2. Pre-operative optimisation of haemoglobin

Why it is important to manage preoperative anaemia?

Preoperative anaemia is caused by disease, disorder or a nutritional deficit. Even mild preoperative anaemia is independently associated with increased perioperative morbidity and mortality. An underlying disease may negatively affect perioperative outcome, and furthermore preoperative anaemia significantly increases the risk of transfusion and its associated risks. A surgical procedure with a moderate or high blood loss will further aggravate the anaemia and deplete iron stores.

Early screening for preoperative anaemia is necessary to allow time for diagnostic workup and for treatment to raise the haemoglobin concentration and reduce perioperative transfusion. Anaemia should be classified and the underlying cause identified and treated, if possible. Iron deficiency anaemia is the most frequent type, e.g. caused by bleeding, diet or malabsorption. Anaemia of chronic inflammation (disease) is also frequent due to e.g. autoimmune disease or cancer, and is often seen in combination with iron deficiency. Other causes of anaemia are haematologic disease, kidney failure, B-vitamin deficiency and haemolytic conditions, and some of these will be more amenable to treatment than others.

Patients with multiple preoperative risks, such as anaemia in combination with anticoagulant treatment and a major surgical procedure may be at risk for intraoperative organ ischemia and/or massive transfusion and a complicated postoperative period. Patients, in whom anaemia diagnosis reveals severe disease, may have to have their surgery postponed or cancelled. In other cases, performing the surgery quickly may be imperative, and further anaemia management may have to be postponed. Therefore, a complete PBM plan should always include an individual risk assessment. Even though PBM should be tailored to the patient, algorithms for anaemia management prior to specific procedures such as cardiac or orthopaedic surgery is useful.

The key elements are

Anaemia:

Definitions according to World Health Organization (1)
There is an increased prevalence among adolescent girls, women 15-49 ears of age, pregnant women and children in low- and middle-income countries.
According to WHO, the prevalence of anaemia varies by country and World Bank income group. Its prevalence is highest in low-income countries. Here involves up to 40% of those ages 65-69 years and up to>60% of ages 85-89 years.
In the middle-aged population, anaemia is associated nutritional deficiency in one-third, kidney disease or anemia of chronic disease/inflammation in another one-third and unexplained other third. Anemia is of concern because of the increased morbidity and mortality associated both with the abnormally low haemoglobin level and with the underlying cause of the anaemia. (2,3)

Preoperative anaemia:

Is frequent and often previously undiagnosed, and depending on age and comorbidity, it is seen in up to 75% of the patients (4)
Even mild, it is a marker for disease, and associated with increased perioperative mortality and morbidity (5)
For truly elective cases the preoperative laboratory tests should be performed at least 4 weeks or more giving adequate time for diagnosis and completion of treatment (6)

How to treat anaemia

Key Points in Treating Preoperative Anemia

1. Early Identification & Timing

All patients should be screened ≥6–8 weeks before major surgery to allow for anemia correction. [sabm.org], [irp.cdn-website.com]
Hemoglobin threshold: aim for ≥13 g/dL in both men and women to optimize outcomes. [sabm.org], [irp.cdn-website.com]

2. Laboratory Evaluation

Basic labs: CBC with Hb, MCV/MCHC for anemia type; reticulocytes help assess bone marrow response. [sabm.org], [sabm.org]
Iron studies: Ferritin, TSAT, TIBC.
- TSAT < 20% or ferritin low → suggests true iron deficiency. [sabm.org], [irp.cdn-website.com]
- Check C-reactive protein CRP to assess inflammation, as elevated CRP may affect interpretation. [sabm.org]

3. Iron Supplementation

Oral iron: First-line if surgery ≥6 weeks away; daily or alternate-day dosing improves absorption and tolerance. [cpoc.org.uk], [irp.cdn-website.com]
Intravenous (IV) iron: For those with insufficient time (<4–6 weeks), poor tolerance to oral iron, or functional iron deficiency. [ashpublications.org], [irp.cdn-website.com]
- RCTs confirm IV iron raises Hb and reduces need for transfusion in high-risk surgeries. [cpoc.org.uk], [pre-op.org], [medicsciences.com]

4. Erythropoiesis-Stimulating Agents (ESAs)

Consider ESAs (e.g., erythropoietin) alongside iron — especially in severe anemia, poor oral/IV option, or for patients with alloantibodies or transfusion objections. [ashpublications.org], [medicsciences.com]
Studies in orthopedic surgery show that ESA + IV iron can roughly halve transfusion need without notable thromboembolic risk. [medicsciences.com]

5. Transfusion Strategy & Perioperative Blood Management

Favor restrictive transfusion thresholds:
- Hb ≤7–8 g/dL for stable patients.
- Hb >8 g/dL may be considered for those with cardiovascular comorbidities. [mdpi.com], [irp.cdn-website.com]
Additional prophylactic strategy: Tranexamic acid reduces blood loss and transfusion needs. [cpoc.org.uk], [pre-op.org]

6. Multidisciplinary Patient Blood Management (PBM)

Guidelines (BSH, CPOC, SABM, NICE, international consensus, etc.) recommend a pathway approach: early screening, targeted iron or ESA therapy, and appropriate transfusion thresholds. [cpoc.org.uk], [b-s-h.org.uk], [irp.cdn-website.com]
Setting up preoperative anemia clinics improves anemia correction and reduces transfusions. [ashpublications.org], [sabm.org]

Summary Table of Interventions

Intervention	Indication/Timing	Notes
Oral iron	≥6 weeks before surgery, mild ID anemia	Daily or alternate-day dosing [cpoc.org.uk], [irp.cdn-website.com]
IV iron	<4–6 weeks pre-op or poor oral tolerance	Faster Hb correction; reduces transfusion [cpoc.org.uk], [medicsciences.com]
ESAs ± iron	Severe anemia or special cases	Reduces transfusion; low thromboembolic risk [medicsciences.com], [ashpublications.org]
Restrictive transfusion	Hb 7–8 g/dL (general); >8 g/dL in cardiac	Based on evidence; aligns with PBM [mdpi.com], [irp.cdn-website.com]
Tranexamic acid	Major surgery blood-loss prophylaxis	Recommended as standard in guidelines [cpoc.org.uk], [pre-op.org]

Evidence & Guidelines

CPOC (UK) updates: emphasize tranexamic acid and cautious transfusions; IV iron reduces transfusions though outcome effects vary. [cpoc.org.uk], [pre-op.org]
BSH 2024 update: aligns with other major societies on screening, iron use, ESAs, and restrictive transfusion. [b-s-h.org.uk]
SABM & ASH consensus (2023): early diagnosis with iron studies, pathway-based management. [sabm.org], [ashpublications.org]

This section was AI Generated by Microsoft Co-Pilot.

Optimizing preoperative hemoglobin through early detection, appropriate iron use, targeted ESA therapy, and judicious transfusion practices reduces surgical risks and improves outcomes for patients undergoing elective or major surgery.