World Health Organization · 2021 web version · 337 pages
WHO learning module for prescribers on appropriate clinical transfusion practice and minimizing unnecessary blood use
- Issuer
- World Health Organization
- Edition
- 2021 web version
- Audience
- Clinical specialists, blood transfusion specialists, district medical officers, general practitioners, registrars, junior doctors, medical students, senior nurses, nurse anaesthetists
- Evidence
- Expert consensus from international team of clinical and blood transfusion specialists; reviewed by WHO technical departments and external reviewers across six WHO regions
- Reviewed
- 23 Oct 2026 · GMJ
What this guideline says
GMJ summary
This comprehensive 337-page WHO learning module provides evidence-based guidance on the clinical use of blood and blood products across six major clinical areas: general medicine, obstetrics, paediatrics, surgery and anaesthesia, trauma, and burns. The document emphasizes that blood transfusion carries inherent risks of transfusion-transmitted infections and adverse reactions, and should only be used when the benefits clearly outweigh these risks.
The guideline establishes that appropriate transfusion means administering safe blood products only to treat conditions leading to significant morbidity or mortality that cannot be prevented or managed effectively by other means. It stresses that transfusion needs can often be avoided through prevention and treatment of anaemia, correction of iron deficiency before surgery, use of intravenous replacement fluids (crystalloids and colloids), and good anaesthetic and surgical techniques to minimize blood loss.
The module is organized in three parts: principles, products and procedures; transfusion in clinical practice across six specialties; and implementation guidance for establishing hospital transfusion committees and developing local guidelines. It emphasizes the Frank-Starling compensatory mechanisms that allow patients to tolerate surprisingly low haemoglobin levels, particularly in chronic anaemia, and provides specific haemoglobin thresholds and clinical criteria for transfusion decisions across different patient populations.
Key points
For clinicians — doses and thresholds as stated in the guideline
- Transfusion should only be prescribed when haemoglobin concentration, patient clinical signs, and need to prevent significant morbidity/mortality all support the decision; haemoglobin alone should not determine transfusion
- Blood from voluntary non-remunerated donors has lower infection risk than family/replacement donors or paid donors; all blood must be screened for HIV-1/2, hepatitis B, hepatitis C, and syphilis before release
- Crystalloid replacement fluids (normal saline, Ringer's lactate) should be infused at 3× the blood volume deficit; colloids at 1× the deficit; these are first-line treatment for hypovolaemia before considering transfusion
- Normal haemoglobin thresholds defining anaemia: adult males <13.0 g/dl, adult non-pregnant females <12.0 g/dl, pregnant women <11.0 g/dl (1st and 3rd trimester) or <10.5 g/dl (2nd trimester), children 6 months–6 years <11.0 g/dl
- Plasma carries the same infection transmission risk as whole blood and should never be used as a replacement fluid; there are very few clinical indications for plasma transfusion
- Red cell transfusion in chronic anaemia should only be considered when compensatory mechanisms fail or when increased oxygen demand (infection, surgery) cannot be met; iron supplementation is the primary treatment for iron deficiency anaemia
- Whole blood is suitable for acute haemorrhage with hypovolaemia; red cell concentrates are preferred for chronic anaemia to avoid volume overload; each unit should raise haemoglobin by approximately 1 g/dl in adults
- Prerequisites for appropriate clinical use include: national policy on blood use, voluntary donor programme, screened safe blood supply, availability of IV replacement fluids, hospital transfusion committees, clinical guidelines, and staff training
Criteria for anaemia based on normal haemoglobin range at sea level
Table extracted from the guideline
| Age/gender | Normal haemoglobin range (g/dl) | Anaemic if Hb less than (g/dl) | Haematocrit threshold (%) |
|---|---|---|---|
| Birth (full-term) | 13.5–18.5 | 13.5 | 34.5 |
| Children: 2–6 months | 9.5–13.5 | 9.5 | 28.5 |
| Children: 6 months–6 years | 11.0–14.0 | 11.0 | 33.0 |
| Children: 6–12 years | 11.5–15.5 | 11.5 | 34.5 |
| Adult males | 13.0–17.0 | 13.0 | 39.0 |
| Adult females: non-pregnant | 12.0–15.0 | 12.0 | 36.0 |
| Pregnant: 1st trimester (0–12 weeks) | 11.0–14.0 | 11.0 | 33.0 |
| Pregnant: 2nd trimester (13–28 weeks) | 10.5–14.0 | 10.5 | 31.5 |
| Pregnant: 3rd trimester (29 weeks–term) | 11.0–14.0 | 11.0 | 33.0 |
Source: World Health Organization, The Clinical Use of Blood in Medicine, Obstetrics, Paediatrics, Surgery and Anaesthesia, Trauma and Burns. Reproduced in summary form.
From the guideline
Verbatim
“The appropriate use of blood means the transfusion of safe blood products only to treat a condition leading to significant morbidity or mortality that cannot be prevented or managed effectively by other means.”
Editor’s perspective
Why this matters for Georgia and the region
Prof. Giorgi Pkhakadze, MD, MPH, PhD
Editor-in-Chief, Georgian Medical Journal · Chair, Public Health Institute of Georgia · WHO consultant, health and migration
As someone who has worked with WHO on health systems strengthening in Georgia and the region, I recognise this document addresses one of our persistent clinical challenges: the overuse of blood transfusion and the underuse of simple, safer alternatives. In Georgia, where we have successfully implemented screening programmes for hepatitis C and improved blood safety infrastructure, the next frontier is ensuring clinicians prescribe transfusion appropriately. The most critical recommendation for our setting is the routine use of intravenous crystalloid solutions—normal saline or Ringer's lactate at three times the volume lost—as first-line treatment for acute blood loss, reserving transfusion for when haemoglobin and clinical signs together indicate genuine need. One realistic implementation challenge is that hospital pharmacies in smaller Georgian facilities often lack reliable supplies of crystalloid fluids, and without functional hospital transfusion committees to audit practice and provide feedback, inappropriate prescribing patterns will persist despite guidelines. We need to couple this guidance with supply chain strengthening and establishment of multidisciplinary transfusion committees in every hospital that administers blood products.
ORCID 0000-0001-7609-4515 · Perspective written for the GMJ Guidelines Library, 23 Oct 2026
Applicability
Georgia and the South Caucasus
This guideline remains highly relevant for Georgia and the South Caucasus region, where blood safety systems have been strengthened over the past two decades but appropriate clinical use remains inconsistent. Georgia’s blood transfusion service has made progress toward voluntary non-remunerated donation, but family/replacement donors are still used in some facilities, particularly in rural areas. The emphasis on preventing unnecessary transfusion through iron supplementation programmes and antenatal care is particularly important given the prevalence of iron deficiency anaemia in women of reproductive age across the region. National programmes would need to assess current transfusion practices through hospital audits, establish transfusion committees in all hospitals performing transfusions, develop national guidelines adapted to local blood product availability (whole blood vs. components), ensure reliable supplies of crystalloid replacement fluids (normal saline, Ringer’s lactate) in all facilities, and implement training programmes for prescribers on transfusion decision-making. The document’s learning-module format with activities is well-suited for continuous medical education programmes.
Questions this guideline answers
Quick answers
What is the most important principle in deciding whether to transfuse a patient?
Transfusion should only be prescribed when the patient's clinical condition (signs and symptoms of inadequate oxygen delivery) combined with the haemoglobin level indicates that significant morbidity or mortality will occur without transfusion. The haemoglobin value alone should never be the sole deciding factor. Patients with chronic anaemia can tolerate surprisingly low haemoglobin levels (7–8 g/dl or lower) through compensatory mechanisms including increased cardiac output and rightward shift of the oxygen dissociation curve.
Why is plasma not recommended as a replacement fluid for hypovolaemia?
Plasma carries the same risk as whole blood of transmitting HIV, hepatitis B and C, and other transfusion-transmissible infections. There is no evidence that plasma offers any clinical benefit over crystalloid replacement fluids (normal saline, Ringer's lactate) or synthetic colloid solutions in treating hypovolaemia. Plasma is expensive while crystalloids are inexpensive and carry no infection risk. Fresh frozen plasma has very few clinical indications, primarily for treating coagulation disorders with bleeding due to multiple clotting factor deficiencies.
How much intravenous fluid is needed to correct hypovolaemia from blood loss?
Crystalloid solutions (normal saline, Ringer's lactate, Hartmann's solution) should be infused at a volume at least three times the blood volume deficit because only about one-quarter remains in the vascular compartment—the rest distributes to the interstitial space. Colloid solutions should be infused at a volume approximately equal to the blood volume deficit. For example, if 1000 ml of blood is lost, give at least 3000 ml of crystalloid or approximately 1000 ml of colloid to restore circulating volume. Blood volume in adults is approximately 70 ml/kg (e.g., 4200 ml for a 60 kg person).
What are the key differences in transfusion safety between voluntary donors and family/replacement donors?
Voluntary non-remunerated donors have consistently lower prevalence and incidence of transfusion-transmissible infections (HIV, hepatitis B and C, syphilis) than family/replacement donors or paid donors. Family/replacement donors are under pressure to donate and may conceal information about health risks or high-risk behaviours. They may also represent hidden paid donation when families pay community members to donate on their behalf. Paid donors have the highest infection rates. Regular voluntary donors who donate repeatedly have the lowest infection risk because they have already passed multiple screening tests.
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GMJ News coverage
- Copper deficiency may explain iron-resistant anaemia: why the overlooked mineral matters for oxygen transportAug 2026
- Iron, Folate, and B12: The Three Nutrients Your Blood Cannot Live WithoutJul 2026
- Copper deficiency may explain iron supplementation failure—why the overlooked mineral mattersOct 2026
- Rwanda's Drone Network Cuts Blood Delivery Times, Improving Transfusion OutcomesSep 2026
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- Issuer
- World Health Organization
- Type
- Guideline
- Edition
- 2021 web version
- Status
- Current
- Published
- 2021-07-22
- Languages
- English (multiple translations exist)
- Scope
- Global guidance on clinical transfusion practice across medicine, obstetrics, paediatrics, surgery, anaesthesia, trauma and burns
- Audience
- Clinical specialists, blood transfusion specialists, district medical officers, general practitioners, registrars, junior doctors, medical students, senior nurses, nurse anaesthetists
- Pages
- 337
- Licence
- © World Health Organization 2021
- Evidence
- Expert consensus from international team of clinical and blood transfusion specialists; reviewed by WHO technical departments and external reviewers across six WHO regions
- Record history
- Created 23 Oct 2026 · updated 23 Oct 2026 · next check Apr 2027
World Health Organization. The Clinical Use of Blood in Medicine, Obstetrics, Paediatrics, Surgery and Anaesthesia, Trauma and Burns. Geneva: World Health Organization; 2021. 337 p. WHO IRIS: 10665/42397.GMJ Guidelines Library records are original summaries written by the GMJ editorial team from the issuer’s published document and reviewed by a physician. They do not replace the full guideline. The document is the copyright of its issuer and is linked, not hosted. Spotted an error or a newer edition? Tell the Guidelines Desk.
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