Pathology of acute renal failure

2021-01-26 12:00 AM

If there are signs of jaundice, jaundice is a manifestation of the common liver damage caused by Leptospirosis, haemolytic malaria.

General and epidemiology

Outline

Acute renal failure is a syndrome that occurs when kidney function (mainly glomerular filtration) is rapidly declining, occurring suddenly in patients without previous renal failure or in patients with pre-existing renal impairment. romantic. The glomerular filtration rate can be severely impaired but may be completely reversed naturally or under the influence of treatment of the cause. Acute renal failure is clinically characterized by anuria, but there are cases where the urine remains conserved. A recent diagnosis of acute renal failure is based on an increase in blood creatinine compared with known basal creatinine: greater than 50mmol / l for basal creatinine less than 250 mmol / l or more than 100 mmol / l for basal blood creatinine over 250 mmol / l.

Epidemiology

Acute renal failure is a relatively uncommon syndrome. In fact, the frequency of this disease can only be assessed by the number of annual hospitalizations: 1-3% of patients are admitted annually.

The prognosis of acute renal failure is usually good if the recovery of kidney function is progressively improved. However, it is important to take into account the aggravating risk factors for acute renal failure: aetiology, ageing, ataxia, in combination with other organ failure, treatment conditions (dialysis, nutrition) and finally the experience of the treatment team.

Pathophysiology

The glomerular filtration function in acute renal failure is reduced or completely lost, resulting from the following mechanisms:

Decreased blood flow through the kidneys (hypovolemia, shock).

The resistance of the arterioles is reduced (post-glomerular dilatation).

The resistance of the arterioles to increase (vasoconstriction before glomeruli).

Glomerular pressure (Baoman cyst) increases (blockage in the lumen of the renal tubule or on the secretory tract).

In addition, acute renal failure may also be due to decreased renal vascular permeability, but the current mechanism is not known.

Reason

Pre-renal causes (functional acute renal failure)

The main causes of functional acute kidney failure include:

Extracellular dehydration:

Loss of skin (sweat, burns).

Loss from the gastrointestinal tract (vomiting, diarrhoea, fistula).

Loss through the kidneys:

Diuretic treatment is too strong.

Osmotic polyuria in decompensated diabetes and in obstructive removal syndrome.

Chronic nephritis

Adrenal insufficiency.

True reduction in blood volume:

Severe nephrotic syndrome.

Decompensated cirrhosis of the liver.

Congestive heart failure.

Hypotension in shock conditions: heart, infection, anaphylaxis, haemorrhage.

Hemodynamic acute renal failure (due to ACE inhibitors, angiotensin II receptor inhibitors, non-steroid anti-inflammatory, calcineurins inhibitors)

Renal causes (acute renal failure)

Acute tubular inflammation:

The most common cause of acute physical failure (80%).

The leading account is to switch to acute functional renal failure.

In Vietnam, it is often caused by haemoglobinuria, and carp bile poisoning.

Poisoning by heavy metal salts: As, Pb, Hg.

Intravascular haemolysis due to wrong blood type transfusion, quinine, fungal poisoning.

Due to drugs: antibiotics (Aminoxides, Amphotericin B), contrast drugs.

Acute glomerulonephritis:

Due to the rapid progression of glomerulonephritis. Often necrotic and extracellular glomerulonephritis in the case of necrotizing vasculitis, or intra-membrane proliferative glomerulonephritis in the case of lupus, rheumatoid purpura. In addition, acute renal failure due to rapid progression of glomerulonephritis is also common in Goodpasture syndrome.

Acute interstitial nephritis:

Due to Bacteria: Acute pyelonephritis.

Due to Drug Poisoning: Usually through an immune-allergic mechanism. In addition to acute renal failure, there is also an increase in blood and urine acidophils, erythema, and hepatocellular destruction.

Post-Renal Causes (Obstructive acute renal failure)

Ureter stone.

Fibroids, prostate cancer.

Benign or malignant pelvic tumours (bladder tumours, cancer of the uterus, cervix, rectum).

Sclerosis of the peritoneum.

Post peritoneal metastasis (rare).

Tuberculosis atrophy of two ureters.

Clinical and subclinical

Clinically, acute renal failure usually progresses through the following stages

Initial stage

As the infiltration and attack phase of the pathogen, progressing depending on the type, in poisoning patients, rapid progress can lead to anuria immediately, in shock patients, it occurs quickly or slowly depending on according to the cause of shock and resuscitation techniques at first.

Minimize anuria

Urinary retention when the number of urine <500ml / 24 hours (or less than 20ml / hour), can start slowly or immediately on the first few days of illness, lasting an average of 1-2 weeks, when oliguria lasts more than 4 weeks then needs to see if the kidneys have shell necrosis, rapid progression of glomerulonephritis, inflammation around the kidney arterioles, ureter blockage stones.