Surgery - Iron Deficiency Anaemia

Question 1

Iron deficiency anaemia

Answer 1

• Persistent or severe anaemia believed to be caused by chronic intestinal blood loss
• Symptoms of chronic anaemia, namely lethargy, generalised weakness, breathlessness or even angina.
• Iron deficiency most common and the only one with a cause likely to need surgical treatment.
• In blood films, iron deficiency anaemia is characterised by hypochromic, microcytic red blood cells
• Iron deficiency anaemia can be caused by chronic low-grade blood loss (often occult), inadequate dietary iron intake or absorption, or a combination.
• The pattern of iron deficiency may be complicated by coexisting anaemia from another cause, particularly the ‘anaemia of chronic illness
• an elderly patient with rheumatoid arthritis may have a chronic normochromic, normocytic anaemia due to chronic disease, as well as an iron deficiency anaemia caused by gastric bleeding provoked by non-steroidal anti-inflammatory drugs.

Question 2

Iron deficiency anaemia

Approach to investigation of anaemia

Answer 2

• History—seeking sources of blood loss from the various tracts and excluding inadequate iron intake.
• Previous gastrectomy may cause vitamin B12 deficiency and also diminished acid output, which may diminish iron absorption
• .vitamin B12 is absorbed in the ileum, which leads to the large intestine. To be absorbed, the vitamin must combine with intrinsic factor, a protein produced in the stomach.
• Drug history
• Physical Exam - abdominal mass/enlarged Virchow’s node (left supraclavicular)/rectal lesion
• Examine blood film, measure ESR, serum iron and transferrin, B12 and folate. When there is a ‘mixed’ anaemia, measuring iron stores in a bone marrow biopsy is the definitive method of diagnosing iron deficiency.
• Small bowel biopsies for coeliac disease in a proportion of patients with simple anaemia without bowel symptoms

Question 3

Iron deficiency anaemia

Conditions causing chronic occult blood loss

Answer 3

Lesions in the gastrointestinal tract:

• Ulcerating tumours or polyps of the following (in order of frequency): caecum, stomach, the rest of the large bowel, and (rarely) stromal tumours of small bowel, e.g. leiomyosarcoma (GIST)

Chronic peptic ulceration:

• hiatus hernia with reflux oesophagitis, gastric and duodenal ulcers or stomal ulceration following gastric surgery.

Other ‘ulcerating’ lesions of the bowel:

• haemorrhoids, angiodysplasias of colon or small bowel
• Angiodysplasias—small vascular malformations, single or multiple, occurring from stomach to rectum which bleed spontaneously

Lesions in the female genital tract:

• Heavy menstrual loss (menorrhagia is an extremely common but easily overlooked cause)
• Carcinoma of uterus or cervix (usually presents as abnormal vaginal bleeding rather than anaemia)

Lesions in the urinary tract (rarely sufficient to cause anaemia):

• Transitional cell carcinoma of bladder, pelvicalyceal systems or ureters
• Renal cell carcinoma (may cause haematuria but rarely anaemia)
• Chronic parasitic infestations, e.g. schistosomiasis (common in some developing countries)