A 50-year-old male, who underwent a partial gastrectomy for the treatment of gastric ulcers 10 years ago, presents with paleness. His laboratory results show a hemoglobin (Hb) of 8 g/dl, a normal MCHC, and an increased MCV. What is the best treatment option for this patient?
A. Vitamin K
B. Iron supplements
C. Inj. B12
D. Vitamin C tablets
E. High protein diet
Correct Answer: C. Inj. B12
Explanation:
This patient’s presentation suggests pernicious anemia, a type of vitamin B12 deficiency anemia, which is commonly seen after gastrectomy. The key diagnostic clues are the increased MCV (mean corpuscular volume), which indicates macrocytic anemia, and the patient’s history of a partial gastrectomy. In this case, the most appropriate treatment is intramuscular vitamin B12 supplementation.
Key Features Supporting Vitamin B12 Deficiency:
- Gastrectomy History:
- A partial gastrectomy leads to the removal of a portion of the stomach, which is responsible for producing intrinsic factor (a glycoprotein necessary for the absorption of vitamin B12 in the ileum). Over time, this can result in vitamin B12 deficiency.
- Macrocytic Anemia (Increased MCV):
- Increased MCV (mean corpuscular volume) suggests macrocytic anemia, which is commonly caused by vitamin B12 or folate deficiencies. However, given the patient’s surgical history and the absence of signs that suggest folate deficiency, the most likely cause is vitamin B12 deficiency.
- Low Hemoglobin (Hb = 8 g/dl):
- The low hemoglobin level (8 g/dl) further supports the diagnosis of anemia, which is commonly seen in vitamin B12 deficiency due to impaired red blood cell production and maturation.
Why Other Options Are Incorrect:
A. Vitamin K:
- Vitamin K is typically used in the treatment of coagulation disorders or vitamin K deficiency, which manifests with easy bruising, bleeding gums, or prolonged bleeding times. This is not consistent with the patient’s symptoms, and there is no evidence here to suggest a vitamin K deficiency.
B. Iron Supplements:
- Iron deficiency anemia typically presents with microcytic anemia (decreased MCV), not macrocytic anemia. This patient’s increased MCV is suggestive of B12 deficiency, not iron deficiency, making iron supplements inappropriate for this case.
D. Vitamin C Tablets:
- Vitamin C is important for iron absorption and general health but does not treat vitamin B12 deficiency. The patient’s anemia is macrocytic, not due to a deficiency in vitamin C.
E. High Protein Diet:
- A high-protein diet is essential for general health but does not address the specific vitamin B12 deficiency that is causing the patient’s macrocytic anemia.
Diagnosis and Treatment:
Given the patient’s history of partial gastrectomy and current laboratory findings of macrocytic anemia, the diagnosis of vitamin B12 deficiency anemia is likely. The best treatment is intramuscular vitamin B12 injections. This method bypasses the need for intrinsic factor, which is lacking in patients who have had gastrectomy, and directly provides vitamin B12, which is necessary for proper red blood cell production and neurological function.
B12 supplementation can be administered via IM injections (usually given once a month) or orally in higher doses if absorption is still functional. For patients who have had a gastrectomy, B12 shots are often preferred, as the absorption of oral B12 may be insufficient due to lack of intrinsic factor.
Further Investigations:
- Serum Vitamin B12 Levels:
- Confirm the diagnosis by measuring serum vitamin B12 levels. A deficiency would confirm the need for B12 supplementation.
- Complete Blood Count (CBC):
- A CBC will show macrocytic anemia (high MCV) and potentially low reticulocyte count, indicating impaired red blood cell production.
- Homocysteine and Methylmalonic Acid (MMA) Levels:
- Both homocysteine and MMA levels are typically elevated in vitamin B12 deficiency, which can help confirm the diagnosis.
Management:
- Vitamin B12 Replacement:
- Initially, intramuscular vitamin B12 is given in higher doses, often as 1,000 micrograms per week for 4-6 weeks, followed by maintenance therapy with monthly injections or high-dose oral vitamin B12.
- Monitoring Response:
- Follow-up with CBC and serum vitamin B12 levels to ensure the anemia is improving and that the B12 levels are normalizing.
- Dietary Modifications:
- Encourage dietary sources of vitamin B12, such as meat, fish, eggs, and dairy, though supplementation will be necessary for those with significant malabsorption.
Conclusion:
The most likely cause of this patient’s anemia is vitamin B12 deficiency, which is common after gastrectomy due to impaired absorption. The best treatment is intramuscular vitamin B12, which directly addresses the deficiency and alleviates the patient’s symptoms. Early detection and treatment are essential to prevent neurological complications and improve overall well-being.