Acute Kidney Injury [ Acute Renal Failure] or kidney failure

Definition | Etiology | Mechanism | Sign and Symptoms | Investigation | Management |

 

Definition:-

Acute kidney injury Previously called Acute Renal Failure is an abrupt loss of kidney functions that develops within 7 days.

It is characterized or manifested by decrease glomerular filtration rate, level of serum creatinine, and urea nitrogen rise and oliguria or anuria.

Etiology of Renal failure:-

Its cause is numerous. Generally, it occurs because of damage to kidney tissue caused by decreased blood flow (ischemic kidney), low blood pressure or hypotension, exposure to substance harmful to the kidney, inflammatory process, or an obstruction of the urinary tract.

The causes of Acute kidney failure can be categorized by into 3 major area’s:-

  1. Pre-Renal cause
  2. Intra-Renal cause
  3. Post Renal cause

1. Pre-Renal Cause:-

  • Pre-Renal causes are those that decrease effective blood flow to the kidney and cause to decrease in GFR.
  • The low blood volume in the body (hypovolemia) [due to vomiting, diarrhea, hemorrhage, burns, and excessive use of diuretics.].
  • Hypotension.
  • Decreased cardiac output.
  • Heart failure.
  • Renal artery stenosis.

2. Intra-Renal / Intrinsic cause :-

The process which directly damages the kidney itself :

  • Glomerular Nephritis.
  • Tubular Necrosis.
  • Renal Surgery.
  • Injury, Trauma, Crush.
  • Electric Shock.
  • Diabetes Mellitus.
  • Infectious Disease.
  • Rejection of the transplanted kidney.
  • Genetic Factors.

3. Post Renal cause:-

Caused by disease states/conditions downstream of the kidney.

  • Urinary tract obstruction.
  • Ureteral or urethral structures (stenosis).
  • B.P.H.
  • calculi.
  • cancer or tumor of bladders & ureters.
  • Surgical Accidents.
  • Spinal cord injury leads to decrease bladder emptying of functional obstruction.

Mechanism / Pathogenesis of Renal failure:-

The mechanism of Acute renal failure is not specific or not clear there are some mechanisms which is:-

  • Ischemic kidney.
  • Activation R.A.S.
  • Tubular injury or infection.
  • Fibrosis and scare formation.
  • Renal Calculi.
  • Decreased osmotic pressure.

Clinical Manifestation or Symptoms of Renal failure:-

  • Headache.
  • Fatigue.
  • Nausea, Vomiting.
  • Diarrhea.
  • Constipation.
  • Loss of Appetite.
  • Flank pain.
  • Edema.
  • Shortness of breath.
  • Hematuria.
  • Oliguria or Anuria.
  • Hypertension.
  • Hand tremors.
  • Decrease G.F.R.
  • Increase Serum Keratinine.
  • Acidosis.
  • Urea nitrogen level Increase.
  • Fluid and Electrolyte Imbalance.
  • Hyperkalemia.
  • Hyponatremia.
  • Hypocalcemia.
  • Hyperattrisemia.

Investigation of Renal failure:-

  • Serum Creatinine level (increases)
  • Blood urea nitrogen
  • Serum potassium
  • Urine analysis
  • Radiological study (CT, MRI, X-ray)

Management of Renal failure:-

The management of Acute Kidney Injury is divided into 4 stages or phases:-

  1. Initiating / onset phase:-  This phase covers the period from the precipitation event to the development of renal manifestation and continues until the sign and symptoms. It can last for a few hours to a week.
  2. Oliguric phase:- The most common initiative manifestation of Acute Kidney Injury is oliguria caused by a reduction in the G.F.R. oliguria usually occurs within 24 hours. The longer oliguric phase clast the poor prognosis for recovery of complete renal function. (1 to 8 week).
  3. Diuretic phase:- The diuretic of Acute kidney injury begin with a gradual increase in urine output of 1 to 3 lit. per day but may reach 3 to 5 liter per day or more although output increased in case nephrons are still not fully functioning. At this stage, the uremia may still serve as infected by the low creatinine clearance, elevated serum creatinine, BUN level, and persistent sign and symptoms of dehydration because of the large loss of fluid and electrolyte ( 25- 30 % of death dehydration).
  4. Recovery phase:- The recovery phase begins when the GFR increases allowing the BUN and serum creatinine levels to decrease some individuals do not recover or progress to chronic kidney failure. The older adults patient are less likely to recovery to fully kidney function. The treatment of the recovery phase lasts for some months or a year in severe cause dialysis or kidney transplantation may be prescribed.

Medical Management of Renal failure:-

  • Avoidance of substance that is toxic to the kidneys called Nephrotoxics, it includes NSAID.
  • Iodinated contrast or contrast medium used in radiographic examination especially CT scan and MRI.
  • Antibiotics.
  • In lower BP:- Non-epinephrine, Inotropes, steroid, Dobutamine.
  • In high BP:- calcium channel blocker, ACE inhibitor, Diuretics.
  • In metabolic acidosis administer sodium bicarbonate.

Surgical management of Renal failure:-

  • Nephrotomy.
  • Catheterization.
  • Dialysis.
  • Renal Transplantation.

Nursing Management of Renal failure:-

Nursing diagnosis –

  • Fluid volume excess related to an inability to the kidney to promote or excrete urine.
  • Fluid volume deficit.
  • Altered nutrition level.
  • The risk of infection.
  • Disturb thought process.
  • The risk of impaired normal skin integrity related to edema.

Related points:-

Pre-Renal Causes

Intra-Renal Causes 

Post-Renal Causes 

 

Related Post:- 

Chronic Kidney Failure

 

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