Flashcards in Calcium Deck (12)
Why is calcium important?
*Activity of various enzymes
*Excitation of neutrons
Where does the homeostasis of Ca occur?
*GIT, kidneys, skeleton
*Parathyroid hormone (PTH)
:mobilises Ca from bones
:induces synthesis of calcitrol
:increase GI absorption
What does calcitrol do?
*acts on GIT to stimulate it to absorb Ca
*provides feedback to limit production of itself as well as PTH
*inhibits bone reabsorption and increases the amount of Ca excreted in urine
What test do you have to use for Hypercalcemia
*PTH and PTH-rp measurements
*Lymph node biopsies
*Bone marrow evaluation
What disease processes causes HyperCa?
*Acute or chronic renal failure
*Toxicities of over supplementation
-Lymphosarcoma (most common)
What are the clinical signs of HyperCa?
*Early signs: PU/PD
*Anorexia, dehydration, Cardiac arrhythmia (Ca has direct inotropic and negative chronotropic effects on cardiac muscle and can cause calcification of the cardiac muscles) , Seizures (due to depressed neurotransmitters in muscles),
Tx for HyperCa
*IVF dilutes ca levels
*Loop diuretic if patient is hydrated
*CVPs and UOP must be monitored
*Corticosteroids after diagnosis is made to inhibit bone resorption and GI absorption of Ca
*Calcitonin lowers Ca levels rapidly
*Ca channel blocker
*more common than HyperCa
:<8.0 mg/dL (Dogs)
:<7.0 mg/dL (Cats)
: <1.25 (dogs
: <1.1 (Cats)
*Low albumin in serum = artificially low total Ca
What causes Hypocalcemia?
Eclampsia (puerperal tetany)
Hypoparathyroidism (primary or secondary)
Ethylene glycol intoxication
Post HCO3- administration
Repeated blood transfusions
Sepsis / SIRs
What are the clinical signs of hypoCa?
*Increased neuromuscular activity due to increased cell membrane excitability
*Muscle tremors and fasiculations
V and D
What are the ECG changes seen in HypoCa?
Prolonged QT interval