QuestionSBA
QuestionChoice
Metformin is a biguanide medication used as first line treatment in type 2 diabetes. There is an established link between taking this metformin and the development of macrocytic anaemia. The patient's clinical picture of fatigue, weakness and shortness of breath all point towards anaemia, which is confirmed by the low haemoglobin levels. The mean cell volume above 100 fL reveals this as a macrocytic anaemia.
10025675
a
Taking mformin
QuestionChoice
Individuals with heavy periods are likely to develop iron deficiency anaemia due to the high levels of blood loss. This patient is unlikely to have an iron-deficiency anaemia as the mean cell volume is > 100 fL, indicating macrocytic anaemia. Iron-deficiency anaemia is typically microcytic, with mean cell volume levels <80 fL.
10025678
d
Menorrhagia
QuestionChoice
Chronic usage of laughing gas can lead to raised homocysteine levels, which can occasionally cause macrocytic anaemia. Raised homocysteine commonly causes neurological symptoms, for example, sensory disturbance as in subacute combined spinal cord degeneration. This is therefore a less likely explanation for this patient's presentation compared to metformin use.
10025676
b
Chronic nitrous oxide (laughing gas) usage
QuestionChoice
Whilst this patient is displaying signs of anaemia (fatigue, weakness etc) as well as presenting with low haemoglobin levels, it is unlikely this is related to an underlying iron deficiency. This is due to the mean cell volume being > 100 fL, a typical sign of macrocytic anaemia. Iron-deficiency anaemia is typically microcytic, with mean cell volume levels  <80 fL.
10025677
c
Poor dietary intake of Iron
QuestionChoice
Whilst there are no signs this woman is pregnant, it is reasonable to check this possibility in a female patient of child-bearing age. Iron deficiency anaemia is the most common form of anaemia in pregnancy. This case is unlikely to be iron-deficiency related due to the mean cell volume being > 100 fL, indicating macrocytic anaemia. Iron-deficiency anaemia is typically microcytic, with mean cell volume levels <80 fL.
10025679
e
Pregnancy
QuestionComment
Laughing gas can also cause B12 deficiency which would also be a cause of macrocytic anaemia so would be good to clarify whether this is megaloblastic or non-megaloblastic anaemia
38689
User
subscriber
Strowger
Concept
Chapter
2693
4086
Pernicious anaemia
Topic
157
Haematology
17533
A 33 year old woman attends a GP appointment after suffering from lethargy, shortness of breath and generalised weakness for the past 6 weeks. She denies any visible blood loss, change in bowel habits or weight loss. She has a past medical history of type 2 diabetes. She has no relevant family history. Her observations are within the normal limit, and a neurological examination is normal.

Concerned by her symptoms, her doctor orders a blood test that shows a haemoglobin level of 10.5 g/dL and mean cell volume (MCV) of 110 fL.

Which of the following is the most likely cause of this patient's symptoms?
a