Anaemias 2024.pdf

Medical Nursing I - SSN 280 E. A. Boateng Department of Nursing, KNUST [email protected]  Review of Anatomy & Physiology  Erythrocytes: biconcave shape (provides large surface area & easy movement through small vessels), thin membrane (permits easy diffusion...

Medical Nursing I - SSN 280 E. A. Boateng Department of Nursing, KNUST [email protected]  Review of Anatomy & Physiology  Erythrocytes: biconcave shape (provides large surface area & easy movement through small vessels), thin membrane (permits easy diffusion of gases); contain haemoglobin (oxygen-carrying protein)  Erythropoiesis: begins in the red bone marrow; myeloid stem cells – erythroblasts – normoblasts – reticulocytes – erythrocytes; erythropoietin needed for 1st stage; iron, vitamin B12 & folic acid needed for a complete process;  Erythrocytes may be normocytic, microcytic or macrocytic; colour may be normochromic or hypochromic  Haemolysis: occurs in the spleen, liver, bone marrow & lymph nodes; most Hb & iron recycled 15/05/2024 16:29 15/05/2024 16:29  Anaemia  Low healthy RBC count or Hb level, or both  Hb level < 11.5 g/dl in women; < 13.5 g/dl in adult men; < 12.5 g/dl in elderly men  Reduces oxygen-carrying capacity of blood  3 major causative categories  Acute blood loss  Increased RBC destruction (haemolytic)  Decreased or faulty RBC production (hypoproliferative); usually due to lack of factors required for erythropoiesis (iron, folic acid, vitamin B12, erythropoietin) or bone marrow failure 15/05/2024 16:29  Anaemia – Types  Anaemia related to acute and chronic blood loss  Anaemia of chronic diseases (including cancers, immunodeficiency syndrome, renal disease, liver diseases, and autoimmune conditions)  Anaemias caused by nutritional deficiencies (such as iron, folate, or vitamin B12 deficiency), and hereditary anaemias (including sickle cell anaemia and thalassemia) 15/05/2024 16:29  Clinical Manifestations  May be asymptomatic  Fatigue due to hypoxia from less oxygen being available to the tissues of the body  Headaches  Dizziness  Pallor – less oxygen to the surface tissues  Tachycardia – the heart attempts to compensate for hypoxia by beating more rapidly to increase blood supply  Chest pain  Weakness due to hypoxia  Systolic murmur due to increased turbulence of blood flow  Dyspnoea or shortness of breath due to hypoxia as body attempts to get more oxygen 15/05/2024 16:29  Specific Clinical Manifestations  Koilonychia – spoon-shaped nails in iron deficiency anaemia  Jaundice - found in haemolytic anaemia  Bone deformities - found in thalassaemia major  Leg ulcers - occur in association with sickle cell disease 15/05/2024 16:29  Diagnostic Investigations  Full blood count (FBC): number, structural and functional characteristics  Serum iron level & total iron-binding capacity (TIBC): low serum iron concentration & elevated TIBC indicates iron- deficiency anaemia  Serum ferritin: depicts depleted iron stores  Sickle cell test: detects HbS  Hb electrophoresis: differentiate sickle cell trait from SCD  Schilling test  Bone marrow studies (aspiration or biopsy): determines function in generating blood cells  Acute Blood Loss Anaemia  Acute blood loss decreases circulating volume; CO falls Compensatory mechanisms are activated – HR increases, and peripheral blood vessels constrict; vessels in the liver also constrict, increasing circulating volume Fluid shifts from the interstitial spaces into the vascular compartment to maintain blood volume, diluting the cellular components of the blood and reducing its viscosity  Acute Blood Loss Anaemia Anaemia is due to haemodilution; RBCs usually normocytic & normochromic If haemorrhage continues, compensatory mechanisms become less effective, increasing the risk for shock and circulatory failure At risk – postoperative clients, clients with an active  bleeding problem  Chronic Blood Loss Anaemia Depletes iron stores as erythropoiesis increases to  maintain RBC levels  Usually caused by GI bleeding or menstrual disorders  RBCs are microcytic & hypochromic Clients usually asymptomatic due to compensatory  mechanisms  Hypoproliferative Anaemias  Due to inadequate production of erythrocytes  Lack of factors necessary for erythropoiesis – due to nutritional deficiencies (e.g. iron) or DNA synthesis (vitamin B12 or folic acid) or bone marrow damage  Characterised by inappropriately normal or low reticulocyte count 15/05/2024 16:29  Hypoproliferative Anaemias Iron-deficiency Anaemia  Commonly results from:  Dietary deficiency  Loss of iron through bleeding  Increased demands  Syndromes of gastrointestinal malabsorption  Common cause is chronic blood loss (e.g. from GI bleeding due to peptic ulcer, haemorrhoids or cancer)  Other factors: aspirin abuse, menstruation, pregnancy, lactation, malabsorption syndromes, growth 15/05/2024 16:29  Hypoproliferative Anaemias Iron-deficiency Anaemia  Results in decreased formation of haemoglobin and a decreased ability for the blood to carry oxygen  Iron stores are typically depleted first, followed by serum iron levels  Once iron stores are replaced, the anaemia should correct and haemoglobin levels return to normal 15/05/2024 16:29  Hypoproliferative Anaemias Manifestations  Brittle nails & hair  Fingernails may be spoon-shaped – thin, concave nails raised at the edges (koilonychia)  Cheilosis (cracks or sores at the corners of the mouth)  Smooth, sore tongue  Pica (a craving for/compulsive eating of unusual substances such as dirt, ice)  Poor cognitive, motor & emotional function in infants (may be due to effects on brain development)  Other manifestations of anaemia 15/05/2024 16:29  Hypoproliferative Anaemias Prevention & Treatment  Use iron fortified cereals for infants  Control chronic blood loss  Increase dietary intake of iron  Administer supplemental iron; with vit. C; not milk or antacids  Ferrous sulphate (oral)  Iron dextran (parenteral); give test dose before full dose to avoid anaphylactic response 15/05/2024 16:29  Hypoproliferative Anaemias Prevention & Treatment  Educate the client about the side effects of iron supplements (black stools, constipation, and foul aftertaste)  Liquid iron preparations stain the teeth – should be taken through a straw; teeth should be brushed after administration 15/05/2024 16:29 The nurse is instructing a client with iron-deficiency anaemia regarding the administration of a liquid oral iron supplement. Which instruction would the nurse tell the client? a. Administer the iron at mealtimes b. Administer the iron through a straw c. Mix the iron with cereal to administer d. Add the iron to apple juice for easy administration 15/05/2024 16:29  Hypoproliferative Anaemias Megaloblastic Anaemias  Caused by impaired DNA synthesis that results in enlarged RBCs due to impaired maturation and division  Common causes are vitamin B12 and folic acid deficiencies 15/05/2024 16:29  Hypoproliferative Anaemias Vitamin B12 Deficiency Anaemia  Vitamin B12 is essential for DNA synthesis & nuclear maturation which in turn leads to RBC maturation & division  Involved in a reaction that prevents incorporation of abnormal fatty acids into neuronal lipids; predisposes one to myelin breakdown  Mostly found in foods from animal sources 15/05/2024 16:29  Hypoproliferative Anaemias Vitamin B12 Deficiency Anaemia  Binds to intrinsic factor in the stomach to prevent its digestion; absorbed in the ileum  Results from inadequate intake of Vitamin B12 or lack of absorption of ingested Vitamin B12 from the intestinal tract 15/05/2024 16:29  Hypoproliferative Anaemias Vitamin B12 Deficiency Anaemia  Pernicious anaemia: results from a deficiency of intrinsic factor; atrophic gastritis leads to loss of parietal cells & production of antibodies that interfere with binding of vitamin B12 to intrinsic factor  Other causes include gastrectomy (resection of stomach), ileal resection, inflammation or neoplasm in the ileum, loss of pancreatic secretions 15/05/2024 16:29  Hypoproliferative Anaemias Clinical Manifestations  Smooth, sore, beefy red tongue  Diarrhoea  Paresthesia (altered sensations such as numbness or tingling) in the extremities  Problems with proprioception/kinesthesia (the sense of one’s position in space)  Macrocytic RBCs (oval rather than biconcave)  Disturbances with gait and balance 15/05/2024 16:29  Hypoproliferative Anaemias Diagnostic Findings  Abnormally low vitamin B12 serum level  Schilling test reveals decreased absorption of vitamin B12  Presence of parietal cell & intrinsic factor antibodies Treatment consists of IM injections or high oral doses of vitamin B12; reverses the anaemia & improves the neurologic changes 15/05/2024 16:29  Hypoproliferative Anaemias Folic Acid-Deficiency Anaemia  Folic acid also required for DNA synthesis and RBC maturation; deficiency results in megaloblastic anaemia; found in vegetables (mostly green leafy), fruits, cereals & meat; absorbed from intestines  Common causes include malabsorption or inadequate dietary intake; pregnancy increases demand; chronic alcoholism; chronic haemodialysis  Manifestations similar to vitamin B12 deficiency and other types of anaemia: glossitis, cheilosis, diarrhoea; no neurologic manifestations 15/05/2024 16:29 The nurse is providing dietary teaching for a client with a diagnosis of chronic gastritis who is at risk for vitamin B12 deficiency. The nurse instructs the client to include which foods rich in vitamin B12 in the diet? Select all that apply a. Meat b. Corn c. Liver d. Apples e. Bananas 15/05/2024 16:29  Hypoproliferative Anaemias Aplastic Anaemia  Occurs when bone marrow fails to produce all types of blood cells; leads to pancytopenia  Bone marrow damage by factors such as exposure to radiation or certain chemical (benzene, arsenic), some antibiotics (e.g. chloramphenicol) is the usual cause  May result from certain viral infections (hepatitis C, HIV)  Pure red cell aplasia: only RBCs are affected; rare  Remaining cells are normocytic & normochromic  Haemolytic Anaemias  Premature destruction of erythrocytes, reducing the total number in circulation  Haemoglobin from the erythrocytes is released into the plasma; it is converted to bilirubin, resulting in high levels of unconjugated/indirect bilirubin & jaundice  Tissue hypoxia stimulates erythropoietin production; leads to increased reticulocyte count  Haemolysis may be caused by intrinsic (within the RBCs) or extrinsic (outside the RBC) factors Intrinsic Factors Extrinsic Factors RBC cell-membrane Drugs, chemicals defects Toxins & venoms Haemoglobinopathies Bacterial and other (e.g., sickle cell infections anaemia, Trauma, severe burns thalassaemia) Mechanical damage Inherited enzyme (prosthetic heart defects (e.g., G-6-P-D valves) deficiency) 15/05/2024 16:29  Haemolytic Anaemias Sickle Cell Anaemia  Abnormal form of haemoglobin (HbS) is synthesised in RBCs; valine replaces glutamic acid in the β chain of the Hb molecule; hereditary & chronic  Characterised by sickling episodes (RBCs become abnormally crescent-shaped) under conditions of hypoxia  Acute & chronic manifestations due to episodes of RBC sickling and haemolysis 15/05/2024 16:29  Haemolytic Anaemias Normal Sickle cell trait: heterozygous Sickle cell disease: homozygous Inheritance pattern for sickle cell disease 15/05/2024 16:29 Haemolytic Anaemias http://sites.google.com/site/geneticdisorders7/_/rsrc/1232680048423/sickle-cell-anemia/genetics2.GIF  Haemolytic Anaemias Manifestations - Sickle Cell Crisis  Vaso-occlusive/thrombotic crisis: results from tissue hypoxia and necrosis due to impaired blood flow to a specific region of tissue or organ; pain, fever, swelling  Aplastic crisis: results from infection with the human parvovirus; Hb level falls rapidly; marrow cannot compensate; an absence of reticulocytes  Sequestration crisis: results when other organs pool the sickled cells; commonly occurs in the spleen (children), liver or lungs 15/05/2024 16:29  Haemolytic Anaemias Manifestations – cont’d Other manifestations and complications include  Acute chest syndrome: fever, chest pain, cough, pulmonary infiltrates, shortness of breath  Priapism (persistent painful erection of the penis)  Stroke, skin ulcers, renal failure Risk Factors (SC Crisis)  Infection  Cold  Dehydration  Stress  Acidosis  Physical exertion  Hypoxia  Haemolytic Anaemias Diagnostic Investigations  Sickle cell test  Haemoglobin electrophoresis; cord blood or heel- stick samples are used for newborns to separate HbF from the small amount of HbA & HbS 15/05/2024 16:29  Haemolytic Anaemias Medical Management Focuses on symptom management, prevention of sickling episodes & prevention/treatment of complications  Oral hydration/IV fluids  Oxygen  Rest  Analgesics  Folic acid  Antibiotics  Haemotransfusion (RBC/packed cell)  Bone marrow transplant  Haemolytic Anaemias Some Nursing Diagnoses  Acute pain related to tissue hypoxia secondary to clumping of sickled RBCs within blood vessels  Ineffective therapeutic regimen management related to deficient knowledge regarding sickle crisis prevention Interventions  Hydration  Analgesia  Rest  Oxygen  Health education 15/05/2024 16:29  Haemolytic Anaemias Thalassaemia  Inherited disorder of haemoglobin synthesis; reduced production of either α- or β-globin chains of HbA  α-thalassaemia common in Asian & Middle East; β- thalassaemia (aka Cooley or Mediterranean anaemia) common in southern Italy & Greece; both types common among Africans  Characterised by hypochromia, microcytosis, haemolysis, & anaemia; bone deformities in thalassaemia major  Anaemia due to reduced intracellular Hb & accumulation of unaffected globin chain 15/05/2024 16:29  Haemolytic Anaemias Glucose-6-Phosphate Dehydrogenase (G6PD) Anaemia  Hereditary abnormality in RBC metabolism; X- linked; defect makes RBCs more vulnerable to oxidants (haemoglobin oxidated to methaemoglobin)  Haemolysis occurs when affected person is exposed to stressors, e.g. aspirin, sulphonamides, primaquine, chloroquine, chloramphenicol, fever, etc  Diagnosis by G6PD assay 15/05/2024 16:29 Red cell characteristics seen in different types of anaemia A. Microcytic and hypochromic red cells, characteristic of iron- deficiency anaemia B. Macrocytic and misshaped red blood cells, characteristic of megaloblastic anaemia C. Abnormally shaped red blood cells seen in sickle cell disease D. Normocytic and normochromic red blood cells, as a comparison 15/05/2024 16:29  Chronic Disease Anaemias  Result from chronic conditions  Common causes include infections (e.g., AIDS, osteomyelitis), cancers, autoimmune disorders (e.g., rheumatoid arthritis, systemic lupus erythematous [SLE]), chronic kidney disease (CKD)  Usually, inflammatory cytokines (e.g. interleukin-1, interferon, TNF) act to reduce life span of erythrocytes and production, response to erythropoietin, and serum iron 15/05/2024 16:29  Management  Medications: supplemental iron, vitamin B12, folic acid  Haemotransfusion  Dietary modifications; anorexia management  Symptomatic management  Fatigue  Maintenance of adequate perfusion: vital signs, IV fluids/haemeotransfusion, oxygen Hypoproliferative (Resulting From Defective RBC Production) Decreased reticulocytes, iron, ferritin, iron Iron deficiency saturation, MCV; increased TIBC Vitamin B12 deficiency (megaloblastic) Decreased vitamin B12 level; increased MCV Folate deficiency (megaloblastic) Decreased folate level; increased MCV Decreased erythropoietin production Decreased erythropoietin level; normal MCV (eg, from renal dysfunction) and MCH; increased Normal MCV, MCH; normal or decreased erythropoietin level; increased % of iron Cancer/inflammation saturation, ferritin level; decreased iron, TIBC Bleeding (Resulting From RBC Loss) Increased reticulocyte level; normal Hgb and Bleeding from gastrointestinal tract, Hct if measured soon after bleeding starts, but epistaxis (nosebleed), trauma, bleeding levels decrease thereafter; normal MCV initially from genitourinary tract (eg, but later decreases; decreased ferritin and iron menorrhagia) levels (later) Hemolytic (Resulting From RBC Destruction) Altered erythropoiesis (sickle cell anemia, thalassemia, other Decreased MCV; fragmented RBCs; increased hemoglobinopathies) reticulocyte level Hypersplenism (hemolysis) Increased MCV Hct, hematocrit; Hgb, hemoglobin concentration; MCH, mean corpuscular hemoglobin; MCV, mean corpuscular volume; RBCs, red blood cells; TIBC, total iron-binding capacity Polycythaemia  Excessive red blood cells, characterised by haematocrit (HCT) >50%  Relative Polycythaemia: HCT increases due to loss of plasma volume; no corresponding decrease in RBC mass; results from excessive dehydration, prolonged diuretic use, GI losses; managed by increasing intravascular fluid volume  Absolute Polycythaemia: increase in HCT due to increase in total RBC mass 15/05/2024 16:29 Primary Polycythaemia  Aka polycythaemia vera; neoplasm of the stem cell; increased RBC, WBC, & platelet count  Manifestations due to increased RBC count, Hb level & HCT, increased blood volume & viscosity  Headache, dizziness, lack of concentration, hearing & vision difficulties due to decreased cerebral blood flow  Thromboembolism & haemorrhage due to platelet abnormalities  Treatment: low dose aspirin for high platelet count; chemotherapy to suppress bone marrow function 15/05/2024 16:29 Secondary Polycythaemia  Physiologic elevation of erythropoietin levels; common type  Usually as a compensatory mechanism for hypoxia; may be in those living at high altitudes; also due to smoking, chronic heart & lung diseases  May also be caused by kidney diseases (e.g. hydronephrosis, renal cysts); obstruct blood flow, causing hypoxia  Manifestations similar to polycythaemia vera  Treatment focuses on relieving hypoxia 15/05/2024 16:29 Nursing Diagnoses  Pain related to effects of altered blood flow in distal extremities  Risk for ineffective tissue perfusion related to sluggish blood flow & increased risk for thrombosis 15/05/2024 16:29 Haematocrit – The haematocrit measures the percentage of cells in 100 mL of plasma:  (A) normal  (B) decreased in anaemia  (C) increased in polycythaemia 15/05/2024 16:29