Hypocalcaemia

Question 1

D?

Answer 1

Hypocalcemia is a state of low serum calcium levels (totalCa2+< 8.5 mg/dLorionizedCa2+< 4.65 mg/dL).Total calciumcomprisesphysiologically-activeionized calciumas well asanion-boundandprotein-bound,physiologically-inactive calcium.

Question 2

Aetiology?

Answer 2

• Increased losses
• Decreased intake
Increased demand

Question 3

CP?

Answer 3

• Spasms (carpopedal spasms = Trous-seau’s sign)
• •Perioral paraesthesiae
• •Anxious, irritable, irrational
• •Seizures
• •Muscle tone ↑ in smooth muscle—hence colic, wheeze, and dysphagia
• •Orientation impaired (time, place and person) and confusion
• •Dermatitis (eg atopic/exfoliative)
• •Impetigo herpetiformis (↓Ca2+and pustules in pregnancy—rare and serious)
• Chvostek’s sign;choreoathetosis;cataract;cardiomyopathy (longqtinterval onecg)

Question 4

Pathophysiology?

Answer 4

• Normally
• Use ligand gated channels which are controlled by hormones and NT
• Or voltage -gated channels in muscle and nerve cells that are controlled by electric membrane potential
• Calcium out of cells via ATP-dependent pumps and Na/Ca exchangers
• Some calcium is also stored in organelles
• Diffusbale EC-free ionised calcium-neruoens coagulation myuscles and hormones
• Complexed-calcium oxalate is a negative ion tat forms a complex with this-neutral-no processes
• Non-diffusable-bound to albumin-not nvolved n cellular processes
• Low Ca detect by receptors in OPTH gland-bones release calcium, calcitriol release and kidney reabsorption
• In alkalosis-more negatively charged COOH or COO- groups in albumin that will attract calcium over H (as there is less of this)-more bound but less ionised

• Presentation
• Tetany-resting state of sodium channels stabilised by calcium and prevents spontaneous depolarisation-less calcium means more unstable sodium channels
See table

Question 5

Investigations?

Answer 5

see ON
also-
• ECG-Prolonged QT
• Arrhythmias
• QRS complex and ST-segment changes
• AV block
• Fundoscopy-Papilloedema

Question 6

M-?

Answer 6

First line:
• Severe-serum calcium≤ 7.5 mg/dL(< 1.9 mmol/L)
• IV calcium supplementation-calcium gluconate or calcium chloride
• Continuous telemetry
• Transfer to CCU

Mild
• Serum calcium7.6–8.4 mg/dL(1.9–2.12 mmol/L)
• Oral calcium supplementation-calcium citrate or calcium carbonate

Treat Underlying Condition
• Hypoparathyroidism-Calcium supplementationPLUSvitamin Dsupplementation and treatment
• Secondary toloop diuretics: consider discontinueloop diureticand change medication tothiazides
• Vitamin D deficiency:vitamin Dsupplementation
• Hypomagnesemia-induced hypocalcemia:magnesiumsupplementation
• Hyperphosphatemiainchronic kidney disease:calcium supplementation

Question 7

P and C?

Answer 7

arrhythmias