Acute Kidney Injury (AKI)
kidney injury (AKI) is a condition where our kidneys suddenly lose their function.
Various causes like severe infections, dehydration, renal toxic drugs/envenomation
(snake bite, wasp sting), blood clots in renal artery and autoimmune
diseases can cause AKI
For chronic kidney disease
(CKD) see the link on CKD
What are the symptoms of kidney disease?
Poor appetite, nausea, vomiting, breathlessness, body swelling,
headache, seizures, reduced urine output will be the presenting
manifestations at the end stage of renal failure as well as in acute
kidney injury. Apart from these symptoms children with CKD can present
with increased water intake secondary to thirst, poor growth, bony
abnormalities (wrist widening, bowing of knees).
How can we find out this problem?
With the above said problems your doctor will decide about few essential
blood/ urine tests and also imaging like ultrasound depending upon the
Urine examination may show protein/ red blood cells in the urine.
Blood tests may show increased levels of toxic products like urea,
creatinine. In renal diseases we can also find electrolyte
abnormalities, anemia, high/low blood levels of calcium, high
phosphorous and parathyroid hormone levels, low vitamin D levels.
Ultrasound may give us a clue about kidney sizes, structural
malformations and renal stones.
In case of suspected glomerular disease renal biopsy will be very
helpful to know the underlying pathology and chronicity of the
Is it safe to undergo renal biopsy in children?
To know the cause of renal failure we do renal biopsy. Before the biopsy
your doctor will do some blood tests to look for the normal blood
clotting mechanisms of the child. It is mandatory to keep the child nil
per oral for 6 hours before the biopsy. Child is asked to lie in prone
position so that the doctor will be facing the back. Procedure will be
done under ultra sound guidance. Child will not feel the pain as we use
intravenous and local anaesthesia. Two tiny pieces of renal tissues will
be taken from the left kidney by using the renal biopsy gun and the same
will be sent to studies like light microscopy, immune fluorescent and
electron microscopy studies. The wound site will be closed with a gauze
and band aid. The pediatric nephrologist will do the procedure. After
the biopsy child is advised to take strict bed rest for 24 hours.
Following the biopsy, child may pass blood stained urine which is
usually benign and settle with subsequent urination. The child can take
food/drink after 4 hours of the procedure.
Can we cure the disease?
Acute kidney injury is curable if the cause is reversible like infection
or a drug causing AKI. Consult the doctor early and start the treatment.
Obstruction like PUV, pelviureteric junction obstruction can be
corrected surgically. Any AKI can progress to CKD. So it is advisable to
be under regular follow up with a pediatric nephrologist/urologist.
We cannot cure chronic kidney diseases. We can keep the disease under
control with supportive treatment. But once a critical fraction of
function has been lost, renal function progressively worsens independent
of the underlying disorder. Childhood nephrotic syndrome is treated with
steroids. In case of recurrent relapses, alternative drugs will be tried
with serial monitoring for drug adverse reactions. Immuno suppressive
therapy may be needed for some glomerular diseases like
vasculitis. Control of proteinuria and hypertension plays a major role
in controlling the CKD progression. Some children will have loss of some
acids, potassium, chloride in the urine which are essential for the
growth of the child. Hence the doctor will give medicines for the same
depending upon the underlying disease. Even after surgical intervention
for PUV, PUJ problems, children should be under follow up to look for
growth, BP and renal functions monitoring. Whenever they get stressed
like any infection/ during the growth spurt of adolescence where muscle
mass increases, the work load to the kidney also may increase. So it is
advisable to be under regular follow up.
Can the children also have high blood pressure?
Yes. Renal problems are the most common cause of hypertension in
children. Optimized BP control has a protective effect on the kidneys.
How do you measure the kidney function? Do you have any
We calculate the estimated GFR(eGFR)
by using serum creatinine levels. We also do 24 hours urine creatinine
clearance in older children. With the either one of the formula CKD is
graded as stage 1 to 5.
AKI also has grading like risk, injury, failure, loss and end stage
renal failure depending on the level of creatinine and urine output.
Do they need any diet restriction?
Your doctor will give careful dietary advice as the children should not
be compromised on their growth but at the same time symptoms due to
accumulation of waste products also have to be minimized. Nutrtion is
important in various phases of growth in children especially during
infancy, early childhood as the growth velocity is very high at this
age. Depending upon the disease stage and associated blood chemistry
alteration they may need restriction. Balanced diet in the form of food
containing carbohydrate 60%, fat 30% and 10% protein is advisable. In
childhood nephrotic syndrome, it is advised to avoid extra salts like
pappad, chips and pickles. Salt restriction is needed in children with
hypertension. Food with high biological value protein like egg and milk
can be given. In CKD stage 3, 4 & 5, risk of getting the elevated
potassium is high. Hence it is advisable to restrict fruit juices, high
potassium containing foods. In case of swelling and increase in intra
dialytic weight, they may need fluid restriction. Children on RRT may
need vitamin supplement to compensate for dialysate loss.
How do you treat?
AKI not responding to conservative measures may need renal replacement
therapy(RRT) in the form of peritoneal dialysis(PD), hemodialysis(HD) or
continuous renal replacement therapy(CRRT). In HUS, therapeutic plasma
exchange is done.
CKD children may need RRT usually at stage 4/ 5 and earlier in case of
growth retardation, electrolyte imbalance. All the RRT measures are the
bridge between the disease stage and kidney transplantation which is the
final treatment for any form of CKD ESRD.
Can you explain about various RRT measures?
During the acute illness it can be done. By using a PD catheter, fluid
will be sent inside the abdominal cavity. The peritoneal membrane will
act as a kidney and toxins will be replaced with good fluid. All the
excessive salt will be drained out. It will go throughout day and night.
In children with CKD, the same will be done by continous ambulatory
peritoneal dialysis(CAPD). The catheter will be placed surgically inside
the abdomen by the pediatric urologist. After a week of procedure,
dialysis can be started. Parents/care taker will be taught about the
technique of doing CAPD at home by a trained CAPD staff.
During the acute illness, your doctor will secure the central venous
line with the catheter on the side of the neck/ thigh region. The blood
will be pumped out from the body through the tubing which is already
connected to the HD machine. The artificial kidney in the machine will
purify the blood and will be sent back to the patient. Usually the
duration will be 4 hours. In case of CKD, fistula will be created by
connecting the vein and artery in one of the hands. It will take 4 to 6
weeks to mature. Then the fistula site will be pierced by the needle,
blood will be pumped out and HD is done. Usually 3 sessions of HD in a
week will be enough to remove the waste products. The fistula is usually
created in the non dominant hand. That hand should not be used for
taking blood samples/ BP checking.
It is done in AKI only, will be done over 24 hours with the CRRT
machine. In children with heart compromise and AKI this will be very
Is it possible to do kidney transplant in children?
Yes. Same like adults children also can undergo transplantation. Few
criteria are there to select the donor. The work up will be done by the
pediatric nephrologist. If everything matches, they will proceed with
transplant. However even after transplant child should be on
immunosuppressive therapy for long period to prevent rejection. .