Fluid and Electrolyte Balance Flashcards
What is the role of the kidney in homeostasis?
Regulates: ECF volume
- normal electrolyte levels
- pH of ECF (retention of H+)
- excretes metabolic waste
What are manifestations of third spacing?
- low urine output with adequate fluid intake
- fluid shifts out of intravascular space
- kidneys receive less blood –> compensate –>less urine production
- increased HR (comp)
- Decreased BP (from fluid)
- edema
- increase body weight
- I & O imbalance
What are factors of movement of fluid?
hydrostatic pressure: pressure on walls of blood vessels
Osmotic pressure: pressure exerted by proteins in plasma
What is the process of osmosis?
movement from area of low solute concentration to high solute
(high fluid concentration to low fluid concentration)
What is process of diffusion?
are of high solute concentration to low solute concentration
what is role of baroreceptors in F&E balance?
detect change in circulating blood volume and blood pressure
What is role of the renin-angiotensis-aldosterone system in F&E balance?
volume regulator releases when: -serum potassium increases -sodium decreases -ACTH increases
what controls thirst?
hypothalamus –> antiduretic hormone released
What lab test reflects concentration of sodium
Osmolality is most reliable indicator of urine concentration:
Serum osmolality: 270 to 300
What lab value measures kidneys ability to excrete or conserve water?
*reflection of kidney function
Urine specific gravity: 1.010 to 1.025
(compared to distilled water)
inversely related to urine volume:
high volume = low specific gravity
What is BUN?
end product of protein metabolism by liver
normal 10-20 mg/dL
Increased BUN = decreased renal function, GI bleed, dehyration, fever, increased protein uptake
decreased BUN: end stage liver diases, low-protein diet, expanded fluid volume
What is the end product of muscle metabolsim that indicated renal function?
Creatinine:
normal 0.7 to 1.4
increases with renal dysfunction
Hematocrit:
% of RBS in whole blood
Male: 42-52%
Females 35-47%
increase Hct: dehydration & polycythemia
decrease Hct: overydration or anemia
what gerontologic considerations are made with F&E balance?
have reduced homeostatic mechanisms (cardiac, renal and respiratory function)
Renal fxn declines with age –> high serum creatinine
Lungs: impaired pH regulation
Hypovolemia:
Causes
S/S
Causes: vomiting, diarrhea, GI suction, sweating, decreased intake, 3rd spacing, DI, adrenal insufficiency, hemorrhage, coma
S/S: acute weight loss, poor skin turgor, oliguria, concentrated urine, low BP, flat neck veins, dizzy, weak, thirty, confusion, increase pulse, muscle cramps, inc temp, cool clammy pale
