6. Electrolytes Flashcards
Why is electrolytes important?
for maintaining osmotic balance, cellular and tissue pH, activation o muscle cells and neurons, conduction of electrical impulses and relating enzyme activity.
What electrolytes are present in higher conc in ICF
K - for nerse signaling
Mg - normal nerve + muscle func
Phosphate - for ATP + DNA prod
What electrolytes are present at higher conc in ECF
Na - major electrolyte for maintaining osmolarity
Ca - muscle contraction, nerve activation
cl - works with an to maintain osmotic balance
Bicarb - maintains acid-base balance
How are electrolytes gained and lost?
Gained by diet
lossed by sweat, urine, feces, V/D
What is hypokalemia?
Low K levels
normally higher lvls inside cell, but hypokalemia, Intracellular lvls drop so the gradient is decreased
Affects ability of muscle cells to depolarize
symptoms include fatigue, muscle weakness, muscle damage
What are the causes of hypokalemia?
anorexia, GI disease, loss in urine, iatrogenic due to chronic use of furosemide
How do you treat hypokalemia?
Oral supplement
supplement by IV fluds
What is hyperkalemia?
high K lvls or increase in the ratio of K to Na
In normal situation, K ions flow out of cell to reset the muscle
excess K ions in EC compartment = loss of ion cradient so muscles can’t reset. Extends time btw contractions
heart muscle most affected, dec rate of contraction
what are some causes of hyperkalemia?
renal disease, urethral obstruction, hypoadrenocortism
Equine hyperkalemia periodic paralysis disease
iatrogenic
What are the symptoms of Hyperkalemia? How do you treat it
dec or irreg HR -> dec BP
muscle weakness, tired, lethargy
Tx by fluid therapy to support BP and restore electrolyte balance. Emergency drugs to inc K uptake into cell
What is hyponatremia? What are the causes of it
low Na lvls, in normal enviro, Na lvls are higher in EC space. Na conc is main factor for maintaining osmolarity of ECF. Loss of Na causes dec osmolarity and water will shift INTO cells -> swells
Causes by acute GI disease, renal disease, uroperitoneum, overhydration w/ water
low Na lvls also result in inc in K lvls - muscle weakness
What is Hypernatremia? What is the pathphysiology?
High Na lvls,
Stage 1: normal to high salt diet - dec h20 - Na distributes thru ECF - Na shifts o IC space bc equilibrium
Stage 2: ingestion of h20 - water fro EC to IC due to high Na conc inside cells - swelling cells
Stage 3: cerebral edema + compression
What are clinical signs of hypernatremia? How can we treat and prevent this?
neurological - central blindness, lack of proper responses, lethargy - circling-twitching-seizures
tx by very slow re-intro of h20 (for Na to equalize)
Prevention by appropriatWe mixing of diets, water access
What is hypophosphatemia?
low phosphate lvls
req for ATP prod. when lvls low, lack of ATP - weakness
Common in refeeding injury - Starvation byt too quick food
Tx w/ increased dietary intake
What is Hypocalcemia?
low ca lvls, haf of ca in blood bound to albumin, other half free Ca; hypocalcemia is dec in free Ca lvls
IC ca ions released during muscle contr. imp for StRENGTH of muscle conc
Ca entering neurons responsible for resting
lack of Ca results in dec muscle conc
What are some causes of hypocalcemia?
Parathyroid disease - dec PTH inc Ca lvls in blood
lack of dietary intake
Vitamin D deficiency - req to absord Ca in intestines
Lack of sunlight
Inc demand for Ca - late gestation pregnancy/ heavy lactation
Describe Chronic hypocalcemia
usually due to lack of Ca and/or Vita D in diet
body has time to adjust. Releases PTH which causes release of Ca from bone
leads to osteoporosis
seldom ife threatening
What is acute hypocalcemia?
body cannot adjust fast enough )no time to release extra Ca from bone stores)
low Ca in ECF causes neurons + muscle cells to depolarize faster
Heart muscles cannot contract efficiently
Clinical signs - CAT
rapidly fatal from cardiac failure
emergency
What is Hypercalcemia?
high extracellular free Ca
pathophysiology - acute hypercalcemia causes sudden muscle contr
prolongs rest period in neurons - neurons cannot be reactivated
results in sudden spurt of muscle contr (tetany, tachycardia) - weakness/collapse
if slow inc in calcium, will see calcification of kidneys and other tissues
Common in dogs, cats
What are some causes of hypercalcemia?
idiopathic
hyperparathyroidism - PTH inc Ca absorption from diet and releases Ca stores from bone
Hypercalcemia of Malignancy - certain cancers prod extra PTH
Vita D toxicity - Vita D inc absorption
Chronic kidney disease
hyperadrenocorticism
iatrogenic hypercalcemia - administration of Ca-gluconate by IV
