BOF: 127
A 50-year-old male presents with malaise. He finds it
difficult to cope with his work, sleeps poorly and has an itch especially at
night. He has difficulty climbing
stairs and also finds it difficult to stand up from a seated position.
He had no significant past illnesses but had been told that he had high
blood pressure years earlier but had taken no action regarding this.
On examination he underweight and pale. His skin was dry
and covered in scratch marks. Blood pressure 190/110. No oedema. Heart sounds
were normal, lungs were clear. Fundus showed arteriovenous nipping and
thickened arteries. On
neurological examination it was noticed that he had difficulty standing from
the seated position.
Investigations:
Hb 8.0
MCV 90 fl
WBC 4.8 x 10 9 /l
Na 138 mmol/l
K 6.1 mmol/l
Chloride 90 mmol/l
Urea 53 mmol/l
Creatinine 1850 micromoles/l
Calcium 1.40 mmol/l
Phosphate 2.31 mmol/l
Albumin 30 g/l
Fasting Blood Glucose 5.2 mmol/l
In this patient:
a)
Excellent control of blood pressure is not a priority as he is not
diabetic
b)
Control of blood pressure is essential but care should be taken not to
lower the blood pressure to less than 130/80 as this will compromise renal
function
c)
ACE inhibitors should be avoided as they will cause further
deterioration of renal function
d)
Treatment of hypertension with ACE inhibitors would be of particular
value
e)
Low dose diuretics should be used so as to avoid dehydration which will
further compromise renal function
Answer:
d)
Non-diabetics with chronic renal failure benefit from
excellent control of blood pressure. Treatment should aim to control blood
pressure to 130/80 or lower. Treatment of hypertension with ACE inhibitors,
which reduce intraglomerular capillary pressure and proteinuria, is of
particular benefit in chronic renal failure.
Large doses of diuretics are usually required to control
sodium and water retention.
In this patient:
a)
Treatment of hypercalcaemia should aim to keep the PTH level below
three times the upper limit of normal
b)
Calcitriol should be given immediately
c)
Dietary restriction of phosphate will control the high phosphate levels
d)
Calcium carbonate will reduce bioavailibilty of dietary phosphate
e)
H2 antagonists should be used to increase the effectiveness
of phosphate binders
Answer:
d)
Reduction of PTH levels to less than 3 times the upper
limit of normal carries the risk of development of adynamic bone disease.
Increasing calcium before lowering phosphate increases
the risk of tissue calcification.
Dietary phosphate restriction is seldom effective as many
foods contain phosphate.
H2 antagonists decrease the effectiveness of
phosphate binders
Revision Tip
Revise chronic renal failure
KEYS to SUCCESS in Medicine page 312-317
