2. Calcium
Normal total calcium level is 8.5 -10.5mg/dl
Normal ionized Ca+2 level is 4.5 – 5.6mg/dl
Hypocalcaemia
Total calcium <8.5 mg/dL, if serum protein is
normal
OR
Ionized calcium < 4.5mg/dL
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3. Role of Mg
• Always measure serum magnesium in a
hypocalcaemic patient.
• Hypomagnesemia impairs PTH secretion
• It also causes resistance to the actions of
PTH at the level of kidney and bone
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11. Trousseau sign:
(very uncomfortable and painful)
• A blood pressure cuff is inflated to 20mm Hg above systolic blood
pressure level.
• arterial blood flow to the hand is occluded for 3 to 5 minutes.
• Carpopedal spasm:
* flexion at the wrist
* flexion at the MCP joints
* extension of the IP joints
* adduction thumbs/fingers
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12. Investigations
• S. Calcium and Phosphate levels
• S. Albumin
• S. & Urinary Creatinine (for renal disease)
• PTH levels in serum
• Parathyroid antibodies (present in idiopathic
hypoparathyroidism)
• Vitamin D serum level (low in Vitamin D def.)
• Magnesium level
• X-rays of metacarpals (showing short 4th
metacarpals which occur in pseudo
hypoparathyroidism)
• ECG
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15. Management
1. Dependent on the underlying cause and
severity
2. Administration of calcium alone is only
transiently effective.
3. Mild asymptomatic cases: Often adequate to
increase dietary calcium by 1000 mg/day
4. Symptomatic: Treat immediately22/06/2013 Hypocalcaemia 15
16. Severe Symptomatic:
• IV 10% Calcium Gluconate 10 ml over 10 minutes
• Continuous IV infusion of Calcium Gluconate @ 0.1
mmol/kg over 24 hours
• Continuous Cardiac monitoring for Bradycardia
Severe Asymptomatic:
Oral Calcium Supplements @ 0.2 mmol/kg
(Max 10 mmols or 400 mg Ca) 4 x a day
Treatment of Hypocalcaemia
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17. • Aim to keep serum Ca between 8-8.5mg/dl
• Oral Calcium supplements
• Active preparations of Vitamin D
• 1,25-dihydroxyvitamin D (Calcitriol)
• 1-α-hydroxyvitamin D (Alfacalcidiol) @ 50
nanograms/kg (Max ~2 micrograms/day)
• Monitoring
• Urine Ca/Cr (<0.7)
• Plasma Ca+2
Treatment of
Hypoparathyroidism
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Although as many as half the patients in a intensive care setting are reported to have calcium concentrations <8.5 most do not have a reduction in ionized calcium.Patients with severe sepsis may have a decrease in ionized calcium (true hypocalcaemia),In other severely ill individuals Hypoalbuminaemia is the primary cause for the reduced total calcium concentration.The serum level of calcium is closely regulated with a normal total calcium of 2.2-2.6 mmol/L (9-10.5 mg/dL) and a normal ionized calcium of 1.1-1.4 mmol/L (4.5-5.6 mg/dL). The amount of total calcium varies with the level of serum albumin, a protein to which calcium is bound. The biologic effect of calcium is determined by the amount of ionized calcium, rather than the total calcium. Ionized calcium does not vary with the albumin level, and therefore it is useful to measure the ionized calcium level when the serum albumin is not within normal ranges, or when a calcium disorder is suspected despite a normal total calcium level.
BLOOD CALCIUM IS TIGHTLY REGULATEDPRINCIPLE ORGAN SYSTEMSGUT, BONE, KIDNEYSHORMONESPARATHYROID HORMONE (PTH), Calcitonin, VITAMIN DINTEGRATED PHYSIOLOGY OF ORGAN SYSTEMS AND HORMONES MAINTAIN BLOOD CALCIUM
TISSUE SPECIFICVit. D responseGUTSTIMULATE TRANSEPITHELIAL TRANSPORT OF CALCIUM AND PHOSPHATE IN THE SMALL INTESTINE (PRINCIPALLY DUODENUM)BONESTIMULATE TERMINAL DIFFERENTIATION OF OSTEOCLASTSSTIMULATE OSTEOBLASTS TO STIMULATE OSTEOCLASTS TO MOBILIZE CALCIUMPARATHYROIDINHIBIT TRANSCRIPTION OF THE PTH GENE (FEEDBACK REGULATION)
Due to mutation in PTH receptor
facial spasms produced by lightly tapping over the facial nerve just in front of the ear
Clinical history and picture is usually diagnostic and is confirmed by a low S. calcium level (after correction for any albumin abnormality)Low PTHHypoparathyroidismPrimary/ secondaryNormalMg deficiencyHigh PTHVit D deficiencyPseudohypoparathyroidism – types 1, 2Severe hypomagnesaemia results in functional hypoparathyroidism which is reversed by magnesium replacement
Albright’s hereditary osteodystrophy have short stature, characteristically shortened fourth and fifth metacarpals, rounded facies, and often mild mental retardation
