Anaemia (weak blood) in adults

• Common in all adults. More common in women
• Iron deficiency anaemia (IDA) most common cause
• Blood loss from gut is the most important cause of IDA in postmenopausal women and men of any age — need to test for cancer in these groups

Check

• Take blood for FBC if
• Very tired
• Short of breath with exercise
• Rectal bleeding
• Heavy menstrual periods
• Gut symptoms, eg chronic abdominal pain, recurrent loose faeces

Diagnosis

• Men — Hb less than 130g/L
• Women
• Not pregnant and more than 6 weeks postnatal — Hb less than 120g/L
• Up to 6 weeks postnatal — Hb less than 110g/L
• Pregnant — Hb less than 110g/L — see Anaemia in pregnancy

To confirm diagnosis and cause

• Take blood for serum ferritin, CRP, serum B12, folate, TFT, LFT
• Take blood for UEC if not done in previous 12 months
• Faecal blood test

Interpreting results

• Serum ferritin 30microgram/L or less — confirms iron deficiency anaemia (IDA)
• Serum ferritin more than 30microgram/L but less than 100microgram/L — possible IDA, or anaemia of chronic disease (inflammation)
• Serum ferritin 100microgram/L or more — IDA unlikely — consider other causes
• If unclear if IDA or other cause of anaemia
  
• Medical consult — talk with haematologist about other tests needed
• If anaemia confirmed as B12 or folate deficiency
  
• Treat with appropriate supplements — medical consult

IDA confirmed on testing

Ask

• Iron in diet — meat consumption, on any special diet
• Gut symptoms — chronic abdominal pain, recurrent loose faeces
• Medicines — aspirin, NSAID, warfarin, apixaban, rivaroxaban 
• Rectal bleeding
• Ceremonial practices
• Menstrual periods
• Family history of bowel cancer

Do

• Medical consult
• Give iron replacement
• Oral iron is sufficient for chronic kidney disease if early stages and not on dialysis. If not working — medical consult for IV iron
• If on dialysis — IV iron — medical/renal consult
• If from area where  hookworm is/has been common — give albendazole oral — adult 400mg single dose
  
• Do not give in first trimester of pregnancy (urine pregnancy test if not sure) without medical consult
• Talk about healthy food choices

• If gut symptoms
  
• Rectal bleeding or family history of bowel cancer — consider colonoscopy
• Upper gastrointestinal symptoms — consider gastroscopy
• If female of childbearing age — offer urine pregnancy test

• If over 40 years or not responding to treatment — gastroscopy and colonoscopy to exclude cancer

Iron replacement

Oral iron

• Iron oral — 60–120mg elemental iron a day. Consider alternate day dosing
• Give Vitamin C to optimise iron absorption
• If required reduce gut side effects by taking at night or with food — absorption is reduced with food
• Repeat FBC in 4 weeks
• Need to continue to take iron for 3 months after Hb returns to normal
• If Hb not improving
  
• Consider reason — tablets not being taken, ongoing blood loss, inflammation
• May need IV iron infusion
• Repeat FBC at 12 weeks
• If Hb still low — medical consult

Iron IV infusion

Use if oral iron doesn’t work or can’t be used — medical consult

• Do not use if signs of infection
• Do not restart oral iron until at least 5 days after infusion given
• Do not give more than 20mL (1,000mg) in a single dose. Give second dose at least 1 week after first
• Ferric (iron) carboxymaltose (eg Ferinject) IV infusion can be given if
• Prescribed by doctor
• Anaphylaxis kit and resuscitation equipment available
• Clinician trained in life support AND stays with person during infusion
• Discuss risk of IV iron — injection site reaction and paravenous (surrounding tissue of vein) leakage causing skin staining 
• Can safely be administered by
  
• Slow IV bolus injection
• IV infusion using a gravity feed giving set
• IV infusion using an IV infusion pump
• See — Giving iron by IV infusion