Reduced effective blood volume

Introduction Hemorrhagic peripheral circulatory failure is a clinical symptom of gastrointestinal bleeding, which is manifested by massive peripheral hemorrhage leading to acute peripheral circulatory failure. The amount of blood loss is large, bleeding or treatment is not timely, which can cause the blood perfusion of the body and the lack of oxygen. Furthermore, due to hypoxia, metabolic acidosis and accumulation of metabolites, the surrounding blood vessels are dilated, and the capillaries are extensively damaged, so that a large amount of body fluid stagnates in the abdominal cavity and surrounding tissues, which reduces the effective blood volume and seriously affects the heart. The blood supply to the brain and kidneys finally formed an irreversible shock, leading to death.

Cause

The cause of effective blood volume reduction:

Gastrointestinal hemorrhage may be caused by inflammation, mechanical damage, vascular disease, tumor and other factors of the digestive tract itself, and may also be caused by lesions of adjacent organs and systemic diseases involving the digestive tract.

(1) The cause of upper gastrointestinal bleeding:

1. Esophageal disease: esophagitis (reflux esophagitis, esophageal diverticulitis), esophageal cancer, esophageal ulcer, esophageal and gastric mucosal tear, device examination or foreign body damage, radiation damage, strong acid and alkali cause chemical damage .

2. Gastric and duodenal diseases: peptic ulcer, acute and chronic gastritis (including drug-induced gastritis), gastric mucosal prolapse, gastric cancer, acute gastric dilatation, duodenitis, residual gastritis, residual gastric ulcer or cancer. There are also lymphoma, leiomyoma, polyps, sarcoma, hemangioma, and neurofibromatosis. , stomach twist, diverticulitis, hookworm disease, etc.

3. Jejunal ulcer and anastomotic ulcer after gastrointestinal anastomosis.

4. Portal hypertension, esophageal and gastric vein rupture, portal hypertensive gastropathy, portal vein obstruction of portal venous inflammation or thrombosis, hepatic vein occlusion (Budd-Chiari syndrome).

5. Diseases of organs or tissues adjacent to the upper digestive tract:

(1) Biliary hemorrhage: biliary or gallbladder stones, biliary ascariasis, gallbladder or biliary tract disease, liver cancer, liver abscess or hepatic vascular disease rupture.

(2) Pancreatic diseases involve the duodenum: pancreatic abscess, pancreatitis, pancreatic cancer, etc.

(3) The thoracic or abdominal aortic aneurysm breaks into the digestive tract.

(4) The mediastinal tumor or abscess breaks into the esophagus.

6. Systemic disease manifests bleeding in the gastrointestinal tract:

(1) Blood diseases: leukemia, aplastic anemia, hemophilia, etc.

(2) uremia.

(3) Connective tissue disease: vasculitis.

(4) Stress ulcer: severe infection, surgery, trauma, shock, adrenal glucocorticoid treatment and stress caused by certain diseases, such as cerebrovascular accident, pulmonary heart disease, severe heart failure and so on.

(5) Acute infectious diseases: epidemic hemorrhagic fever, leptospirosis.

(B) the cause of lower gastrointestinal bleeding:

1. Anal tube disease: sputum, anal fissure, anal fistula.

2. Rectal disease: rectal injury, non-specific proctitis, tuberculous proctitis, rectal tumor, rectal carcinoid, adjacent malignant tumor or abscess invading the rectum.

3. Colonic diseases: bacterial dysentery, amoebic dysentery, chronic non-specific ulcerative colitis, diverticulum, polyps, cancer and vascular malformations.

4. Small bowel disease: acute hemorrhagic necrotic enteritis, intestinal tuberculosis, Crohn's disease, jejunal diverticulitis or ulcer, intussusception, small intestine tumor, gastrointestinal polyposis, small intestinal hemangioma and vascular malformation.

an examination

Related inspection

Platelet examination program

Check diagnosis of effective blood volume reduction:

The clinical manifestations of gastrointestinal bleeding depend on the nature, location, blood loss and speed of the bleeding lesions, and are also related to the patient's age, heart and kidney function and other general conditions.

(1) Bleeding method: Most of the acute massive hemorrhage is hematemesis; chronic small amount of bleeding is positive for fecal occult blood; when the hemorrhage is above the jejunal ligament, the clinical manifestation is hematemesis, such as blood retention time in the stomach after hemorrhage For a long time, it is brown because it becomes acidic hemoglobin by gastric acid. Such as bleeding speed and bleeding volume. The color of hematemesis is bright red. Black feces or tar-like stools indicate that the bleeding site is in the gastrointestinal tract, but if the bleeding rate of the lesion in the duodenum is too fast, the residence time in the intestine is short, and the color of the stool becomes purple-red. When the right colon is bleeding, the color of the stool is bright red. Black faeces may also be present when a small amount of oozing occurs in the space ileum and right colonic lesions.

(B) Hemorrhagic peripheral circulatory failure: massive bleeding in the upper digestive tract leads to acute peripheral circulatory failure. The amount of blood loss is large, bleeding or treatment is not timely, which can cause the blood perfusion of the body and the lack of oxygen. Furthermore, due to hypoxia, metabolic acidosis and accumulation of metabolites, the surrounding blood vessels are dilated, and the capillaries are extensively damaged, so that a large amount of body fluid stagnates in the abdominal cavity and surrounding tissues, which reduces the effective blood volume and seriously affects the heart. The blood supply to the brain and kidneys finally formed an irreversible shock, leading to death.

During the development of circulatory failure around hemorrhage, dizziness, palpitations, nausea, thirst, black sputum or syncope may occur clinically; the skin is gray and wet due to vasoconstriction and insufficient blood perfusion; it is pale after pressing the nail bed, and Recovery has not been seen for a long time. Poor vein filling, body surface veins often collapse. The patient feels tired and weak, and can be further apathetic, restless, even unresponsive, and confused. The elderly have low organ reserve function, and the elderly often have senile underlying diseases such as cerebral arteriosclerosis, hypertension, coronary heart disease, and chronic bronchus. Although the amount of bleeding is not large, it also causes multiple organ failure, which increases the risk factors for death.

(3) Nitrogenemia: It can be divided into three types: intestinal, renal and pre-renal azotemia. Intestinal azotemia refers to the absorption of the intestinal tract of blood protein decomposition products after a large amount of upper gastrointestinal bleeding, resulting in an increase in blood nitrogen. Prerenal azotemia is a temporary reduction in renal blood flow due to hemorrhagic peripheral circulatory failure, a decrease in glomerular filtration rate and renal excretion, resulting in nitrogen storage. After correcting hypotension and shock, the blood urea nitrogen can be quickly reduced to normal. Renal azotemia is caused by severe and persistent shock leading to tubular necrosis (acute renal failure), or loss of blood damage to kidney damage in the original kidney disease. There may be less or no urine in the clinic. In the case of bleeding stop, azotemia often lasts for more than 4 days. After supplementing blood volume and correcting shock, blood urea nitrogen can not be normal.

(4) Fever: After a large amount of bleeding, most patients often experience low fever within 24 hours. The cause of fever may be due to factors such as decreased blood volume, anemia, peripheral circulatory failure, and absorption of blood-decomposing proteins, leading to dysfunction of the thermoregulatory center. When analyzing the cause of fever, pay attention to other factors, such as the presence or absence of pneumonia.

(5) Compensatory function after hemorrhage: When the amount of gastrointestinal bleeding exceeds 1/4 of the blood volume, the cardiac output and diastolic blood pressure are significantly decreased. At this time, a large amount of catecholamines are released in the body, and the peripheral circulation resistance and heart rate are increased to maintain the blood perfusion of each organ. In addition to cardiovascular reactions, hormone secretion and hematopoietic systems are compensated accordingly. The secretion of aldosterone and vasopressin is increased to minimize the loss of moisture between tissues to restore and maintain blood volume. If it is still not compensated, it will stimulate the hematopoietic system, blood cell proliferation is active, and red blood cells and reticulocytes are increased.

Differential diagnosis

Symptoms of confusing effective blood volume reduction:

Hypovolemic shock: refers to the pathophysiological process of effective circulating blood volume and cardiac output reduction, tissue perfusion, cell metabolic disorder and impaired function caused by loss of circulating capacity caused by various reasons. Tachycardia, shortness of breath, narrowing of pulse pressure difference, decreased urine output, wet skin, spotted, poor capillary filling, low CVP, and decompensated hypotension and altered consciousness.

Blood pressure drop: It is caused by drug or insufficient blood volume, which is caused by blood pressure drop, which is common after taking antihypertensive drugs, concussion or alcoholism.

Hemolysis: A phenomenon in which red blood cells rupture and hemoglobin escapes from the cells. In vitro, hypotonic solution, mechanical strong oscillation, sudden low temperature freezing (-20 ° C ~ -25 ° C) or sudden freezing, peracid or over-alkali, and alcohol, ether, soap, choline salt, etc. can cause hemolysis . Hemolysis in the body, mainly due to the intrinsic defects of red blood cells (such as sickle cell anemia), or due to certain factors in the plasma (such as hemolytic bacteria or some snake venom invasion, antigen-antibody reaction, various mechanical damage, some The role of some drugs, etc., causes red blood cells to be excessively destroyed.

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