The ethanol dilution is, in essence, a non-invasive dilution method. It is of interest because of how ethanol readily dissolves itself exclusively into the water space of the body[4], is non-toxic in reasonable concentrations, is metabolized in a 0th order reaction above concentrations of 0.015 g/dL[4], and there are non-invasive methods for determining blood alcohol concentration[5, 6]. Thus, by drinking a known amount of ethanol, total body water can be calculated after a few hours of periodic breathalyzer analyses. Ethanol has been validated against deuterium oxide, the invasive gold standard for determining total body water[4]. The ethanol dose will be 0.5g/kg body weight.

30mL/kg body weight of saline will be rapidly infused after the baseline measurements completed in Aim 1. Non-invasive methods for fluid volume determination (CO-pulse-oximetry, ethanol breathalyzer, BIS) will be conducted and change from baseline calculated. To determine if non-invasive fluid volume techniques can accurately determine fluid changes in healthy participants.Non-invasive methods for fluid volume determination (CO-pulse-oximetry, ethanol breathalyzer, BIS) will be conducted and change from baseline calculated.

Ethanol has been validated against deuterium oxide, the invasive gold standard for determining totally body water

The non-invasive methods being investigated will be non-inferior in measuring the blood or fluid volumes in healthy participants when compared to the gold standard.