Fluids & Electrolytes

movement of solutes accross cell membrane in absence of a favorable chemical or concentration gradient. From an area of higher solute concentration-- against the gradient--Pumping Uphill--REQUIRES ENERGY (ATP) from cell and carrier substances

Anions - electrolyte ions carrying a - elec. Charge

Cations - electrolyte ions carrying a + elec. Charge

Solvents - liquids that hold a substance in solution

Solutes - substances that are dissolved in a solution

Plasma proteins, especially ALBUMIN that create a pulling force that brings water back into capilarries

the movement of solutes from an area of higher concentration to an area of lower concentration

• Excess fluid in interstitial space
• 1+ pitting edema = 2mm
• 2+ = 4mm
• 3+ = 6mm
• 4+ = 8mm
• BRAWNEY EDEMA-Fluid cannot be displaced, warm, soft, shiny skin surface

passage of fluid through a permeable membrane

from higher pressure to lower pressure

the pushing force that moves a fluid through a permeable mebrane

• 1. venous = 12 mm Hg
• 2. Colloidal osmotic/oncotic pressure = 22 mm Hg
• 3. aterial = 32 mm Hg

• Greater osmolarity than Plasma
• > 295 mOsm/L

• Lower osmolarity than plasma
• < 275 mOsm/L

275-295 mOsm/L = normal plasma

an excess of isotonic fluid volume in the Extra Cellular Fluid (ECF)

Loss of equal portions of water and solutes (isotonic) in the Extra Cellular Fluid (ECF)

Passage of a solvent through a semi-permeable membrane from low to high concentration until equilibrium is established

• TRANSPORT:
• nutrients to cells, waste from cells, substances such as hormones, enzymes, WBC & RBC
• Cellular METABOLISM/CHEMICAL reactions
• SOLVENT for electrolytes & non electrolytes
• Maintain nromal BODY TEMP
• facilitate DIGESTION
• ELIMINATION
• TISSUE LUBRICANT

• + muscle = + water
• + fat = - water

• infants have highest water by % (60 =/-)
• Men more than women
• adults more than elderly

Body is 50-60% water, of that 25 liters

• ICF - intracellular fluid 40%
• ECF - extracellular fluid 20%
• intravascular (Plasma), interstitial (surrounding
• cells and in lymph)
• Trancellular - 3rd space - cerebrospinal, pericardal,
• synovial, intraoccular, pleural fluids

• Large molecules unable to pass through membranes
• ALBUMIN
• GLOBULIN
• FIBRINOGIN
• Proteins that hold water creating osmotic pull/osmotic presssure that holds water in blood vessels

• Number of dissolved particles in a solution
• Normal Blood osmolality lab value = 280-300 mOsm/kg of water

Most of that is Na+ (salt)

• normal saline, 0.9% NaCl
• Ringers
• D5W (changes inside body)

used to add vascular volume BP goes up

lower than norm saline, like 0.45% NaCl

causes osmosis, increasing water in cells

• ie. 3% NaCl
• addition of 5% Dextrose to 1/2 NS/Isotonic fluid

• water is pulled from the cells
• reduces edema, lowers/stabilizes BP, regulates urine output

• IN
• ingested water 1300 ml
• ingested food 1000 ml
• metabolic oxidation + 300 ml
• 2600 ml
• OUT
• kidneys 1500 ml
• skin 600 ml
• lungs 300 ml
• gastrointestinal +200 ml
• 2600 ml

Made in Adrenal Cortex

Causes Kidneys to re-absorb Na+, and therefore water

secreted when vascular volume is low-vomiting, blood loss, etc

• too much ADH = to much water-Soggy Sue:
• SIADH

Not enuf ADH= Diabetis Insipidus (DIuresis) loosing water to fast-dehydrating

• distended neck veins
• distended peripherial veins
• slow emptying peripherial veins
• CVP over 11 cm H2O in vena cava
• moist lungs, SOB, dyspnea
• Ascites-plueral effusion (severe FVEfluid moves into
• body cavities
• Decreased Hematocrit due to plasma dillution
• Bounding full pulse elevated BP
• Pulmunary edema, if severe

• renal disease
• low blood flow to kidneys ie. cardiac insufficiency, liver
• disease
• IV fluids infusing to rapidly
• steroid therapy or Cushing's Syndrome
• stress
• Production of ADH