scanning in paediatric patients.