“…Given the undeniable complexity that underlies fluid shift between the intravascular and interstitial compartments, it can be challenging to mathematically model the fluid shift in an individual subject or patient. Existing models of fluid shift can reproduce the volume changes in the blood and interstitial fluid (Cervera and Moss, 1974 ; Pirkle and Gann, 1975 ; Hedlund et al, 1988 ; Mazzoni et al, 1988 ; Arturson et al, 1989 ; Carlson et al, 1996 ; Gyenge et al, 2003 ; Tatara et al, 2007 ) and even intracellular fluid (Hedlund et al, 1988 ; Mazzoni et al, 1988 ; Arturson et al, 1989 ; Carlson et al, 1996 ; Ursino and Innocenti, 1997 ; Gyenge et al, 2003 ; Fernandez de Canete and Del Saz Huang, 2010 ; Siam et al, 2013 ). However, there are so many disparate factors that, without exhaustive and impractical measurements, it is not possible to comprehensively characterize the fluid shift associated with an individual.…”