Trip Answers

Question answered:17/02/06 Warning! this question is over two years old.

Using TRIP, we found two sources of information that may be of use to read in more detail. Below are the links, but we include some extracts.

The British Society of Gastroenterology published “Guidelines for the management of iron deficiency anaemia” (1), which say:

“These guidelines are primarily intended for gastroenterologists and GI surgeons but are applicable for other doctors seeing patients with IDA.

The WHO defines anaemia as a haemoglobin below 13 g/dL in men over 15 years, below 12 g/dL in non-pregnant women over 15 years, and below 11 g/dL in pregnant women. There is little consensus as to the level of anaemia that requires investigation. The Department of Health referral guidelines for suspected lower GI cancer suggest that only patients with Hb less than 11 g/dl in men or less than 10 g/dl in postmenopausal women be referred, despite there being no supporting evidence. A cut-off value of 8 g/dL has been shown to be the most discriminatory for detecting patients with and without cancer (regardless of gender), but this value lacks sensitivity. It is recommended that any level of anaemia should be investigated in the presence of iron deficiency.”

The executive summary of the guidelines says:

“Background:
Colonic cancer, gastric cancer and coeliac disease are the most important gastrointestinal causes of iron deficiency anaemia.
Definitions:
The lower limit of the normal range should be used to define anaemia.
Iron deficiency should be confirmed by a low serum ferritin, red cell microcytosis or hypochromia in the absence of chronic disease or haemoglobinopathies.
Any level of iron deficiency anaemia should be investigated.
Investigations:
Rectal examination and urine testing should be performed.
All patients should be screened for coeliac disease.
Upper and lower GI investigations should be considered in all male patients unless there is a history of significant overt non-GI blood loss.
Colonoscopy has advantages over barium enema for investigation of the lower GI tract in IDA, but either is acceptable.
Further direct visualisation of the small bowel is probably not necessary unless the IDA is transfusion dependent.
Faecal occult blood testing is of no benefit in the investigation of IDA.
Only post-menopausal women and men aged over 50 years should have GI investigation of iron deficiency without anaemia.”

PRODIGY has guidance entitled “Anaemia – iron deficiency” (2) which looks at definitions of both iron deficiency and iron deficiency anaemia, investigations and management. It says in particular of ferritin levels:

“Serum ferritin level: low (an indicator of reduced body-iron stores). However, as ferritin is an acute-phase protein, levels may be normal or elevated in infective, inflammatory or malignant disease despite iron deficiency. Serum ferritin level is also increased by excessive alcohol consumption.”

It later says:

“A reason for iron deficiency should always be sought. History-taking should attempt to determine whether gastrointestinal (GI) blood loss, menstrual loss, malabsorption, or nutritional deficiency is likely. Drug history of nonsteroidal anti-inflammatory use is particularly important, as this might point to possible GI bleeding. In developed countries dietary deficiency, by itself, is rarely a cause of iron deficiency anaemia … Both upper and lower GI investigations should be considered, because of the high incidence of pathology (except possibly in premenopausal women with heavy periods).”

References

1. Goddard, A.F. et al on behalf of the BSG British Society of Gastroenterology.  “Guidelines for the management of iron deficiency anaemia”, May 05.
(http://www.bsg.org.uk/pdf_word_docs/iron_def.pdf)
2.  PRODIGY.  “Anaemia – iron deficiency”, last revised July 05.
(http://www.prodigy.nhs.uk/guidance.asp?gt=Anaemia%20—%20iron%20deficiency)
 

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