Pediatric liver failure

Introduction to Pediatric Liver Failure Hepatic failure (HF) is also known as fulminanthepatitis and severe hepatitis. It is a very dangerous clinical syndrome caused by various causes (in China, viral hepatitis is the most common) leading to extensive necrosis of liver cells or severely impaired liver function. It is the end result of severe liver disease. basic knowledge The proportion of illness: 0.001--0.002% Susceptible people: children Mode of infection: non-infectious Complications: shock, gastrointestinal bleeding, ascites, hyponatremia

Causes of liver failure in children

(1) Causes of the disease

1. Infectious viral hepatitis is the first place. In recent years, the number of people infected with hepatitis B virus has increased significantly. In addition, EB virus, herpes virus, cytomegalovirus, etc. can be caused.

2. Poisoning includes isoniazid, rifampicin, acetaminophen and tetracycline and other drug poisoning, poisoning and other food poisoning and chemical poisoning such as carbon tetrachloride, snake bites and so on.

3. Hereditary metabolic defects A small number of hepatolenticular degeneration, galactosemia, fructose intolerance, tyrosinemia and glycogen accumulation syndrome type IV can also occur liver failure.

4. Others (1) Liver brain steatosis syndrome, Reyes syndrome.

(2) severe combined trauma, major surgery, extensive burns, sepsis, ischemia and hypoxia damage, shock for various reasons, etc.

(3) Other diseases that invade the liver such as malignant proliferative histiocytosis, Langhans cell histiocytosis and the like.

(two) pathogenesis

Liver failure occurs after hepatocytes are attacked again on the basis of liver damage. The occurrence of liver failure is the result of synergistic effects of various factors. Liver necrosis is the root cause of liver failure. In recent years, people have been involved in apoptosis. The research and understanding of the gradual deepening, the research and understanding of liver necrosis continue to deepen.

1. Viral factors Hepatic necrosis caused by hepatitis virus accounts for about 85% to 95%, of which HBV, HCV is more, HAV, HEV is less, HDV is occasionally seen, and the effect of HGV-induced liver necrosis is still controversial.

2. Inflammatory mediators mainly include monophage macrophages (Macrophage), mononuclear factors (Monokine), endotoxin (ET) and leukotriene (LT), which have the presence of hepatic necrosis. Important role, sometimes even a key role.

3. Immune response In the pathogenesis of liver failure, the most studied and most concerned is the immunological changes leading to liver necrosis. The immunological studies on liver necrosis caused by HBV, HAV and HDV are more in-depth, taking HBV as an example. ,There are:

(1) Cytotoxic T lymphocyte (CTL) mediated cytotoxic effects.

(2) Cytokines: Cytokines are the products of immune responses and promote immune damage. They are lymphotoxins secreted by target cells. They form a chain reaction of cytokines, leading to the continuous expansion of immune damage, which is associated with liver necrosis. The main cytokines are tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-6, IL-8, platelet activating factor (PAF), transforming growth factor-1 (TGF-1).

4. Other factors

(1) Drugs, poisons: The common feature of liver necrosis caused by drugs and poisons is the history of drug use and exposure to poisons, and these substances have clearly defined their hepatotoxic effects.

(2) Metabolic abnormalities: mainly Wilson disease and Reye syndrome.

(3) ischemia: the typical is shock liver.

5. The pathological features caused by hepatitis virus, drug poisoning and poisonous poisoning are extensive hepatocyte necrosis, liver cells disappear, and liver volume shrinks. Generally, there is no hepatocyte regeneration, the reticular scaffold collapses, residual hepatic cells are cholestatic, and inflammatory cells infiltrate in the portal area.

Pediatric liver failure prevention

First, work on time to prevent infection. Patients with liver disease should pay special attention to rest because the liver has the function of storing blood and regulating blood volume. The greater the amount of activity, the smaller the blood flow in the liver, so the less nutrients reach the liver, the slower the recovery, so rest is very important for patients with liver disease. The amount of activity is based on the principle of not causing fatigue. Because of the low immunity of patients with liver disease, it is easy to cause infections, such as colds, bronchitis, urinary tract infections, etc., according to changes in temperature, increase or decrease clothes.

Second, the diet is reasonable, pay attention to avoidance. The purpose of diet therapy for liver disease is to protect the damaged liver. The principle is high protein, high sugar, high vitamin and low fat. Diet should pay attention to the following points: 1, regular meals; 2, diet quantitative, each meal should not be full; 3, eat less greasy food is not easy to digest; 4, eat more fresh fruits, green leafy vegetables, foods containing more vitamins and rich Protein food. There are mainly fish and shrimp, eggs, milk, lean meat, soy products and so on.

Third, do not use drugs, check liver disease regularly. The patient should be prescribed by a doctor. Drugs that are harmful to the liver should be used as little as possible, and should be used with caution for tonics, health care drugs, and tea. Because many drugs have to be metabolized by the liver, indiscriminate use of drugs will inevitably increase the burden on the liver. Dietary tea can only play a supporting role. It is necessary to go to the hospital to review the liver function regularly, and if necessary, do a B-ultrasound examination to know the condition of your liver and use it regularly.

Fourth, proper exercise and enhance physical fitness. According to the physical condition, strengthening physical exercise, such as walking, swimming, etc., is conducive to enhancing physical fitness, improving immunity, and gradually enhancing self-immunity, which can protect the body and liver.

Five, supplement selenium and liver. The general immune function of patients with liver disease is low. The most obvious manifestation is that the virus in the body is difficult to completely remove, and the disease is easy to recur. Selenium is a powerful and effective immunomodulator, which can stimulate humoral immunity and cellular immune system, enhance the function of the immune system, and use the selenium malt powder and schisandra as the main raw material for the body to strengthen the liver, to nourish the liver, protect the liver and increase the liver disease. The appetite has a good effect, which is beneficial to improve various symptoms of patients with liver diseases. Selenium supplement can greatly improve symptoms such as loss of appetite, exertion and dullness in a relatively short period of time.

Pediatric liver failure complications Complications, shock, digestive tract hemorrhage, ascites, hyponatremia

Severe cases often complicated by hepatic encephalopathy and hemorrhage, especially gastrointestinal bleeding is the most common, bleeding can be up to shock, with ascites, cerebral edema, water and electrolyte imbalance, common hypokalemia, hypoproteinemia, low sodium It is very easy to have hypoglycemia and secondary infections.

Symptoms of hepatic failure in children Common symptoms Increased intracranial pressure, bloating, nausea and vomiting, loss of appetite, ascites, hemorrhage, phlegm, reflex, pterygium, tremor, diarrhea, behavioral abnormalities

Symptom typing

The clinical manifestations of patients with liver failure are progressive liver damage, varying degrees of hepatic encephalopathy, increased intracranial pressure, hemorrhage, etc., due to different causes, there are still symptoms of primary disease.

1. The classification of liver failure is not uniform. At present, most scholars in China believe that liver failure is divided into 3 types:

(1) fulminant hepatic failure: refers to the original liver-free disease, hepatic encephalopathy within 8 weeks after acute hepatitis, including acute severe hepatitis with encephalopathy within 2 weeks and subacute severe hepatitis with encephalopathy within 2 to 8 weeks .

(2) Delayed liver failure: refers to hepatic encephalopathy or other hepatic failure syndrome within 2 to 6 months after the onset of liver disease, which is more serious than the consequences of fulminant hepatic failure.

(3) Chronic liver failure: refers to the gradual deterioration of liver disease caused by chronic liver disease, and liver failure caused by viral hepatitis is called severe hepatitis in China.

2. Clinical manifestations

(1) Progressive liver damage: children with viral hepatitis, gastrointestinal symptoms are significantly aggravated, loss of appetite, nausea, vomiting, abdominal distension, occasional diarrhea; jaundice rapidly deepens, generally above moderate; liver progressive reduction, especially The right lobe of the liver is obvious, the liver atrophy progresses very rapidly after the disease is aggravated, and a few have spleen enlargement; children are more prone to edema and ascites, and severe exhaled have liver odor, which is a sign of poor prognosis in the late stage.

(2) Hepatic encephalopathy (hepatic encephalopathy) or hepatic encephalopathy (hepatic coma): According to different primary diseases, hepatic encephalopathy can be divided into endogenous and exogenous, endogenous and common fulminant hepatitis, onset Within a few days, you can enter a coma, no prodromal symptoms before coma; exogenous hepatic encephalopathy is a portal shunt encephalopathy, more common in cirrhosis, mainly with chronic recurrent stupor and coma, often with incentives, hepatic encephalopathy The post-survival time varies with the speed and extent of liver failure, with multiple onsets and coma gradually deepening.

1 staging:

A. Prodromal period: mild personality changes and behavioral abnormalities, such as excessive irritability, repeated language, or some words that are not related to the current environment, or a sticky note that is different from usual habits, etc., may have flapping tremors.

B. Pre-coma: abnormal mental and neurological, exacerbation of symptoms in the prodromal period, with confusion, sleep disorders, and behavioral disorders, with obvious neurological signs, such as hyperreflexia, increased muscle tone, obvious sputum, and tremor And EEG abnormalities, liver odor.

C. Stiffness: Mainly due to lethargy and severe mental confusion, various neurological signs continue or worsen.

D. Coma: Unconsciousness, can not wake up, when fainting, respond to discomfort and painful stimuli, tendon reflexes and muscle tension are still hyperthyroidism, when deep coma, various reflexes disappear, muscle tension decreases, pupil dilated, Excessive ventilation and paroxysmal convulsions, some patients with skin, mucosal bleeding, cerebral edema, bilateral pupils are not equal.

E. Awakening period: gradually improve, can answer questions, the above stages of the boundary can not be completely separated, the clinical performance can be overlapped in the early and late stages, when the disease develops or improves, the performance can be aggravated or reduced, hepatic encephalopathy with severe liver damage is often obvious Astragalus, liver odor, bleeding tendency, easy to be complicated by various infections, liver and kidney syndrome and brain edema.

2 type:

A. acute hepatic encephalopathy (acute hepatic encephalopathy): seen in severe viral hepatitis, cirrhosis decompensation, mostly due to some inducement.

B. fulminant hepatic encephalopathy: seen in severe hepatitis, the onset is rapid, rapid, and can enter a coma without a prodromal period.

C. Hepatic encephalopathy of chronic intermittent type: After cirrhosis or portal vein anastomosis, recurrent conscious disturbance, mental disorder, unconsciousness, slow development, remission, but easy relapse.

D. Temporary hepatic encephalopathy: seen in children with good liver function, for some reason to promote hepatic encephalopathy, but easy to control, in 1995, China's Pediatric Digestive Professional Group set the classification of hepatic encephalopathy.

(3) Increased intracranial pressure: about 80% of patients with cerebral edema, manifested as increased intracranial pressure, baby eyes are sluggish, screaming, irritability, vomiting, anterior bulging, older children may have severe headache, frequent ejection Vomiting, increased blood pressure, convulsions and disturbance of consciousness, accompanied by limb stiffness and twist, positive pathological reflex, high fever due to cerebral circulatory disorder, excessive heat, peripheral vasoconstriction caused pale skin, cyanosis of the extremities, cold, and sulcus When sputum, the pupils on both sides are not equal; when the occipital foramen magnum occurs, the bilateral pupils are scattered, the breathing rhythm is not uniform, and even pauses.

(4) Hemorrhagic phenomenon: Hepatic failure has different degrees of bleeding, light is skin mucosal bleeding or oozing, nose bleeding and gum bleeding are more common, severe visceral bleeding, gastrointestinal bleeding occurs most, can vomit blood or blood It can also spit coffee and tar-like stools, often caused by a large amount of bleeding, or aggravation of hepatic encephalopathy; there may be other parts such as hemoptysis, hematuria or intracranial hemorrhage, etc., major bleeding is often directly caused by death. the reason.

(5) Hypoglycemia: When the liver of the child is seriously damaged, the glycogen decomposition is weakened, and the vomiting cannot be eaten. The glycogen storage is significantly reduced, so it is prone to hypoglycemia and aggravate coma. Hypoglycemia can also occur simultaneously. I was neglected and ignored. The children were cold in the hands and feet in the morning, cold sweats, low blood pressure, or occasional paralysis. Children who were fasted without intravenous glucose infusion overnight were prone to hypoglycemia.

(6) Hepatorenal syndrome (HRS): HRS is a serious complication of advanced liver failure. The renal histology of the child can be completely normal or slightly damaged. If liver disease can be reversed, renal function can be improved, and HRS in liver failure. The incidence rate is about 30% to 50%, and the mortality rate is extremely high. HRS often appears in strong diuretics, a large amount of ascites, upper gastrointestinal bleeding or infection, there are also about 30% no incentives, the diagnosis points:

1 oliguria or no urine;

2 azotemia, serum creatinine > 133 mol / L;

3 early renal tubule function is good;

4 The effect of expansion is not obvious, pay attention to the identification of pre-renal azotemia, which can be quickly corrected after expansion.

(7) secondary infection: the incidence of concurrent infection in children with liver failure is higher, the most common bacteremia, but also complicated by pneumonia, biliary tract infection or urinary tract infection, the pathogen is Staphylococcus, Escherichia coli, Streptococcus or anaerobic infection may also occur, sometimes fungal infections are seen, the clinical manifestations of children are mainly fever, and focal symptoms are not easy to find, need to be carefully examined, or timely blood, urine, ascites and other body cavity fluid culture, in order to Clear diagnosis.

(8) water and electrolyte imbalance: children are prone to hypokalemia, which is due to vomiting, can not eat, a large number of applications of potassium and diuretics and glucocorticoids, increased aldosterone, a large amount of glucose, etc., potassium is too low Can be complicated by metabolic alkalosis, the latter is conducive to the production of ammonia, due to insufficient intake, malabsorption, hypoproteinemia and the use of diuretics, etc., may appear hypomagnesemia, magnesium can cause increased muscle excitability in children Hand, foot and ankle, sputum, similar to low calcium symptoms, advanced persistent hyponatremia, suggesting cell lysis and necrosis, poor prognosis, water and electrolyte balance disorder, but also due to improper rehydration.

Examination of liver failure in children

Serological examination

(1) Serum bilirubin: serum total bilirubin generally exceeds 171.0 mol/L (10 mg/dl), with an average daily increase of 17.1 mol/L (1 mg/dl) or more, with direct bilirubin elevation. the Lord.

(2) Separation of enzyme bile: adenine aminotransferase (ALT) and aspartate aminotransferase (AST) in severe liver disease decreased significantly, and it was separated from the increase of bilirubin, that is, "enzyme bile separation". Because alanine aminotransferase is mainly distributed in hepatocyte cytoplasm, mild hepatitis or some patients with liver disease, cell membrane permeability changes, enzymes in the cytoplasm are released into the blood, alanine aminotransferase is elevated; when liver cells are seriously damaged At the time, mitochondria are also involved, and the alanine aminotransferase in the blood is reduced. The aspartate aminotransferase is distributed in the hepatocyte cytoplasm and mitochondria. When the human is suffering from acute hepatitis, it is released into the blood, but it is inactivated faster, so it is lower than the alanine aminotransferase value. When the mitochondria is destroyed, the aspartate aminotransferase is released into the blood circulation. Increased blood concentration and greater than alanine aminotransferase, changed the ratio of alanine aminotransferase to aspartate aminotransferase, so monitoring alanine aminotransferase/aspartate aminotransferase is important for judging hepatocyte injury. The decrease in ratio indicates severe hepatocyte necrosis and prognosis. bad.

(3) Blood amino acid measurement: when the ratio of branch/aromatic amino acid is normal, the molar ratio is 3:1 to 4:1, and those with severe hepatitis are reduced to 1:1 to 1.5:1 or less. Free tryptophan is significantly increased, which plays an important role in promoting the occurrence of hepatic encephalopathy.

(4) Pre-albumin assay: early response to liver failure. Liver failure affects protein synthesis. The half-life of albumin in the body is about 20 days, and the pre-albumin is only 1.9 days, so its blood concentration in patients is earlier.

(5) AFP-positive: indicates that the liver cell regeneration ability is strong, found in normal newborns or liver cancer patients. AFP was also positive when hepatocytes were regenerated after liver injury. If the hepatocytes undergo progressive necrosis, the AFP changes from negative to positive, and the concentration gradually increases, indicating that hepatocytes are regenerated and the prognosis is good.

2. Coagulation examination

(1) prolonged prothrombin time or decreased prothrombin activity: important for diagnosis and estimation of prognosis. Mild prothrombin activity is less than 60%, and severe cases are often less than 40%, indicating poor prognosis.

(2) Diffuse intravascular coagulation related tests: abnormal red blood cell morphology, triangular, thorn-like or fragmented, progressive reduction of platelets, decreased fibrinogen, prolonged prothrombin time, are early indicators of disseminated intravascular coagulation . If fibrin degradation products (FDP) are found to increase and euglobulin dissolution time is shortened, there is fibrinolysis.

3. Pathogen detection using enzyme-linked immunosorbent assay or radioimmunoassay to detect serum viral hepatitis-associated antigen or antibody, or DNA probe hybridization to detect viral nucleic acid to determine the pathogen, if necessary, detect viral antigen by liver immunohistochemistry and in situ hybridization And viral nucleic acids. Blood culture and other tests should be performed multiple times for concurrent bacterial infections or fungal infections.

4. B-mode ultrasound can monitor the size of the liver, spleen, gallbladder, bile duct and other organs, ultrasound images, and the presence or absence of ascites, tumors and so on.

5. EEG examination of hepatic encephalopathy in the early stage, the patient is abnormal.

6. Liver biopsy uses 1s acupuncture vacuum suction technique for liver biopsy, which is easy to operate, safe and has a high success rate. Hepatitis and hereditary metabolic liver disease can help to confirm the diagnosis or help to judge the prognosis. The prognosis of patients with viral hepatitis with extensive and severe necrosis is poor; the prognosis of patients with cell swelling is better.

Diagnosis and diagnosis of liver failure in children

diagnosis

If the child has liver damage or exposure to poison, drugs and other medical history, clinical gastrointestinal symptoms are aggravated, jaundice is rapidly deepened, liver progressive reduction and signs of brain disease and bleeding, liver failure should be considered, early diagnosis should be combined with serology, Ultrasound, EEG and other auxiliary examinations, acute hepatic failure diagnosis must meet the following conditions:

1 did not have any liver disease performance before 8 weeks;

2 patients have clinical manifestations consistent with hepatic encephalopathy;

3 has liver odor;

4 routine blood biochemistry and hematology results suggest liver dysfunction and low, such as at least early in the early detection of serum transaminase values and prolonged prothrombin period, the latter is difficult to be corrected by vitamin K.

Differential diagnosis

The clinical manifestations of hepatic encephalopathy should be differentiated from low-sodium syndrome, hepatolenticular degeneration, and organic psychosis.

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