CH. 8 Disorders of Fluid and Electrolytes Flashcards
Functions of body fluids
transport gases, nutrients and wastes, helps generate the electrical activity needed to power body functions, take part in the transformation of food into energy, maintain the overall function of the body.
ICF
consists of fluid contained within all the billions of cells in the body larger of the two comparments. 2/3 of body water in healthy adults high concentration of K. n almost no Ca, moderate amount of mg
ECF
contains the rest of the body water. all the fluids outside the cells, including that in the interstitial or tissues spaces and blood vessels. h
high concentration of Na.
large amounts of na and chloride
moderate amounts of bicarbonate.
small quantities of k, mg, ca, and phosphate
ECF is broken into
instertitial fluid compartment (between veins and capillaries), plasma (noncellular portion), transcellular compartment (CSF and joint fluids)
Third spacing
fluid in the transceullar section, it just accumulates
Diffusion
movement of charged or uncharged along a gradient, to lower
Osmosis
water movement from high water concentration to low water concentration. selectively permeable membrane.
Tonicity
the tension or effect that the effective osmotic pressure of a solution with impermeable solutes exerts on cell size because of water movement across the cell membrane
Isotonic
neither shrink nor swell
Hypotonic
swell. increase in the water. water into the cell.
Hypertonic
shrink. increase in the solute. water out of the cell
Edema
accumulation of fluid in extracellular space
pitting, non-pitting
Brawny
Brawny Edema:
edema seen related to other disease process. lipid disorder, thyroid.
Edema Formation
increase the capillary filtration pressure, decrease the capillary colloidal osmotic pressure, increase capillary permeability, produce obstruction to lymph flow.
Methods of Assessing Edema
daily weight, visual assessment, measurement of the affected part, application of finger pressure for pitting edema.
Water and Na balance
baroreceptors regulate effective volume. modulating sympathetic nerous system outflow and ADH secretion.
RAAS: angiotensin 2 and aldosterone
Gain: water, oral intake and metabolism of nutrients, na
Loss: kidneys, skin, lungs, GI
Assessment of body fluid loss
history of conditions that predispose to sodium and water losses, weight loss, and observations of altered physiologic function indicative of decreased fluid volume.
HR, BP, venous volume, /filling, capillary refill rate.
Regulators of sodium
kidney. Sympathetic nervous system.
monitors arterial pressure, retains sodium when arterial pressure is decreased, and eliminates it when arterial pressure is increased, the rate is coordinated by the sympathetic and RAAS.
Physiologic mechs for regulating water
thirst (hypothalamus), and ADH (water output)
respond to changes in EC osmolality and volume
Polydipsia: symptomatic thirst
with a loss of body water and resolves with replacement. associated with diarrhea, vomiting, diabetes, sweat
Polydipsia: inappropriate or excessive thirst
thirst may persist despite adequate hydration. common complaint in people with CHF, diabetes mellitus, and CKD.
can also be seen with people on corticosteroids.
Psychogenic Polydipsia
compulsive water drinking, psychiatric disorders, schizophrenia, drinking large amounts of water and excrete large amounts of urine (water intoxication), and antipsychotic medications increase ADH levels
Diabetes insipidus
def of or a dec response to ADH. pt unable to concentrate urine during periods of water restriction and excrete large volumes of urine. neurogenic or central diabetes insipidus: occurs because of a defect in the synthesis or release of ADH Nephrogenic: occurs because the kidneys do not respond to ADH.
SIADH
failure of the negative feedback system that regulates the release and inhibition of ADH.
Causes of fluid volume excess
inadequate sodium and water elimination, excessive sodium intake in relation to output.
excessive fluid intake in relation to output.
