CALCIUM, MAGNESIUM, PHOSPHORUSSANGIL LEE, MD, MSRESIDENT LECTURE 12/1/2016

DISCLOSURE

• None

OBJECTIVES

• 1. Understand the mechanism of Ca/Mg/PO4 associated pathology• 2. List differentials and propose diagnostic workup• 3. Propose therapeutic intervention

HERE ARE SOME QUESTIONS

• Q1. You should use Calcium Gluconate/Calcium Chloride for emergent calcium supplementation.

• Q2. Name three medications you can use for hypercalcemia.• Q3. Name electolyte treatment for Torsades De Pointes. And also,

indicate the dosage.• Q4. Indicate the level of Magnesium when DTR diminishes• Q5. What are the signs and symptoms of low phosphorus?

CALCIUM

• Regulation by GUT, BONE, Kidneys • Parathyroid hormone, Calcitonin, Vitamine D

CALCIUM

• Normal range 8.5 to 10.5 mg/dl • Ionized fraction if physiologically active (>2.0meq/l)

CALCIUM

• Hypocalcemia (Serum Ca <8.5mg/dl, i-Ca<2.0meq/L)• Causes: Systemic illness, Vitamin D and Drugs

Shock, Sepsis, Renal failure, Pancreatitis and low albumin

Vitamin D: Hypoparathyroidism, Hyperphosphatemia,

Malignancy

Drugs: Phosphates, Dilantin,

Phenobarbital, Cisplatin, Heparin,

Loop diuretics, Glucocorticoids,

Magnesium, Sulfate

SIGNS AND SYMPTOMS OF HYPOCALCEMIA

Neurological: Circumoral and Digital paresthesias, Tetany, Chvostek sign, Trousseau sign, Confusion, Hallucination, Seizures

MSK: Spasms, Weakness, Osteodystrophy, Rickets, Osteomalacia

CV: Heart failure, Prolongeal QT

Video for Chvostek and Trousseau signs

TREATMENT FOR HYPOCALCEMIA

• Symptomatic or severe• 10% Calcium Gluconate, 10-30ml• 10% Calcium Chloride IV, 10ml

Chloride=CODE

HYPERCALCEMIA

• Total Ca >10.5 mg/dl• i Ca>2.7 meq/L

DrugsEndocrinopa

thyMalignancy

HYPERCALCEMIA- SIGNS AND SYMPTOMSSTONES, BONES, MOANS, AND GROANS

Am Fam Physician. 2003 May 1;67(9):1959-1966.

HYPERCALCEMIA -RX

• IVF to restore euvolemia- hours• Lasix 40mg-100mg IV Q2-4hr- hours• Decrease bone/GI absorption (Calcitonin, Corticosteroid, Bisphosphate)-

days

MAGNESIUM

• Intracellular Cation• Range 1.5meq/L-2.5meq/L• Tends to correlate with K and Ca

HYPOMAGNESEMIA

Redistribution of lytes (DKA Rx)

Decreased intake(ETOH, malnutrition)

Extrarenal loss (diarrhea, burn, sepsis)Renal loss (Drugs, SIADH, Hyperthyroidism, Hyperparathyroidism

MAGNESIUM- HYPOMGNESEMIA

MAGNESIUM- HYPOMAGNESEMIA

Treatment???

1. Remove offending agent2. Add K3. Cardioversion4. Isopretelenol5. Atropin and Pacing6. Magnesium – 1-2GM IV

HYPERMAGNESEMIA- MG >2.5MEQ/L

Renal failure

Increased Mg load

Increased renal absorption

HYPERMAGNESEMIA- SIGNS AND SYMPTOMS

Nausea >2.0meq/L

Somnolence >3.0meq/L

Decreased/absent DTRs >4.0meq/L

ECG abnormality >5.0meq/L

Apnea >8meq/L

HYPERMAGNESEMIA- RX

• Dilution w IVF• Lasix 40-80mg IV• Calcium (antagonist for neuromuscular and cardiovascular effect)• HD

PHOSPHORUS

• Intracellular anion• 2.5 to 4.5 mg/dl

PHOSPHORUS-LOW PHOS

• Sx at PO4 < 1.0mg/dl• Weakness• Paresthesia• Decreased DTR• Confusion• Anorexia• Rx: 2.5mg/kg IV over 6hrs

Decreased oral intake

Excessive loss

Shift from ECF-ICF

Endocrine (Parathyroidism, DKA,

AKA)

PHOSPHORUS-HIGH PHOS

• Sx at PO4 > 2.5mg/dl• Sx of renal failure• Sx of low Mg, low Ca• Rx: Rx underlying cause• Rx: Dilute with IVF• Rx Acetazolamide• Rx Aluminium Carbonate/Hydroxide

Decreased excretion

Shift from ICF-ECF

Increased intake

Endocrine (Hypoparathyroidis

m)

SUMMARY

• Q1. You should use Calcium Gluconate/Calcium Chloride for emergent calcium supplementation.

• Q2. Name three medications you can use for hypercalcemia. • Q3. Name electolyte treatment for Torsades De Pointes. • Q4. Indicate the level of Magnesium when DTR diminishes • Q5. What are the signs and symptoms of low phosphorus?

SUMMARY

• Q1. You should use Calcium Gluconate/Calcium Chloride for emergent calcium supplementation. A: Calcium Chloride

• Q2. Name three medications you can use for hypercalcemia. A: Lasix, Calcitonin, Dexamethasone

• Q3. Name electrolyte treatment for Torsades De Pointes. A: MgSO4, 1-2GM IV

• Q4. Indicate the level of Magnesium when DTR diminishes A: 4.0meq/L• Q5. What are the signs and symptoms of low phosphorus? A: Weakness

THANK YOU!

• Questions?