Hereditary spherocytosis is an autosomal dominant red blood cell membranopathy that is caused by a lack of proteins that have vertical interactions (ankyrin, spectrin, and band 3) in the red cell membranes. Red blood cells that lack these proteins lose…
Drug-induced haemolytic anaemia is a Coombs-positive anaemia that is linked to drug use.
Cold-agglutinin haemolytic anaemia occurs when IgM molecules are produced against red blood cells. The IgM molecules activate complement, leading to intravascular haemolysis.
Warm-agglutinin haemolytic anaemia (warm coombs positive anaemia) occurs when IgG antibodies are produced against red blood cells. These tagged red blood cells are destroyed in the spleen (extravascular hemolysis), leading to anaemia. It is usually seen in lymphoproliferative disorders and…
Hypernatremia is an elevated serum sodium level. It is commonly caused by sodium gain or water loss exceeding sodium loss. Classification of hypernatremia Category Description Hypovolaemic hypernatremia Gastrointestinal losses – diarrhea, vomiting, or fistulas; renal losses – diabetes inspidus; cutaneous…
Hyponatremia is a low serum sodium concentration. Classification of hyponatremia Category Causes Nota bene Hypovolemic hyponatremia Gastrointestinal losses – diarrhoea and vomiting; renal losses – diuretic overuse and mineralocorticoid deficiency; cutaneous losses – burns and sweating; third spacing of fluid…
Osmotic demyelination syndrome (central pontine myelinolysis) can occur due to overcorrection of severe hyponatremia.
Hyperkalaemia is a serum potassium concentration above the reference range. Severity K+ concentration (mEq/L) EKG progression Mild hyperkalaemia 5.5 – 6.5 Peaked T waves and prolonged PR segment Moderate hyperkalaemia 6.6 – 7.5 Loss of P wave, prolonged QRS complex,…
Hypokalaemia is a serum potassium concentration below the reference range.
Hypercalcaemia is characterised by an elevated concentration of serum calcium above the normal range. It is commonly caused by primary hyperparathyroidism or malignancy. Classification of hypercalcemia Classification Description Primary hypercalcaemia Commonly due to primary hyperparathyroidism or malignancy – breast cancer,…