FLUID ELECTROLYTE AND ACID BASE BALANCE II Flashcards
major electrolytes
(S,P,C,M,C,P,S,B)
sodium potassium calcium magnesium chloride phosphate sulphate bicarbonate
normal plasma lvl = 135-145 mEq/L
predominant cation in the ECF
plays a crucial role in the excitability of muscles and neurons
important in regulating fluid balance
regulation at the cellular level is controlled by Na-K pump
sodium
loss of sodium from fluid loss
excessive sweating, vomiting, diuretics, renal failure (inability to concentrate and save sodium)
fresh water drowning
water moves into cell such as brain cells causing brain expansion within limited space inside the cranium
hyponatremia
renal failure
excessive salt ingestion
over administration of hypertonic IV fluids
salt water drowning
decreased fluid intake
water transfers from cell into the ECF causing cellular dehydration
hypernatremia
normal plasma level = 3.5=5.5 mEq/L
major cation in the ICF
critical for electrical conduction of nerve impulses - particularly cardiac electrical conduction
kidneys can excrete K and in exchange for Na- controlled by aldosterone
potassium
loss of K; excessive vomiting, diarrhea
acute alcoholism
medication: diuretics, laxative, insulin
hypotension, elevated pulse due to decreased cardiac output, weakness
hypokalemia
use of K supplements
receiving old/improperly administered blood
inadequate potassium excretion
cell destruction; crushing injuries and burns
diarrhea, apathy, confusion, numbness in hands and feet, acidosis
hyperkalemia
normal level: 4.0-5.5 mEq/L or 8.5 - 10mg/dl
required for normal skeletal, cardiac, and smooth muscle contraction
needed for blood clotting
intestinal absorption of dietary calcium requires vitamin D
regulated by PTH and vitamin D
calcium
failre of normal regulatory mechanisms such as acute or chronic renal failure, malabsorption syndromes. acute pancreatitis, alkalosis
low serum levels —> bones release calcium —–> osteoporosis
(+) trousseau’s sign and chvostek’s sign
seizures arrhythmia and ECG changes
hypocalcemia
disturbances in regulation, excess parathyroid hormone, excessive intake of calcium
polyuria (if kidney function is normal)
kidney stones
Homan’s sign
hypercalcemia
normal value: 1.5-2.5 mEq/L
needed to prevent overexcitability of muscles
sedative effect on neuromuscular junction, inhibits acetylcholine release, and diminishes muscle cell excitability
acts as a cofactor in enzyme reactions
magnesium
decreased GI absorption
hypoaldosteronism
high dose steroids
excessive intake of calcium, vitamin D
(+) chvostek’s and trousseau’s sign
confusion, agitation, seizures
hypomagnesemia
combination of increased intake and decreased renal function, antacids and laxatives
lethargy and drowsiness, depressed respirations, low blood pressired
hypermagnesemia
precise _______ is essential because the activities of almost all enzyme systems in the body are influenced by H+ concentration
hydrogen regulation
normal ph of blood
7.4
normal ph of venous blood
7.35
normal ph of arterial blood
7.45
a state of excess hydrogen ion
reduction in excitability especially in the brain
confusion, coma, death
acidosis
results when the blood pH is less than 7.35
acidemia
a state of excess bicarbonate (HCO3+)
overactivity, numbness, muscle spasm, convulsion as a result of excessive nervous activity in the brain
alkalosis
results when the blood pH is greater than 7.45
alkalemia
any compounds which can release hydrogen ions in solution
examples: HCl, H2CO3
proton donors
acids
a compound that ionizes completely in solution to form hydrogen ions and a base (ex. HCl)
Strong acids
compounds that are only partially ionized in solution
weak acids and bases
