Flashcards in Chapter 17 Fluids: Med Surg Deck (56)
if the cell is surrounded by hypertonic fluid:
water leaves the cell to dilute the ECF and the cell shrinks and may eventually die ICF -> ECF e.g. 3% saline
force within the fluid compartment, blood pressure generated by the contaction of the heart and pushes water out of the vascular system
osmotic pressure exerted by colloids in solution, pulls fluid from the tissue space to the vascular space
protein, which does not dissolve completely since they are too large of molecules
what two pressures move water into the capillaries?
plasma oncotic pressure and interstitial hydrostatic pressure
what two pressures move water out of the capillaries?
capillary hydrostatic pressure and interstitial oncotic pressure
normal distribution of fluid in ECF and ICF
abdnormal accumulation of interstitial fluid (edema)
fluid accumulates in a portion of the body (transcellular fluid) from which it is not easily exchanged with the rest of the ECF, not functional e.g. ascites, edema with burn, trauma
how does the hypothalamus, pituitary, and adrenal cortex respond in water regulation?
the hypothalamus recognizes a fluid deficit and increases plasma osmolality sending osmoreceptors to the posterior pituitary and releasing ADH, which acts in the distal tubules to cause water reabsorption
osmolarity changes once dextrose is metabolized
at the arterial end of the capillary:
capillary hydrostatic pressures exceeds plasma oncotic pressure, which draws fluid into interstitium (EDEMA)
at the venous end of the capillary:
capillary hydrostatic pressure is lower than plasma oncotic pressure and fluid is drawn back into the capillary
cortisol, which has an antiinflammatory effect and increases glucose levels
aldosterone, which enhances sodium retention and potassium excretion
primary organ that controls f&e balance
insensible water loss
600-900 mL lost a day, ONLY water, sweating is sensible perspiration and causes f&e loss
how do you calculate fluid requirement for a pediatric patient?
convert weight to kg, 100 mL/kg for first 10 kg, 50 mL/kg for second 10 kg, and 20 mL/kg for the remainder of weight. IF ASKED FOR IN ML/HR SIMPLY DIVIDE ANSWER BY 24
fluid volume deficit
restless, drowsy, thirst, decreased skin turgot and capilarry refill, increased pulse, decreased urine, increased respirations, weight loss
fluid volume excess
headache, edema, venous distention, bounding pulse, increased blood pressure, dyspnea, crackles, muscle spasms, weight gain
assess neurologic fx
LOC, pupillary response to light and equality of size, voluntary movement of extremities, degree of muscle strength, reflexes
assess skin turgor where?
first signs of deficit:
tachycardia, decreased blood pressure, increased respirations