What is acute kidney injury
Most kidney diseases are progressive. As the glomeruli are gradually destroyed, blood creatinine gradually rises. This gradual decline in renal function is called chronic renal failure.
Generally speaking, sclerosis and necrosis of glomeruli are irreversible, and glomerular necrosis is small in one batch. Therefore, chronic renal failure is also irreversible, and the gradual increase in blood creatinine cannot be reduced to normal. However, active treatment is still required. The purpose of active treatment is not to restore blood creatinine to normal, but to protect the remaining glomeruli from damage. In other words, the purpose of active treatment is to avoid further increases in blood creatinine.
There is also a special case. After the kidney is injured, the blood creatinine rises rapidly in a short time, which is called acute renal function injury.
According to the degree of increase in blood creatinine or decrease in urine output, acute kidney injury can be divided into 3 levels:
During the risk period, serum creatinine increased by 1.5 to 2.0 times or increased by ≥ 26.5 micromoles per liter (μmol/L), or urine output was less than 0.5 ml/kg/hour for more than 6 hours.
During the injury period, the blood creatinine increased by 2 to 3 times, or the urine output was less than 0.5 ml/kg/hour for more than 12 hours.
The time when serum creatinine increased by more than 3 times or blood creatinine ≥353.6 micromole per liter (μmol/L) and at least 44.2 micromole per liter (μmol/L) during failure, or urine output was less than 0.3 ml/kg/hour More than 24 hours or no urine for more than 12 hours.
Common causes of acute kidney injury
The common causes of acute kidney injury are grouped into 3 categories:
Prerenal cardiac arrest causes transient blood supply to the kidneys to stop, or massive blood loss, severe dehydration, etc., resulting in decreased blood volume and insufficient blood supply to the kidneys.
Postrenal causes, such as huge ureteral calculi, clots, etc., block the urinary tract, abdominal tumors, prostatic hyperplasia, close the ureter, etc., cause urinary tract obstruction and cause acute kidney injury.
Renal causes refer to acute kidney injury caused by kidney disease itself. The most common causes are acute tubular necrosis, acute tubular interstitial nephritis, and a small number of glomerular diseases and renal vascular diseases. Renal cause is the most common cause of acute kidney injury. It is ubiquitous in life. If you don’t pay attention to it, you can “step on the pit”, such as: eating a meal of crayfish; eating a fish bile raw, causing acute glomerular necrosis Cause acute kidney injury; a whim of fitness, or a night run caused acute myolysis; poisonous bee sting caused acute tubulointerstitial nephritis, etc.
According to statistics, common drugs that are likely to cause acute kidney injury include: all antibiotics, including penicillins, cephalosporins, aminoglycosides, quinolones, sulfonamides, and anti-tuberculosis drug rifampin; non-steroidal anti-inflammatory drugs (solutions) Thermal analgesics), including aspirin, acetaminophen (tylenol), indomethacin (indomethacin), naproxen, naproxen, diclofenac (voltarin), ibuprofen, nimesulide, ro Noncoxib, celecoxib, etc.; there are also some Chinese medicines.
There is another situation, which is more common clinically. Originally, normal kidneys can have acute kidney injury after encountering the above conditions, but the more common clinical situation is that they have chronic kidney disease and their renal function has declined. Acute kidney injury is more likely to occur after severe infection or improper medication. This condition is medically called acute kidney injury based on chronic renal failure, and it is a common condition in nephrology. In fact, this old man is an acute kidney injury based on chronic renal failure. After this condition stabilized, we performed renal function imaging for this old man, which is the gold standard for judging renal function. The results showed that her glomerular filtration rate was only 37.25 ml/min, which was already moderate to severe renal failure. Up. In other words, her kidney function had declined before she had a shoulder joint infection and took a lot of medication. So why was her blood creatinine normal at the beginning of her hospitalization?
This is the "short board" of using blood creatinine to determine renal function. Serum creatinine is produced by human muscles and meat in food. This old man is relatively thin, has muscle atrophy, has a small appetite, and produces very little blood creatinine. Even if the kidney function is not good, the blood creatinine may be normal or slightly elevated. The blood creatinine value alone is prone to deviations. How was her kidney damaged before?
It turned out that the old man had found high blood pressure for at least 6 years, with a maximum blood pressure of 160/100 millimeters of mercury (mmHg). Prior to this, her blood pressure was not well controlled. Long-term high blood pressure led to her hypertensive kidney disease. In other words, on the basis of hypertensive kidney disease, because of severe infections and extensive use of antibiotics, analgesics, and antipyretics, she caused acute kidney injury on the basis of chronic renal failure.
Treatment of acute kidney injury
Although acute kidney injury is fierce, many cases often do not require dialysis, and even hemodialysis aggravates the kidney ischemia and may aggravate the condition. Sometimes eliminating the acute cause can solve the problem. The original acute kidney injury with normal renal function, when the cause is eliminated and treated properly, the blood creatinine can be reduced to the original level, and the kidney function can be restored to normal in most cases.
For acute renal ischemia caused by cardiac arrest, timely cardiopulmonary resuscitation is the most effective treatment; for blood loss caused by massive blood loss and severe dehydration, timely blood transfusion, fluid supplementation, and blood volume supplementation are the most effective treatment.
In internal medicine or surgery, the best treatment is to relieve the obstruction.
In the treatment of acute kidney injury caused by drugs, suspicious drugs should be stopped first, and the intake should be strictly controlled for those with oliguria and anuria to avoid aggravation of edema. For acute tubulointerstitial nephritis, glucocorticoid therapy can be used to reduce inflammation and necrosis and promote the repair of renal tubules. Hormone therapy can also be used for short-term treatment of acute tubular necrosis caused by myolysis.
Hemodialysis may aggravate renal ischemia, while blind hemodialysis may aggravate kidney damage. Therefore, it is necessary to strictly grasp the indications of hemodialysis and use hemodialysis with caution. Especially for acute kidney injury caused by non-steroidal anti-inflammatory drugs, we must be more cautious. However, when the disease progresses rapidly and severe edema, heart failure, acidosis, etc. threaten the life of the patient, urgent dialysis treatment is needed to save lives.
