A Case Of Hypercalcaemia

Intern Case Presentation Mrs EB

Overview • Mrs B, 80yo woman, home alone, I with ADLs • Presents with: ▫ ▫ ▫ ▫ ▫

1/52 vomiting & diarrhoea, fatigue, malaise 5/7 constipation 3-4/7 severe generalised abdominal pain ~20kg weight loss since 4/08! Nil fevers/sweats; nil haematemesis/melaena/PR bleed

• PHx

▫ Metastatic breast ca  T3, ribs, femur, lungs on exemestane, monthly zolendronic acid (Zometa) ▫ Sick sinus sx (PPM inserted 4/4/08) ▫ Parathyroid adenoma ▫ Past DVT/PE on warfarin ▫ Rx: tamoxifen, warfarin, perindopril, vitamin D, pantoprazole, bisoprolol, GTN

Further PMHx • Breast Ca: ▫ Dx 26 years ago: mastectomy, chemo, radiotherapy ▫ Recurrence 5 years ago; lung mets discovered and resected; commenced on aromatase inhibitor ▫ 4/08: bony mets  ribs 8 & 9, T3, femur  Switched from aromatase inhibitor  tamoxifen Commenced on monthly zolendronic acid (bony mets)

Further PMHx • Parathyroid adenoma: ▫ Episode of hypercalcaemia 4/08 ▫ PTH found to be high ?cause ▫ Sestamibi parathyroid scan: area of avid sestamibi uptake right lower neck corresponding to 2.0x1.0cm density on SPECT/CT ?parathyroid adenoma ▫ Surgery refused at this stage

• Sick sinus syndrome: ▫ Permanent pacemaker inserted 4/08

Examination Findings • General findings ▫ ▫ ▫ ▫

Unwell thin looking elderly lady JVP low Dry mucous membranes BP 110/50, HR 100/regular, SaO2 95% RA, afebrile

• Abdominal exam

▫ Generalised tenderness w/o peritonism ▫ Bowel sounds present

• Chest

▫ Clear lung fields ▫ Dual heart sounds no added sounds

Investigations • FBE: Hb 143/WCC 9.7/PLT 268 • UEC: Na 129/K 3.3 Urea 13.4 Creat 92 eGFR 54 (baseline >60) • Ca2+: 3.29; albumin 37; corr ca 3.35; Phos 0.75; Mg2+ 0.61 • CRP 1.4, LFT normal • AXR: multiple fluid-air levels suggestive of small bowel ileus. • CXR: old right lower zone changes

Diagnosis • Hypercalcaemia causing secondary ileus and marked volume depletion • Dx Dilemma: cause = bony mets, parathyroid tumour or both?

Initial Management • Rehydration: 1L N. Saline/2hrs (ED), 4L N. Saline/24hrs (and continued) • Not for bisphosphanates as already on monthly zolendronic acid • Ileus managed conservatively

Further Ix & Mx Date

0145 24/6 0731 24/6 1900 24/6 0950 25/6

26/6

Calcium

3.29

2.57

2.84

2.92

2.81

• PTH 6/4/08 = 26.3, Sestamibi- right lower neck PTH adenoma; sestamibi-avid metastatic disease right ribs, pleura, hilum ?PTHrP secreting mets • Endocrinology:

▫ Dx likely due to combination of met breast ca and primary parathyroidism ▫ Recommended surgical referral for r/o adenoma

• However: PTH now = 0.1 (Suppressed by very high calcium?) • Sestamibi scan for diagnosis of parathyroid lump, surgical opinion to follow • Therefore diagnosis: Hypercalcaemia secondary to bony metastatic disease.

Hypercalcaemia

The presentation of Hypercalcaemia can be as vague and confusing as this patient!

Calcium, Vit D, PTH metabolism

Calcium, Vit D, PTH metabolism

Calcium, Vit D, PTH metabolism

Causes :: Overview • • • • • • •

Parathyroid Adenomas Account for >90% of cases! Malignancy Renal failure Paget’s Disease Drugs – thiazides, calcium, lithium… Endocrine: Hyperthyroidism, addisonism Genetic – Hypervitaminosis D, Hypercalcaemic hypocalciuria • Sarcoidosis, Granulomatosis (incl TB)

Causes :: When to suspect • Past history of malignancy- esp bony mets, multiple myeloma • Endocrine problems • On calcium supplementation • Renal patients • Old people, delirium, confusion of unknown aetiology • Specific drugs – calcium, lithium, thiazides, vitamin D etc • Other indicators in HOPC/PHx

Causes :: Malignancy  (Poor prognostic factor)

Investigations • Serial Ca, PO4 • Correct Ca with albumin!!

▫ (40-Alb)*0.2 + serum Ca = corrected Ca

• UEC – renal function (ARF 2° dehydration/hypercalcaemia, CRF causing hypercalcaemia) • PTH level, ALP, Vit D • Consider multiple myeloma screen – ESR, serum electrophoresis, urine BJP etc. • Consider ordering urine calcium – 24 hour urine calcium collection • High PTH - Hyperparathyroidism: Sestamibi parathyroid scan • Low PTH - Malignancy: CT chest, abdo, pelvis, bone scan

Management • REHYDRATE aggressively with normal saline (aim for 200-300mL/hr initially then urine output 100150mL/hr) ▫ Volume depletion most dangerous complication acutely ▫ Na+, H2O administration  renal Ca excretion

• • • •

Frusemide if overloaded – promotes renal ca excretion IV bisphosphanate eg pamidronate if Ca>3 Calcitonin if Ca resistant to intervention Steroids in granulomatous disease, multiple myeloma, others • If Ca still doesn’t come down- consider haemodialysis

And of course… • Treat the underlying cause. • Renal failure: ▫ 2° hyperparathyroidism (high PTH)  Calcimimetics – cinacalcet Vit D analogues (not increasing Ca) – paracalcitriol

▫ 3° hyperparathyroidism (autonomic PTH) Surgical intervention

• • • •

Parathyroid nodule/tumour: surgical intervention Granulomatous disease: steroids Drugs: cease offending drug Treat endocrine conditions