What Is Hypovolemia?

Decreased effective blood volume is a manifestation of clinical symptoms.

Reduced effective blood volume

Causes of decreased effective blood volume

Gastrointestinal bleeding can be caused by inflammation of the digestive tract itself, mechanical damage, vascular lesions, tumors and other factors. It can also be caused by diseases of neighboring organs and systemic diseases involving the digestive tract.

(A) the etiology of upper gastrointestinal bleeding

1. Esophageal diseases Esophagitis (reflux esophagitis, esophageal diverticulitis), esophageal cancer, esophageal ulcers, esophageal and gastric cardia mucosa tear, injury caused by device inspection or foreign body, radiation damage, strong acid and alkali cause chemical damage.

2. Stomach, duodenal disease, peptic ulcer, acute and chronic gastritis (including drug-induced gastritis), gastric mucosal prolapse, gastric cancer, acute gastric distension, duodenitis, remnant gastritis, remnant gastric ulcer or cancer. There are also lymphomas, leiomyomas, polyps, sarcomas, hemangiomas, and neurofibromas. Diaphragmatic hernia, gastric torsion, diverticulitis, hookworm disease, etc.

3. Jejunal ulcer and anastomotic ulcer after gastrointestinal anastomosis.

4. Portal hypertension, esophageal gastric fundus rupture curve bleeding, portal hypertension gastric cirrhosis, portal phlebitis or

Examination and diagnosis of reduced effective blood volume

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

(I) Hemorrhage: Most acute bleeding is manifested as vomiting. Chronic small amount of bleeding is positive with fecal occult blood. When the bleeding part is above the jejunal flexor ligament, the clinical manifestations are vomiting. For a long time, it turned into an acidic hemoglobin due to the action of gastric acid and turned brown. Such as rapid bleeding and heavy bleeding. The color of vomiting blood is bright red. Black feces or tar-like feces indicate that the bleeding site is in the gastrointestinal tract. However, if the bleeding rate of a lesion in the duodenum is too fast, the stay time in the intestinal tract is short, and the color of the feces will turn purple. When the right colon is bleeding, the stool color is bright red. Black faeces can also occur when small amounts of bleeding occur in the space ileum and right hemicolonic lesions.

(B) Hemorrhagic peripheral circulation failure A large amount of bleeding from the upper digestive tract leads to acute peripheral circulation failure. The amount of blood loss is large, the bleeding is not continuous or the treatment is not timely, which can cause the body's tissue blood perfusion to be reduced and the cells to be hypoxic. Furthermore, due to hypoxia, metabolic acidosis, and accumulation of metabolites, the surrounding blood vessels are dilated, and the capillaries are extensively damaged. As a result, a large amount of body fluid is stagnated in the abdominal bones and surrounding tissues, which effectively reduces the effective blood volume and seriously affects the heart The blood supply to the brain, kidneys, and kidneys finally formed an irreversible shock, leading to death.

During the development of circulatory failure around bleeding, clinically dizziness, palpitations, nausea, thirst, darkness, or syncope may occur; the skin is pale and wet due to vasoconstriction and insufficient blood perfusion; pale after pressing the nail bed, and Long time no recovery. Venous filling is poor, and the surface veins are often sagged. The patient feels fatigued and weak, and may further suffer from dementia, irritability, and even sluggishness and confusion. The organ reserve function of the elderly is low, and the elderly often have basic senile 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 and increases the risk factors for death.

(Three) azotemia can be divided into three types: intestinal, renal and prerenal azotemia. Enterogenic azotemia refers to the intestinal absorption of blood protein breakdown products after a large amount of upper gastrointestinal bleeding, which leads to an increase in blood nitrogen. Prerenal azotemia is due to temporary reduction of renal blood flow due to hemorrhagic peripheral circulation failure, reduced glomerular filtration rate and renal excretory function, resulting in nitrogen retention. After correcting hypotension and shock, the blood urea nitrogen can quickly drop to normal. Renal azotemia is caused by severe and prolonged shock, which results in renal tubular necrosis (acute renal failure), or blood loss which worsens the kidney damage of the original kidney disease. Clinically, oliguria or anuria may occur. When the bleeding stops, azotemia often lasts for more than 4 days. After supplementing blood volume and correcting shock, blood urea nitrogen cannot reach normal.

(4) After a large amount of fever and bleeding, most patients often have low fever within 24 hours. The cause of fever may be due to reduced blood volume, anemia, peripheral circulation failure, absorption of hemolytic proteins and other factors leading to dysfunction of the thermoregulatory center. When analyzing the cause of fever, pay attention to looking for other factors, such as the presence or absence of concurrent pneumonia.

(5) Compensatory function after bleeding When the amount of gastrointestinal bleeding exceeds 1/4 of blood volume, cardiac output and diastolic blood pressure significantly decrease. At this time, a large amount of a few theophylline is released in the body, which increases the peripheral circulation resistance and heart rate to maintain the blood perfusion of various organs. In addition to cardiovascular reactions, hormone secretion and hematopoietic systems are compensated accordingly. Increased secretion of aldosterone and posterior pituitary, minimizing the loss of water between tissues in order to restore and maintain blood volume. Failure to compensate will stimulate the hematopoietic system, proliferate blood cells, and increase red blood cells and reticulocytes.

Reduced effective blood volume

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

Blood pressure drop: It is caused by drug or insufficient effective blood volume, which is usually caused by blood pressure drop, concussion or alcoholism.

Hemolysis: The phenomenon of erythrocytes rupturing and allowing hemoglobin to escape from the cell. In vitro, hypotonic solutions, strong mechanical shaking, sudden low temperature freezing (-20 ° C to -25 ° C) or sudden thawing, excessive acid or alkali, and alcohol, ether, soap, choline salts, etc. can cause hemolysis. . In vivo hemolysis, mainly due to inherent defects of red blood cells (such as sickle cell anemia), or due to certain factors present in the plasma (such as invasion of hemolytic bacteria or certain snake venom, antigen-antibody reactions, various mechanical injuries, Some drugs, etc.), the red blood cells are excessively destroyed.

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

(I) Hemorrhage: Most acute bleeding is manifested as vomiting. Chronic small amount of bleeding is positive with fecal occult blood. When the bleeding part is above the jejunal flexor ligament, the clinical manifestations are vomiting. For a long time, it turned into an acidic hemoglobin due to the action of gastric acid and turned brown. Such as rapid bleeding and heavy bleeding. The color of vomiting blood is bright red. Black feces or tar-like feces indicate that the bleeding site is in the gastrointestinal tract. However, if the bleeding rate of a lesion in the duodenum is too fast, the stay time in the intestinal tract is short, and the color of the feces will turn purple. When the right colon is bleeding, the stool color is bright red. Black faeces can also occur when small amounts of bleeding occur in the space ileum and right hemicolonic lesions.

(B) Hemorrhagic peripheral circulation failure A large amount of bleeding from the upper digestive tract leads to acute peripheral circulation failure. The amount of blood loss is large, the bleeding is not continuous or the treatment is not timely, which can cause the body's tissue blood perfusion to be reduced and the cells to be hypoxic. Furthermore, due to hypoxia, metabolic acidosis, and accumulation of metabolites, the surrounding blood vessels are dilated, and the capillaries are extensively damaged. As a result, a large amount of body fluid is stagnated in the abdominal bones and surrounding tissues, which effectively reduces the effective blood volume and seriously affects the heart. The blood supply to the brain, kidneys, and kidneys finally formed an irreversible shock, leading to death.

During the development of circulatory failure around bleeding, clinically dizziness, palpitations, nausea, thirst, darkness, or syncope may occur; the skin is pale and wet due to vasoconstriction and insufficient blood perfusion; pale after pressing the nail bed, and Long time no recovery. Venous filling is poor, and the surface veins are often sagged. The patient feels fatigued and weak, and may further suffer from dementia, irritability, and even sluggishness and confusion. The organ reserve function of the elderly is low, and the elderly often have basic senile 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 and increases the risk factors for death.

(Three) azotemia can be divided into three types: intestinal, renal and prerenal azotemia. Enterogenic azotemia refers to the intestinal absorption of blood protein breakdown products after a large amount of upper gastrointestinal bleeding, which leads to an increase in blood nitrogen. Prerenal azotemia is due to temporary reduction of renal blood flow due to hemorrhagic peripheral circulation failure, reduced glomerular filtration rate and renal excretory function, resulting in nitrogen retention. After correcting hypotension and shock, the blood urea nitrogen can quickly drop to normal. Renal azotemia is caused by severe and prolonged shock, which results in renal tubular necrosis (acute renal failure), or blood loss which worsens the kidney damage of the original kidney disease. Clinically, oliguria or anuria may occur. When the bleeding stops, azotemia often lasts for more than 4 days. After supplementing blood volume and correcting shock, blood urea nitrogen cannot reach normal.

(4) After a large amount of fever and bleeding, most patients often have low fever within 24 hours. The cause of fever may be due to reduced blood volume, anemia, peripheral circulation failure, absorption of hemolytic proteins and other factors leading to dysfunction of the thermoregulatory center. When analyzing the cause of fever, pay attention to looking for other factors, such as the presence or absence of concurrent pneumonia.

(5) Compensatory function after bleeding When the amount of gastrointestinal bleeding exceeds 1/4 of blood volume, cardiac output and diastolic blood pressure significantly decrease. At this time, a large amount of a few theophylline is released in the body, which increases the peripheral circulation resistance and heart rate to maintain the blood perfusion of various organs. In addition to cardiovascular reactions, hormone secretion and hematopoietic systems are compensated accordingly. Increased secretion of aldosterone and posterior pituitary, minimizing the loss of water between tissues in order to restore and maintain blood volume. Failure to compensate will stimulate the hematopoietic system, proliferate blood cells, and increase red blood cells and reticulocytes.

Prevention of effective blood volume reduction

People should master some basic first aid knowledge in daily life. The following items must be kept in mind.

If a large amount of bleeding fails to be delivered to the hospital in a timely manner, the patient should be comforted immediately to eliminate the tension, pay attention to keep the patient warm, keep him lying on his side, take his head down, and put a pillow on the feet, The angle of the face is 30 degrees, which will help the blood in the lower limbs to return to the heart, and first ensure the blood supply to the brain. When vomiting blood, the patient's head should be tilted to one side to prevent blood from being sucked into the trachea and causing suffocation.

The patient's vomit or feces should be retained temporarily, and the total amount should be roughly estimated, and a part of the specimen should be taken for testing at the doctor.

Move the patient less, not to let the patient move around, while closely observing the patient's consciousness, breathing, pulse, and quickly notify the emergency center.

The clinical manifestations of gastrointestinal bleeding are vomiting blood and blood in the stool. The vomiting blood may be bright red or brown; the blood coming out of the stool may be bright red or dark red, or it may be black like tar.

When vomiting blood, it is best to let the patient rinse his mouth and apply cold water to the heart socket. Do not drink water at this time, but may contain ice cubes.

These basic first-aid measures combined with the scientific treatment of first-aid doctors will definitely save patients' lives to the greatest extent. Finally, patients with liver disease, especially those with liver cirrhosis, must be regularly reviewed. Endoscopic diagnosis should be performed if necessary to prevent the occurrence of gastrointestinal bleeding, and scientific treatment and maintenance should be strictly followed in accordance with the doctor's instructions.