Phosphate

Info

🌱 來自: Huppert’s Notes

Phosphate🚧 施工中

Phosphate

Phosphate regulation (PO4– 3.0–4.5 mg/dL)

•   Distribution: Most phosphorus is in the bones (85%), remainder is in the soft tissues (15%)

•   Phosphate absorption: Vitamin D controls phosphate absorption in the GI tract

•   Phosphate excretion: PTH inhibits phosphate absorption in the kidney, thus promoting excretion in the urine

Hypophosphatemia (PO4– <3.0 mg/dL)

•   Etiology:

-   Decreased intestinal absorption: Alcohol use, vitamin D deficiency, malabsorption, excessive antacid use, TPN

-   Increased renal excretion: Excess PTH, hyperglycemia, ATN, hypokalemia, hypomagnesemia, Fanconi’s syndrome

-   Other: Refeeding syndrome, respiratory alkalosis, steroids, DKA, hungry bone syndrome

•   Clinical features:

-   Mild: Patients are usually asymptomatic

-   Severe: Can affect many organ systems: Neurologic (confusion, numbness), MSK (weakness, osteomalacia), heme (hemolysis), cardiac (cardiomyopathy, myocardial depression), rhabdomyolysis, anorexia

•   Diagnosis: Low serum phosphate. Also check Cr. Consider checking PTH, vitamin D.

•   Treatment:

-   Mild: Oral supplementation (milk, Neutra-Phos, K-Phos)

-   Severe: IV sodium phosphate or potassium phosphate

Hyperphosphatemia (PO4– >4.5 mg/dL)

•   Etiology:

-   Decreased renal excretion because of renal insufficiency (most common), bisphosphonates, hypoparathyroidism, vitamin D toxicity, tumor calcinosis

-   Increased phosphate supplementation

-   Rhabdomyolysis, cell lysis, acidosis

•   Clinical features: Metastatic soft tissue calcification, hypocalcemia

•   Diagnosis: High serum phosphate. Also check Cr. Consider checking PTH, vitamin D.

•   Treatment:

-   Phosphate binders (bind phosphate in the bowel and prevent absorption)

-   Hemodialysis if the patient is in renal failure or becoming severely hypocalcemic