Hepatic encephalopathy in children

Introduction to Pediatric Hepatic Encephalopathy Hepatic encephalopathy (hepatic encephalopathy), also known as hepatic coma (hepaticcoma) or hepatic and brain syndrome, is caused by severe acute and chronic liver disease, which is based on metabolic disorders and is accompanied by complex neuropsychiatric syndrome. And development often marks liver failure, high mortality, hepatic encephalopathy including liver coma, liver coma and chronic intercourse hepatic encephalopathy. Acute causes of various causes, chronic liver disease can be associated with hepatic encephalopathy. basic knowledge The proportion of illness: 0.001% Susceptible people: children Mode of infection: non-infectious Complications: diarrhea, jaundice, shock, liver and kidney syndrome, hyperkalemia, cerebral palsy

Causes of hepatic encephalopathy in children

First, the cause of the disease:

On the basis of liver lesions, certain factors can cause coma in sick children. These factors are:

1, bleeding:

The most common cause of massive bleeding in the digestive tract, due to rupture of esophageal varices during cirrhosis, is likely to lead to hepatic encephalopathy.

2, infection:

Health search for severe liver disease combined with infection, pathogens and their toxins damage the liver, aggravate hepatocyte necrosis and dysfunction, and increase metabolism, so that the body's endogenous ammonia production increases.

3. Blood pH changes and hypokalemia:

When the blood pH increases, blood ammonia increases and easily enters the brain cells through the blood-brain barrier. Alkalosis is prone to occur when hypokalemia occurs, increasing the toxicity of ammonia.

Therefore, vomiting, diarrhea, use of diuretics or hormones, etc., potassium-extracting drugs can promote hepatic encephalopathy, respiratory hyperalkaline poisoning also aggravate ammonia poisoning.

4, drugs:

Due to the reduced liver detoxification function, many drugs such as acetaminophen, chlorpromazine sodium diureate, and aluminum chloride are susceptible to hepatic coma.

5, a lot of ascites:

When cirrhosis has ascites, a large number of abdominal punctures through the ascites, so that the intra-abdominal pressure suddenly decreases, the portal vein vasodilation returns to the liver, the blood is reduced, leading to liver ischemia and promoting hepatic encephalopathy.

Second, the pathogenesis:

The pathogenesis of hepatic encephalopathy is not fully understood.

Clinical and experimental studies are preliminarily believed to be due to a series of metabolic pathological biochemical processes caused by extensive degeneration and necrosis of hepatocytes. The toxic substances produced in the body accumulate in the body and act on the central nervous system, so that the normal physiological activities of brain tissue are severely inhibited. .

1. When blood ammonia is elevated in liver failure, the ornithine cycle is disordered, and the liver cannot synthesize urea normally, resulting in an increase in ammonia concentration in the blood.

2, -aminobutyric acid increased:

-aminobutyric acid (GABA) is an inhibitory transmitter of the brain, which is dying from the brain tissue of patients with hepatic encephalopathy. Increased -aminobutyric acid receptor 3. Na+-K+ adenosine triphosphatase activity is inhibited against fulminant hepatic failure The patient's study found that there were abnormal movements of Na+, K+, and water, that is, Na+ entered the cell and K+ was removed from the cell.

These changes are due to the presence of substances that inhibit Na+-K+ adenosine triphosphatase activity in the serum of the patient. Brain tissue is extremely sensitive to this enzyme activity, and the enzyme activity is only slightly reduced to affect the nerve conduction function. When Na+ enters the cell in the brain tissue, the water When it enters, the brain cells are swollen and manifest as cerebral edema.

3. Abnormal amino acid metabolism:

In patients with cirrhosis, the concentration of branched-chain amino acids is reduced, and the equilibrium state of normal branched-chain amino acids (branches) and aromatic amino acids (aryl) in patients with acute or chronic liver disease is destroyed, so that the molar ratio of branch/aro is reduced from normal 3 to 4. It is up to 1 to 1.5. Branched-chain amino acids can inhibit the transfer of aromatic amino acids into the brain. When the former is reduced, the latter enters the brain and causes inhibition of the central nervous system.

4. Pseudo-neural media:

In patients with liver failure, the liver enzyme system is not detoxified. These amines enter the brain and act as -hydroxylase to form phenylethanolamine and -hydroxytyramine, respectively, which have similar structures to catecholamines and can compete with them. Receptors, but the two are pseudo-medias, abnormally increased in the brain and can not transmit nerve impulses, thus interfering with the normal activities of the brainstem reticular structure, inhibiting brain function with varying degrees of disturbance of consciousness. Clinical treatment of levodopa with liver Sexual encephalopathy, when the patient's brain content exceeds the pseudo-neural medium, can restore normal neurotransmission activity, has a certain effect on the recovery of consciousness, but levodopa treatment has damage to the liver.

5. Increase in short-chain fatty acids:

Short-chain fatty acids can induce hepatic coma, and patients with hepatic encephalopathy have increased short-chain fatty acids in blood and cerebrospinal fluid.

Short-chain fatty acids can interfere with brain cell metabolism and nerve conduction, and are associated with hepatic encephalopathy. In short, toxic substances produced by metabolic disorders such as protein amino acids, sugars and fats in liver function are accumulated in the body;

And the liver's detoxification effect on toxic substances and other factors affect the central nervous system, severely inhibit the normal physiological activities of the brain tissue, and the signs of encephalopathy.

Abnormal liver function and abnormal blood coagulation often only reflect the functional status of hepatocytes, and do not indicate the severity of hepatic encephalopathy. Water, electrolyte imbalance and acid-base balance disorders can promote and aggravate hepatic encephalopathy. A progressive increase in blood urea nitrogen indicates that renal failure will occur. Elevated blood ammonia is visible in children and its concentration is not proportional to the depth of the coma. Blood ammonia levels can be measured when conditions are available, which can help guide treatment.

Pediatric hepatic encephalopathy prevention

Infection is the main cause of cirrhosis in children, strengthen pregnancy care, prevent various infectious diseases during pregnancy, especially hepatitis B virus, cytomegalovirus, rubella virus, herpes simplex virus, congenital syphilis and other infections, so as not to cause liver damage in children. In the occurrence of this disease, there are hundreds of drugs and poisons that can cause damage to liver cells, avoid long-term, large-scale contact, in order to prevent the occurrence of this disease, and should be properly fed, balanced diet, and various vaccination work for children after birth. , to develop good health habits, prevention and treatment of various chronic inflammatory bowel diseases, etc., all children with chronic liver disease should adhere to active treatment.

Pediatric hepatic encephalopathy complications Complications diarrhea jaundice shock liver and kidney syndrome hyperkalemia cerebral palsy

Often complicated by diarrhea, jaundice, bleeding, bleeding, leading to shock, intracranial hemorrhage and severe bleeding often cause death, kidney involvement can be complicated by hepatorenal syndrome, azotemia, acidosis, hyperkalemia, hypokalemia Etc., arrhythmia can occur, 80% of children with cerebral edema, and severe cerebral palsy can cause death.

Symptoms of Pediatric Hepatic Encephalopathy Common Symptoms Thrombocytopenia, azotemia, coma, increased intracranial pressure, irritability, behavioral abnormalities, liver failure, less urinary hepatic lobe, atrophy, hyperreflexia

According to the different primary liver diseases, the clinical manifestations of hepatic encephalopathy are various, and the symptoms appear and develop at different speeds. For example, hepatic encephalopathy caused by severe toxic hepatitis occurs rapidly, progresses rapidly, and the disease is serious; the progress of liver cirrhosis progresses. Slower, hepatic encephalopathy gradually occurs, when the time is light and heavy, the course of disease is longer, and the coma can be repeated many times.

Clinical manifestation

(1) Symptoms of the nervous system: early personality changes and behavioral abnormalities, infants often show sleep disorders, sleepy sleepy during the day, excitement at night, crying for no reason, wilting, restlessness, and semi-coma, coma, etc. Systemic signs have hyperreflexia, increased muscle tone, sometimes "grimace"-like involuntary movements, non-sustained tendons, sputum sputum positive, flapping tremors, sometimes congenital reflexes such as holding and sucking, occasionally There are signs of meningeal irritation and Babinski's sign. When deep coma, all kinds of reflexes disappear. Flapping-like tremor is a characteristic clinical manifestation of hepatic encephalopathy.

(2) Acute severe hepatitis: liver damage progresses progressively with the disease, the liver shrinks, becomes thinner, and the texture becomes softer, which marks the massive necrosis of the liver parenchyma, while the jaundice is obviously aggravated, and the total bilirubin increases by 17.1 mol/L per day. Above, chronic liver disease can increase liver, hard texture, advanced liver atrophy, and the edge of physical examination is not easy to touch. Due to liver failure, intermediate metabolites of methionine such as dimethyl sulfide and methyl mercaptan cannot continue to metabolize, and exhale with exhalation. Can smell a slightly sweet smell of mildew called liver odor, a sign of poor prognosis.

(3) Bleeding: The tendency of early bleeding is only found during laboratory tests, such as prolonged prothrombin time, significant swelling of the spleen, thrombocytopenia, bleeding in various parts of the late body, and more common bleeding points of skin, mucous membrane and conjunctiva. , purpura, ecchymosis, oozing blood at the injection site, nosebleeds of varying severity, occasionally hemoptysis and hematuria, and complicated by portal hypertension, easy to cause esophageal-gastric varices bleeding, hematemesis, blood in the stool, life-threatening .

(4) Increased intracranial pressure: intracranial pressure continues to exceed 2.0 kPa.

1 There are three major signs of increased intracranial pressure: A. Headache: It is the most common symptom, mostly forehead and two sputum, exerting force, coughing, bending and bowing, B. vomiting: jetting when the headache is severe Vomiting, may be associated with nausea, C. Optic disc edema: is an important sign, manifested as pan head congestion, blurred edges, foveal disappearance, optic disc bulging, venous engorgement, arterial distortion, early physiological blind spots, and then the field of vision narrowed Vision loss eventually ends to blindness.

2 can be associated with incomplete development of nerve paralysis, double vision, paroxysmal erythema, dizziness, disturbance of consciousness, scalp vein anger, increased blood pressure, pulse slowness and so on.

3 children can have a head enlargement, cranial suture widening, the door full of bulge, head pp diagnosis broken cans, scalp superficial vein expansion.

(5) Hepatorenal syndrome: Symptoms of renal failure such as oliguria, no urine, azotemia, acidosis, and hyperkalemia.

2. Clinical staging

The clinical manifestations of hepatic encephalopathy are very different. In order to facilitate observation, treatment and efficacy evaluation, it is generally divided into four phases:

(1) Phase I (precursor period): mild personality changes and behavioral disorders, such as bad temper, no crying, no depression, indifference, inattention, increased speech, abnormal appetite, but accurate answer questions, unclear words The speech rate is slowed down. In this period, flapping tremor or asterixis may also be called liver tremor. (Inspection method: the child extends the forearm and the hand is horizontal, the fingers are open, and the wrist joint is fixed at a certain position. The child's finger is rapidly tremor, no rhythm, which is positive), flapping tremor is often bilateral symmetry, also occurs on one side, EEG is more normal, this period is several days or weeks, the symptoms are more Not typical.

(2) Phase II (pre-coma): characterized by changes in consciousness, sleep disorders and behavioral disorders, loss of orientation and comprehension, computational and writing abilities, unclear language, abnormal behavior, and inability to perform simple puzzles, such as Building blocks, inserting puzzles, using wooden sticks and pentagrams and other geometric figures, sleep habits are upside down, and there may be mental symptoms such as arrogance, hallucinations, fears, etc. In this period, in addition to flapping tremor-positive, EEG shows symmetrical slow waves. Increased muscle tone, positive for sputum, Babinski positive, accompanied by movement disorders.

(3) Phase III (sleeping period): Mainly due to lethargy and mental disorder, the child is drowsy for most of the period, and can wake up and respond, often with confusion and hallucinations.

(4) Phase IV (coma period): The mind is completely lost, can not wake up, when it is shallow coma, it responds to painful stimuli, the pressure of reflex is present, and the flapping tremor can not be elicited. When deep coma, various reflexes disappear, muscle tension Lower, pupils often enlarge, paroxysmal convulsions, convulsions, etc., EEG can appear very slow waves, the opinion of hepatic encephalopathy staging is not uniform, and the performance of each period often overlaps, the boundaries are not very Clear.

3. Classification

Clinically, according to the onset of encephalopathy, it can usually be divided into 2 types:

(1) Acute hepatic encephalopathy: acute massive necrosis of the liver and acute hepatic cell failure, characterized by rapid onset, rapid progress, sinister conditions, and high mortality.

(2) Chronic hepatic encephalopathy: The disease develops slowly, and timely treatment with correct treatment can be relieved, but it is also easy to relapse, showing intermittent onset of symptoms and relief.

Examination of pediatric hepatic encephalopathy

Abnormal liver function and abnormal blood coagulation often only reflect the functional status of hepatocytes, and do not indicate the severity of hepatic encephalopathy. Water, electrolyte imbalance and acid-base balance disorders can promote and aggravate hepatic encephalopathy, and the progressive increase of blood urea nitrogen indicates Renal failure occurs, blood ammonia elevation is seen in children, its concentration is not proportional to the depth of coma, blood ammonia concentration can be measured when conditions are available, which helps to guide treatment.

1. Biochemical examination

(1) Liver function test: the total value of bilirubin is often above 171mol/L (10mg/dl), increasing by 17.1mol/L (1mg/dl) or more per day, mainly due to the increase of direct bilirubin, serum The value of transaminase increased in the early stage. As the condition worsened, the jaundice deepened and decreased, showing the separation of bile enzymes. The decrease of alanine aminotransferase/aspartate aminotransferase ratio indicates severe necrosis of hepatocytes and poor prognosis.

(2) Plasma protein: The plasma albumin value is often lowered, the globulin is often increased, and the ratio of white globulin is reduced or inverted.

(3) water and electrolyte and acid-base balance disorder: blood ammonia level is not proportional to the degree of coma, blood urea nitrogen elevation indicates renal failure, water, electrolytes and acid-base balance disorders can aggravate hepatic encephalopathy.

(4) Determination of blood amino acid: The molar ratio of branched chain amino acid/aromatic amino acid is 3 to 4, and the number of severe hepatitis is reduced to 1 to 1.5. The free tryptophan is obviously increased, which plays an important role in promoting the occurrence of hepatic encephalopathy.

2. Coagulation test

Prothrombin time can be significantly prolonged at an early stage. If the platelet count is reduced, DIC should be considered, and fibrin degradation products should be further examined.

3. Etiology check

It can detect serum viral hepatitis related antigens or antibodies, or polymerase chain reaction (PCR), DNA probe hybridization, etc. to determine the pathogen. For patients with concurrent bacterial or fungal infections, blood culture should be checked several times.

4. Liver biopsy uses 1s acupuncture vacuum suction technique for liver biopsy, easy to operate, safe, high success rate, can help diagnose hepatitis, genetic metabolic liver disease, or help to judge prognosis, viral hepatitis The prognosis of patients with extensive and severe necrosis of liver cells is poor; the prognosis of patients with cell swelling is better.

5. Other tests for alpha-fetoprotein, such as positive, suggesting hepatocyte regeneration, lumbar puncture to obtain cerebrospinal fluid test, simultaneous pressure measurement, to determine the cause and cerebrospinal fluid pressure has a certain significance, there are obvious manifestations of increased intracranial pressure, bogey Wear the waist.

Auxiliary inspection

Ultrasound examination

Although B-mode ultrasound often cannot accurately measure the size of the liver or spleen, it can not diagnose the hardness of the liver, but it can evaluate the diameter of the portal vein and its degree of distortion, and help detect a small amount of ascites and abnormal kidney structure. Doppler ultrasonography, the formation of collateral vessels around the portal vein is a sign of extrahepatic portal vein obstruction. Under normal circumstances, it can be seen that breathing has a regulating effect on portal blood flow. If this sign disappears, it indicates portal hypertension, but this occurs. The sign can not absolutely rule out portal hypertension, and brain ultrasound has diagnostic significance for intracranial lesions.

2. Esophageal X-ray barium angiography

Esophageal X-ray barium angiography can show the presence or absence of esophageal varices and its extent. The varicose veins are located 2/3 of the lower esophagus, indicating the shadow of the filling defect of the tincture, such as when the varicose veins are severe and wide. The degree of varicose veins, the degree of varicose veins has nothing to do with the cause or the age of the child. In general, thicker sputum is better than thin sputum, but sometimes it is necessary to use thick and thin sputum to make delicate esophagus Mucosal lines are more clearly shown. In adults, the sensitivity of esophageal varices detected by barium angiography is about 70%. In recent years, due to the wide application of endoscopy, this technique has rarely been used for the examination of esophageal varices. Moreover, the detection value of upper gastrointestinal active bleeding is extremely limited, and the X-ray of the skull and ventriculography can help diagnose the intracranial hypertension.

3. Gastroscopic examination

Gastroscopic examination can directly observe the presence or absence of esophageal varices and its extent. At present, endoscopic examination is feasible and safe for all pediatric age groups, and it is the most accurate and sensitive method for confirming the existence of esophageal varices. For children with upper gastrointestinal bleeding, once the condition is stable, a gastroscopy should be performed immediately to determine the location of the bleeding as soon as possible, the nature of the lesion and rapid hemostasis treatment. For patients with asymptomatic or stable period, gastroscopy can also be performed. In order to predict the risk of variceal bleeding and the timing of the choice of preventive sclerotherapy.

4. Selective superior mesenteric artery angiography

The femoral artery is inserted into the catheter and the superior mesenteric artery angiography is performed. Under normal circumstances, the portal vein can be developed within 10 to 20 s. When the portal vein thrombosis occurs, the portal vein cannot be filled. In patients with cavernous hemangioma-like variation, There are many small collateral vessels around the occluded portal vein. Possible vascular images include: reverse flow of portal vein blood flow, esophageal varices, and other parts of the portal.

5. EEG examination

In the early stage of hepatic encephalopathy, the patient showed an abnormal phenomenon.

6. Other

An electrocardiogram should be performed, and if necessary, brain CT and magnetic resonance examinations should be performed.

Diagnosis and diagnosis of hepatic encephalopathy in children

On the basis of severe liver disease, liver disease progresses progressively, jaundice continues to deepen, the liver progressively shrinks, becomes thinner, softer, has liver odor, and has abnormalities in the nervous system, or is accompanied by bleeding, oliguria, etc. It can be diagnosed as hepatic encephalopathy.

Some of the sick children's primary liver disease is relatively hidden, long-term undetected, such as hepatolenticular degeneration, sometimes mental abnormalities, easy to mistaken for mental illness, must be carefully examined, close observation of the condition, early diagnosis, should also be Identification of low sodium syndrome and organic psychosis.

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