027 - Measurement of Insensible Water Loss in Healthy Children

Publication Number: 27.5904

Hiroki Kato, National Center for Child Health and Development, Setagaya-ku, Tokyo, Japan; Nobuyuki Yotani, National Center for Child Health and Development, Sertagaya-ku, Tokyo, Japan; Satoru Takada, Kobe University, Kobe, Hyogo, Japan; Chisato Miyakoshi, Kobe City Medical Center General Hospital, Kobe, Hyogo, Japan

Background: Maintenance fluid therapy in children aims to replace water lost through urine and insensible water loss, but the accurate maintenance fluid volume remains uncertain. Many pediatricians use the Holliday-Segar formula to calculate maintenance fluid volume, but recent studies have highlighted the risks of overhydration associated with this formula. Accurate calculation of maintenance fluid volume requires accurate measurement of insensible water loss in children.

Objective: This study aims to measure insensible water loss in healthy children.

Design/Methods: This exploratory, prospective study is being conducted at a tertiary pediatric hospital in Japan, the National Center for Child Health and Development, from February 2023 to December 2026. Participants are healthy infants born at our hospital without complications requiring admission to the Neonatal Intensive Care Unit and we conduct measurements at three distinct time points (within five days of birth, at one month, and four to seven months) to assess insensible water loss gravimetrically, with advice and guidance from an architectural research collaborator. We record participants' weights continuously at five-second intervals using a precision electronic scale and calculate insensible water loss by tracking weight loss. While measuring insensible water loss, we also record age, height, weight, temperature, humidity, skin temperature, skin moisture content, and body coverage rate by clothing. This study is supported by the Grants-in-Aid for Scientific Research, funded by the Japan Society for the Promotion of Science, Grant number 23K02253.

Results: The study is ongoing, and we present interim results based on the data collected. A total of 25 participants were recruited, and 65 measurements were conducted. Of these, 20 measurements were excluded due to instability that prevented accurate measurement. Finally, 44 measurements were included. The median insensible water loss was 15.3 g/m²/day within five days of birth, 52.9 g/m²/day at one month, and 56.7 g/m²/day at four to seven months. Multivariable regression analysis showed a significant positive correlation between insensible water loss and age (coefficient 0.17, 95% CI 0.07-0.26).

Conclusion(s): The median insensible water loss was 15.3 g/m²/day within five days of birth, 52.9 g/m²/day at one month, and 56.7 g/m²/day at four to seven months. These results suggest that insensible water loss in healthy children may vary with age.