Hypercalcemia A diagnostic and treatment approach UCI Internal Medicine – Mini Lecture

Objectives Understand the most common etiologies Have a clear diagnostic plan Understand acute management

Initial evaluation A 68 year-old female with no PMH or home meds is brought to the ER by family with altered mental status, nausea, and diffuse bony pain.

Initial Evaluation VS unremarkable. A&Ox1, tries to get out of bed and is distracted. Rest of exam is normal Diff wnl Corrected Calcium = (0.8 * (Normal Albumin - Pt's Albumin)) + Serum Ca

Calcium reminders: Absorbed through small intestine via a vitamin-D dependent pump Excreted by the kidney PTH: production of active Vitamin D, renal reabsorption and osteoclast activity

Diagnostic Approach PTH-mediated? PTHrp? Excess vitamin D? Something else? (eg: genetic, MM)

Diagnostic Approach ✓ PTH ↑ Likely 1° ↑ PTH Poss. FHH ✓ urine Ca ↑ (>200mg/day)1° ↑ PTH ↓ (<100mg/day)FHH ↓ Non-PTH mediated ✓ PTHrp & Vitamin D ↑ PTHrpLook for cancer ↑ 1,25D CXR (Lymphoma, Granulomatous disease) Normal D and PTHrp SPEP, UPEP, TSH ↑ 25DRecheck meds

Treatment Mild (<12): No acute tx necessary – Avoid thiazides and lithium, volume depletion – Low calcium diet Moderate (12-14): May or may not require tx

Severe Hypercalcemia (>14) Normal Saline (UTD recommends 200cc/hr, adjust for UOP cc/hr) – With Lasix as necessary Calcitonin 4 IU/kg Q12 hrs (if Ca>14) Cancer: Bisphosphonates (Reclast 4mg IV over 15 mins) Dialysis if these fail Monitor with Q8 serum calcium levels

Treat Underlying Cause Multiple Myeloma Squamous Cell Cancer Gynecologic Cancer Sarcoidosis Tuberculosis Thyrotoxicosis Pituitary Adenoma Multiple Endocrine Neoplasia

The case Admitted to medicine for IVF PTH 77 (normal 11-55); Urinary calcium 425mg/day Tc99m-sestamibi demonstrated a single parathyroid adenoma Referred to surgery for parathyroidectomy

Take home points Hypercalcemia can present asymptomatically or with very vague symptoms (stones, bones, groans…) Still worth treating (risk for nephrolithiasis, arrhythmias, vascular calcification)

Take home points 1° hyperparathyroidism and malignancy are the most common causes Check PTH first. If not elevated, check vitamin D (both 25-OH and 1,25-OH) Treat all symptomatic patients with IVF