OVERVIEW
Hemorrhagic shock and encephalopathy syndrome is a rare disease in which children develop severe shock, encephalopathy, and other symptoms that lead to extremely severe neurologic damage and even death. The disease has a rapid onset and survivors are prone to severe neurologic sequelae. It is clinically characterized by sudden coma and convulsions, shock, BCD, watery diarrhea, metabolic acidosis, liver and kidney dysfunction. Hemorrhagic shock and encephalopathy syndrome (HSES) occurs predominantly in infants between the ages of 3 and 8 months (mean age 5 months), but has been reported to occur as early as 15 years of age.
Etiology
The etiology of the disease is unclear. There are reports of rotavirus, poliovirus, and echovirus detected in the stools of affected children, and rhinovirus and parainfluenza virus detected in sputum and pharyngeal secretions, but it is not possible to clarify that the pathogenic bacteria isolated are the causative agents. In terms of pathogenesis, it is now believed that children with HSES are preceded by factors that clearly cause hyperthermia, such as over-wrapping. Hyperthermia may be the key trigger, leading to decreased intestinal blood flow, compromising the intestinal mucosal barrier and allowing enterotoxins to enter the hepatic circulation. In addition, the number of intestinal lymphocytes is significantly reduced in children, coupled with severe liver damage, the loss of intestinal immune protection and liver detoxification, a large number of endotoxins can be displaced into the circulation, a systemic inflammatory response occurs, producing a large number of inflammatory mediators, which can damage the blood-brain barrier, causing cerebral edema, resulting in encephalopathy. At the same time, children may have hereditary or acquired ⍺1-antitrypsin reduction, and small infections and inflammation can cause leukocytes and tissues to release proteases into the blood circulation, causing uncontrolled coagulation reactions, activating complement and kinin, and thus participating in organism damage.
Symptoms
Most children have prodromal fever, upper respiratory symptoms, vomiting and diarrhea. The predominant clinical signs are acute onset encephalopathy (manifested by convulsions, coma, and decreased muscle tone) and severe shock. Other common clinical features include high fever (up to 43.9°C, rectal temperature), diffuse intravascular coagulation, blood in the stool, metabolic acidosis, elevated hepatic transaminases, acute renal failure, thrombocytopenia and decreased erythrocyte pressure volume. Primary pulmonary and myocardial involvement is rare.
Examination
1. Electroencephalogram
Electroencephalographic bursts are seen at the beginning of the course of the disease, followed by a decrease in the amplitude of electrical activity and diffuse slow waves. The electroencephalogram may reflect damage to the cerebral cortex.
2. Cranial CT
Cerebral edema, infarction, hemorrhage and softening can be seen. Cerebral edema can be seen in 2-3 days after the onset of the disease, and subside after 1 week, or can be seen as cerebral infarction and cerebral atrophy. Follow-up examination can help to determine the destruction of brain structure and the degree of neurological damage.
3. Laboratory examination
Blood gas analysis can have metabolic acidosis; hemoglobin reaches the lowest value in 30 hours after the onset of the disease, which can be reduced to 4.3g/L; blood transaminase is significantly elevated, blood bilirubin and blood ammonia are slightly elevated; blood creatinine and urea are elevated, and peritoneal dialysis is required in severe cases; coagulation function is abnormal, with prolongation of prothrombin and activated partial thromboplastin time, decrease of fibrinogen, and decrease of platelet.
Diagnosis
1. Clinical manifestations
Shock, coma and convulsions, bleeding (or basis for DIC), diarrhea, oliguria.
2.Laboratory examination
Hemoglobin is lower than at admission, 30g/L; platelets <150×109/L; prolonged prothrombin time, activated partial thromboplastin time, decreased fibrinogen; elevated fibrin degradation products, blood creatinine and urea, elevated blood transaminases; metabolic acidosis
3. Other
Exclude toxic shock due to established infections and metabolic diseases, Reye’s syndrome, staphylococcal infections.
Differential diagnosis
Differential diagnosis includes septic shock, Reye’s syndrome, toxic shock syndrome, hemolytic uremic syndrome, heat stroke and viral hemorrhagic fever, Reye’s syndrome and toxic shock, which are excluded based on their clinical course or laboratory manifestations.
Treatment.
Supportive treatment, application of large amounts of colloid volume expansion, intravenous infusion of isotonic fluids and blood products, plus vasoconstrictors (e.g., dopamine, epinephrine) necessary to maintain circulation. Those with increased intracranial pressure due to cerebral edema require endotracheal intubation and hyperventilation, and diffuse intravascular coagulation is often further exacerbated despite the application of fresh frozen plasma. The key is to ensure oxygenation, ventilation and cerebral perfusion, i.e., rapid stabilization of circulatory and respiratory function. Rapid and bold antishock, anti-DIC, and suppression of inflammatory response are all conducive to the improvement of circulatory function and rapid correction of cerebral hypoperfusion; early onboarding, correction of hypoxemia, and simultaneous positive-pressure ventilation are conducive to the support of cardiac function as well as to the correction of acidity; lowering of the cranial pressure improves the survival rate, but does not improve the neurological prognosis. For severe coagulation dysfunction, fresh frozen plasma, platelets, fibrinogen and other alternative therapies can be applied. Glucocorticoids can reduce the systemic inflammatory response and favor early remission.
Prognosis
Mild to severe motor dysfunction exists, with motor degeneration and epileptic sequelae mostly after a few months, with the majority (>60%) of all cases dying and 70% or more of survivors having severe neurologic sequelae.