About of Acute Kidney Disease


Acute Kidney Injury (acute kidney disease) is a clinical condition that is specific to the clinical manifestations vary widely, ranging from mild asymptomatic, up to very heavy with multiple organ failure. Incidence of acute kidney injury in all patients who undergo hospitalization was reported about 7% and 30% in patients treated in the intensive care unit. In patients with critically ill prevalence of acute kidney injury requiring dialysis procedures amounted to 5.7%, with a mortality rate reached 60.3%.

Conceptually acute kidney injury was defined as a sudden decline in kidney function in a few hours to several weeks, followed by kidney failure in excreting the rest of the metabolism of nitrogen with or without fluid and electrolyte balance disorders.

According KDIGO (Kidney Disease Improving Global Outcomes), Acute Kidney Injury is defined as follows:

  • Increase in serum creatinine same or more than 0,3 mg / dl (same or more than 26,5 mol / l) in 48 hours or
  • Increase in serum creatinine same or more than1,5 times the base value, and known / assumed to occur within 7 days or
  • Urine output decreases less than 0.5 cc / kg / hour for more than 6 hours

Based on the RIFLE and AKIN criteria, KDIGO provide recommendations Acute Kidney Injury in stages classification as in Table of Classifications of Acute Kidney Injury by KDIGO, 2012, below :


Criteria of Creatinine serum


Criteria of Urine Production (Urine Output/UO)



Increasing of creatinine serum 1.5–1.9 times from baseline (basic value)

Or increasing same or more than 0.3 mg/dl (same or more than 26.5 mmol/l)

UO same or less than 0.5 ml/kgBW/hour during 6–12 hours





Increasing of creatinine serum 2,0–2.9 times from baseline (basic value)


UOsame or less than 0.5 ml/kgBW/hour during same or more than 12 hours









Increasing of creatinine serum 3,0 times from baseline (basic value) or

Increasing of creatinine serum same or more than 4.0 mg/dl (same or more than 353.6 mmol/l)


require initiation of renal replacement therapy
in patients <18 years of age, eGFR decreased to <35 ml / min per 1.73 m2

UO<0.3 ml/kg/BW/hour during more than 24 hours, or anuria during 12 hours







Based on the pathogenesis Etiology of Acute Kidney Injury divided into 3 groups;

1. Prerenal, Diseases that causes renal hypo perfusion without causing disruption of the renal parenchyma, for example:

  • Hypovolemia
  • Decreased cardiac output
  • Changes in renal systemic vascular resistance ratio
  • Renal hypo perfusion with impaired renal autoregulation
  • Hyper viscosity syndrome

2. Renal, Diseases which directly cause disruption of the renal parenchyma.

  • Obstruction renovaskuler
  • Glomerular disease or renal microvascular
  • Acute tubular necrosis
  • Interstitial nephritis
  • Obstruction and deposition Intratubular

3. Post Renal, Diseases associated with urinary tract obstruction, for example:

  • Ureteral obstruction
  • Bladder neck obstruction
  • Obstruction of the urethra

Clinical symptoms of Acute Kidney Injury vary widely, depending on the stage of Acute Kidney Injury and etiology. Ranging from asymptomatic to severe to require renal replacement therapy. Clinical classification of Acute Kidney Injury is as follows:

  1. Acute Kidney Injury Oliguria, with a 24-hour urine output <400 cc
  2. Acute Kidney Injury non oliguria, normal urine production
  3. Acute Kidney Injury in Chronic Renal Failure (Acute on Chronic Renal Failure): AKI occurred in patients who have already had CKD (Chronic Kidney Disease).

As supporting investigations, Not required expensive diagnostic investigations to establish the diagnosis of Acute Kidney Injury. Investigations more often done in the enforcement of the etiology of Acute Kidney Injury.

Blood biochemical examination. Currently used as biological markers (biomarkers) for diagnosis is creatinine levels of serum or urea-N, when both parameters of this diagnosis is influenced by many other factors.

Urine production per unit time is how to make a diagnosis according to RIFLE criteria. Some parameters are frequently used osmolality, sodium excretion fraction (FENa) and examination of the sediment. To calculate FENa (fraction excretion of sodium) used the formula:  FENa = (Na urine levels x serum creatinine levels) / (serum Na levels x urine creatinine levels) x 100

Radiological examination which can quickly know the anatomy of the kidney is ultrasound. At AKI pre-renal and renal anatomy of the kidney is usually normal, unless previously existing chronic kidney disease (CKD), the kidneys may seem smaller. On suspicion of obstruction post renal therefore necessary stone plain abdominal.

The results of diagnostic investigations that are essential and can distinguish the three etiology Acute Kidney Injury as in Table of The essential diagnostic investigations, as below,

Diagnostic investigations


Renal (ATN)


Ratio BUN/Creatinine >20:1 20 : 1
FENa <1% > 3%
Specific gravity >1.020 1.010-1.020
Osmolality urine >500 mOsm 250-300 mOsm
Natrium urine <20 mmol/day > 40 mmol/day
Sediment Granular cast Hyaline cast Red cell cast
USG normal normal Hydro nephrosis pyelonephritis



Complications of Acute Kidney Injury

1. Excess intravascular fluid

• Pulmonary edema

• Acute left heart failure


2. Metabolic acidosis


3. Electrolyte Disorders

• hyperkalemia


4. Some of the compilation of Acute Kidney Injury else to note

• hyperphosphatemia and hypocalcemia,

• hematologic complications e.g. anemia, bleeding

• gastrointestinal complications: gastrointestinal bleeding

• infection


There are two types of treatment in the management of the complications of Acute Kidney Injury, namely:

1. conservative therapy (supportive)

2. Renal Replacement Therapy (RRT)

It should be noted in addition to treatment for complications of Acute Kidney Injury, should also be given therapy to the etiology of Acute Kidney Injury.

Conservative therapy is the use of drugs or fluids in order to prevent or reduce the progression, morbidity and mortality due to complications of Acute Kidney Injury. The principle of conservative therapy:

a) Avoid nephrotoxic drugs

b) Avoid circumstances that cause and extracellular fluid volume depletion and hypotension

c) Avoid radiological examinations with contrast no strong indication

d) protein proportional Diet

e) treatment according to etiology Acute Kidney Injury


Table of Conservative Therapy (Supportive) in Acute Kidney Failure





• Fluid overload • Salt limiting (1-2 gram/day) and water (<1   litter/day)
• Hyponatremia


• Fluid limiting (< 1 liter/day)
• Avoid fluids hypotonic (including dextrose 5%)
• Hyperkalemia




• Limit intake of potassium (<40 mmol / day)
• Avoid potassium supplements and potassium-sparing diuretics
• Give resin “potassium-binding ion exchange” (kayaxalate)
• Give glucose 50% 50 cc + insulin 10 units
• Give sodium bicarbonate (50-100 mmol)


Currently there is no established guidelines based on evidence based medicine to determine the initiation (start) Renal Replacement Therapy (RRT) in patients with Acute Kidney Injury in critical condition. Indications to start dialysis in patients with Acute Kidney Injury is very different from the indication in patients with Chronic Kidney Disease. Very appropriate if we use the criteria of glomerular filtration rate or creatinine levels in the blood as it is used to initiate Renal Replacement Therapy in patients with terminal renal failure.
In patients with Acute Kidney Injury, Renal Replacement Therapy indicated very broad, depending on the clinical condition encountered. Currently the criteria commonly used form the basis for initiation of dialysis in Acute Kidney Injury is the clinical symptoms of excess fluids and biochemical signs of the imbalance of electrolytes such as hyperkalemia azotemia, or metabolic acidosis. RRT indication on Acute Kidney Injury is as shown in Table below:

Table of Indications Initiation Renal Replacement Therapy in Acute Kidney Injury

Metabolic disorders









BUN > 76 mg/dl

BUN > 100 mg/dl

Hyperkalemia > 6 mEq/L

Hyperkalemia > 6 mEq/l (with disorders of EKG)


Hypermagnesemia > 8 mEq/L

Hypermagnesemia > 8 mEq/l (with anuria or loss tendon reflex













pH > 7,15

pH < 7,15















Indications and criteria for the initiation of Renal Replacement Therapy (RRT) in Acute Kidney Injury in ICU (Quoted from: Bellomo R, Ronco C. Kidney Int 1998; 53 (66): S106-109) :

  1. Oliguria (urine output <200 cc / 12 hours)
  2. Anuria / severe oliguria (urine output <50 cc / 12 hours)
  3. Hyperkalemia (K +> 6.5 mmol / L)
  4. Severe acidosis (pH <7.1)
  5. Azotemia (urea> 30 mmol / liter)
  6. Severe clinical symptoms (especially pulmonary edema)
  7. Uremic encephalopathy
  8. Uremic pericarditis
  9. Neuropathy / myopathy uremic
  10. Dysnatremia weight (NA> 160 or <115 mmol / L)
  11. Hyperthermia / hypothermia
  12. Overdose of drugs that are dialyzed if uric acid levels <15 mg / dl


When available:

  • One of the above symptoms can already be an indication for initiation of dialysis
  • Two of the above symptoms is an indication for the immediate initiation of dialysis, and
  • More than two is an indication for the immediate initiation of dialysis, although the level is not reached listed in the table yet.



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