Iron Deficiency Anaemia -BSG guidelines 2011

Anaemia

• Hb <13g/dL in men over 15 yrs• Hb <12g/dL in non-pregnant women over

15yrs• Hb <11g/dL in pregnant women over 15yrs• Low MCV and MCH (ie microcytosis and

hypochromia) are predictive factors of iron deficiency

• Other causes of the above

Investigations to define iron deficiency anaemia

• Ferritin– 12-15 μg/l in patients with no inflammatory

disease– 50 μg/l in patients with inflammatory disease

• Iron studies:– Low iron level– Low transferrin saturation – Raised TIBC– Raised serum transferrin receptor

‘Functional’ iron deficiency anaemia

• Chronic kidney disease• Inadequate iron supply to the bone marrow• Chronic diseases eg rheumatoid arthritis and

IBD• Require iron supplementation prior to

responding to erythropoetin

Causes• Contributor Prevalence• Occult GI blood loss• Common

– Aspirin/NSAID use 10-15%– Colonic carcinoma 5-10%– Gastric carcinoma 5%– Benign gastric ulceration 5%– Angiodysplasia 5%

• Uncommon– Oesophagitis 2-4%– Oesophageal carcinoma 1-2%– Gastric antral vascular ectasia 1-2%– Small bowel tumours 1-2%– Cameron ulcer in large hiatus hernia <1%– Ampullary carcinoma <1%– Ancylomasta duodenale <1%

Causes• Malabsorption• Common

– Coeliac disease 4-6%– Gastrectomy <5%– Helicobacter pylori colonisation <5%

• Uncommon– Gut resection <1%– Bacterial overgrowth <1%

• Non-GI blood loss• Common

– Menstruation 20-30%– Blood donation 5%

• Uncommon– Haematuria 1%– Epistaxis <1%

History taking and examination

• Family history– Haemoglobinopathies, colorectal cancer,

angiodysplasias, bleeding disorders• Drug history eg NSAIDs, aspirin, steroids• Blood donation• DIET• Clinical signs eg. In Peutz-Jeghers or HHT

GI investigations

• OGD– Gastric cancer or coeliac disease most definitive

diagnoses to deter lower GI endoscopy– D2 biopsies plus TTG serology to diagnose coeliac

disease• Colonoscopy vs radiology– Biopsy and removal of adenomata/polyps, viewing

of angiodysplasias, NSAID damage– CT colonography detection rate of lesions >10mm:

90%

Coeliacs

• Recommendations:– 1 year screening post diagnosis in patients >50yrs

and with significant family history of colorectal carcinoma

– Screening in patients with treated coeliac disease who develop IDA >50yrs old

Further investigations

• Small bowel investigations– Capsule endoscopy• 40-50% diagnostic yield• Would have to perform invasive procedure to treat

pathology– Small bowel enteroscopy• Many lesions detected reachable by gastroscope thus

there is an end to repeating an OGD– Imaging eg MRI enteroclysis, ba meal & follow-

through etc

Rarer causes

• H.pylori infection– Decreases iron uptake and increases iron GI loss

• Autoimmune gastritis• Giardia lamblia – Associated with diarrhoea– Small bowel (D2) biopsies & ELISA testing of stool

• Angiogram– In transfusion-dependent anaemia

Treatment

• Treat cause• Iron supplementation– Oral

• Ferrous sulphate at 200mg bd or od for longer if poorly tolerated

• Other preparations– Intravenous

• Venofer, cosmofer• Ferric carboxymaltose (similar side effect profile but no

anaphylaxis to date)• Transfusion

Follow-up

• Once restored levels– 3 monthly first year– 1 year after that

• Further investigations only if Hb and indices not maintained after above management

• Most patients with negative upper and lower GI endoscopy and testing for coeliac disease, have no recurrence of iron deficiency

Special considerations• Pre-menopausal women

– History for GI symptoms• Pregnant women

– OGD, unsedated flexible sigmoidoscopy safe– MRI is advisable to avoid in the first trimester

• Patients with significant co-morbidities• Patients due to have surgery

– Transfusion than iron supplementation• Post gastrectomy patients

– Iron loss also due to poor absorption of ascorbic acid – 2 to 3 fold increased risk of gastric cancer and increased risk of

colorectal cancer• Post gastric banding iron deficiency responds to iron

supplememntation

References

• http://bsg.org.uk/images/stories/docs/clinical/guidelines/sbn/bsg_ida_2011.pdf