Overview.
Hyperviscosity syndrome, also known as viscous syndrome, purpuric hyperglobulin syndrome, and Reimann syndrome, is a condition caused by increased blood viscosity. It is a series of characteristic clinical manifestations that occur when the hematocrit exceeds 70% or more and the viscosity of the blood rises dramatically, causing an increase in hemohydrodynamic resistance and difficulty in driving red blood cells in the child. It is currently categorized as erythrocytosis and hyperglobulin syndrome according to its etiology.
Etiology
1. Tissue hypoxia or impaired oxygen release
(1) Physiological ① Fetal period; ② insufficient oxygen content in the environment, such as plateau area.
(2) pathological ① insufficient lung ventilation: lung diseases such as bronchiectasis, pulmonary heart disease, obesity; ② pulmonary arteriovenous fistula; ③ cyanotic congenital heart disease; ④ anomalous hemoglobinopathies: sulfated hemoglobin and ferrohemoglobin with poor oxygen carrying capacity.
2. Enhancement of the function of bone marrow in generating red blood cells
(1) endogenous ① renal: renal embryonal tumors, adrenal adenomas, polycystic kidneys, renal artery stenosis, etc., ② adrenal: pheochromocytoma, Cushing’s syndrome, congenital adrenal hyperplasia, adrenal adenomas combined with primary aldosteronism, etc., (3) hepatic: hepatocellular carcinomas, and (4) cerebellar: angioblastomas.
(2) Exogenous ① application of testosterone or similar drugs; ② application of growth hormone.
3. Neonate
(1) Transplacental blood transfusion Mother transfuses blood to fetus.
(2) Umbilical cord Late ligation.
Symptoms
1. Neonate
Vomiting, jaundice, tremors, tachycardia, heart failure, tachypnea, dyspnea, hepatosplenomegaly, thrombocytopenic purpura, hypoglycemia, hypocalcemia and cerebral symptoms.
2. Bleeding
It is common, often sudden nosebleed and gingival bleeding, bleeding and M protein inhibit the role of coagulation factors, in recent years, the blood viscous syndrome is thought to be one of the causes of diffuse intravascular coagulation (DIC), the coagulation dysfunction of cyanotic congenital heart disease in children may be related to this.
3. Thrombosis
Thrombosis occurs in hypoxic infants under 2 years of age, and the hematocrit is often not very high at this age.
4. Anemia
Most often seen in primary anemia, but also associated with increased serum viscosity, plasma volume compensation increase caused by hemodilution.
5. Ocular manifestations
Ocular symptoms include visual field abnormalities, diplopia and visual impairment, and fundus lesions are characteristic of this disease.
6. Neurological symptoms
Dizziness, hearing impairment, movement disorders, nystagmus, tinnitus and other peripheral nerve damage and cone bundle symptoms.
7. Cardiovascular symptoms
The symptoms of cardiac insufficiency can be seen in the increase of serum viscosity, the increase of blood volume and the corresponding increase of cardiac load, as well as the peripheral circulatory disorders caused by the increase of serum viscosity and the aggregation of erythrocytes in the blood vessels, such as Raynaud’s phenomenon, skin and mucous membrane ulceration and gangrene phenomenon.
8. Renal function changes
Mostly seen in myeloma patients, the increase of serum viscosity can cause the decrease of renal blood flow, which leads to the damage of renal function.
Examination
1. Plasma protein analysis
When plasma protein is measured, fibrinogen is not increased, but globulin is increased obviously; after paper electrophoresis or agar electrophoresis, macroglobulin band is found, or the obvious increase of gammaglobulin or the so-called M component appears, then the diagnosis of abnormal globulinemia can be confirmed.
2. Qualitative and quantitative determination of abnormal proteins
In severe cases, when venepuncture is performed, the blood taken out coagulates very quickly and it is not possible to continue blood collection, even if normal amount of anticoagulant is used, it cannot block the coagulation of the blood. Blood viscosity measurement, immunoelectrophoresis analysis, immunoassay of radiation and sedimentation coefficient measurement can qualitatively and quantitatively determine the abnormal proteins.
3. Chest X-ray, ultrasound, electrocardiogram, electroencephalogram and CT.
Chest X-ray, ultrasound, electrocardiogram, electroencephalogram and CT are routinely performed.
Diagnosis
Diagnosis can be made on the basis of the cause and clinical manifestations, but confirmation of the diagnosis depends on laboratory tests, such as hematocrit, plasma viscosity (the normal value is 3.5-5 times that of water), and protein chemistry studies, including immunoelectrophoresis, radioimmunoassay and sedimentation coefficient, which can qualitatively and quantitatively analyze the abnormal proteins, and can be of great help in the diagnosis.
Treatment
1. Symptomatic treatment
(1) Treatment of primary diseases, such as macroglobulinemia, multiple myeloma, etc., to reduce the source of abnormal plasma proteins.
(2) Vasodilators can be used to reduce the resistance of peripheral circulation, such as aminophylline, diphazole, niacin and poppy seed;
(3) Improvement of circulatory function Low molecular dextrose may be used.
(4) Anticoagulants can be used, but the effect is not obvious, such as heparin and bicoumarin;
(5) Adrenocorticotropic hormone Use high doses of adrenocorticotropic hormone. For bleeding tendency, except with gastrointestinal hemorrhage, usually should not use hemostatic drugs, large doses of adrenocorticotropic hormone, sometimes can receive the effect of temporary relief.
2. Special therapy
(1) When the condition worsens and the symptoms are obvious, plasma cleansing can be used, i.e., the blood taken out, removing abnormal proteins, making red blood cell saline suspension and re-infusing it to the patients, so as to achieve the purpose of reducing plasma proteins, reducing the load on the myocardium, lowering the viscosity of the blood, and improving the circulation of the tissues and organs.
(2) For children with rare myeloma in pediatrics, it can also improve the resulting kidney damage. Thus, the symptoms can be reduced rapidly; early blood exchange therapy is appropriate for neonates with hyperviscosity.