Pernicious Anemia

Iyyabo G. G. L

Definition • It is a megaloblastic anemia characterized by

decreased gastric production of hydrochloric acid and deficiency of intrinsic factor (IF)

• It refers to anemia due to decreased absorption of Vitamin B12 (cobalamin)

• The deficiency of vitamin B12 causes serious neurologic, gastric and intestinal abnormalities

Incidence • It is most prevalent from vitamin B12

deficiency in USA and Canada• Pernicious anemia occurs in only 0.1% of

the population• It mainly strikes men and women over the

age of 50 years.• It primarily affect people of northern

European

Incidence cont….

• Occasionally, it develops in southern European, Asia and African Americans

• Pernicious anemia is rarely found in juvenile under 10 years of age.

• Juvenile pernicious anemia is a congenital disorder in which the stomach secretes abnormal intrinsic factor.

Etiology • Pernicious anemia is caused by impaired

vitamin B12 absorption through the small intestine as a result of a deficiency in the intrinsic factor

• Can also be caused by chronic gastritis and gastrectomy.

• It may be inherited as a single dominant autosomal factor

Other causes • Insufficient dietary intake• Drugs that impede absorption in the stomach,

i.e azathioprine, pyrimidine analogs, hydroxyurea, anticonvulsants e.t.c

• Drugs that impair uptake in the ileum, i.e Nitrous oxide, cholestyramine, para-aminosalicylic acid, neomycin,e.t.c

Pathophysiology

• Four major characteristics of pernicious anemia are; abnormally large red blood cell (macrocytic

anemia)Hypochlorhydria (deficiency of gastric

hydrochloric acid)Neurologic and gastrointestinal symptomsA fatal outcome unless the client receives lifelong

injections of vitamin B12

Pathophysiology cont...

• Pernicious anemia inevitably develops after total gastrectomy

• 15% of clients develop pernicious anemia after partial gastrectomy or gastrojejunostomy for a peptic ulcer

• Lack of vitamin B12 also alters the structure and disrupts the function of the peripherals nerves, spinal cord and brain

Pathophysiology cont...

• The disorder disturbs nervous system function and in extreme cases, permanent neurologic damage unresponsive to vitamin B12 therapy

• Clients with this anemia tend to be fair-haired or prematurely gray

• Clients with the disorder have a high incidence of benign gastric polyps and gastric carcinoma

Pathophysiology cont...

• Untreated pernicious anemia causes death• Delayed intervention results in permanent

dissabilities• Severe macrocytic anemia of long duration

can trigger congestive heart failure and angina pectoris in the elderly

Fundus atrophy

Intrinsic factor

Chronic gastritis gastrectomy

Permanent damage of nervous system

Degeneration of nervous system

Immature erythrocytes

Pathophysiology

Signs and symptoms

• Weakness, sore tongue, numbness and tingling in the extremities

• The lips, gums and tongue appear markedly bloodless

• The patient may become highly susceptible to infection, especially of the genitourinary tract

Other systemic symptoms are:

• Gastrointestinal – gastric mucosal atrophy and decreased hydrochloric acid production, disturb digestion and lead to;

NauseaVomitingAnorexiaweight lossFlatulenceDiarrheaConstipation

Other systemic symptoms cont….• Central nervous system – demyelination

caused by vitamin B12 deficiency affects the peripheral nerve system

Neurologic effects of pernicious anemia include: weakness in extremitiesPeripheral numbness and paresthesiasDisturbed position senseLack of coordinationataxia

impaired fine finger movementLight- headednessAltered visionTaste and hearing (tinnitus)Optic muscle atrophyLoss of bowel and bladder controlIn males, the effect produce, Irritability,

poor memory, headache, depression and delirium

Other systemic symptoms cont….

• Cardiovascular : increasingly fragile cell membranes induce widespread destruction of RBCs, resulting in low hemoglobin levels.

Cont..

• The impaired oxygen carrying capacity of the blood secondary to lowered hemoglobin leads to weakness, fatigue, and light-headedness.

• compensatory increased cardiac output result in palpitation, wide pulse pressure, dyspnea, orthopnea, tachycardia, premature beats , and eventually, congestive heart failure

Diagnosis

• Positive family history, typical ethnic heritage and result of blood studies, bone marrow aspiration, gastric analysis and schilling test establish the diagnosis

• Microscopic examination of a blood smear reveals many large, immature erythrocytes

Laboratory findings that confirm a diagnosis of pernicious anemia include:

• Decreased hemoglobin (4 to 5g/100ml) and decreased RBCs

• Possible low WBC and platelet counts, and large, malformed platelets

• Serum vitamin B12 assay levels less than 0.1mcg/ml

• Bone marrow contains high numbers of megaloblasts

Nursing diagnosis and planning

• Nursing diagnosis applicable to patient with pernicious anemia include constipation or diarrhea related to changes in

the gastrointestinal mucosaKnowledge deficit

Schilling’s test

• It is a definitive test for pernicious anemia• Patient receives small (0.5 – 2mcg) oral dose

of radioactive vitamin B12 after fasting for 12hrs

• A larger (1 mg) dose of nonradioactive vitamin B12 is given I.M 2hrs later as parenteral flush

• Radioactivity of a 24-hrs urine specimen is measured

Schilling’s test cont...

• About 7% of the radioactive B12 dose is excreted in the first 24hrs

• Persons with pernicious anemia excrete less than 3%

• When schilling test is repeated with IF added, the test shows normal excretion of vitamin B12

Statements of nursing diagnosis

1. constipation or diarrhea related to changes in the gastrointestinal mucosa

2. Knowledge deficit: nature of disease, diet, and use of prescribed medications

1. constipation or diarrhea related to changes in the gastrointestinal mucosa

Planning:

patient outcome

• Patient report normal stool consistency without diarrhea or constipation

• Patient eats food that promote adequate bowel eliminations

• Patient eats small, frequent meal to prevent digestive problems

• Patient drinks adequate fluids to promote proper elimination

Nursing intervention and evaluation: constipation or Diarrhea

Help the patient maintain adequate bowel elimination

Encourage intake of eight glasses of fluid daily

Instruct the patient regarding a balanced diet high in protein, vitamins, and of water or other non irritating fluid daily

• Instruct the patient regarding a balance diet high in protein, vitamin and iron. i.e food like fish, red meat, milk, egg to increase Vitamin B12 intake.

• Provide six to eight small meals daily to conserve energy and decrease gastrointestinal distress

• Monitor the patient’s bowel movements, noting the colour, consistency and amount

2. knowledge deficit: nature of disease, diet, and use of prescribed medications

Planning:

patient outcome

• patient states accurate information about relationship of vitamin B12 to symptoms of disorder

• Patient states dose, time, frequency, side effects, and toxic effects of prescribed medications.

Nursing intervention and evaluation: knowledge deficit: nature of disease, diet, and use of prescribed medications

Help patient gain knowledge about the disorder by explaining the signs and symptoms, causes and life long treatment needed to prevent complications.

Discuss those complications with the patient and family, explain the signs of hypokalamia and when to seek medical intervention

Encourage the patient and family to ask questions and express concerns.

Teach the patient about prescribed medications, including the dose, route, time, frequency, side effects, and toxic effects

Encourage the patient to continue with the follow-up visit to the physician’s office, at least twice a year

Help the patient to decrease stress level to maximize coping mechanisms

Medical management

• Immediate care and lifelong therapy with maintenance vitamin B12 should be given to clients with pernicious anemia

• Vitamin B12 injection may be given to the client during the acute phase of illness

• Treat with Oral or I.V iron supplements if the haemoglobin level fails to rise in proportion to an increased red blood cell count.

• Therapeutic trial of folate should never be given without PA first being ruled out.

• Digestants may be given to enhance the metabolism of vitamin such as Hcl dilluted in water and given with meal

• Multidrug combinations of high doses of folate, cobalamin and pyridoxine prevent neurologic complications.

Prescribed medications

• Vitamin derivatives – to correct nutritional or metabolic deficiency, i.e. cynacobalamin, folic acid

• Hematinic agents – to correct nutritional deficit, i.e. ferrous sulphate or ferrous gluconate

• Digestants – to enhance metabolism of vitamins, i.e. Hcl diluted in water with meals during the 1st few weeks of vitamin B12 therapy

• Clients with pernicious anemia respond to vitamin B12 injections, therefore blood transfusions are unnecessary

Nursing intervention

• Plan activities, rest periods, and necessary diagnosis test to conserve the patient energy

• Monitor pulse rate often.• For adequate schilling test results, all urine

over 24 hrs period should be collected and the specimen not contaminated with feces

• Warn the patient to guard against infections and to report signs of infection promptly

• Provide well balanced diet, including foods high in vitamin B12

• Avoid giving irritating food since the patients mouth and tongue are sore and painful

• Warn the patient with sensory deficit not to use a heating pad since it may cause burn

Reference

• Barbara K. Timby and Nancy Smith (2005) - introductory medical nursing. 8th edition. Pg 530-532

• Helen Klusek Hamilton (1982) – diseases: causes and diagnosis current therapy nursing management patient education. Pg 1028 – 1031

• Joyce M. Black, Esther Matassarin (1993) – medical surgical nursing: a psychophysiologic approach, 4th edition. Pg 1341 – 1342

• Joyce M. Black, Jane Hokanson Hawks (2005) - medical surgical nursing: clinical management for positive outcomes. 7th edition, vol. 2 Pg 2289-2291

• Monahan, Frances Donovan (1998) – Medical surgical nursing: foundation for clinical practice. 2nd edition. Pg 476 – 479