Calcium

Question 1

Why is calcium important?

Answer 1

• Muscle contraction
• Blood coagulation
• Activity of various enzymes
• Excitation of neutrons
• Hormones secretion

Question 2

Where does the homeostasis of Ca occur?

Answer 2

*GIT, kidneys, skeleton
*Parathyroid hormone (PTH)
:mobilises Ca from bones
:induces synthesis of calcitrol
*Vit D3
:increase GI absorption

Question 3

What does calcitrol do?

Answer 3

• 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

Question 4

What test do you have to use for Hypercalcemia

Answer 4

• PTH and PTH-rp measurements
• Lymph node biopsies
• Bone marrow evaluation

Question 5

What disease processes causes HyperCa?

Answer 5

• Acute or chronic renal failure
• Ostemyelitis
• Skeletal disorders
• Toxicities of over supplementation
• Rodenticide (Cholecalciferol)
• Toxic plants
• Hypoadrenocorticism
• Primary hyperparathyroidism
• Neoplasia
• Malignant processes
• Lymphosarcoma (most common)

Question 6

What are the clinical signs of HyperCa?

Answer 6

• 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),

Question 7

Tx for HyperCa

Answer 7

*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
*GI decontamination
*If oliguria
:peritoneal dialysis
:Hemodialysis

Question 8

HypoCa

Answer 8

*more common than HyperCa
*Serum Ca
:<8.0 mg/dL (Dogs)
:<7.0 mg/dL (Cats)

*Ionized Ca
: <1.25 (dogs
: <1.1 (Cats)
*Low albumin in serum = artificially low total Ca

Question 9

What causes Hypocalcemia?

Answer 9

CRF
Eclampsia (puerperal tetany)
ARF
Acute pancreatitis 
Tissue trauma
Rhabdomyolysis
Hypoparathyroidism (primary or secondary)
Ethylene glycol intoxication 
Phosphate enemas
Post HCO3- administration 
Hypomagnesemia
Repeated blood transfusions
Hypovitaminosis D
Sepsis / SIRs
Furosemide diuresis

Question 10

What are the clinical signs of hypoCa?

Answer 10

*Increased neuromuscular activity due to increased cell membrane excitability
*Muscle tremors and fasiculations
Hyperexcitability
Restlessness
Tetany
Seizures
Hyperthermia
Panting
Anorexia
V and D

Question 11

What are the ECG changes seen in HypoCa?

Answer 11

Prolonged QT interval

Question 12

Treatment for hypoCa

Answer 12

• Administer parenteral Ca
• Calcium gluconate or calcium chloride should be given initially IV over 10-30 mins
• last about 1-12hours
• Vit D (if primary parathydroidism)