Introduction
Blood loss causes anemia, in which the body lacks healthy red blood cells by two main mechanisms. The direct depletion of red blood cells and extended blood loss result in reduced oxygen supply to the body tissues. It will slowly decrease iron stores, eventually resulting in iron deficiency. Having anemia means that you have low hemoglobin, which can make you weak. Posthemorrhagic anemia accompanies acute blood loss. This can be external (after trauma or obstetric hemorrhage) or internal (from bleeding in the gastrointestinal tract, fracture of the spleen, fracture of an ectopic pregnancy, or hemorrhage).
What Is Anemia?
Anemia is a result of either a lesser than normal amount of circulating red blood cells (RBCs), the amount of hemoglobin (Hgb), or the volume of packed RBCs (hematocrit). The World Health Organization (WHO) defines anemia as a level of hemoglobin less than 13 g/dL in men and less than 12 g/dL in women.
Anemia classified as either acute or chronic:
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Acute anemia occurs when there is a sudden drop in RBCs resulting from hemolysis or acute hemorrhage.
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Chronic anemia is a gradual decline in RBCs, and causes include iron or other nutritional deficiencies, chronic diseases, and other causes.
What Is Anemia of Acute Blood Loss?
Acute anemia is seen when there is an instant drop in RBCs, causing excessive loss than the production itself, most often by hemolysis or acute hemorrhage.
Pathophysiologic Stages:
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At the start, hypovolemia produces a threat to organs like the brain and the kidneys, affecting loss of consciousness and kidney failure. During this stage, the blood count will not show anemia because the hemoglobin concentration is not disturbed.
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Next, as an emergency response, the release of vasopressin and other peptides, and the body will shift fluid from the outside to the inside, resulting in hemodilution (diluted blood); thus, the hypovolemia gradually converts to anemia. This stage of anemia will depict the amount of blood lost.
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Provided bleeding is arrested, the bone marrow response will gradually improve anemia, and the reticulocyte count and erythropoietin levels will be elevated.
What Causes Anemia of Acute Blood Loss?
The major role in life-threatening acute anemia is a sudden drop in the oxygen-carrying capacity of the blood. This may occur with or without a reduction in the total volume. It is seen that an acute drop in hemoglobin to a level of 7-8 g/dL is symptomatic, whereas levels of 4 to 5 g/dL may be tolerated in chronic anemia, as the body can gradually replace the loss of intravascular volume. Iron deficiency anemia is the most common and could be due to blood loss but may occasionally be due to poor absorption of iron.
Some life-threatening causes are as follows:
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Trauma.
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Immense upper or lower gastrointestinal (GI) hemorrhage.
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Punctured ectopic pregnancy.
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Punctured aneurysm.
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Distribution intravascular coagulation.
1. Excessive Bleeding : The most common cause of acute anemia is excessive bleeding. When blood is drained, the body recompense by extracting the water from tissues outside tissue in an attempt to maintain the blood vessels filled, making it diluted. In due course, an increment of red blood cells may resolve the anemia. However, continued bleeding reduces the iron in the body, so the bone marrow is not able to increase the production of new red blood cells to replace those lost.
2. Rapid Blood Loss: The symptoms develop quickly and are severe as a result of the sudden loss of blood due to an injury, surgery, childbirth, or a ruptured blood vessel. Losing a huge amount of blood suddenly causes:
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Fall in blood pressure as the amount of fluid left in the blood vessels is insufficient.
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Reduction in oxygen supply of the body. This could lead to heart issues.
3. Chronic Blood Loss: This is more common, such as that from nosebleeds and hemorrhoids, which are obvious, but small amounts of bleeding may not be noticed. This type of blood loss is known as occult (hidden). A significant amount of blood loss can happen over a large period.
What Are the Symptoms of Anemia of Acute Blood Loss?
Symptoms are varied depending on mild to severe, such as fatigue, weakness, pale or yellowish skin color, irregular heartbeats, shortness of breath, lightheadedness, and cold extremities.
Further depends upon how much blood is lost and how rapidly blood is lost. The symptoms can be the following.
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When the blood loss is rapid, over some hours or less, dropping just one-third of the blood can be fatal. Weakness upon sitting or standing after a period of lying down (orthostatic hypotension) is seen with rapid blood loss.
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When the blood loss is slower, over weeks or longer, the loss of up to two-thirds of the blood volume may cause only fatigue and weakness or no symptoms at all if you drink enough fluids.
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You may notice black, dark stools if you have bleeding from the stomach or small intestine. Bleeding from the kidneys or bladder may result in urine discoloration.
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Women may notice long, heavier-than-usual menstrual periods.
How to Diagnose Anemia of Acute Blood Loss?
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Blood tests.
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Sometimes imaging or endoscopy is recommended.
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Stool and urine are tested for blood to identify the source of injury, along with imaging or endoscopy.
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Blood samples should be typed and cross-matched.
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Complete blood count (CBC) to check the hemoglobin and hematocrit.
In an actively bleeding patient, the hematocrit level on initial presentation could be normal.
How Is Anemia of Acute Blood Loss Treated?
1. Initial Management:
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Evaluate ABCs (airway, breathing, and circulation).
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Prioritize any life-threatening conditions immediately.
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Supplement oxygen.
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Obtaining two large-bore intravenous (IV) lines.
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IV fluid resuscitation.
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Apply direct pressure to any bleeding spot to secure it.
2. Treatment:
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By arresting profuse blood loss, the source of the bleeding must be found and stopped. A blood transfusion may be required.
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Supplementing iron, which is required to produce red blood cells, is lost as a result of bleeding. Iron is supplemented through tablets or intravenously.
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All treatment for anemia depends on its underlying cause.
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Other nutritional anemias, such as folate or vitamin B-12 deficiency, may result from a poor diet or from an inability to absorb them.
Is Anemia Preventable?
Most forms of anemia cannot be prevented, but eating healthy foods can help you avoid and manage both iron and vitamin deficiency anemia. Especially those with high levels of iron (dark green leafy vegetables), vitamin B12 (meat), and folic acid (citrus juices). A daily multivitamin will also help prevent nutritional anemias; however, older adults should not take supplements unless instructed by their physicians.
Conclusion
Acute anemia occurs when there is a sharp drop in RBCs, hemolysis, or hemorrhage. The patients have to be admitted to the hospitals, prioritize the ABCs (airway, breathing, circulation), and start rejuvenation. Send a blood sample to check for type and to detect other abnormalities; Initial management involves supplemental oxygen, obtaining IV access, intravenous (IV) fluid resuscitation, and applying direct pressure to a bleeding spot. Transfusion of packed red blood cells is indicated when hemoglobin is less than 7 g/dL.
