Renal failure

　　The causes of renal failure are as follows:

　　Chronic renal failure

　　The causes of chronic renal failure mainly include diabetic nephropathy, hypertension, renal arteriosclerosis, primary and secondary glomerulonephritis, renal tubulointerstitial lesions (chronic pyelonephritis, chronic uric acid nephropathy, obstructive nephropathy, drug-induced nephropathy, and so on), renal vascular lesions, hereditary kidney diseases (such as polycystic kidney disease, hereditary nephritis), and so on.

　　Acute renal failure

　　According to the traditional classification method, acute renal failure is divided into pre-renal, renal, and post-renal types. Since pre-renal acute renal failure does not resolve for a long time and develops into acute tubular necrosis, and there are significant differences in treatment between the two, it is necessary to make a clear distinction. The diagnosis of pre-renal acute renal failure mainly depends on the following points: there are factors causing a decrease in effective blood volume, urine relative density > 1.020, urine osmolality > 500mmol/L, sodium excretion fraction < 1%, renal failure index < 1mmol/L, and an increase in urine volume after fluid replacement.

　　Among the pre-renal factors, severe infection is the most common, mainly acute gastroenteritis, severe pneumonia, chronic congestive heart failure, bleeding due to various causes, including trauma, intraoperative bleeding, upper gastrointestinal bleeding, and so on.

　　Post-renal acute renal failure, some are due to bilateral ureteral calculi, and some are due to tumor metastasis compression, including rectal cancer, fallopian tube cancer, cervical cancer, gastric cancer, and bladder cancer. There are also recurrences and metastases after tumor surgery.

　　In renal acute renal failure, there are glomerular and microvascular lesions, acute tubular necrosis, acute interstitial nephritis, including drug hypersensitivity acute interstitial nephritis, infection-related acute interstitial nephritis. In renal acute renal failure, kidney damage caused by drugs accounts for 47.1%. Other causes include infection, fish bile poisoning, rhabdomyolysis syndrome, pesticide poisoning, multiple myeloma renal damage, and so on.

　　Renal failure often complicates with hypertension, anemia, heart failure, renal osteodystrophy, and so on.

　　Hypertension

　　In the absence of antihypertensive medication, systolic blood pressure ≥ 139mmHg and/or diastolic blood pressure ≥ 89mmHg, hypertension is classified into grade 1, 2, and 3 according to blood pressure levels. Systolic blood pressure ≥ 140mmHg and diastolic blood pressure

　　Anemia

　　Hypochromia is defined as having a lower count of red blood cells, hemoglobin levels, and hematocrit in a certain volume of circulating blood than the normal standard. Among them, hemoglobin is the most important. In adult males, it is considered anemia if it is below 120g/L (12.0g/dl), and in adult females, it is considered anemia if it is below 110g/L (11.0/dl).

　　Heart failure

　　Heart failure, also known as 'myocardial failure,' refers to the condition where the heart is unable to pump an adequate supply of blood to meet the needs of the venous return and body tissue metabolism. It is often caused by various diseases that weaken the myocardial contraction ability, reducing the cardiac output and not enough to meet the body's needs, leading to a series of symptoms and signs.

　　Renal osteodystrophy

　　Osteodystrophy caused by chronic renal failure is a bone metabolic disease. Abbreviated as renal osteodystrophy. It is characterized by calcium-phosphorus metabolism disorders, acid-base imbalance, skeletal deformities, and can cause secondary hyperparathyroidism. Skeletal manifestations include osteoporosis, osteomalacia, fibrocystic osteitis, osteosclerosis, and metastatic calcification. It may cause growth and development disorders in children.

　　In addition, kidney failure may also be accompanied by pericarditis, myocardial disease, electrolyte imbalance and acid-base imbalance, fractures, infection, and other complications.

　　Acute renal failure is a group of clinical syndromes caused by an acute decrease or loss of kidney physiological function due to different causes.

　　The clinical manifestations are mainly significant azotemia, electrolyte imbalance, and acid-base imbalance, with most patients having oliguria or anuria. In some cases, such as acute renal failure caused by aminoglycoside antibiotics (gentamicin, etc.), urine output may not decrease. Acute renal failure is a common critical kidney disease in pediatrics, with a high mortality rate and an increasing incidence trend year by year.

　　Chronic renal failure is the result of kidney damage caused by various causes and progressive deterioration, which is the late stage of various chronic kidney diseases, characterized by the retention of toxins and metabolic disorders.

　　Chronic renal failure is a serious condition with extremely complex clinical manifestations. Chronic renal failure is divided into 4 stages according to the degree of renal function damage: ① Decreased renal reserve, with no symptoms. ② Renal insufficiency, compensated. ③ Renal insufficiency, decompensated (azotemia), with fatigue, loss of appetite, and anemia. ④ Uremia stage, with uremic symptoms.

　　1. Keep warm

　　Surveys have found that patients with deteriorating kidney function in winter far exceed those in other seasons. The main reason is that under low temperatures, blood vessels constrict, blood pressure spikes, urine output decreases, blood coagulation strength increases, which easily leads to kidney problems.

　　2. Do not take medicine indiscriminately

　　Many over-the-counter painkillers, cold remedies, and traditional Chinese herbal medicines have kidney toxicity. Do not take them without a doctor's prescription, and you should also be aware of the side effects of antibiotics and painkillers prescribed by a doctor.

　　3. Avoid overeating

　　Eating too much protein and salt will increase the burden on the kidneys. In addition, sports drinks contain extra electrolytes and salt, which people with kidney disease need to be careful of.

　　4. Treat the common cold

　　If you have a cold that comes and goes, or if you have high blood pressure, edema, or small bubbles in your urine after a cold, it is best to consult a nephrologist for screening.

　　Be cautious of recurrent tonsillitis

　　When the throat or tonsils are infected with Streptococcus, it is necessary to be cured thoroughly, otherwise, it is easy to lead to kidney inflammation.

　　6. Drink enough water and do not hold urine

　　Urine retention in the bladder is like a blocked drain, which is easy to breed bacteria. Bacteria can infect the kidneys through the ureter.

　　7. Control diabetes and hypertension

　　Poor blood pressure control and long-standing diabetes can lead to vascular sclerosis, and the kidneys are composed of millions of microglomeruli. Poor control of blood sugar and blood pressure leads to rapid kidney damage.

　　8. Do not drink well water and river water of unknown composition

　　To avoid damage to the kidneys from excessive levels of heavy metals such as lead, cadmium, and chromium.

　　9. Urological stones need to be treated

　　The absence of pain in kidney stones does not mean that they are cured, especially for ureteral stones, which can easily cause hydronephrosis. Over time, the kidneys may be completely damaged without the patient being aware of it.

　　10. Regular check-ups

　　It is best to have urine and blood creatinine and blood urea nitrogen tests every six months. During pregnancy, the renal burden on women increases, and renal function should be monitored to prevent the development of uremia due to pregnancy toxemia.

　　The following laboratory tests are required for renal failure:

　　Laboratory examination

　　1. Urine examination: Urinary routine protein is generally >2.0g/L, and when renal function damage is significant in the late stage, urinary protein may actually decrease. The specific gravity of morning urine may decrease to below 1.018 or remain fixed at around 1.010.

　　2. Blood examination: Since anemia is common in CRF, routine blood tests are important for the diagnosis of CRF. Other tests include determination of plasma total protein, albumin, globulin, and their ratios; determination of blood electrolyte levels.

　　Serum creatinine (Scr) and blood urea nitrogen (BUN) levels rise, and the determination of urine concentration and dilution function indicates a decrease in内生肌酐清除率 (Ccr).

　　3. Liver function and hepatitis B two pairs and half examination.

　　4. Serum immunological examination includes serum IgA, IgM, IgG, complement C3, complement C4, T lymphocyte subsets, B lymphocyte population CD4/CD8 ratio, etc.

　　5. Nutritional status indicators detection - determination of serum total protein, serum albumin, serum transferrin, and low molecular weight protein. Extremely low levels of cholesterol are also considered as indicators of malnutrition.

　　Imaging examination

　　1. Renal ultrasound - renal cortex thickness

　　2. Other routine examinations include electrocardiogram, X-ray chest film, bone film, and gastroscopy, as well as certain special examinations such as X-ray contrast, radionuclide renal scan, CT, and magnetic resonance imaging, which are helpful in determining the shape, size, and whether there is urinary tract obstruction, hydronephrosis, calculi, cysts, and tumors in the kidneys.

　　The dietary care principles for renal failure patients are as follows:

　　1 It is advisable to consume high-quality protein. Renal failure patients should strictly control their protein intake and opt for high biological value protein foods such as eggs, lean meat, etc.; avoid consuming low biological value protein, such as beans, bean products, gluten products, stone fruits, etc. Control the intake of rice and wheat products in staple foods and replace them with wheat starch, potato flour, and lotus root starch to reduce the intake of plant proteins and avoid the production of excessive nitrogenous waste in the body. It is recommended that patients consume 30-40g of high-quality protein per day.

　　2 Consume sufficient calories Patients with renal failure should ensure sufficient calorie intake every day when limiting protein intake, including carbohydrates and fats. Starch is the first choice, followed by corn flour, potato flour, and lotus root flour as staple foods to meet energy needs. The calorie intake of patients with renal failure is 30-35 kcal/kg·d, with a total daily intake of 2000-3000 kcal, and 85%-90% of the energy comes from starch, a small amount of rice and noodles, and fat.

　　3 Limit salt intake Chronic renal failure patients should strictly control the intake of salt. Excessive sodium intake can increase the burden on the kidneys, causing hypertension and edema. It is recommended to consume 2-3g of salt per day, and less than 1g per day in cases of severe edema and hypertension. Avoid eating preserved foods such as salted eggs and salted vegetables, and use other seasonings to improve the taste of food to enhance appetite.

　　4 Limit potassium intake Patients with poor kidney function cannot effectively metabolize excessive potassium. Therefore, it is recommended to avoid vegetables and fruits with high potassium content, such as bananas, oranges, and various green vegetables, and avoid eating raw vegetables; other foods such as coffee, strong tea, juice, and chicken essence also have high potassium content, and should be avoided.

　　5 Control water intake Patients with renal failure have water and sodium metabolism disorders, and excessive water accumulation in the body cannot be excreted, forming edema. Instruct patients to drink small amounts of water frequently, swallowing a sip of water slowly multiple times; chew gum; and in summer, chew ice cubes to improve thirst symptoms. The amount of liquid intake through the mouth should not exceed the total urine output plus 500ml.

　　6 Increase calcium intake Patients with renal failure are prone to osteoporosis and muscle cramps due to low blood calcium levels. Therefore, it is recommended to consume foods high in calcium, such as green vegetables and sesame sauce. Try to reduce the intake of phosphorus in food, such as when cooking fish and lean meat, you can boil them in water and then remove them before stir-frying, which can effectively reduce the phosphorus content in fish and meat.

　　7 Diet should be light and easy to digest. Avoid spicy and刺激性 foods such as lamb and seafood. Avoid hard and fried foods to prevent gastrointestinal bleeding and prefer soft foods. In addition, increase the intake of dietary fiber to improve glucose tolerance and lower cholesterol levels.

　　The strategies to delay or reverse the progression of early and middle-stage chronic renal failure are as follows:

　　Primary prevention

　　Timely and effective treatment of existing kidney diseases or diseases that may cause kidney damage (such as diabetes, hypertension, etc.) is called primary prevention to prevent the occurrence of CRF.

　　Secondary prevention

　　Timely treatment of mild to moderate chronic renal failure (CRF) can delay, stop, or reverse the progression of CRF and prevent the occurrence of uremia, which is called secondary prevention. The basic strategies of secondary prevention include the following aspects.

　　Treatment of the underlying cause

　　Such as adhering to long-term and reasonable treatment for hypertension, diabetic nephropathy, glomerulonephritis, and so on.

　　Avoiding or eliminating the risk factors for the rapid deterioration of CRF

　　Such as recurrence or acute exacerbation of kidney basic diseases, uncontrolled severe hypertension, acute hypovolemia, acute decrease in local blood supply of the kidney, severe infection, tissue trauma, urinary tract obstruction, other organ failure (such as severe heart failure, severe liver failure), improper use of nephrotoxic drugs, and so on.

　　Blocking or inhibiting various pathways of progressive damage to renal units

　　Protecting the remaining renal units, the indicators such as blood pressure, blood glucose, urinary protein quantification, and glomerular filtration rate (GFR) should all be controlled within the 'ideal range'. ①Strictly control hypertension: Continuous and effective control of hypertension for 24 hours is important for protecting target organs and is one of the main factors for delaying, stopping, or reversing the progression of CRF. The blood pressure of CRF patients before dialysis (GFR≥10 ml/min) should generally be controlled below 130/80 mm Hg. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have good antihypertensive effects and also have unique effects of reducing hyperfiltration and proteinuria. ②Strictly control blood glucose: Fasting blood glucose should be controlled at 90-130 mg/dl, and glycated hemoglobin <7%, which can delay the progression of CRF. ③Control proteinuria: Keeping the patient's urine protein below 0.3 g/day or gradually reducing microalbuminuria can improve their long-term prognosis, including delaying the progression of CRF and improving survival rates. ④Dietary treatment: Applying low-protein, low-phosphorus diet, and using essential amino acids or α-keto acids alone or in combination may have the effect of reducing glomerular sclerosis and renal interstitial fibrosis. ⑤Other: Actively correcting anemia, reducing the accumulation of uremic toxins, using statins for lowering blood lipids, quitting smoking, and other measures may have a certain protective effect on renal function.

　　Acute renal failure can be treated with hemodialysis, which can be performed by standard hemodialysis (HD) or CRRT (or +Hn), while providing treatments such as fluid replacement, anti-inflammatory drugs, and hormones for the underlying cause.