Test 3: 31 fluids Flashcards
what is the 60-40-20 rule
60% of body weight is water
40% of body water is intracellular fluids
20% of body water in outside cells: extracellular fluid
the number of —- in each space determines the volume of fluid in the ICF and ECF
osmotically active particles
osmolality
number of osmoles per kg of solvent
osmolarity refers to the number of osmoles per liter of solution
osmotic effect is dependent only on the number of particles in solution not their chemical formula, weight, size or valence
in serum what effects osmolality
sodium, potassium, Cl, bicarb, urea, glucose and others
movement of water between ICF and ECF is controlled by
osmolality/osmosis
movenet of water across semi-permeable membrane from area of lower to higher osmotic pressure
fluid movement between IVF and ISF is controlled by
starling forces: fluid movement across capillary wall determined by imblance between osmotic absorption pressure created by plasma proteins (colloid osmotic pressure COP) and capillary hydrostatic pressure
hydrostatic pressure pushes water out, colloid osmostic pressure pulls water back in
clinical signs of interstitial dehydration 0-5%
not detectable
clinical signs of interstitial dehydration 5-6%
subtle loss of skin turgor
clinical signs of interstitial dehydration 6-8%
definite loss of skin turgor, prolonged CRT, dry mucus membranes, eye sunken in orbit
clinical signs of interstitial dehydration 8-10%
considerable loss of skin turgor, prolonged CRT, dry mm, eyes sunken in orbit. weak pulse possible
clinical signs of interstitial dehydration >10%
dead at 12
complete loss of skin turgor, marked prolonged CRT, eyes severely sunken in orbits, very dry mm, weak thready pulse, changed consciousness
why give IV fluids during anesthesia
- replace sensible losses: blood and tissue fluid losses, urine
- replace non measurable losses: fluid lost through evaporation from respiratory system and/or exposed body cavities
- maintain a patent IV
- manage CV alterations induced by anesthesia (vasodilation, decreased SV)
- treat dehydration, electrolyte and/or acid base disorders
- be prepared for emergencies
why use isotonic crystalloids
does not cause shift to or from ICF unless previous free water loss occurred from the ICF compartment
used for resuscitation, peri-op under general
hypertonic saline is what % Na
5 or 7%
hypertonic saline will do what
5-7% Na
will cause fluid to be pulled into the vessels→ increased preload, HR, contractility, decreased SVR → increased CO
will also cause decreased neutrophil interaction with endothelial cells, reduced neutrophilic activation and improved activity of lymphocytes and NK cells
will tell kidney to produce ADH to conserve water
