Acute Renal Failure
CASE 1
Mr. B. is a patient in the intensive care unit with ARF
whose arms are observed to flex in intermittent
involuntary tonic contractions. Urea and electrolyte
results revealed the following
(normal value)
Sodium
142 mmol/L
(135-145)
Potassium
5.1 mmol/L
(3.5-5.0)
Calcium
1.72 mmol/L
(2.20-2.55)
Phosphate
1.8 mmol/L
(0.9-1.5)
Urea
34.9 mmol/L
(3.0-6.5)
Creatinine
485 μmol/L
(50-120)
Question:
What is the cause of this condition and how should it
be treated?
CASE 2
Mr D has been admitted to an intensive care unit with
ARF which developed following a routine
cholecystectomy . his electrolyte picture shows the
following
Sodium
138 mmol/L
(135-145)
Potassium 7.2 mmol/L
(3.5-5)
Urea
32.1 mmol/L
(3-6.5)
Bicarbonate 19 mmol/L
(22-31)
Creatinine
572 μmol/L
(50-120)
pH
7.28
(7.36-7.44)
CASE 2
the patient was connected to an ECG
monitor and the resultant trace
indicated absent p-wave and a broad
QRS complex.
Question:
Explain the biochemistry and ECG
abnormalities and indicate what
therapeutic measures must be
implemented.
Answer of case 1
Convulsion is due to electrolyte disturbance
Treatment:
Correction of electrolytes (ca- gluconate ,
phosphate binder)
Anticonvulsant and hemodialysis
Answer of case 2
Hyperkalemia is one of the principal problems encountered in
patients with renal failure.
The increased levels of k arise from failure of the excretory
pathway &also from intracellular release of k. attention should
also be paid to pharmacological or pharmaceutical processes
that might lead to k elevation “k-supplement, ACE I “. The
acidosis noted in this patient, which is common in ARF, also
aggravates hyperkalemia by promoting leakage of k from cells.
Serum k level greater than 7 m mol\L indicates that emergency
ttt is required as the patient risk-life-threatening ventricular
arrhythmia &asystolic cardiac arrest if EEG changes are
present as in this case emergency ttt should be initiated when
serum k rise above 6.5 m mol\L .
Answer of case 2
The emergency ttt should include the following:
1-Stabilization of the myocardium by I.V
administration of 10-30 ml ca.gluconate 10%
over 5-10 min the effect is temporary but the
dose can be repeated.
2-I.V adm. Of 10-20 units of soluble insulin with 50
ml of 50% glucose to stimulate cellular k uptake
the dose may be repeated. The blood glucose
should be monitored for at least 6 hr to avoid
hyperglycemia.
Answer of case 2
3-I.V salbutamol 0.5 mg in 100ml 5%dextrose over
15 min has been used to stimulate the cellular
sod-k-atpase pump & thus drive k into cells. This
may cause disturbing muscle tremors at the
doses required to reduce serum k levels.
4-Acidosis may be corrected with I.V dose 50-100
ml of NaHCO3 8.4% correction of acidosis
stimulates cellular k –uptake. Hypertonic HCO3
soln(8.4%)can cause volume expansion &
should be used with extreme caution.