Level 2 of 6Must-remember

Severe anaemia: transfusion and treating the cause

Assess, manage and stay safe — enough on its own

1 / 7

The card — assess, manage, caution

Assessment— look, ask, measure

Ask first whether this is bleeding or chronic anaemia: acute blood loss is a resuscitation problem, chronic severe anaemia is a diagnostic problem in which the patient is fully compensated and more likely to be killed by over-enthusiastic transfusion than by the anaemia itself.
Take the bleeding history: haematemesis, melaena, fresh rectal bleeding, menstrual loss (suspect if exceeding 80 mL per cycle), obstetric or traumatic haemorrhage, and occult loss into the retroperitoneum or a fractured femur.
Take the symptom history: fatigue, exertional breathlessness progressing to breathlessness at rest, palpitations, headache, dizziness, tinnitus, and in severe cases syncope, confusion and drowsiness — plus angina, claudication or decompensated heart failure where vascular disease pre-exists.
Ask about the cause: weight loss, dark urine, jaundice, bone pain, bruising, paraesthesiae and unsteady gait, NSAID use, hookworm exposure, poor diet, pregnancy, known kidney or liver disease.
Inspect: pallor of conjunctivae, palmar creases and tongue is classic but insensitive, especially in poor lighting and pigmented skin — do not rely on it.
Cardiovascular signs are more dependable than pallor: tachycardia, a wide pulse pressure with a bounding pulse, and a soft ejection systolic flow murmur that disappears when the anaemia is corrected; also tachypnoea, postural hypotension, and a raised JVP with basal crepitations in high-output failure.
Measure and use these cut-offs as red flags: systolic blood pressure below 90 mmHg, heart rate above 110/min, capillary refill beyond 3 seconds, postural hypotension, urine output below 0.5 mL/kg/h, respiratory rate above 24/min, breathlessness at rest, altered mental state or syncope.
Know the haemoglobin bands: WHO grades adult anaemia as mild (110–129 g/L in men, 110–119 g/L in women), moderate (80–109 g/L) and severe (below 80 g/L); in children under 5 the bands are 100–109, 70–99 and below 70 g/L. Treat below 70–80 g/L as severe and below 50 g/L as life-threatening.
A reassuring first haemoglobin in a bleeding patient is meaningless: whole blood leaves the body, and until plasma refill occurs over some hours the haemoglobin in the residual circulation is near-normal — the haemoglobin and haematocrit do not reflect the volume lost.
Look for signs that name the cause: koilonychia, angular cheilosis, atrophic glossitis and pica (iron deficiency); a lemon-yellow tinge, beefy sore tongue and posterior column signs (vitamin B12 deficiency); jaundice, splenomegaly, dark urine and leg ulcers (chronic haemolysis); petechiae, bruising, oral ulceration and fever (marrow failure); lymphadenopathy and bone tenderness (haematological malignancy); a rapidly enlarging tender spleen in a child with sickle cell disease (splenic sequestration).
In a child, blood pressure is maintained until 30–40% of blood volume is lost, so hypotension is a late and near-terminal sign; shock declares itself through tachycardia, cool peripheries, prolonged capillary refill and altered consciousness. Circulating volume is about 80 mL/kg in an infant and 70 mL/kg in an older child.
A child with haemoglobin below 40 g/L and deep sighing (acidotic) breathing is in immediate danger — classically severe falciparum malaria.
In the elderly, presentation is non-specific — falls, confusion, functional decline, worsening heart failure, new angina — and severe anaemia decompensates coexisting cardiac, cerebral and renal disease with little warning.
Two more red flags: fever with neutropenia in a pancytopenic patient (the infection, not the anaemia, is the emergency), and bleeding from puncture sites suggesting disseminated intravascular coagulation.
Draw the diagnostic bloods BEFORE the first unit runs: ferritin, B12, folate, reticulocytes, blood film, LDH, haptoglobin and direct antiglobulin test all become uninterpretable once donor cells circulate — take them at the same venepuncture as the group-and-save.
Remember the reticulocyte count is the single most informative test: high (above 100 × 10⁹/L) means bleeding or haemolysis; low or inappropriately normal means the marrow is not responding.

Management— do this, in order

Resuscitate before you analyse: a shocked, bleeding patient is managed as haemorrhagic shock and the transfusion decision does not await a haemoglobin result.
Stop the bleeding: no volume of transfused blood substitutes for control of the source.
Oxygen: high-flow to any patient who is shocked, breathless or has chest pain — it does not correct anaemic tissue hypoxia but buys time.
Position: a shocked patient supine with legs elevated; an overloaded patient upright.
Access: two large-bore cannulae, 16 G or 14 G in an adult; in a shocked child in whom access fails quickly use an intraosseous needle — blood may be given by that route.Doctor / Nurse
Keep the patient warm: hypothermia impairs coagulation, and blood stored at 4 °C makes it worse.
Crystalloid is a bridge, not a treatment: warmed 0.9% sodium chloride or Ringer's lactate 500 mL IV over 15 minutes in an adult, 10 mL/kg in a child, then reassess — repeated large boluses dilute red cells and clotting factors, and in febrile African children with severe anaemia they worsen outcome. Blood is the fluid for blood loss.Doctor / Nurse
Transfuse for physiology, not a number, one unit at a time in the non-bleeding patient: stable non-bleeding adult below 70 g/L targeting 70–90 g/L; known cardiovascular disease or an older adult with acute blood-loss anaemia after surgery below 80 g/L targeting 80–100 g/L; massive active haemorrhage transfuse regardless of the haemoglobin.Doctor / NurseNot available at your setup — Blood & blood products.
One unit of packed red cells raises the haemoglobin by approximately 10 g/L in an adult who is not bleeding; if it does not rise as expected the patient is still bleeding or still haemolysing.Not available at your setup — Blood & blood products.
Give the unit safely: over 90 minutes to 2 hours in a stable adult, completed within 4 hours of leaving controlled storage; in chronic anaemia, heart failure or frailty give one unit over 4 hours with furosemide 20–40 mg IV (child 0.5–1 mg/kg IV).Doctor / NurseNot available at your setup — Blood & blood products.
Children: 10–15 mL/kg over 3–4 hours raises the haemoglobin by roughly 20–30 g/L; where severe anaemia coexists with cardiac failure give 5 mL/kg slowly under furosemide cover and reassess.Doctor / NurseNot available at your setup — Blood & blood products.
Observations at baseline, at 15 minutes — when acute haemolytic and anaphylactic reactions declare themselves — hourly, and at completion of every unit; bedside identity checking is the single most important safety step.Doctor / Nurse
In major haemorrhage give components in a balanced ratio of 1:1:1 (red cells : fresh frozen plasma : platelets), or 4:4:1; fresh frozen plasma 15–20 mL/kg, platelets kept above 50 × 10⁹/L (above 100 × 10⁹/L with intracranial bleeding), fibrinogen above 1.5 g/L (2 g/L in obstetric haemorrhage).Doctor / NurseNot available at your setup — Blood & blood products.
Tranexamic acid 1 g IV over 10 minutes, then 1 g IV over 8 hours, as early as possible in traumatic and obstetric haemorrhage (child 15 mg/kg, maximum 1 g, over 10 minutes, then 2 mg/kg/h).Doctor / Nurse
Treat the cause — nutritional anaemias are cured by the missing nutrient: ferrous sulphate 200 mg orally (about 65 mg elemental iron) once to three times daily continued 3 months after the haemoglobin normalises (child 3–6 mg/kg/day elemental iron); hydroxocobalamin 1000 µg IM, 6 doses 2–3 days apart, then 1000 µg every 3 months for life; folic acid 5 mg orally daily for about 4 months.Doctor / Nurse
If a transfusion reaction occurs, stop the transfusion, keep the vein open through a new giving set, recheck the identity of patient and unit, and return the unit intact to the laboratory with a fresh sample for repeat grouping and crossmatch, FBC, coagulation and direct antiglobulin test.Doctor / NurseNot available at your setup — Blood & blood products.
Circulatory overload (TACO) — dyspnoea with hypertension and a raised JVP during or within 6 hours: sit upright, oxygen, furosemide 20–40 mg IV (child 0.5–1 mg/kg); restart only after diuresis.Doctor / Nurse
Anaphylaxis during transfusion: adrenaline 0.5 mg IM (1:1000) every 5 minutes as needed, plus chlorphenamine 10 mg IV and hydrocortisone 200 mg IV (child over 12 years 0.5 mg IM, 6–12 years 0.3 mg, 6 months–6 years 0.15 mg); never restart.Doctor / Nurse

Caution— what harms

Never treat the number and discharge the patient: anaemia is a sign, never a diagnosis, and a cause must always be sought — this is the commonest error in the field.
Never transfuse before the diagnostic bloods are drawn: transfusion destroys ferritin, B12, folate, reticulocytes, film and direct antiglobulin test.Not available at your setup — Blood & blood products.
Never prescribe two units reflexively in the non-bleeding patient: the chronically anaemic patient has an expanded plasma volume and is already normovolaemic or hypervolaemic — circulatory overload is the commonest cause of transfusion-related death, and the elderly, cardiac, renal and megaloblastic patients are the ones who drown.Not available at your setup — Blood & blood products.
Never withhold blood from a massively bleeding patient because the haemoglobin looks acceptable: delay in transfusion was judged responsible for 23% of transfusion-related deaths.Not available at your setup — Blood & blood products.
Never give folic acid alone when the B12 status is unknown: the blood count corrects while cord degeneration progresses. If the patient cannot wait, give both.
Never treat iron, B12 or folate deficiency with blood unless the patient is haemodynamically compromised or deteriorating rapidly — the treatment is the missing nutrient.Not available at your setup — Blood & blood products.
Never give a diuretic for TRALI: hypoxia and fever with bilateral infiltrates and a NORMAL JVP within 6 hours is TRALI — oxygen and ventilatory support, no diuretic; a raised JVP with hypertension means TACO and needs the diuretic.
Never restart a transfusion after acute haemolytic (ABO) reaction, anaphylaxis, TRALI or bacterial contamination — only febrile or urticarial reactions in a well-perfused patient may be restarted, cautiously.Not available at your setup — Blood & blood products.
Do not expect cyanosis in a severely anaemic patient: central cyanosis requires more than 40 g/L of reduced haemoglobin in capillary blood, unattainable when the total haemoglobin is 50 g/L.
Do not be reassured by a normal haematocrit in acute haemorrhage, and do not chase a normal blood pressure with repeated crystalloid boluses, which dilute the remaining red cells and clotting factors.
Do not transfuse steady-state anaemia or an uncomplicated painful crisis in sickle cell disease: the baseline haemoglobin is characteristically 60–80 g/L and that number alone is not an indication for anything.Not available at your setup — Blood & blood products.
Do not overtransfuse in variceal bleeding: it raises portal pressure and increases rebleeding.Not available at your setup — Blood & blood products.
Watch for the metabolic complications of massive transfusion hourly: hypothermia from 4 °C components; citrate toxicity with hypocalcaemia (perioral tingling, tetany, prolonged QT, hypotension unresponsive to volume) treated with calcium gluconate 10%, 10 mL IV over 10 minutes (child 0.5 mL/kg, maximum 20 mL, with cardiac monitoring); hyperkalaemia; and dilutional coagulopathy.Not available at your setup — Serum electrolytes.
Never accept anaemia as a normal feature of ageing, and never let a low haemoglobin in a pancytopenic febrile patient distract you from the neutropenic sepsis that is the actual emergency.

Refer / escalate

Refer or transfer urgently any patient with shock, ongoing uncontrolled bleeding, haemoglobin below 50 g/L, chest pain or ischaemic ECG change, high-output failure, pancytopenia with fever, suspected haemolysis with a difficult crossmatch, or a child with haemoglobin below 40 g/L and acidotic breathing — and move them before the blood bank, endoscopy or marrow examination you lack becomes urgent.

The card — assess, manage, caution

Severe anaemia: transfusion and treating the cause — Level 1: CorePrevious Severe anaemia: transfusion and treating the cause — Level 3: Core practiceNext

Read the full lesson free

Create a free account to unlock every page, the level exams, and progress tracking.