Anaemia And Pneumonia Flashcards
What is Anaemia?
What is Hb,Hct,RBcs
What 3 things does the degree to which a patient become symptomatic depend on?
When do most patients experience some symptoms related to anemia?
Anemia is a reduction in hemoglobin (Hb) or hematocrit (HCT) or RBC count
•Anemia is not a diagnosis, but a presentation of an underlying condition.
•Whether or not a patient becomes symptomatic depends on the etiology of anemia, the acuity of onset, and the presence of other comorbidities, especially the presence of cardiovascular disease.
•Most patients experience some symptoms related to anemia when the hemoglobin drops below 7.0 g/dL.
Reduction in the volume of RBC’s (hematocrit) or concentration (hemoglobin) when compared to similar values from a reference population.
•Hgb = expression of amount (g/dL).
•Hct = expression of volume (% or decimal fraction).
•RBC = expression of number (#/mm3).
What are the normal Hb levels for men, women and kids?
How does RBc production occur?
What things prevent RBC production
Normal Hemoglobin (Hgb)-specific laboratory cut-offs will differ slightly, but in general, the normal ranges are as follows:
•13.5 to 18.0 g/dL in men
•12.0 to 15.0 g/dL in women
•11.0 to 16.0 g/dL in children
•Varied in pregnancy depending on the trimester, but generally greater than 10.0 g/dL
Myeloid stem cells turn to erythroblasts turn to reticulocyte (immature RBCs) then turn to erythrocyte
RBc production occurs in red bone marrow. In red bone marrow there is myeloid stem cell which can become an RBC,WBC or platelet.
Hormonal stimulants drive RBc production- stimulants such as thyroid hormones, erythropoietin (from kidneys and liver), Iron-B12-Folate from GIT
Toxins and alcohol suppress bone marrow
Intrinsic problems with bone marrow function- cancer of bone marrow cells can reduce RBcs, chemo radiation destroying intrinsic bone marrow
State and explain the three main mechanisms of Anaemia(State ten causes of Anaemia)
What happens when RBcs are low?
Blood loss
•Acute- hemorrhage, surgery, trauma, menorrhagia(heavy menstrual bleeding)
•Chronic-, chronic gastrointestinal blood losses [6] (in the setting of hookworm infestation, ulcers, etc.), urinary losses (BPH, renal carcinoma, schistosomiasis)
Hemolytic anemia
•Acquired- immune-mediated, infection, microangiopathic, blood transfusion-related, and secondary to hypersplenism
•Hereditary- enzymopathies, disorders of hemoglobin (sickle cell), defects in red blood cell metabolism (G6PD deficiency, pyruvate kinase deficiency), defects in red blood cell membrane production (hereditary spherocytosis and elliptocytosis)
Intravascular-Intravascular hemolysis occurs in hemolytic anemia due to the following:
Prosthetic cardiac valves
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Thrombotic thrombocytopenic purpura
Disseminated intravascular coagulation
Transfusion of ABO incompatible blood
Paroxysmal nocturnal hemoglobinuria (PNH)
COVID-19 [4, 5]
Pyruvate kinase deficiency [6]
Extravascular-Autoimmune hemolytic anemia and hereditary spherocytosis are examples of extravascular hemolysis because the red blood cells are destroyed in the spleen and other reticuloendothelial tissues. [3]
Deficient/defective erythropoiesis (hypoproliferative anaemia)
•Microcytic
•Normocytic, normochromic
•Macrocytic
When RBcs are low, they make the myeloid stem cells produce more RBCs if the bone marrow is working properly
State five conditions under each hypoproliferative Anaemia
What is the MCV (mean corpuscular volume which shows the sizes of the RBCs) for each type?
Macrocytic Anaemia can be caused by either what or what?
How will you know what is causing the macrocytic Anaemia
What drugs cause normocytic anaemia?
How will you differentiate megaloblastic Anaemia from non megaloblastic anaemia?
1) Hypoproliferative Microcytic Anemia (MCV<80 fl(femtolitres)
•Iron deficiency anemia
•Anemia of chronic disease (AOCD)
•Sideroblastic anemia (may be associated with an elevated MCV as well, resulting in a dimorphic cell population)
•Thalassemia
•Lead poisoning( which can also cause sideroblastic Anaemia)
Causes
2)Hypoproliferative Normocytic Anemia (MCV 80-100 fL)
•Anemia of chronic disease (AOCD)
•Renal failure
•Aplastic anemia
•Pure red cell aplasia
•Myelofibrosis or myelophthisic processes
•Multiple myeloma
Hypoproliferative Macrocytic Anemia (MCV>100 fL)
•Alcohol
•Liver disease
•Hypothyroidism
•Folate and Vitamin B12 deficiency [3]
•Myelodysplastic syndrome (MDS)
•Drug-induced ( chemo drugs, anti seizure meds, TB meds , HIV meds, some antibiotics
Macrocytic anemia can be caused by either a hypoproliferative disorder, hemolysis, or both.
•Thus, it is important to calculate the corrected reticulocyte count when evaluating a patient with macrocytic anemia.
•In hypoproliferative macrocytic anemia, the corrected reticulocyte count is <2%, and the MCV is greater than 100 fl.
•But, if the reticulocyte count is > 2%, hemolytic anemia should be considered
So under macrocytic Anaemia we have megaloblastic and non Megaloblastic
Megaloblastic have hypersegmented PMN on peripheral blood smear or blood film but Non megaloblastic have hyposegmented PMN on peripheral blood smear or blood film
Megaloblastic anaemia suggest Iron deficiency, B12,folate deficiency, alcohol, medications causing the Anaemia
Haemolytic Anaemia is divided into two
State, define and give examples of each
Hemolytic anemia (HA) is divided into extravascular and intravascular causes
•Extravascular hemolysis: red cells are prematurely removed from the circulation by the macrophages in the liver and spleen. This accounts for a majority of cases of HA
•Hemoglobinopathies (sickle cell, thalassemias)
•Enzyemopathies (G6PD deficiency(G6PDH reduces oxidative stress on RBcs and since it’s not present, oxidative stress causes RBc to lose their integrity making them likely to taken by the macrophages in the liver or spleen when blood with such RBCs pass through these organs) , pyruvate kinase deficiency)
•Membrane defects (hereditary spherocytosis, hereditary elliptocytosis)
•Drug-induced
Intravascular hemolysis: red cells lyse within the circulation, and is less common.
•PNH(paroxysmal nocturnal haemoglobinuria)
•AIHA
•Transfusion reactions
•MAHA(microangiopathic Haemolytic Anaemia)
•DIC
•Infections
•Snake bites/venom
What questions will you ask on history?
(Ask in accordance to the three mechanisms of Anaemia or causes of Anaemia)
A thorough history and physical must be performed.
•Some important questions to obtain in a history:
•Obvious bleeding- per rectum or heavy menstrual bleeding, black tarry stools, hemorrhoids
•Thorough dietary history
•Consumption of nonfood substances
•Bulky or fatty stools with foul odor to suggest malabsorption
•Thorough surgical history, with a concentration on abdominal and gastric surgeries
•Family history of hemoglobinopathies, cancer, bleeding disorders
•Careful attention to the medications taken daily
:
State five signs and symptoms each of Anaemia
How does permicious Anaemia occur?
Classically depends on the rate of blood loss. Symptoms usually include the following:
•Weakness
•Tiredness
•Lethargy
•Restless legs
•Shortness of breath, especially on exertion, near syncope
•Chest pain and reduced exercise tolerance- with more severe anemia
•Pica- desire to eat unusual and nondietary substances
•Mild anemia may otherwise be asymptomatic
Skin may be cool to touch
•Tachypnea
•Hypotension (orthostatic)
•Pallor of the conjunctiva
•Jaundice- elevated bilirubin is seen in several hemoglobinopathies, liver diseases and other forms of hemolysis
•Lymphadenopathy: suggestive of lymphoma or leukemia
•Glossitis (inflammation of the tongue) and cheilitis (swollen patches on the corners of the mouth): iron/folate deficiency, alcoholism, pernicious anemia
Pernicious anemia is a type of vitamin B12 anemia. The body needs vitamin B12 to make red blood cells. You get this vitamin from eating foods such as meat, poultry, shellfish, eggs, and dairy products.
A special protein, called intrinsic factor (IF), binds vitamin B12 so that it can be absorbed in the intestines. This protein is released by cells in the stomach. When the stomach does not make enough intrinsic factor, the intestine cannot properly absorb vitamin B12.
Common causes of pernicious anemia include:
Weakened stomach lining (atrophic gastritis)
An autoimmune condition in which the body’s immune system attacks the actual intrinsic factor protein or the cells in the lining of your stomach that make it.
On abdominal exam, what are signs of anemia seen and what may cause it?
How does Anaemia affect the CVS
Abdominal exam
•Splenomegaly: hemolysis, lymphoma, leukemia, myelofibrosis
•Hepatomegaly: alcohol, myelofibrosis
•Scar from gastrectomy: decreased absorptive surface with the loss of the terminal ileum leads to vitamin B12 deficiency
•Scar from cholecystectomy: Cholesterol and pigmented gallstones are commonly seen in sickle cell anemia are hereditary spherocytosis
Cardiovascular
•Tachycardia
•Systolic flow murmur
•Severe anemia may lead to high output heart failure
How do you evaluate Anaemia (think about for each type of Anaemia)
Start from the top
How is reticulocyte count calculated?
How Is the value gotten interpreted
What normal HCT for men and women to claukate the reticulocyte count
Evaluation
•Complete blood count (CBC) including differential
•Calculate the corrected reticulocyte count = percent reticulocytes x (patient’s HCT/normal HCT)
•For normal HCT, use 45% in men and 40% in women
•If result > 2, this suggests hemolysis or acute blood loss, while results < 2 suggests hypoproliferation.
How is microcytic Anaemia evaluated?
After calculating the reticulocyte count, check the MCV.
MCV (<80 fl)
•Iron deficiency- decreased serum iron, percent saturation of iron, with increased total iron-binding capacity (TIBC), transferrin levels, and soluble transferrin receptor, decreased ferritin levels
•Lead poisoning- basophilic stippling on the peripheral blood smear, ringed sideroblasts in bone marrow, elevated lead levels
•Thalassemia- RBC count may be normal/high, low MCV, target cells, and basophilic stippling are on peripheral smear. Alpha thalassemia is differentiated from beta-thalassemia by a normal Hgb electrophoresis in alpha thalassemia. Elevated Hgb A2/HgbF is seen in the beta-thalassemia trait.
•Sideroblastic anemia- elevated serum iron and transferrin with ringed sideroblasts in the bone marrow
How is normocytic Anaemia evaluated
Evaluation
•MCV (90-100fl)
•Renal failure: BUN/Creatinine
•Aplastic anemia- ask for drug exposure, check for infections (EBV, hepatitis, CMV, HIV), test for hematologic malignancies and paroxysmal nocturnal hemoglobinuria (PNH)
•Myelofibrosis/myelophthisis- check bone marrow biopsy
•Multiple myeloma- serum and urine electrophoresis
Macrocytic Anaemia evaluated
MCV (>100 fl)
•B12/folate levels- B12 and folate deficiency can be differentiated by an elevated methylmalonic and homocysteine level in B12 deficiency and only an elevated homocysteine level in folate deficiency. Methylmalonic levels are relatively normal.
•MDS- hyposegmented PMNs on peripheral smear, bone marrow biopsy
•Hypothyroidism- TSH, free T4
•Liver disease- check liver function
•Alcohol- assess alcohol intake
•Drugs
How do you evaluate Haemolytic Anaemia
Bite cells on PBS indicate what?
Target cells on PBS indicate what?
Schistocytes on PBS indicate what?
Acanthocytes on PBS indicate what?
State three other investigations that may be needed
Steps to evaluate for hemolytic anemia
•Confirm the presence of hemolysis- elevated LDH, corrected reticulocyte count >2%, elevated indirect or unconjugated bilirubin
•Examine the peripheral blood smear
•Spherocytes: immune hemolytic anemia (Direct antiglobulin test DAT+) vs. hereditary spherocytosis (DAT-)
•Bite cells: G6PD deficiency
•Target cells: hemoglobinopathy or liver disease
•Schistocytes: TTP/HUS, DIC, prosthetic valve, malignant HTN
•Acanthocytes: liver disease
•Parasitic inclusions: malaria, babesiosis, bartonellosis
Other investigations that might be warranted include:
•esophagogastroduodenoscopy for the determination of an upper GI bleed,
•colonoscopy for the determination of a lower GI bleed,
•imaging studies if malignancy, or internal hemorrhage is suspected.
•If a menstruating woman has heavy vaginal bleeding, evaluate the presence of fibroids with a pelvic ultrasound.
How are Anaemia due to nutritional deficiencies managed?
What are the common side effects of supplement iron
How long does it take for haemoglobin to normalize afte taking oral iron
Anemia due to nutritional deficiencies:
•Oral/IV iron, B12, and folate.
•Oral supplementation of iron is by far the most common method of iron repletion. The dose of iron administered depends on the patient’s age, calculated iron deficit, the rate of correction required, and the ability to tolerate side effects.
•The most common side effects include metallic taste and gastrointestinal side effects such as constipation and black tarry stools. For such individuals, they are advised to take oral iron every other day, in order to aid in improved GI absorption.
•The hemoglobin will usually normalize in (2 weeks earliest) 6-8 weeks, with an increase in reticulocyte count in just 7-10 days.
•IV iron may be beneficial in patients requiring a rapid increase in levels. Patients with acute and ongoing blood loss or patients with intolerable side effects are candidates for IV iron.
Management of anemia depends on what?
What is the target haemoglobin for most patients?
What is the target hamoglobjn for people with cardiovascular disease
Management depends primarily on treating the underlying cause of anemia.
•Anemia due to acute blood loss- Treat with IV fluids, crossmatched packed red blood cells, oxygen.
•Always remember to obtain at least two large-bore IV lines for the administration of fluid and blood products.
•Maintain hemoglobin of > 7 g/dL in a majority of patients.
•Those with cardiovascular disease require a higher hemoglobin goal of > 8 g/dL.
How is Anaemia due to defects in the bone marrow and stem cells managed?
How is anemia due to chronic disease managed?
Anemia due to defects in the bone marrow and stem cells: Conditions such as aplastic anemia require bone marrow transplantation.
•Anemia due to chronic disease: Anemia in the setting of renal failure, responds to erythropoietin. Autoimmune and rheumatological conditions causing anemia require treatment of the underlying disease.
How is Anaemia due to increased RBC destruction managed?
Anemia due to increased red blood cell destruction:
•Hemolytic anemia due to medications requires the removal of the offending drug.
•Persistent hemolytic anemia requires splenectomy.
•Hemoglobinopathies such as sickle anemia require blood transfusions, exchange transfusions, and even hydroxyurea to decrease the incidence of sickling.
•DIC, which is characterized by uncontrolled coagulation and thrombosis, requires the removal of the offending stimulus. Patients with life-threatening bleeding require the use of antifibrinolytic agents.
When do you send blood films in patients?
Why will you give vitamin C to patients with nutrient deficiencies
Always send blood films in patients with an unclear etiology of anemia.
•Start haematinics early (iron, B12, and folate).
•Inform patients of the side effects of iron therapy, including constipation and black, tarry stools.
•Consider screening for sickle cell and thalassemia in patients with unexplained anemia or with a family history of these diseases.
•Vitamin C aids iron absorption, so coadministration of vitamin C with iron, or encouraging the patients to take iron supplements with orange juice, will aid therapy.
State ten complications of Anaemia
Anemia, if undiagnosed or left untreated for a prolonged period of time can lead to multiorgan failure and can even death.
•Pregnant women with anemia can go into premature labor and give birth to babies with low birth weight
•Anemia during pregnancy also increases the risk of anemia in the baby and increased blood loss during pregnancy.
Complications are more predominant in the older population due to multiple comorbidities
•The cardiovascular system is the most commonly affected in chronic anemia. Myocardial infarction, angina, and high output heart failure are common complications. Other cardiac complications include the development of arrhythmias and cardiac hypertrophy.
•Severe iron deficiency is associated with restless leg syndrome and esophageal webs.
•Severe anemia from a young age may lead to impaired neurological development in the form of cognitive, mental, and developmental delays. These complications are unlikely to be amenable to medical management.
When do you do consultations with other departments?
Gastroenterologist if a gastrointestinal bleed is suspected
•Nephrologist if anemia of chronic disease in the setting of renal failure is suspected
•Hematologist if a bone marrow disorder is suspected
•Gynecologist if intractable menorrhagia is suspected
•Cardiologist if severe anemia leads to angina, myocardial infarction, heart failure, or arrhythmias