Hemodynamic disorder

Introduction Hemodynamics refers to the mechanics of blood flow in the cardiovascular system, mainly studying blood flow, blood flow resistance, blood pressure and the relationship between them. Blood is a fluid, so the basic principles of hemodynamics are the same as those of general fluid mechanics. However, because the vascular system is a relatively complex elastic piping system, blood is a liquid containing various components such as blood cells and colloidal substances rather than an ideal liquid. Therefore, hemodynamics has both common fluid mechanics and its own characteristics.

Cause

Blood is a fluid, so the basic principles of hemodynamics are the same as those of general fluid mechanics. However, because the vascular system is a relatively complex elastic piping system, blood is a liquid containing various components such as blood cells and colloidal substances rather than an ideal liquid. Hemodynamics is the study of blood and blood vessel flow and deformation, and explores blood and The effect of plasma viscosity on the body. Pay attention to the effects of blood viscosity changes, vascular abnormalities, abnormal blood pressure and other factors.

an examination

Related inspection

Blood routine blood test

The body's regulation of the distribution of blood flow is carried out by controlling the caliber of the resistance vessels of each organ. The main factors affecting hemodynamics in the circulatory system can be divided into five parts:

1 resistance vessels, including arteries and arterioles;

2 capillaries;

3 volume of blood vessels;

4 blood volume;

5 heart.

Almost all types of shock are circulatory dysfunctions caused by the different effects on these five parts. It can be checked by the above aspects.

Differential diagnosis

Hemodynamic disorder confusing symptoms

Pulmonary blood flow is rare: the length of life of patients with tricuspid atresia is closely related to pulmonary blood flow. Pulmonary blood flow is close to normal, the survival period can be up to 8 years or more; those with many pulmonary blood flow can only survive for 3 months after birth; if the pulmonary blood flow is less than normal, the survival time after birth is in the above two cases. between. Keith et al reported that 50% of patients with tricuspid atresia can survive to 6 months, 33% survive to 1 year old, and only 10% can survive to 10 years. Cases with small septum in the room showed clinical systemic venous congestion, jugular vein engorgement, hepatomegaly and peripheral edema. Due to the small amount of blood in the pulmonary circulation, most cases can appear purpura from the neonatal period, and they are anxious after exertion, and can take the position of sputum or hypoxic fainting. The clubbing (toe) often occurs in patients over 2 years of age. In cases of increased pulmonary blood flow, the degree of purpura is reduced, but often there is shortness of breath, rapid breathing, prone to pulmonary infection, often present with congestive heart failure.

Portal venous stasis: thrombosis often occurs in: 1 cirrhosis or extrahepatic compression caused by portal vein congestion and portal venous stasis; 2 intra-abdominal purulent infections, such as gangrenous appendicitis, ulcerative colitis, strangulation Sexual paralysis, etc.; 3 certain blood abnormalities, such as polycythemia vera, hypercoagulable state caused by oral contraceptives; 4 trauma caused by trauma or surgery, such as mesenteric hematoma, splenectomy, right colon resection and so on. About 1/4 of patients have no obvious cause, called primary mesenteric venous thrombosis. After venous thrombosis, it can continue to spread to the proximal and distal ends. When the venous return of the affected bowel is completely blocked, the intestine is congested and edematous, and the subserosal bleeds first, then spreads into pieces. The intestinal wall and mesentery are thickened and edematous. In addition, hemorrhagic infarction occurred in the intestines, which was dark purple. A large amount of bloody fluid oozes from the intestinal wall and mesentery to the intestinal and abdominal cavities. Acute venous occlusion can also reflect the process of stenosis and thrombosis of visceral arteries and accelerate intestinal necrosis. Finally, it also leads to hypovolemia and toxic shock in infection.

Venous blood flow stagnation: thrombophlebitis is a venous vascular disease characterized by acute non-suppurative phlebitis secondary to intracavitary thrombosis. The skin of the superficial venous area is red and swollen, spontaneously involved in pain, and can be touched. Painful strips or nodules, venous blood flow is slow.

Increased blood flow resistance: The resistance of blood flowing in blood vessels due to various reasons increases. Blood rheology tests can be diagnosed.

Slow blood flow in all organs of the body: due to increased blood volume, blood viscosity increases, resulting in slow blood flow and tissue ischemia in all organs of the body. Polycythemia vera (PV) is a myeloproliferative disease characterized by clonal erythrocytosis. The clinical features are slow onset, long course of disease, red and purple skin mucosa, hepatosplenomegaly with vascular and nervous system symptoms, red blood cells increased, and whole blood volume increased, often accompanied by total white blood cells and thrombocytosis.

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