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29 Cards in this Set
- Front
- Back
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Calcium Stats
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1kg in an adult
99% in bone 1% in ECF and soft tissue 40% protein bound (mostly albumin) 10% complexed (citrate, phosphate) 50% ionized (tightly regulated) |
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Increase serum Ca++ by ____ mmol/L for every ___g/L below ___g/L of serum albumin
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0.2
10 40 |
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Parathyroid hormone, gland, feedback loop
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PTH -N terminal active
Parathyroid glands feedback loop with serum Ca++ levels |
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Actions of PTH (3)
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Stimulates osteoclast activity leading to release of Ca++ and Phosphate
Stimulates resorption of Ca++ and elimination of PO4 in tubules of kidney Stimulates renal 1alpha hydroxylase leading to activation of Vit D3 and thus increased intestinal absorption of calcium and phosphate |
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Vitamin D3 Name, Activation
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Cholecalciferol
D3 - liver- 25(OH)D3 - kidney - 1, 25(OH)2D3 |
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Vitamin D actions
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Stimulates Ca++ absorption in intestine
Stimulates Ca++ and PO4 resorption from bones Increases Ca++ resorption from distal renal tubule |
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Calcitonin
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Secreted by parafollicular cells of the thyroid gland
Not necessary for normal calcium metabolism Inhibits osteoclasts therefore downregulates Ca and PO4 Increases urinary Calcium secretion therefore downregulates Ca |
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4 mechanisms of high serum Ca
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Inreased osteoclast activity
Increased renal secretion Increased intestinal absorption Impaired bone mineralization by osteoblasts |
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Neurologic symptoms of hypercalcemia (5)
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Fatigue
Decreased concentration Depression muscle weakness Coma |
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GI symptoms of hypercalcemia (6)
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anorexia
nausea vomiting abdominal pain constipation pancreatitis |
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Renal symptoms of hypercalcemia (3)
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Polyuria (Ca inhibits the action of ADH)
Nephrolithiasis Nephrocalcinosis |
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CVS symptoms of hypercalcemia (3)
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Short QT
Bradycardia First degree AV block |
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Differential for hypercalcemia (7)
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90% primary hyperparathyroidism or
Malignant ectopic production of PTH or active Vit D Hyperthyroidism Sarcoidosis Renal failure Genetic Drugs |
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Drugs that can cause hypercalcemia (3)
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Thiazide diuretics
Lithium Vit D intoxication |
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Primary Hyperparathyroidism, Cause (3)
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Autonomously functioning parathyroid
80% solitary adenoma 20% Four gland hyperplasia (MEN 1 or 2) < 1% carcinoma |
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Secondary Hyperparathyroidism, Cause (2)
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High PTH compensating for low Ca due to:
Renal failure Severe Vit D deficiency |
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Tertiary Hyperparathyroidism
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Following Secondary disease, the Parathyroid gland does not respond to regulation --> hypercalcemia
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Lab results for hyperparathyroidism (6)
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Hypercalcemia
Hypophosphatemia Elevated PTH ** Elevated active Vit D Mild hyperchloremia and acidosis High urinary cAMP (old) |
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Hyperparathyroidism Localization (3)
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Surgery is the best
Sesta MIBI parathyroid scan U/S |
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Management of hyperparathyroidism (7)
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Surgery
Hydration Ambulation Avoid thiazide diuretics Bisphosphonates Calcimimmetic No need to avoid dietary calcium |
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Sign of malignancy in hypercalcemia
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Low PTH
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Treatment of Hypercalcemia (5)
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Tumor ablation
Diuresis + Rehydration Increase urinary Ca loss Decrease intestinal Ca absorption Inhibit Osteoclasts |
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Agents which increase Urinary Ca loss (4)
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Saline
Lasix Calcitonin Dialysis |
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Agents which decrease intestinal Ca absorption (2)
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glucocorticoids
phosphate |
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Agents which inhibit Osteoclasts (2)
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Calcitonin
bisphosphonates |
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Hypocalcemia symptoms (8)
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Parasthesia
Muscle cramps Tetany Laryngiospasm/bronchospasm Seizures Prolonged QT Cataracts Soft tissue calcification |
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PTH causes of hypocalcemia (6)
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Surgical
Idiopathic Hypomagnesemia diGeorge syndrom hemochromotosis pseudohypoparathyroidism (PTH Resistance - high PTH) |
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Vit D causes of hypocalcemia (7)
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Insufficient D3 synthesis in the skin
Intestinal malabsorption of Vit D Hepatic dysfunction Nephrotic syndrome disorder in conversion to 1,25(OH)2D3 Vit D dependent Rickets X linked hypophosphatemic rickets |
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Treatment of Hypocalcemia (3)
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ABCs (Airway management, Ecg monitoring)
IV or oral calcium Active or oral D2/D3 |
