Flashcards in Fluids-Electrolytes Deck (18):
What are the complications of hypercalcemia?
"Bones, stones, abdominal moans, psychiatric overtones."
Bones: osteoporosis, osteomalacia, fractures, osteitis fibrosis cystica
Stones: Nephrolithiasis, nephrocalcinosis and nephrogenic diabetes insipidus
Abdominal groans: nausea, vomiting, constipation
Psychiatric overtones: coma, delirium, depression, fatigue, psychosis
What is the initial treatment for hypercalcemia?
What is the treatment for hypercalcemia due to immobilization?
IV hydration + loop diuretics
What are the symptoms of hypocalcemia?
Ca level < 8.5
iCal < 4.5
Paresthesias, tetany, seizures that do not respond to benzodiazepines, laryngospasm, prolonged QT
What crystals are associated with ethylene glycol poisoning?
Calcium oxalate crystals in the urine
What symptoms are associated with hypokalemia?
Constipation, lethargy, weakness
What are the findings in SIADH?
- Excess ADH secretion -> excess water retention -> increased total body water
- Decreased urine output
- Serum hyposmolality and hyponatremia
- Concentrated urine
- Normal/high urine sodium
How is SIADH treated?
- Fluid restriction
- Demeclocycline (diuretic) or Fludrocortisone if fluid restriction is not working and sodium level is persistently less than 120
What are the two causes of diabetes insipidus?
Central diabetes insipidus
Nephrogenic diabetes insipidus
What are the features of central diabetes insipidus?
- Insufficient ADH -> constant water loss
- Hypernatremia when the patient does not have access to free water
- Polyuria and dilute urine
- Treat with DDAVP/ADH
What are the features of nephrogenic diabetes insipidus?
- X-linked recessive
- Massive urine output
- No response to DDAVP/ADH supplementation
- Tx: hydrochlorothiazide, salt restriction
What is the formula for corrected calcium?
Add 0.8 to the calcium level for every drop in albumin of 1 g/dL
How is the sodium level affected by hyperglycemia?
Sodium decreases by 1.6 for every 100 increase in glucose
How do you calculate the anion gap?
Na+ - Cl- - HCO3-
What is the adjusted anion gap for hypoalbuminemia?
(4-pt albumin) x 2.5 = x
12-x = anion gap max normal
How do you calculate the expected PCO2?
(1.5 x HCO3-) + 8 +/- 2
How do you calculate for sodium correction?
(desired Na - measured Na) x wt(kg) x 0.6 + 3 mEq/kg (for maintenance Na requirements) = amount of sodium needed in 24 hours
* Note: never correct more than 12 mEq/day