Exam 2 Flashcards
Intracellular fluid
Within cells
70% of water total body water (TBW)
Extracellular fluid
Outside of cells
30% of TBW
Intravascular
Liquid component in blood
Interstitial
Fluid that surrounds tissue cells and includes lymph
Transcellular
Cerebrospinal, pericardial, synovial, intraocular, pleural
Variations of fluid in body
- Age
-Infants have more total body fluid and ECF
-Older people:
+Decreasing percentage of
body fluid bc of increase in fat
cells
+Lose muscle mass
+Reduced total body water - Sex
- Women = more fat => less body fluid
- Amount of fat cells in body
- Little water compared to lean tissue
Fluid Volume Deficit (FVD) definition
Loss of water and solutes of same proportion in ECF
Hypovolemia
Interstitial fluid is moved into intravascular space
Cellular fluid drawn into interstitial space
Cells without adequate water
Causes of FVD
Loss of body fluids
Decreased intake
Third space fluid shift Definition
Distributional shift of body fluids into transcellular compartments, joint cavities, bowel, or excess accumulation in interstitial space
Fluid moves out of intravascular space into these spaces
Deficit in ECF volume
Fluid NOT lost but trapped
So, no body weight loss so immeasurable
Causes of third space fluid shift
Disrupted colloid osmotic pressure, increase fluid volume (renal failure, excess IV), increased capillary hydrostatic pressure (heart failure), hyponatremia, increased in capillary membrane permeability (gross tissue trauma), severe burn, bowel obstruction, surgical procedures, pancreatitis, ascites, sepsis
Fluid Volume Excess (FVE) Definition
Excessive fluid retention of water and sodium in ECF in near equal proportions
Causes of FVE
Malfunction of kidneys
Failure of heart to work as pump
Effects of FVE
Fluid pulled from cells to equalize tonicity
By time ECF and ICF are equal, excess of water and sodium is in ECF, so cells are depleted
Accumulates in either intravascular compartments (Hypervolemia) or interstitial space (edema)
Edema is graded based on pit
Normal levels of Sodium
135-145 meq/L
Hyponatremia
Definition
Sodium deficit in ECF
Loss of sodium or gain of water
Hyponatremia causes
Vomiting, diarrhea, fistulas, sweating, diuretics
Fluid moves from ECF to ICF bc it is less concentrated
Hyponatremia Signs
Swelling cells
Confusion, hypotension, edema, muscle cramps, weakness, dry skin
Severe
Increasing intracranial pressure
Lethargy, muscle twitching, focal weakness, hemiparesis, seizures, death
Hypernatremia definition
Surplus of sodium in ECF
Excess water loss or excess sodium intake
Hypernatremia Causes
Fluid deprivation, lack of fluid consumption (diarrhea, unable to feel thirst, hyperventilation, burns)
Fluid moves from cells
CNS symptoms of Hyperatremia
Restlessness, weakness, disorientation, delusion, hallucinations
Potassium
Normal levels
3.5-5.0 meq/L
Hypokalemia Definition
Potassium deficit in ECF
Hypokalemia causes
Vomiting, gastric suction, alkalosis, diarrhea
ECF K+ lost
K+ moves from cells to ECF
Intracellular K+ deficit
Sodium and hydrogen retained by cells to maintain isotonic fluids
Skeletal muscles first demonstrate deficiency
Hypokalemia signs
Muscle weakness, leg cramps, fatigue, paresthesias, dysrhythmias
Hyperkalemia definition
Excess of K+ in ECF
Hyperkalemia Causes
Renal failure, hypoaldosteronism, medications
More dangerous than hypokalemia