F&E (Exam 3) Flashcards
How much of body weight is water?
-50-60%
Fluid Compartments:
-Intracellular = 70%
-Extracellular = 30%
Extracellular space areas
-Interstitial fluid - between cells
-Intravascular fluid - plasma (liquid part of the blood)
4 Processes that facilitate the movement of fluid and electrolytes
-Diffusion
-Facilitated Diffusion
-Active Transport
-Osmosis
Osmosis
-Movement of water down a concentration gradient
-Water movement from low to high solute concentation
-From a region of low solute concentration to one of high solute concentration across a semipermeable membrane
(Maintain homostasis)
When does osmosis stop
-When concentration differences disappear or when hydrostatic pressure builds and opposes further movement
Diffusion
-Movement of molecules from an area of high concentration to a lower concentration
-Movement stops when the concentration is equal in both areas
Fluid and Electrolyte Balance
-Water follows electrolytes
What electrolytes are primarily outside of the cell?
Sodium and Chloride
What electrolytes are primarily inside the cell
-Potassium, magnesium, phosphate
Osmosis is
The movement of water across the cell membrane toward the more concentrated solutes
Osmotic pressure is
The amount of pressure needed to prevent the movement of water across a cell membrane
Colloids
-Substances that increase colloid osmotic pressure (oncotic pressure)
What do colloids do?
-Move fluid from interstitial compartment to plasma compartment
3 Primary colloids:
-Albumin
-Globulin
-Fibrinogen
How do we measure colloids?
Total Protein level
Colloid oncotic pressure __________ with age and overall __________
Decreases and Malnutrition
Hydrostatic Pressure
-Force of fluid in compartment pushing against a cell membrane or vessel wall
-Generated by blood pressure
-At capillary level, major force that pushes water out of the vascular system into interstitial space
Changes in hydrostatic presssure equates to
Changes in blood pressure
Oncotic Pressures
-Also called osmotic pressure
-Caused by plasma colloids (large molecules) in solution
Plasma has LOTS of colloids, interstitial space has little
-Plasma proteins attract water, pulling fluid from tissue space into vascular space
Hydrostatic pressure is dictated by?
Blood pressure
Oncotic pressure is dictated by
colloids
Watch the video in the power points
What do electrolytes influence?
-Fluid balance, acid base balance, never impulses, muscle contraction, heart rhythm, and many other cell functions
Because electrolytes function ______________, changes in one electrolyte can affect the ____________ of other electrolytes
collaboratively
balance
What are electrolytes?
-Substances that are electrically charged when in a solution
Concentrations of electrolytes depend on
-Electrolyte intake
-Electrolyte absorption (small intestines)
- Electrolyte distribution (Postive vs negative charges)
-Electrolyte excretion (kidney function)
Intracellular electrolytes
-Potassium
-Magnesium
-Phosphorous
Extracellular electrolytes
-Sodium
-Calcium
Positively charge electrolytes
-Cations
-Potassium, Sodium, Magnesium, Calcium
Negatively charge electrolytes
-Anions
-Phosphorus, chloride, bicarbonate
Sodium Imbalances
- <136 = Hyponatremia
- > 145 = Hypernatremia
Key point with sodium
-Primary driver of fluid balance. (water follows sodium)
Sodium
Main ECF cation
Governs osmolality
influences water distribution
Activates muscle and nerve cells
interstitial and intravascular spaces
Hyponatremia: Causes
GI losses: Diarrhea, vomiting, fistulas, NG suction
Renal losses: Diuretics, adrenal insufficiency
Skin losses: Burns, wound damage
Fasting diest, polydipsia
-Excess hypotonic fluid
Sodium is high associated with symptoms related to what?
Our brain
Hyponatremia: Signs and Symptoms
-Confusion and Altered LOC (not enough sodium in cells cause water in go into cells and cause the cells to swell)
-Anorexia and muscle weakness
-Seizures and coma
(Cellular swelling)
Dilution Hyponatremia
-Taking in to much water
-Hypervolemia
- Increase BP
-Increase weight gain
-Bounding rapid pulse
-Increase urine Sp. gravity
Depletional hyponatremia
-Hypovolemia
-Decrease BP and Tach pulse
-Weight loss
- Decrease urine sp. gravity
Hyponatremia
Too much fluid volume (Dilutional)
or
Too little sodium (Depletional)
Hyponatremia Treatment
-Sodium Replacement (SLOWLY)
-PO/IV
-IV normal saline (Depletional)
-Fluid Restriction (Dilutional)
-Treat underlying problem
What happens if we treat hyponatremia too quickly
-Irreversible neurological or brain damage
-Osmotic demylenation syndrome
Dilutional Hyponatremia Treatment
-Restrict fluid causing fluid levels in the body to decrease and sodium concentation will be corrected
Depletional Hyponatremia
IV normal saline
Sodium Bicrobonate
-Used for long term hyponatremia (Acid base issues)
Sodium Bicarbonate: MOA
Dissociates to provide bicrabonate ion which neutralizes ion concentration and raises blood and urinary pH
Sodium Bicarbonate: Indication
Metabolic acidosis
Sodium Bicarbonate: Adverse effects
-Edema, cerebral hemorrhage, hypernatremia, lots of electrolyte abnormalities, metabolic alkalosis, flatulence with PO, tetany, pulmonary edema, heart failure exacerbation
Sodium Bicarbonate: Nursing consideration
-Monitor cardiac , ABG’s and electrolytes
-If IV, monitor patency thoroughly
-Lots of drug interaction if the drug mixing with is diluted with sodium solutions
-PO-give 1-3 after or before meals
Sodium Bicarbonate at high concentations
Is a vesicant
-Can cause tissue damage
-Give via central lines and things to help decrease vesicant
Hypernatremia Causes
-IV fluids, tube feeds, near drowning in salt water
-Not enough water intake or to much water loss (Cognitively impaired, diarrhea, high fever, heat stroke)
Hypernatremia: Signs and Symptoms
-Alter LOC/Confusion, seizure, coma
-Extreme thirst (hyperosmolatity)
-Dry sticky mucous membranes
(Water shifting out of cells into extracellular space) (Shrinking brain cells)
Hypernatremia: Treatment
-If H2O is cause then add water
-If sodium excess is cause remove sodium
Gradually achieve normal sodium level over a 48 hour period to avoid edema of cerebral cells
-Too quick removal can damage brain cells and be lethal
-Physicians order: Infuse NSS @ 50cc/hr x 2hr then @ 75 cc/hr x 4h, then 100cc/hr
