Pre-Operative Anaemia (BSH 2015)

 

Intro

 

-       Pre-op anaemia is a risk factor for complications and death from surgery

o   Mild anaemia (Hb >100) increase morbidity risk by 30%

-       It increases healthcare costs and risk of needing blood transfusion

o   Transfused patients have greater morbidity and mortality

-       DoH and National Blood Transfusion Committee recommend pre-op screening for anaemia

-       Three reasons for this

o   Identify previously undiagnosed disease, e.g. cancer

o   Reduce need for transfusion, conserving

o   Reducing patient exposure to risks of blood transfusion

 

Timing of Assessment

 

-       No specific research, options include

o   With GP at time of referral, During the diagnostic pathway (e.g. abnormal endoscopy), Surgical Clinic, Pre-Op Assessment Clinic.

-       Suggested that testing with GP ideal as increase available time to correct anaemia.

 

Diagnosis of Anaemia

 

-       In a pre-op setting, most concerned with iron-related anaemia vs anaemia of other causes

-       Anaemia due to iron metabolism

o   Iron Deficiency Anaemia – insufficient absolute body iron stores

o   Functional Iron Deficiency – In sufficient iron available to bone marrow despite presence of iron in the reticulo-endothelial system.

o   Up to 15% of unexplained IDA à malignancy

o   Approx 1% of hypoferritinaemia in men and menopausal women à malignancy

 

Investigatory Algorithm

 

-       CCG’s should develop local pathways of investigation and agree funding arrangements between primary and secondary care

o   Correction of pre-op anaemia saves money in both domains

 

Management

 

-       Should consider

o   Cause and severity of anaemia

o   Anticipated peri-op blood loss

o   Time available between diagnosis and surgery

o   Whether surgery may be safely postponed.

-       Oral Iron

o   Cheap, safe and widely available

o   Slow – at best Hb rise of 10g/l per week, and need to continue for further 3 months

o   Absorption impaired by tannins, PPIs, chronic inflammation, renal failure

-       Parenteral Iron

o   More rapidly effective than oral iron

o   Must be given in facilities with resus equipment – though SAEs <1 in 200,000

 

-       Others

o   B12/Folate correction

o   Erythropoiesis-stimulating agents (ESA)

§  Recombinant variants of erythropoietin

§  Expensive, DVT side effects

§  Not recommended for pre-op anaemia unless in context of another licensed indications, e.g. renal failure

-       Short-term therapy

o   Very short therapy with IV Iron +/- daily ESA in one week prior to surgery

o   Shown to reduce transfusion requirement

o   But did not report on safety or adverse outcomes

-       Pre-op Transfusion

o   Not recommended, no good evidence for it despite previous widespread use