Acute Anemia

What is Acute Anemia?

Anemia is a condition where there’s a shortage in the count of red blood cells, the level of hemoglobin, or the volume of packed red blood cells, which is called hematocrit. According to the World Health Organization (WHO), anemia is diagnosed when the hemoglobin level is less than 13 g/dL in men and less than 12 g/dL in women.

Anemia is categorized into two main types:

1. Acute anemia, where there’s a sudden and swift drop in red blood cells. This is usually caused by the quick destruction of red blood cells (hemolysis) or a severe bleeding (acute hemorrhage).

2. Chronic anemia, defined by a slow decrease in red blood cells over a period. Causes for this type can be numerous, ranging from lack of iron or other nutrients, ongoing diseases, impacts of certain medications, or different pre-existing health problems.

What Causes Acute Anemia?

Anemia can be caused by blood loss, which results in fewer red blood cells (RBCs). Many common causes of acute anemia, especially in emergency room situations, include traumatic injuries, ruptured aneurysms, severe gastrointestinal bleeding, ruptured ectopic pregnancies, and a condition called disseminated intravascular coagulation (DIC).

Hemolytic anemias – or anemias caused by destruction or decreased lifespan of RBCs – can also cause both acute and chronic anemia. There are two kinds of these anemias: intracorpuscular (within the cell) and extracorpuscular (outside the cell).

In intracorpuscular hemolytic anemias, the issue stems from the RBC itself. These issues can be defects in the cell’s membrane, enzymes, or the molecules that make up hemoglobin. These defects can make the cells break down too early, causing anemia. There are several types, including sickle cell disease, which affects the shape of the RBCs, and thalassemia, which affects the production of certain proteins in the blood. Enzymopathies are conditions that involve abormal performance of certain enzymes inside RBCs which can also cause anemia.

The table below shows examples of these conditions and their details:

Glucose-6-phospate dehydrogenase (G6PD) deficiency, Hemophilia A, Phosphofructokinase (PFK) deficiency, Pyruvate kinase (PK) deficiency, Aldolase deficiency, and Triosephosphate isomerase (TPI) deficiency.

In some of these conditions, the structure of the RBCs can be altered as well, as is the case with Hereditary spherocytosis and Hereditary elliptocytosis diseases. Paroxysmal nocturnal hemoglobinuria (PNH), another condition, leads to hemolysis, thrombosis, and marrow aplasia, and is caused by clonal autoimmune mechanism.

In extracorpuscular hemolytic anemias, the defect leading to RBC destruction stems from outside the cell. These conditions might be due to factors in the bloodstream or external to the RBCs. Conditions like Thrombotic thrombocytopenic purpura (TTP), familial hemolytic-uremic syndrome (HUS), and immune thrombocytopenic purpura can lead to these anemias due to the formation of clots or the abnormal function of the immune system. An accelerated coagulation process, leading to clot formation in response to trauma, infections or complications during pregnancy, known as Disseminated intravascular coagulation can also cause anemia.

Exposure to certain toxic agents and drugs, or infections such as malaria and Shiga toxin-producing E. Coli can lead to the destruction of RBCs. Conditions involving the immune system could also cause RBC destruction, as in autoimmune hemolytic anemia. Hypersplenism is a condition in which the spleen is enlarged and destroys more blood cells, including RBCs, than normal, consequently contributing to anemia.

Risk Factors and Frequency for Acute Anemia

Anemia is a common illness affecting about a quarter of the general population and even more people who are in hospital settings. In fact, 75% of older hospitalized individuals are affected by this condition.

Data from a 2000 study that included 81,000 health plan members showed different rates of anemia in people with different health conditions:

• Chronic kidney disease patients had the highest rate of anemia at 34.5%
• About 21% of cancer patients were affected by anemia
• 18% of people with chronic heart disease had anemia
• Inflammatory bowel disease and rheumatoid arthritis patients each accounted for 13% and 10% of anemia cases, respectively
• 10% of individuals with HIV infection also had anemia

Signs and Symptoms of Acute Anemia

If someone is showing signs of anemia, understanding their past medical history is important for figuring out what might be causing it. The first thing that medical professionals will do is to ensure that critical body functions, like airway, breathing, and circulation, are working properly. If not, immediate emergency actions will be taken to stabilize the patient.

When the person is unable to communicate, getting even a small amount of their medical history can be very valuable. This information can come from those who responded to the emergency call or people who are with the patient. Going through any accessible previous medical records can also provide beneficial insights into the patient’s past health conditions and can help in identifying why the anemia may have occurred.

A more detailed medical history should also be asked about if there is a chance that the anemia is due to blood loss. Depending on where the bleeding is thought to have happened, a more specific series of questions can be asked. For instance, if the bleeding might be from the digestive system, any prior incidents of internal bleeding, symptoms or medical conditions related to the digestive system should be discussed. Similarly, if the bleeding might have happened due to gynecological causes, information related to menstruation and pregnancy should be gathered.

Regular monitoring of vital signs is crucial while dealing with a patient suffering from anemia. These indicators can give an idea about the patient’s state of health and whether the interventions are working or not. Physical examinations should focus on the area where bleeding is suspected, like the chest, abdomen, pelvis, or extremities, especially if trauma is suspected. Imaging studies might also be conducted based on the patient’s condition to find any injuries or areas of bleeding.

Depending on the severity of blood loss, hemorrhagic shock can be broken down into multiple stages. Each stage comes with its own signs:

• Class 1: Less than 15% blood loss. Mild increase in heart rate might be observed, though blood pressure remains normal. The patient’s skin may start feeling cold.
• Class 2: 15% to 30% blood loss. Increase in heart rate becomes more noticeable, and the patient begins to breathe rapidly. The difference between systolic and diastolic blood pressure decreases.
• Class 3: 30% to 40% blood loss. Increased heart rate becomes worse with a rapid, weak pulse. Blood pressure decreases more, skin becomes pale and mottled, and urine output decreases significantly.
• Class 4: More than 40% blood loss. This is a dangerous stage with a high likelihood of death. Rapid heart rate and decreased blood pressure continue to worsen, potentially leading to loss of consciousness. If there is more than 50% blood loss, the pulse may disappear.

Extra signs that can be observed during a skin examination could give more information when evaluating someone with potential bleeding disorders or hemorrhage. These might include:

• Flank ecchymosis (Grey-Turner sign): Bruising in the side area of the body can indicate bleeding within the retroperitoneum, the space behind the abdominal cavity.
• Umbilical ecchymosis (Cullen sign): Bruising around the belly button might mean bleeding inside the abdomen or retroperitoneum.
• Jaundiced, yellow skin: Yellowing of the skin could indicate conditions like liver disease, certain disorders related to the protein hemoglobin, or other sorts of red blood cell breakdown.
• Purpura and petechiae: These skin marks could suggest problems with platelets or difficulties with blood clotting.
• Hemarthrosis: Bleeding into the joints might suggest a bleeding disorder like hemophilia.
• Widespread bleeding from intravenous sites and mucous membranes: This could be a sign of disseminated intravascular coagulation (DIC), a serious condition that affects the blood’s ability to clot.

Testing for Acute Anemia

In order to understand the source and severity of bleeding, doctors need to conduct a variety of tests and procedures.

The process begins with blood typing and cross-matching, in which a blood sample is sent to the lab. This test ensures that if a patient needs a blood transfusion, the blood given is safe and compatible with their body’s blood type.

Another crucial test is the complete blood count (CBC). This can provide insight into the volume of red blood cells, levels of hemoglobin, and hematocrit levels, which helps assess the amount of blood loss and the severity of anemia. It’s important to remember that a person who’s actively losing blood may not have accurate results initially due to a temporary dilution of their blood. It’s for this reason that doctors often run this test multiple times to keep track of how hemoglobin and hematocrit levels change over time and how well the treatment is working.

Another parameter that doctors use is called Mean corpuscular volume (MCV), which helps classify anemia based on how big the red blood cells are. For instance, there are microcytic, normocytic and macrocytic anemias, each associated with different causes and characterized by small, normal-sized, or large red blood cells respectively.

Additional blood tests, like Lactate dehydrogenase (LDH), haptoglobin, and bilirubin and blood urea nitrogen (BUN) levels, along with a reticulocyte count can hint towards the underlying cause of anemia, with different pattern of results indicating various conditions such as upper GI bleeding or different types of anemia.

Screening for a condition called DIC (Disseminated Intravascular Coagulation) involves checking blood clotting times, fibrinogen levels, fibrin split products, and platelets count. The condition, which can be triggered by a variety of health issues, can cause excessive bleeding and clotting simultaneously.

Further investigations might involve checking folate and vitamin B12 levels, assessing lead levels, conducting hemoglobin electrophoresis, factor deficiency tests, bleeding time check, bone marrow aspiration, and Coombs test, among others.

Imaging studies are also crucial in identifying the source of bleeding and assessing the severity of anemia. Ultrasonic scans, chest x-rays, CT scans, esophagogastroduodenoscopy, and sigmoidoscopy or colonoscopy are among the imaging tools that doctors use to diagnose and sometimes treat different kinds of bleeding.

Treatment Options for Acute Anemia

The treatment for acute anemia is important in stabilizing the patient and handling the root cause of the condition. Quick intervention is needed to ensure sufficient oxygen is delivered to the body’s tissues, and to avoid further issues. Usually, treatments involve a mix of methods including stopping ongoing bleeding, replacing the lost blood volume, and treating the main cause of the anemia.

Initial treatment involves checking and taking care of life-threatening conditions, giving extra oxygen, setting up intravenous lines for fluid resuscitation, and applying pressue to stop the bleeding if possible.

Blood transfusions are the primary treatment for acute anemia, aimed at replacing lost blood volume. Ideally, each unit of blood cells increases the level of red blood cells in the blood by about three points.

The decision on when to perform a transfusion depends on different patient conditions. For stable adult patients, blood transfusion is usually only considered when their hemoglobin levels drop to 7 g/dL or lower. But for patients with heart disease, transfusion is considered when hemoglobin falls below 8 g/dL.

For patients with severe bleeding, decisions should be based on their clinical condition and the seriousness of the bleeding. Sometimes, a more liberal approach is needed to maintain stability during ongoing bleeding until it is controlled.

If a patient has a severe condition like sickle cell anemia, the treatment focus is on managing symptoms, preventing complications, and improving the quality of life. Treatments may include blood transfusions, replacing the patient’s blood, or using medication like Hydroxyurea that helps prevent red blood cells from forming a ‘sickle’ or crescent shape.

Patients with low platelet count may need a transfusion if there are signs of bleeding. Certain conditions may also require specific treatments, like plasmapheresis or the use of antiplatelet agents like aspirin.

Patients with inherited bleeding disorders like Von Willebrand disease or hemophilia, which causes blood clotting problems, are often managed with specific treatments like factor concentrates or drugs that replenish or enhance the function of blood clotting factors.

For a condition like disseminated intravascular coagulation, which causes small blood clots to form throughout the bloodstream, the main focus is on treating the root cause to stop ongoing coagulation and blood clot formation. Transfusions of platelets and coagulation factors may be used in severe cases.

What else can Acute Anemia be?

When doctors are trying to understand why someone has anemia, they need to consider a range of potential causes:

• Trauma or blood loss, which might come from an injury
• A GI bleed, which might be noticeable, or might be a side effect of certain medications like NSAIDs, corticosteroids, alcohol, anticoagulants, or related to liver cirrhosis
• A ruptured blood vessel that might come with sudden severe pain or even fainting
• Recent surgery that resulted in a significant loss of blood, especially if the patient also has a history of bleeding or bruising easily or has been using antibiotics
• Very heavy menstrual cycles lasting over a week
• Dietary deficiencies or lack of proper nutrition leading to a lack of iron, vitamin B12, or folate
• Specific blood disorders such as Myelodysplastic syndrome or Leukemia. Acute leukemia is defined by a decrease in all blood cells and the presence of 20% blasts. Chronic leukemia can cause normocytic anemia.
• Cancer that has spread to the bone marrow, often associated with weight loss, fatigue, and fevers
• Exposure to certain toxic drugs
• Anemia associated with long-term illnesses such as inflammatory, autoimmune, or infectious diseases
• Chronic kidney disease or chronic liver disease
• Pregnancy, especially in the later stages

It’s important to remember that all these possibilities need professional medical assessment and diagnosis.

What to expect with Acute Anemia

The outlook for acute anemia is connected to how severe it is, how quickly it develops, and any other illnesses the patient has. Usually, anemia makes a patient’s overall health worse, as it puts additional strain on the body and could speed up the progression of any underlying diseases.

Fast action is crucial in managing acute anemia. If the root cause isn’t identified and addressed quickly, it can lead to serious consequences, including a swift worsening of the patient’s health. Therefore, it’s vital to intervene promptly and manage the condition properly to prevent negative outcomes related to acute anemia.

Possible Complications When Diagnosed with Acute Anemia

The worst outcome of acute anemia usually results from a considerable blood loss that can cause low blood volume, a condition known as hypovolemic shock. This can deprive the organs of the oxygen they need, leading to potential damage in crucial body organs. These could include heart attacks, heart failure, kidney failure, acute respiratory failure due to lack of oxygen, or other signs of organ struggle.

Common Complications:

• Heart attacks
• Heart failure
• Renal (kidney) failure
• Acute hypoxic respiratory failure (difficulty breathing caused by a lack of oxygen)
• Other manifestations of organ dysfunction

Preventing Acute Anemia

Chronic anemia, a condition where the body doesn’t have enough healthy red blood cells or hemoglobin, can occur without any noticeable symptoms as the body slowly adapts to the lower levels. On the other hand, sudden or acute anemia usually comes with more obvious signs and explanations as to what might be causing it. However, in these sudden occurrences, it is vital for healthcare providers to quickly identify and deal with the cause, to prevent any serious problems that could arise.

When it comes to managing anemia, working together well as a medical team is crucial. It’s also extremely important for patients to work in tandem with the healthcare staff by following the suggested treatment plans and instructions.