Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (763 page)

Increased In

   Normal total serum calcium associated with hypoalbuminemia may indicate ionized hypercalcemia.

   About 25% of patients with hyperparathyroidism have normal total but increased ionized calcium levels.

   Acidosis

   Metastatic bone tumor

   Milk-alkali syndrome

   Multiple myeloma

   Paget disease

   Sarcoidosis

   Tumors producing a PTH-like substance

   Vitamin D intoxication

Decreased In

   Alkalosis (e.g., hyperventilation, to control increased intracranial pressure) (total serum calcium may be normal), administration of bicarbonate to control metabolic acidosis

   Increased serum free fatty acids (increased calcium binding to albumin) due to

   Certain drugs (e.g., heparin, IV lipids, epinephrine, norepinephrine, isoproterenol, alcohol)

   Severe stress (e.g., acute pancreatitis, DKA, sepsis, AMI)