Procedure Practice 10/15/99 - Coding Recommendations

Feature Article 10/15/99:

Coding Anemia

Introduction - Types of Anemia
  

Introduction

Anemia is a commonly encountered clinical condition. It may be caused by an acquired or hereditary abnormality of red blood cells or their precursors, or it may be a manifestation of a nonhematologic disorder. Anemia is defined as a decrease in the circulating red blood cell (RBC) mass and a corresponding decrease in the oxygen-carrying capacity of the blood. While some anemia codes do not impact inpatient reimbursement, other codes reflect complicating or comorbid conditions (CC) that change the DRG assignment. Accurate coding requires a basic understanding of the many kinds of anemia that may be documented in a medical record. This month we review the types of anemia, what to look for in blood work and lab results, and correct code assignment. Remember to use lab values only as clues to improve coding accuracy. Always get physician confirmation of a suspected diagnosis before coding it.
 

General Signs and Symptoms

The clinical manifestations vary with patient age, type and severity of the anemia, and rapidity of onset. The presence of other chronic diseases also contributes to the overall clinical presentation. The main symptoms are exercise dyspnea, fatigue, palpitations, pica (consumption of substances such as ice, starch, or clay), and syncope (particularly following exercise). Dizziness, headache, syncope, tinnitus or vertigo, irritability, and difficulty sleeping or concentrating are more frequent in severe chronic anemia.

The main physiological consequence of anemia is tissue hypoxia. Symptoms of anemia are pallor (pale color of skin, palms, oral and conjunctival mucous membranes, and nail beds), tachycardia, a systolic ejection heart murmur, and mild peripheral edema. In elderly people, angina pectoris can be an important clinical manifestation. Women often develop abnormal menstruation which may present as either amenorrhea or menorrhagia and men can suffer from impotence.
 

Basic Laboratory Terms and Exams

In laboratory blood tests, the size, hemoglobin content, and shape of erythrocytes provide clues to the type of anemia present. The red cell distribution width (RDW) measures the size of circulating red cells and their heterogeneity. Red cell volume, or mean corpuscular volume (MCV), is estimated by dividing the patient's hematocrit (the percentage of red cells in whole blood) by the red cell count. Normal values are normocytic, low values are microcytic, and abnormally high values are macrocytic.

Hemoglobin content refers to the average amount of hemoglobin in each red blood cell. This value is called the mean cell hemoglobin (MCH). Normal values are normochromic, low values are hypochromic, and elevated values are hyperchromic.

Shape is determined by looking at red cells under the microscope. Normal red cells have a smooth, slightly concave shape. Irregularly shaped cells are called poikilocytes, a general term indicating an irregular shape. Other terms referring to specific abnormal shapes include helmet cells, schistocytes, sickle cells, target cells, teardrop cells, acanthocytes, leptocytes, and nucleated erythrocytes. Variation in the size of red blood cells is called anisocytosis.

Other tests that may be performed include a hemoglobin electrophoresis, serum ferritin levels, serum iron, and total iron binding capacity (TIBC). A bone marrow aspiration is a useful diagnostic procedure for any unexplained anemia, especially if underproduction of red cells is suspected.

The table below shows general reference ranges for some basic normal hemogram values. Each hospital may have a slightly different reference range depending upon the techniques and equipment used to perform these tests.
 

Types of Anemia

Iron Deficiency Anemia

... is a decrease in red cells caused by too little iron, and it is the most common form of anemia. Approximately 20% of women, 50% of pregnant women, and 3% of men are iron deficient. Iron is an essential component of hemoglobin, the oxygen carrying pigment in the blood. Iron is normally obtained through the food in the diet and by recycling of iron from old red blood cells. Causes of iron deficiency anemia include inadequate dietary consumption, poor absorption of iron by the body, and loss of blood (including blood loss from heavy menstrual bleeding). Children may suffer from iron deficiency anemia secondary to lead poisoning. Anemia develops slowly after the normal stores of iron have been depleted in the bone marrow. Women have smaller stores of iron than men and also have increased loss through menstruation, placing them at higher risk for anemia than men. In men and postmenopausal women, anemia is usually due to gastrointestinal blood loss associated with ulcers, gastrointestinal cancers or bleeding hemorrhoids, or gastritis resulting from prolonged use of aspirin or nonsteroidal anti-inflammatory medications (NSAIDS).

Treatment is directed at the underlying disorder. A mild iron deficiency may be treated with oral iron supplementation in the form of ferrous sulfate tablets. Intravenous or intramuscular iron injections may be given to patients when iron taken orally is not tolerated.

Coders should review the history and physical for a subjective description of symptoms and the physician's objective findings for the signs and symptoms discussed above. Check lab work for low hematocrit and hemoglobin levels. Review the treatment plan and medication list for oral iron pills or other forms of iron supplementation therapy. Iron deficiency anemia is coded to the 280 category. The only code in this range that is a CC is the code for normocytic anemia due to chronic blood loss, 280.0.
  

Anemia of Chronic Disease

... develops as a result of long-term infection or illness. This form of anemia is frequently seen in elderly patients and often complicates other illnesses. Certain chronic infections and diseases cause changes within the hematopoietic system. These changes include a shortened red blood cell life span, decreased iron stores, and decreased cell production within the bone marrow. In the presence of these three effects a low to moderate anemia develops. The symptoms of the anemia may go unnoticed in the face of the primary disease.

Conditions associated with the anemia of infection and chronic disease include such diverse diseases as chronic bacterial endocarditis, osteomyelitis, rheumatoid arthritis, rheumatic fever, Crohn's disease, and ulcerative colitis. Chronic renal failure may produce a similar anemia because it causes reduced levels of erythropoietin, the hormone which stimulates the production of red blood cells in the bone marrow. Treatment of the underlying disease can prevent or reverse the anemia. Chronic diseases such as Crohn's disease are difficult to treat and patients may suffer from intermittent anemia that varies with their condition.

The presence of any of the above chronic conditions is the first clue for the coder that anemia of chronic disease may also be present. Review lab work for a low hematocrit, hemoglobin, reticulocyte count, and serum ferritin level. Anemia of chronic disease is coded 285.9 per Coding Clinic March/April 1985. Don't be confused by the description for code 281.9, Chronic simple anemia. Category 281 is for anemia due to deficiencies of various kinds. Anemia of chronic disease is due to the underlying disease condition, not a deficiency.
  

Acute Blood Loss Anemia

... occurs when a significant amount of blood has been lost more rapidly than the body can replace it. The etiology of this anemia may be trauma, spontaneous rupture of a blood vessel (e.g. a ruptured aneurysm), surgical procedures with excessive blood loss, bleeding ulcers or neoplasms, or extravasation due to a coagulation defect such as hemophilia.

Rapid acute blood loss is a double threat because it can acutely decrease the total blood volume to the point of cardiovascular collapse, shock, and death. In this instance, the loss of blood cells is less important than the rapid depletion of total blood volume. Second, if total blood loss is more gradual the circulating red blood cells may be so depleted that their ability to deliver oxygen to peripheral tissues is severely impaired. A normal person can rapidly lose up to 20% of the total blood volume without noticeable signs or symptoms of anemia or cardiovascular distress. Loss of 30, 40, or 50% of total blood volume causes progressive cardiovascular distress and, without volume replacement, leads to shock and death.

Regardless of the cause of acute hemorrhage, the immediate clinical manifestations are essentially the same and depend upon the amount of blood lost. They include dizziness and syncope, thirst, rapid respirations, a weak, rapid pulse, orthostatic changes in blood pressure, and hypovolemic shock.

Treatment requires rapid identification of the source of bleeding and establishment of hemostasis, blood transfusions and intravenous hydration to restore plasma volume and maintain blood pressure, iron supplementation, and monitoring for hypovolemic shock.

Review the record for documentation of rapid acute blood loss as the result of trauma, obstetrical delivery, internal hemorrhage, or operative procedure. Look for documentation of transfusion therapy, vitamin K administration, and IV therapy for volume replacement. A hematocrit does not always reflect the severity of the patient's blood loss, so documentation of the physician's clinical assessment and treatment is important. Blood work during and immediately after hemorrhage generally shows high erythrocyte, hemoglobin and hematocrit levels due to vasoconstriction. The thrombocyte count will also be high during this time period as the body attempts to stop the blood loss. Within a few hours, these blood indices will drop as the plasma volume is replaced with IV therapy. Assign code 285.1 (a CC code that affects DRG assignment) for acute blood loss anemia. If the blood loss occurs as the result of an obstetrical procedure, also assign 674.3x to identify a complication of an obstetrical surgical wound. Acute blood loss anemia due to an operative procedure requires the addition of code 998.11 accompanied by the appropriate E code to identify the cause of the hemorrhage. If the blood loss is due to a complication of an implant device, or graft, select a code from the 996.7x range in addition to assigning 285.1.
  

Pernicious Anemia (Addison's Anemia)

... is the most common type of vitamin B12 deficiency anemia. It is caused by lack of a stomach secretion called intrinsic factor. In healthy people, vitamin B12 is absorbed by the terminal ileum of the small intestine. Before absorption can occur, the vitamin must combine in the stomach with intrinsic factor. If the gastric mucosa fails to secrete intrinsic factor, pernicious anemia results.

Pernicious anemia sometimes is due to hereditary factors. It is also seen in association with some autoimmune endocrine diseases such as type I diabetes, hypoparathyroidism, Addison's disease, hypopituitarism, testicular dysfunction, Graves disease, myasthenia gravis, vitiligo, and candidiasis. In infants or young children, pernicious anemia may be secondary to poor absorption of vitamin B12 caused by celiac disease (sprue), methylmalonic aciduria, homocystinuria, poor infant diet, or a maternal dietary deficiency during pregnancy.

Vitamin B12 is a key ingredient for maintenance of the nervous system. Over time, the deficiency of vitamin B12 can damage sensory and motor nerves, the brain, and spinal cord. The anemia also affects the gastrointestinal and cardiovascular systems.

People with pernicious anemia may have gastric polyps, and they have twice the incidence of gastric cancer than the normal population. Vitamin B12 deficiency affects the appearance of all epithelial cells; therefore, an untreated woman may obtain a false positive Pap smear.

Vitamin B12 injections are the definitive treatment for this disorder. When treatment is initiated, 5 to 7 injections may be given in a short span of time. Blood transfusions are not usually needed. Life-long therapy with vitamin B12 injections every month or two is required. A well-balanced diet is essential to provide other components for healthy blood cell development such as folic acid, iron, and vitamin C.

Lab tests that may indicate a diagnosis of pernicious anemia include: CBC results that show low hematocrit and hemoglobin with elevated MCV, low white blood count, low platelets and low reticulocyte count; a serum LDH below normal and a low serum vitamin B12 level. A Schilling test is a 2-stage lab procedure that may be performed to measure the amount of B12 absorption before and after the administration of intrinsic factor. This disease may also alter the results of the following tests: TIBC, peripheral smear, leukocyte alkaline phosphatase, gastrin, cholesterol levels, and serum bilirubin. Pernicious anemia is coded 281.0.
  

Folic Acid Deficiency Anemia/Nutritional Megaloblastic Anemia

... is a decrease in red cells caused by folate (folic acid) deficiency. Folate or folic acid is necessary for red blood cell formation and normal growth. In folate deficiency anemia, the red cells are abnormally large and are referred to as megalocytes. Causes of the condition are poor dietary intake of folic acid, chronic alcoholism, malabsorption diseases such as celiac disease, and certain medications such as Dilantin. A relative deficiency due to increased need for folic acid may occur in the third trimester of pregnancy. In pregnant women, folate deficiency has been associated with neural tube defects such as spina bifida in newborns.

Treatment is directed at the underlying cause of the anemia, which may be dietary or a malabsorption disease. Oral or parenteral folic acid supplements may be taken on a short term basis until the anemia has been corrected or, in the case of loss of absorption by the intestine, replacement therapy may be lifelong. Dietary treatment consists of increasing the intake of green leafy vegetables and citrus.

Look for blood tests that show low red blood cell count and low serum folate levels. A bone marrow aspiration may be done to detect this disease. The code for folic acid deficiency anemia is 281.2. Use an E code to identify the drug if the anemia is secondary to drug toxicity.
  

Sickle Cell Anemia

... is an inherited, chronic blood disease in which the red blood cells become crescent shaped and function abnormally. The disease is caused by an abnormal type of hemoglobin called hemoglobin S and is inherited as an autosomal recessive trait. It occurs in people who have inherited hemoglobin S from both parents. If hemoglobin S is inherited from one parent, the child will have sickle cell trait and usually have no disease symptoms. The disease occurs primarily in people of African heritage, with 1:400 African-Americans affected.

The disease produces a chronic anemia that can become life-threatening if hemolytic crises (the breakdown of red blood cells) or aplastic crises (bone marrow failure to produce blood cells) occur. Repeated crises can lead to damage of the kidneys, lungs, bone, liver, and central nervous system. Acute painful episodes occur when the sickle cells clog blood vessels and prevent blood from reaching tissues. The manifestations of this disease are a result of the fragility and inflexibility of the sickled cells. When exposed to dehydration, infection, and low oxygen supply, these fragile red blood cells assume a crescent shape causing red blood cell destruction and thickening of the blood. Although this disease is inherited and present at birth, symptoms usually don't occur until after 4 months of age.

Complications include recurrent aplastic and hemolytic crises, multisystem disease, papillary necrosis (tissue death) of the kidney, and the need for splenectomy if the spleen has atrophied. Death from organ failure frequently occurs between the ages of 20 and 40.

No cure exists for sickle cell anemia. The objective of therapy is the comprehensive management and control of symptoms relating to crises. Analgesics and IV hydration are provided for acute, painful episodes. Bed rest to minimize energy expenditure and oxygen requirements during a crisis is recommended since low oxygen levels result in acidosis which in turn causes sickling. Folic acid supplementation is a continuous therapy. Blood transfusions may be given for aplastic or hemolytic crises. A pneumococcal vaccine is given to prevent overwhelming infection in patients who have had a splenectomy. Research is currently being done on a compound called hydroxyurea which can induce some patients to produce a more normal blood protein and at least postpone sickle-cell attacks.

Tests performed to detect sickle cell anemia include a CBC, hemoglobin S screening test, hemoglobin electrophoresis, and a sickle cell test. Sickle cell trait is coded 282.5. Remember that patients with sickle cell trait are not usually sick from the disease, but have inherited the sickle cell gene from one parent. Sickle cell anemia is assigned a code from the 282.60-282.69 range. All the codes in this range are complications or cormorbidities and thus affect proper DRG assignment. A sickle cell crisis is coded 282.62.
  

Thalassemia

... describes inherited anemia. Thalassemia is also known as Cooley's anemia, Mediterranean anemia, microdrepanocytosis, or sickle-cell thalassemia. Patients with only a single thalassemia gene have thalassemia trait or thalassemia minor. Like people with only a single sickle cell gene, these individuals are not sick, but they are carriers of the disease. If a baby inherits a defective gene from both parents, a severe anemic condition called thalassemia major results.

Thalassemia is characterized by absent or decreased production of normal hemoglobin, resulting in anemia of varying degrees. Normal adults have three types of hemoglobin that are maintained in a consistent ratio. In the thalassemia patient, a mutation or deletion of the genes that control hemoglobin production occurs. This defect leads to a decreased production of the corresponding hemoglobin and a resultant abnormal hemoglobin ratio. The type of hemoglobin that is produced in normal amounts becomes excessive in relation to the other two hemoglobins and forms red cell aggregates or inclusions. These aggregates damage the red cell membranes, leading either to hemolysis, ineffective erythropoiesis, or both. The quantity and properties of these hemoglobin aggregates determine the characteristics and severity of the thalassemia.

Left untreated, thalassemia deprives the body's organs and tissues of oxygen, making them unable to function properly. Children with the disease become jaundiced and severely anemic. Bone marrow in the cranium, face, and long bones expands in an effort to produce more red blood cells, becoming brittle and causing disfigurement. The spleen, heart, and liver will enlarge greatly, and the child is highly susceptible to infections.

Thalassemia major is treated with repeated blood transfusions. The treatments often cause a build-up of iron within the body that can damage the pituitary gland, heart, and liver. Deferoxamine and other chelating drugs are routinely administered to reduce iron overload and minimize risk to these vital organs.

The only cure for thalassemia is a bone marrow transplant. A recent development in transplantation involves using blood from the umbilical cord of a newborn infant. Since the newborn's cells are immature, there is less chance that the recipient will reject the transplant.

Pregnant patients or people receiving genetic counseling prior to pregnancy may have blood tested for thalassemia trait. Thalassemia trait is reflected in a low hematocrit and an extremely low MCV. Peripheral blood smears show a variety of cell abnormalities including hypochromia and acanthocytes (cells with irregularly spaced bulbous projections), microcytosis, and poikilocytosis. The following tests may also be performed to detect thalassemia trait: hemoglobin electrophoresis, quantitative A2, quantitative F, ferritin levels, or iron studies. Thalassemia major is reflected in highly abnormal peripheral blood smears with bizarre cell formation, extremely low (less than 10%) hematocrit, the presence of little or no hemoglobin A, and large amounts of hemoglobin F. All thalassemias, including thalassemia trait and thalassemia major, are coded 282.4, a CC code that affects DRG assignment.
  

Hemolytic Anemia

... is caused by the premature destruction (hemolysis) and/or shortened lifespan of mature red blood cells. The bone marrow cannot produce red blood cells fast enough to compensate for those being destroyed. The disease may be hereditary and due to instrinsic defects in the red blood cells themselves, or it may develop later in life as the result of external factors (acquired hemolytic anemia). Some of the intrinsic red cell abnormalities responsible for hemolytic anemia include hereditary spherocytosis, hereditary elliptocytosis, disorders of glutathione metabolism, and other enzyme deficiencies. External factors that cause the condition include autoimmune diseases (responsible for most cases of acquired hemolytic anemia) such as systemic lupus erythematosus or chronic lymphocytic leukemia; blood transfusions; drug toxicity; the presence of artificial heart valves; metastatic adenocarcinoma; severe burns; and Plasmodium, Clostridium, and Borrelia infections.

The symptoms of hemolytic anemia depend upon the cause of the disease. Both spherocytosis and elliptocytosis can cause fatigue, jaundice, splenomegaly, and cholelithiasis. The dominant type of acquired hemolytic anemia, autoimmune hemolytic anemia, is manifested by a rapid onset of severe red blood cell depletion that may be life-threatening. Symptoms include fatigue, jaundice, splenomegaly, angina, and congestive heart failure. The complications vary with the specific type of hemolytic anemia. Severe anemia can aggravate pre-existing heart disease, lung disease, or cerebrovascular disease.

Treatment for this condition depends upon the type and cause of the hemolytic anemia. Folic acid, iron replacement, and corticosteroids may be used. In emergencies, transfusion of typed and washed packed red cell may be necessary. The outcome depends upon the type of hemolytic anemia.

Test results include elevated indirect bilirubin levels, low serum haptoglobin, hemoglobin in the urine, increased urine and fecal urobilinogen, elevated reticulocyte count, low red blood cell count and low hemoglobin. Direct measurement of the red cell life span by isotope tagging techniques shows a decreased life span. Category 282 contains the series of codes for hereditary hemolytic anemia. Hereditary spherocytosis is coded 282.0. Elliptocytosis is coded 282.1. Hemolytic anemia due to disorders of glutathione metabolism are coded 282.2, and hemolytic anemia due to other enzyme deficiencies are coded 282.3. Select a code from the 283 category for acquired hemolytic anemia. Hemolytic anemia due to autoimmune disorders is assigned to 283.0. 283.10 through 283.19 are for nonautoimune acquired hemolytic anemia. Assign 283.0 to hemolytic anemia caused by drug toxicity along with the appropriate E code to identify the drug. All codes in category 283 are CC codes.
  

Aplastic Anemia

... is a disease manifested by pancytopenia - a reduction in all blood cell types (red cells, white cells, and platelets). A variety of associations have been made in the attempt to find a specific cause, but no one cause can be identified. Treatment must be instituted promptly after diagnosis to avoid death. Unfortunately, patients treated successfully for aplastic anemia then have a higher risk of developing other diseases later in life, including cancer.

Although the specific cause of aplastic anemia is not readily identifiable in most cases, various categories have been noted. The most common congenital cause of aplastic anemia is Fanconi's anemia, an autosomal recessive disorder in which over 90% of affected children develop severe aplastic anemia by 8 or 9 years of age. External agents include viruses such as HIV, Parvovirus, Epstein-Barr virus, and hepatitis C virus. The most frequent external cause of aplastic anemia is drug or chemical exposure. Some agents, such as chloramphenicol, ionizing radiation, and antineoplastic drugs, cause an aplasia that is dose related, with bone marrow recovery after withdrawal of the agent. Other agents, including pesticides and some anticonvulsants and antimicrobials cause an aplastic reaction which is not dose related and may occur even after cessation of chemical exposure.

The typical symptoms of weakness and fatigue occur as the result of low red cell production. Other problems include infections due to lack of white cells and bleeding due to thrombocytopenia. Splenomegaly and heart palpitations are other symptoms of aplastic anemia.

Mild cases of aplastic anemia are treated with supportive care. Blood transfusions and platelet transfusions help correct the abnormal blood counts and relieve some symptoms. In young patients with severe anemia, bone marrow transplantation achieves complete remission in nearly 80% of cases. For patients who are ineligible for bone marrow transplant, immunosuppression is used to treat the aplasia, with a patient response rate of 30-70% .

CBC results show low hematocrit and hemoglobin levels, low white blood cell count, low reticulocyte count, low platelet count, elevated bilirubin levels. Diagnosis is based on finding anemia, neutropenia, and thrombocytopenia in both blood and bone marrow specimens. X- rays are done to rule out bone lesions or neoplastic infiltrates. Since the diagnosis is one of exclusion, all other causes of pancytopenia and other lab findings must be ruled out before aplastic anemia can be diagnosed. Aplastic anemia is coded to category 284. Hereditary forms of the disease are coded 284.0. For aplastic anemia due to infection, radiation, drug toxicity, or chronic systemic disease, assign 284.8 with an E code to identify the external agent. All codes in this category are CC codes.
  

Sideroblastic Anemia

... is a condition in which iron is not used properly by the body to form hemoglobin. Because the iron cannot be used it accumulates in a ring around the nucleus of immature red blood cells. This kind of iron-ringed immature red blood cell is called a ringed sideroblast.

Siderblastic anemia may be congenital or acquired as the result of another disease condition. Some forms of the disease are reversible while other forms are irreversible. Of the hereditary forms, X-linked sideroblastic anemia is the most common. Women often are carriers of the trait and their anemia is usually mild. The condition is more severe in men.

Acquired irreversible sideroblastic anemia may result from myelodysplastic syndrome, leukemia, or myeloproliferative disorders. These kinds of anemia are usually stable and chronic, but may become more severe or may transform into leukemia.

Acquired reversible forms of aplastic anemia may be caused by alcoholism, lead poisoning, or drug toxicity. In reversible aplastic anemia, once the individual is no longer exposed to the offending agent, the anemia resolves.

Symptoms of the various forms of siderblastic anemia include malaise, weakness, and the other general symptoms of anemia described above.

Treatment for sideroblastic anemia depends upon the causative agent. Vitamin therapy, particularly with B6 (pyroxidine) and folic acid, is effective in some people with hereditary sideroblastic anemia, and may cause partial or complete remission as long as the large doses are taken. If lead poisoning is the underlying problem, chelation therapy is required. Transfusions are done in cases of severe anemia. Bone marrow transplant is the only curative known for the hereditary form of aplastic anemia.

Sideroblastic anemia is diagnosed with a bone marrow biopsy. Significant laboratory findings include a high serum iron and high transferrin level. The hematocrit is moderately low in the range of 20-30%. All types of sideroblastic anemia are coded 285.0, a CC code that impacts DRG assignment.

Practice Makes Perfect!

Are you ready for some hands-on practice?

Read the patient report(s) on our procedure practice page. Assign the appropriate codes and then compare your answers with our coding recommendations. Good luck!

Back to:
Top - Introduction - Types of Anemia
   

If you have comments or suggestions about our code selections or about any topic on our Coding Edge® pages, please e-mail us at codingedge@lagunamedsys.com.