Paglialonga F, et al. - In this study, researchers proposed and assessed a novel index of pre-hemodialysis (HD) volume overload based on blood volume (BV) monitoring, the first hour refill index (RI), calculated as the ratio between the ultrafiltration rate indexed for body weight during the first HD hour and the percent BV change at the first hour of the treatment. They observed that in children and young adults on chronic HD, the ratio between the ultrafiltration rate per body weight and the BV change during the first hour of a HD session could be a promising index of refill capacity and pre-HD volume overload.