HypovolemiaDextransDextran SulfateBlood VolumeLower Body Negative PressureShockPlasma VolumePlasma SubstitutesFluid TherapyDehydrationBlood Volume DeterminationIsotonic SolutionsHypotension, OrthostaticFluid ShiftsDiureticsVascular CapacitanceFurosemideShock, HemorrhagicHemodilutionThirstHypernatremiaBed RestHead-Down TiltHemodynamicsInappropriate ADH SyndromeHemorrhageIntracranial HypotensionBlood PressureIron-Dextran ComplexCardiac OutputHeart RateHypotensionHematocritSupine PositionHydroxyethyl Starch DerivativesHyponatremiaDrinkingColitisResuscitationStroke VolumeWater-Electrolyte BalanceSpectroscopy, Near-InfraredCardiovascular System