Short notes on renal failure and treatment

Short notes on renal failure and treatment

Renal failure refers to non performance of the functioning of the kidneys when they fail to filter the blood of the waste products. As a result waste products accumulate in the blood leading to severe complications.

Renal failure is not a disease in itself; it is the result of one or many dis­eases that affect the kidneys. There are two types or renal failure- Acute renal failure (ARF) and Chronic renal failure (CRF).

Acute renalfailure (ARF):

This is characterized by the sudden decline in the Alteration rate of the glomerules, which limits the ability of the kidney. Metabolic wastes like urea, creatinine etc accumulate in the blood. ARF occurs in two forms-

(i) Oliguric ARF in which urine output is less than 400ml/day.

(ii) Non olliguric ARF in which urine output is more than 400ml/day. Causes of ARF are three types

a. Pre renal: includes dehydration, hypotension and heart failure.

b. Renal: Nephritis, drug induced injury, mismatched blood transfusion.

c. Post renal: Obstruction of the urethra by stones, tumours; bladder ob­struction by hypertrophy of prostrate glands.

Treatment of ARF:

(i) Hypotension may be remedied by infusion of saline solutions. If hypotension is due to blood loss, blood transfusion has to be undertaken; heart failure also to be treated if it is a cause.

(ii) Blood potassium and other electrolytes have to be estimated regularly in order not to allow their accumulation. Excess potassium if any may have to be removed by intravenous bicarbonates.

(iii) Proper diet is necessary which should include all the essential nutri­ents. Excessive protein and magnesium containing compounds are to be avoided.

(iv) Dialysis:

Dialysis is a process of Alteration of a solution in which solutes are separated from the solvent as they pass through a selectively permeable membrane. In normal kidneys, the nephrons filter the blood (dialyse) through their membrane and separate out the solutes (waste prod­ucts) and throw them out along with urine. When the nephrons fail to perform their filtering activity the waste products are not removed from the blood and result in blood poisoning due to retention of toxic wastes (retention of urea is called uremia). This results in complications leading to fatality.

When kidneys fail to perform and drug and other treatments are of no help artificial filtering of the patient’s blood has to be performed and this is known as dialysis. In dialysis, a saline solution with the same concentra­tion of the normal body fluid will be made to surround a selectively per­meable membrane. When blood passes through this membrane based on principle of diffusion, solutes (waste products) are filtered out of the mem­brane into the saline solution.

There are two types of dialysis- Peritoneal dialysis (PD) and Haemodialysis (HD).

Peritoenal dialysis:

In this, the blood is filtered inside the body of the patient using the serous membrane of the peritoneum for dialysis. This is performed by slowly introducing one or two litres of saline solution (di- alysate) over a period of 20 minutes through a catheter. After a period of 20 minutes stay in the peritoneum, the saline solution is drained out slowly for the next 20 minutes. Dialysis (taking one hour approximately) has to be performed several times over a period of 24-72 hours.

In this method of dialysis, the peritoneum acts as dialysis membrane across which waste products diffuse into dialysate fluid. This treatment is simple and should be continued till condition of the patient improves.

Haemodialysis:

In this, blood and saline solution are placed across a membrane to remove unwanted materials from the blood and at the same time adding useful compnents to it. A constant flow of blood on one side of the membrane and dialysate on the other side allows removal of waste’ products in the same way as glomerular Alteration takes place in the kid­ney.

Blood from the patient is continuously drained into a haemodialysis machine by surgically creating a fistula between an artery and a vein (ei­ther in the hand or leg). The haemodialysis machine functions exactly like a nephron and filteres out waste products while platelets and blood cells remain in the blood. After Alteration, the blood is pumped back into the blood vessel of the patient. The temperature of the blood is brought to normal body level before it is pumpted into the body.

Haemodialysis takes about 7-8 hours as the entire blood of the body has to come out and get Altered. Haemodialysis about thrice a week is necessary to maintain the normal health of the patient.