A1 A
The mean corpuscular haemoglobin concentration (MCHC) is a red cell index
that forms part of haematology tests. It measures the average concentration
of haemoglobin in erythrocytes (red blood cells). It is decreased in different
presentations of anaemia, including iron deficiency anaemia and in thalassemia.
In iron deficiency anaemia, the haematocrit value (space occupied by
packed erythrocytes) is decreased.
A2 B
The measurement of total and differential white blood cell (WBC) count is a
part of all routine laboratory diagnostic evaluations. It is helpful in the evaluation
of a patient with an infection, although a high WBC count may also be
found in other conditions such as neoplasma, allergy and immunosuppression.
One type of WBCs is the lymphocytes, their primary function being to fight
chronic bacterial infection and acute viral infections. Lymphocytes can be
further classified into B cells and T cells. The mature B cells produce immunoglobulins.
The T cells have cell-mediated immunity as a major property, where
they act directly to eliminate certain microorganisms and regulate the activity
of B cells in producing immunoglobulins. An increased number of lymphocytes
(lymphocytosis) occurs with viral infections, such as in patients with upper
respiratory tract infections, mumps and infectious mononucleosis.
Thrombocytes (platelets) are elements in blood, their main role being the
maintenance of vascular integrity. In idiopathic thrombocytopenia purpura
there is a deficiency of platelets leading to bruising and bleeding. Idiopathic
thrombocytopenia purpura is associated with the occurrence of antibodies to
Questions 4–6
When approaching therapeutic management of a patient, it is essential to
familiarise yourself with background information on the disease state(s) and
on the patient’s presenting complaints.
A4 D
Myopathy is a condition affecting the skeletal muscle, and which is manifested
by muscle weakness and wasting. Histological changes occur in the muscle
tissues, similar to those that occur in muscular dystrophies.
A5 A
Tachypnoea is an abnormally fast breathing rate. It is characteristic of
respiratory diseases and occurs in hyperpyrexia. It occurs as a result of overactivity
at the level of the sympathetic nervous system.[size=9]
Dysphasia (aphasia) is a condition resulting in impairment of the language
aspect of speech. It usually occurs as a result of cerebral cortex injury, such
as after surgery for a brain tumour or after a cerebral stroke. The presence of
dysphasia is frequently accompanied by writing disorders.
Questions 7–26
Prednisolone is a corticosteroid with a predominantly glucocorticoid activity.
However, owing to minor mineralcorticoid activity, it may still cause electrolyte
imbalance, namely sodium and water retention and potassium loss. Salbutamol
and propranolol do not interfere with plasma sodium electrolyte levels.
Salbutamol may precipitate hypokalaemia, especially with parenteral administration
or after nebulisation. The risk of hypokalaemia with salbutamol therapy
may be increased with concomitant administration of certain drugs, such as
corticosteroids and diuretics.
A8 A
Paget’s disease, neuropathy and haemophilia are all conditions that are
associated with the occurrence of muscular or joint pain. Paget’s disease is a
disease of the bone where there is excessive bone destruction and abnormalities
in bone repair. The condition may be associated with bone pain, bone
deformity, fractures and pain caused by pressure on nerves. However, Paget’s
disease may be asymptomatic. Neuropathy is a condition where there is
inflammation or degeneration of the peripheral nerves. It may occur as a
complication of long-standing uncontrolled diabetes. Patients complain of
excruciating pain in the peripheries. In haemophilia there is a deficiency of
one of the factors necessary for blood coagulation. Patients with haemophilia
are prone to develop bleeding in joints, resulting in pain.