CH 42 Electrolyte/ Acid base Flashcards
What fraction of total body fluid is intracellular/ extracellular fluid?
Intracellular fluid - 2/3 of body water
Extracellular fluid - 1/3 of body water
Interstitial fluids
the fluids between cells and outside the blood vessels. These include lymph (fluid in the lymphatic channels).
What are the 3 divisions of interstitial fluids?
Interstitial
Intravascular
Transcellular
Intravascular fluid
blood plasma found in the vascular system
Transcellular fluids
secreted by epithelial cells and include cerebrospinal, pleural, peritoneal, and synovial fluids
Osmolality
Osmolality of a fluid is a measure of the number of particles per kilogram of water.
Isotonic solutions
have the same osmolarity as blood, similar to normal saline (0.9% sodium chloride).
A hypertonic solution such as 3% sodium pulls fluid from or moves fluid into cells?
pulls fluid from cells, causing them to shrink.
A hypotonic solution such as 0.45% sodium chloride pulls fluid from or moves fluid into cells?
moves fluids into cells, causing them to enlarge.
nonpermeant particles
Particles that cannot cross cell membranes easily that determine the tonicity of a fluid
Filtration
Movement across a membrane, under pressure, from higher pressure to lower pressure
Diffusion
passive movement of electrolytes or other particles down the concentration gradient
Osmoreceptors
continually monitor plasma osmolality; when it increases, they cause thirst by stimulating neurons in the hypothalamus
Insensible water loss
through the skin and the lungs - not visible measurable
regulate ECF volume by influencing how much sodium AND water is excreted in urine
ADH
RAAS (Renin angiotensin aldosterone system
ANP (Atrial Natiuretic Peptide)
About what should daily fluid intake be?
2300 mL/day
What is the pH of blood?
7.35 - 7.45
Metabolic Acids
any acids besides carbonic acid - citric acid, lactic acid
True or False? People who have kidney disease often have difficulty with normal excretion of metabolic acids.
true
Respiratory alkalosis
Arises from alveolar hyperventilation
Lungs excrete too much CO2
Deficit of carbonic acid in the blood increases pH
Respiratory acidosis
Arises from alveolar hypoventilation
Lungs unable to excrete enough CO2
Excess carbonic acid in the blood decreases pH.
Metabolic alkalosis
Arises from direct increase in base (bicarbonate) or decrease in metabolic acid
Results in increased blood bicarbonate
Metabolic acidosis
Arises from increase in metabolic acid or decrease in base (bicarbonate)
Kidneys unable to excrete enough metabolic acids, which accumulate in the blood
Results in decreased level of consciousness
D5W
5% dextrose in water is hypotonic so it moves fluid into the cells out of the circulation
D5NS
5% dextrose in normal saline. Is hypertonic so it moves fluid out of the cells and into the circulation.
Why do you initiate a blood transfusion slowly and stay with the patient for the first 15 minutes?
To watch for transfusion reactions and catch them early
sodium
regulates water in and out of cell, muscle and nerve function
135-145 mEq/L
hyponatremia
Lethargy
Tendon reflexes diminished
Shallow respirations
hypernatremia
Restless, really agitated
Edema
Potassium
Watch heart
3.5-5.0 mEq/L
hypokalemia
Caused by extreme fluid loss/diuretics
flat or inverted T wave
prominent U wave
Lethal cardiac dysrhythmias
may be sign of digoxin toxicity
furosemide/ thiazide diuretics
waste potassium
P O T A S S I U M
Potatoes Oranges Tomatoes Avocados Strawberries Spinach fIsh mUshrooms Musk melons, cantaloupe
hyperkalemia
Spironolactone
K sparing diuretics
ACE inhibitors
renal failure
Decreased cardiac contractility
Tall peaked T waves
widened QRS and prolonged PR
calcium
8.6-10.5 mg/dL
hypocalcemia
low parathyroid hormone
Laryngospasm
Trousseaus signs - hand
Chvosteks signs - face
young sally’s calcium serum continues to randomly mess-up
Yogurt Sardines Cheese Spinach Collard greens Tofu Rhubarb Milk
hypercalcemia
increase risk for kidney stones
Magnesium
1.5-2.5 mg/dL
supplement with during pregnancy
hypomagnesemia
hypocalcemia
twitching
everything is hyperexcitable
seizure precautions
hypermagnesemia
lethargy
bradycardia
impaired breathing
monitor respiratory, cardiac, renal, neuro
Phosphorus
Calcium and phosphorus inversely related
2.5-4.5 mg/dL
hypophosphatemia
alcoholism
malnutrition
rhabdo
risk of bone fractures
hyperphosphatemia
main cause is renal failure
Trousseau/Chvostek signs
seizures
confusion
