1. Water
Humans can live 1 month without food and only 6 days without water
Muscle 60%, Fat 30%, Bone 10% water, with total weight 50-60%, infants 80%
Regulation of fluid balance, aquaproteins. Albumin, Na, K, kidneys, cardia function
Intracellular 65% of fluid, Extracellular 35% with Extracellular more easily lost

7. Extracellular
Interstitial, fluid located between or around cells and used for transport
Intravascular, fluid in blood vessels know as plasma, or without clotting factors serum
Lymphatic, collects fluid outside the venous system and returns it to the heart
Transcellular fluid, found in pericardium, pleural space, gastrointestinal

9. Absorption
Total volume, 15L/d intestine, 5L/d in colon, or held in interstitial space as edema
With trauma capillaries become permeable and lack of proteins off set osmotic pressure causing swelling
Caused by DVT, heart failure, severe protein loss, and deadly in pulmonary and cerebral excess
80% of fluid comes from liquids, 20% from foods, with needs based on wt in Kg - 20kg ml, or KCALS/mL

14. Electrolytes
Ions are charged elements, Na+ (cation), Cl- (anion) which form ionic bonds to form isotonic solutions
With excess Na+, Cl- will shift fluid compartments to form balance, Na+ Extracellular, K+ Intracellular, HCO3- Intracelluar
Minerals and proteins affect fluid balance by osmotic pressure, where solvents (H2O) crosses membranes and solutes don't
Osmosis is the movement of solvents (H2O) across a semipermeable membrane by active or passive transport
Active transport requires energy for Na/K pumps, while passive transport only needs hyper/hypo tonic elements

20. Osmolarity
Passive movement of a solvent across a semipermeable membrane into a concentration of less particles
Osmotic pressure is two concentrations both acting against each other on either side of a semipermeable membrane
Osmolarity is the number of particles per volume of water, with serum blood at mOsm/L
Isotonic fluids are = blood osmolarity (D5W, 0.9% NaCl), less is hypotonic, more is hypertonic
Water is hypotonic, milk is typically isotonic, and sodas are hypertonic

24. Regulation of Fluid
Thirst occurs when 10% of the intravascular space is lost and when serum osmolarity rises
Antidiuretic Hormone or Vassopressin, causes retention of fluid decreasing osmolarity and also increases PBH
In diabetes insipidus (DI), ADH does not secrete and excess amount of fluid is lost
Aldosterone retains sodium, which pulls fluid back into the body from the kidneys caused by hypotension

27. Water Balance
Skim milk is 91%, EN formula is 70-80% hard water has Ca, Mg, and Fe+, soft water replaces these with Na
4 cups with food/d, mostly vegetables and metabolism produces 1 cup/d, except alcohol which requires H2O
Sensible fluid loss is urine, emesis, and GI loss from stool that should count in total I/Os
In extreme perspiration is >2L or 6-8% of UBW, with a L providing 40mEq Na, 3.9mEq K and 3.3 mEq Mg
Hypoalbuminemia can cause < colloidal mOsm/L, resulting in third spacing or volume loss from the interstitial space

34. Water Balance
At a minimum urine output must be >600ml/d to remove waste, typical output is 40-80ml/hr
Gastric fluid loss is vomiting or NGT suction, decompression above the pylorus, pH< 6.8
Intestinal loss is diarrhea with 2-3L/d along with1L of bile
Insensible loss is 1L from lungs, skin, and shivering which can be increased by illness, burns, fever

39. Water Balance
1L of fluid = 1kg, with mild loss 2-5%, moderate 5-10%, and severe >10%, causing hypotension
I/Os should be equal, subtract diaper from fluid, or use a urinal for output
Needs are wt/kg , in CHF ml, in ESRD urine, mL/KCALS in obese

43. Water Balance
OHT, should be hypotonic mOsm/L, 2-3gm CHO, 45-90mEq Na, 20-25mEq K
Hypertonic fluids should NOT be used, Gatorade, Juice
>330 mOsm/L stays in the stomach, draws fluid out of the colon, cause diarrhea, reduces thirst
For fluid overload 1000ml restriction, 2gm Na, and diuretics are typically used