Pre-Operative Anaemia (BSH 2015)

 

Intro

 

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

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

It increases healthcare costs and risk of needing blood transfusion

  • Transfused patients have greater morbidity and mortality

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

  • Three reasons for this

    • Identify previously undiagnosed disease, e.g. cancer

    • Reduce need for transfusion, conserving stocks

    • Reducing patient exposure to risks of blood transfusion

 

Timing of Assessment

 

No specific research, options include

  • 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

  • Iron Deficiency Anaemia – insufficient absolute body iron stores

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

  • Up to 15% of unexplained IDA —> malignancy

  • Approx 1% of hypoferritinaemia in men and menopausal women —> malignancy

 

Investigatory Algorithm

 

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

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

 

Management

 

General Considerations

  • Cause and severity of anaemia

  • Anticipated peri-op blood loss

  • Time available between diagnosis and surgery

  • Whether surgery may be safely postponed.

Oral Iron

  • Cheap, safe and widely available

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

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

Parenteral Iron

  • More rapidly effective than oral iron

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

 

Others

  • B12/Folate correction

  • 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

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

    • Shown to reduce transfusion requirement

    • But did not report on safety or adverse outcomes

  • Pre-op Transfusion

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