CALCIUM HOMEOSTASIS

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CALCIUM HOMEOSTASIS PARATHYROID DISORDERS

• DR. MAHMUDUL HUQUE
• HOLY FAMILY RED CRESCENT MEDICAL COLLEGE

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Calcium Homeostasis

• calcium homeostasis is the mechanism by which the
  body maintains adequate calcium levels.
  Derangements of this mechanism lead to
  hypercalcaemia or hypocalcaemia, both of which
  can have important consequences for health.

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• Normal range
• 910.5 mg/dL or
• 2.22.6 mmol/L

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Corrected Ca level

• Corrected calcium (mg/dL) measured total Ca
  (mg/dL) 0.8 X (4.0 - serum albumin g/dL

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Hypercalcemia

• Polyurea, polydipsia
• Renal colic, lethargy
• Anorexia, nausea, dyspepsia
• Peptic ulcer, depression, drowsiness
• Impaired cognition
• Acute/chronic onset
• Malignant Hypercalcaemia Cagt12 mg/dl

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Causes of Hypercalcemia

• Abnormal parathyroid gland function
• Primary or tertiary hyperparathyroidism
• Lithium induced
• familial hypocalciuric hypercalcaemia
• Malignancy
• Lungs, breast, renal, ovarian, colon, Thyroid
  malignancy.
• haematologic malignancy (multiple myeloma,
  Lymphoproliferative disorders)

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Contd

• Vitamin-D metabolic disorders
• hypervitaminosis D (vitamin D intoxication)
• elevated 1,25(OH)2D levels (e.g. sarcoidosis)
• Others
• Thyrotoxicosis TSH, FT3, FT4
• Thiazide use
• Paget's disease of the bone
• Addisons disease
• severe secondary hyperparathyroidism
• milk-alkali syndrome

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Treatment

• Hydrate with Normal saline 4-6L deficient
• Diuretics Look for K, Mg
• Salmon calcitonin BD, 5-8 u/Kg, 3-4 days
• BISPHOSPHONATES Pamidronate Zoledronic acid
• Plicamycine / Gallium nitrate (toxic)
• Steroids 40mg/day In granulomatous sarcoidosis
• Haemodialysis
• Treat cause

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Hypercalcaemia

• Oral, perioral and acral paresthesias, tingling
  or 'pins and needles' sensation. This is often
  the earliest symptom of hypocalcaemia.
• Carpopedal Spasm and generalized tetany
• Latent tetany Trousseau sign of latent tetany
  (eliciting carpal spasm by inflating the blood
  pressure cuff and maintaining the cuff pressure
  above systolic).
• Chvostek's sign (tapping of the inferior
  portion of the zygoma will produce facial
  spasms).
• Epilepsy, Psycosis
• Papilloedema
• Basal ganglia Calcification
• Metastatic calcification
• Severe Hypocalcaemia lt6mg/dl

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Causes of Hypocalcaemia

• Absent parathyroid hormone (PTH)
• Hereditary hypoparathyroidism
• Following parathyroidectomy
• Following thyroidectomy, the parathyroid glands
  are located very close to the thyroid and are
  easily injured or even accidentally removed
  during thyroidectomy
• In DiGeorge Syndrome, a disease characterized by
  the failure of the third and fourth pharyngeal
  pouches to develop, the parathyroid glands do not
  form and there is thus a lack of PTH.
• Storage Al, Cu, Fe
• Trauma or vascular formation

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Contd.

• Alkalosis Resp. Metabolic
• CRF
• Vit. D deficiency, Malabsoption syndrome
• Pseudo hypoparathyroidism
• Acute pancreatitis
• Drug- Ca lowering drugs
• Massive Blood transfusion
• Osteoblastic metastasis

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Treatment of Hypocalcaemia

• If alkalosis Rebreath expired air or 5 CO2 in
  O2 .
• 10 Calcium gluconate slow IV to keep Ca gt7mg/dl
  till relief.
• Oral Calcium 1.5-3 gms elemental Ca, 500 mg of
  Ca tab.
• If serum Ca fall bellow 7mg/dl, give again after
  6hrs Ca gluconate Upto 100mg/day.
• Tab. 1a in persistant hypo parathyroidism
• Magnesium (nalepsin) in calcium resistant persons

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Hyperparathyroidism
Primary Single adenoma-90 Multiple adenoma-4 Nodular hyperplasia-5 Carcinoma-1 S. Ca PTH
Secondary CRF (specially) Malabsorption Osteomalacia ricket S.Ca PTH
Tertiary Esp. CRF S. Ca PTH
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Contd.

• Serum biochemical hyper and hypo calcaemia
  occupies the clinical spectrum of parathyroid
  disease. So are the features of hyper/hypo
  calcaemia.

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Diagnosis

• Features of hypercalcaemia
• PTH radio-immuno assay
• 24 hr urinary calcium increased
• Radiology Osteitis fibrosa cystica,
• Pepperpot skull,
• Bone cyst- brown tumour
• Tumour localisation by- Surgery, USG, CT, Neck
  catheterisation, PTH measurement, Technetium
  isotope imaging.

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Treatment

• Manage hypercalcaemia
• Remove the tumour
• Tagging the remnant
• Transplant in symptomatic, young progressive
• Secondary Calcitriol to suppress PTH
• Tertiary Remove

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Hypoparathyroidism

• Hypocalcaemia, signs and symptoms of decreased
  Ca.
• Hyperphosphatemia
• Undetectable PTH
• Exclude serum Mg deficiency. If () Functional
  Hypoparathyroidism.

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Hypoparathyroidism

• It is due to destruction,
• surgery,
• Vascular damage, or
• idiopathic as part of poly-glandular failure or
  agenesis (DiGeorge syndrome)

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Pseudohypoparathyroidism

• Pseudohypoparathyroidism is a condition
  associated primarily with resistance to the
  parathyroid hormone. Patients have a low serum
  calcium and high phosphate, but the parathyroid
  hormone level (PTH) is actually appropriately
  high (due to the hypocalcaemia).
• Increased PTH biochemically Low Ca and High PO4
  body stigma.
• Features Short stature, obese with round face,
  short 4th and 5th metacarpal, mental retardation,
  defective teeth bone formation

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• Short stature, obese with round face

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Short 4th and 5th metacarpals
blunting of the fourth and fifth knuckles of the
hand
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Pseudopseudohypoparathyroidism

• Pseudopseudohypoparathyroidism (pseudoPHP) is an
  inherited disorder, named for its similarity to
  pseudohypoparathyroidism in presentation. The
  term pseudopseudohypoparathyroidism is used to
  describe a condition where the individual has the
  phenotypic appearance of pseudohypoparathyroidism,
  but is biochemically normal.
• It is sometimes considered a variant of Albright
  hereditary osteodystrophy.

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Young woman with short stature, disproportionate
shortening of the limbs, generalized obesity, and
round, flattened face. Radiograph of the hand
showing the shortened 4th and 5th metacarpals
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Thank You