EMQs in Clinical Medicine.pdf - Peshawar Medical College

Electrolyte and metabolic disturbances – answers 205
I Coeliac disease results in malabsorption of the fat-soluble vitamins (A, D,
E, K). There are several vitamin K-dependent clotting factors (II, VII, IX,
X) and so vitamin deficiency can lead to abnormal coagulation.
K
F
A 25-year-old African man presents with symmetrical dermatitis on
sun-exposed skin, diarrhoea and depression. He has recently been on
anti-TB treatment.
Isoniazid therapy can lead to nicotinic acid/vitamin B 6 deficiency.
Pellagra is the name attributed to the symptoms of nicotinic acid deficiency.
There is a predisposition to pellagra in patients with carcinoid
syndrome because tryptophan metabolism is diverted away from
nicotinamide production to produce amines.
A 12-year-old boy presents with night-blindness.
Vitamin A deficiency causes xerophthalmia with symptoms of nightblindness.
Bitôt’s spots are white areas of keratinized epithelial cells that
can be seen in the conjunctivae of young children with vitamin A deficiency.
Conjunctivae and corneas are typically dry and thickened.
80 Electrolyte and metabolic disturbances
Answers: A H K D J
A
H
K
A 40-year-old woman treated with spironolactone and lisinopril for
heart failure presents with bradycardia. ECG shows tall, tented ‘t’
waves.
There is significant risk of hyperkalaemia when spironolactone is
co-prescribed with an angiotensin-converting enzyme (ACE) inhibitor.
However, this combination is widely prescribed in the treatment of
patients with moderate/severe heart failure because the addition of
spironolactone to ACE inhibitor therapy was shown to improve survival
in the RALES trial.
A 30-year-old woman presents with tetany, perioral paraesthesia and
carpopedal spasm after thyroid surgery.
These are signs associated with hypocalcaemia resulting from inadvertent
removal of parathyroid glands.
A 30-year-old man being treated for a systemic fungal infection presents
with muscle weakness, arrhythmias and tetany. His ECG shows
prolonged P–R interval and prominent U waves.
Hypokalaemia is a well-recognized adverse effect of amphotericin treatment
secondary to increased renal loss. Flattened T waves and prominent
U waves are ECG changes observed in hypokalaemia.
A 50-year-old woman on TPN presents with red crusted lesions
around the nostrils and corner of the mouth.