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