Blood transfusion and massive haemorrhage

The most serious transfusion accidents rarely stem from laboratory errors but from the wrong blood being given to the wrong patient — a mislabelled tube, or an identity check performed at the nurses' station instead of at the bedside. The check against the patient's own identity immediately before transfusion is the single most important safety measure in the entire chain. In massive haemorrhage a second problem is added: transfusion saves no one whose bleeding is not stopped, and it is the time to haemorrhage control that determines the outcome.

Indications

• Symptomatic anaemia, or a haemoglobin below the applicable transfusion threshold (see below).
• Ongoing bleeding with haemodynamic compromise, whatever the current haemoglobin — haemoglobin falls late in acute haemorrhage and a normal value does not exclude significant blood loss.
• Massive haemorrhage meeting the criteria for activation of the massive transfusion protocol.
• Plasma and platelets: in ongoing bleeding with coagulopathy, or as part of balanced transfusion in massive haemorrhage.

Transfusion thresholds in the stable, non-bleeding patient

A restrictive strategy is at least equivalent to a liberal one in virtually every group studied. Transfuse one unit at a time and assess the effect clinically and with a repeat haemoglobin before ordering the next unit. In chronic anaemia with a treatable cause — iron deficiency, B12 deficiency, folate deficiency — transfusion is rarely the right measure.

Contraindications

• Anaemia that can be corrected with iron, B12 or folate in a stable patient.
• Transfusion given solely to reach a laboratory value without a clinical question.
• A patient who declines blood transfusion. The decision must be documented and alternatives (iron, tranexamic acid, cell salvage, haemorrhage control) planned in advance.
• A history of a severe transfusion reaction: contact transfusion medicine before transfusing again.

Preparation and equipment

Compatibility testing

Both the type and screen and the serological crossmatch have a limited period of validity — usually about five days — because new antibodies can form after transfusion or pregnancy. Check the validity before ordering blood; an expired type and screen discovered when the patient is already bleeding costs precious time. Exact validity periods and the rules for electronic issue differ between regions — follow the local transfusion medicine regulations.

In life-threatening haemorrhage without a valid blood group, give group O RhD-negative blood (always RhD-negative to women of childbearing age) while awaiting the result.

Equipment

• A large-bore peripheral cannula — at least 1.3 mm (green) for rapid transfusion, preferably two lines in a bleeding patient.
• A transfusion set with a filter. Blood components must not be given through a set without a filter.
• Sodium chloride 9 mg/mL for flushing. No drugs and no other fluid may be given through the same line as the blood component — Ringer's acetate contains calcium, which can cause clot formation in the giving set.
• A blood warmer for rapid transfusion, massive haemorrhage or cold antibodies.
• Monitoring equipment: blood pressure, heart rate, oxygen saturation, temperature.

Procedure

Identity check and transfusion

The check is made at the bedside, by the person starting the transfusion, with the patient present — never in advance at the nurses' station and never by anyone else.

flowchart TD
  A[Blood unit collected to the ward] --> B[Take the unit to the patient's bedside]
  B --> C{The patient states their own name and personal identity number}
  C -- Unable to answer --> D[Check against the identity wristband]
  C -- Answers --> E[Compare with the delivery note and the unit label]
  D --> E
  E --> F{Do the name, identity number, blood group and unit number all match?}
  F -- No --> G[Do not transfuse. Contact the blood bank]
  F -- Yes --> H{Is the unit intact, in date and normal in appearance?}
  H -- No --> G
  H -- Yes --> I[Check vital signs and temperature before starting]
  I --> J[Start slowly and stay with the patient for the first 15 minutes]
  J --> K[Document unit number, time and signature]

Figure 1. The identity check before transfusion. All four items — name, personal identity number, blood group and the unit's identification number — must match both the delivery note and the bag. At the slightest discrepancy the unit is not given.

Transfusion rate:

• Start slowly, about 2 mL/min for the first 15 minutes, and stay with the patient — most life-threatening reactions begin during this phase.
• Thereafter a unit of red cells is normally given over 1–2 hours in a stable patient.
• A unit must be fully transfused within 4 hours of leaving the blood bank's cold chain.
• In heart failure or a high risk of fluid overload: a slower rate, and consider a diuretic between units.
• In ongoing bleeding, the bleeding dictates the rate — the blood is then given as fast as the line allows, through a blood warmer.

Massive haemorrhage

Activate the massive transfusion protocol early in ongoing uncontrolled bleeding with circulatory compromise, when several units are expected to be needed within a short time, or when the estimated bleeding risk is high according to local decision support. Activation must be based on clinical assessment, not on waiting for a haemoglobin value.

flowchart TD
  A[Uncontrolled bleeding with circulatory compromise] --> B[Activate the massive transfusion protocol]
  B --> C[Alert surgery, anaesthesia, interventional radiology and the blood bank simultaneously]
  B --> D[Tranexamic acid 1 g IV, then 1 g over 8 hours]
  B --> E[Two large-bore lines, blood tests including blood gas and coagulation]
  C --> F[Haemorrhage control: surgery, endovascular intervention or compression]
  E --> G[Balanced transfusion: red cells, plasma and platelets 1:1:1]
  G --> H[Blood warmer on everything, active warming of the patient]
  G --> I[Check ionised calcium, give calcium if low]
  H --> J{Bleeding stopped?}
  I --> J
  F --> J
  J -- No --> G
  J -- Yes --> K[Deactivate the protocol, return unused units]
  K --> L[Move to goal-directed replacement guided by laboratory and viscoelastic testing]

Figure 2. The massive transfusion protocol. Activation starts three parallel tracks: haemorrhage control, balanced transfusion, and treatment of hypothermia, acidosis and hypocalcaemia. The protocol is actively deactivated once the bleeding is under control so that unused components can be returned.

Key measures in massive haemorrhage:

• Balanced transfusion in a 1:1:1 ratio of red cells, plasma and platelets, until the bleeding is controlled and goal-directed replacement can take over.
• Tranexamic acid 1 g intravenously as early as possible, followed by 1 g over 8 hours. In trauma the first dose must be given within 3 hours — later administration has not been shown to be of benefit.
• Calcium. Citrate in the blood components binds ionised calcium, and hypocalcaemia impairs both coagulation and myocardial function. Check ionised calcium early and repeatedly, and replace according to local protocol with calcium gluconate or calcium chloride.
• Avoid large volumes of crystalloid. Fluid dilutes the coagulation factors, cools the patient and worsens the acidosis.
• Permissive hypotension until haemorrhage control may be considered in trauma without head injury — follow the local trauma protocol.

Complications

flowchart TD
  A[Symptoms during or shortly after transfusion] --> B[Stop the transfusion immediately]
  B --> C[Keep the line open with sodium chloride through a new giving set]
  C --> D[Re-check the identity against the bag and the delivery note]
  D --> E{Which picture predominates?}
  E -- Fever, rigors, flank pain, dark urine --> F[Suspected haemolysis: samples, fluid, contact transfusion medicine]
  E -- Hypoxia without volume overload --> G[Suspected TRALI: oxygen and ventilatory support, no diuretics]
  E -- Hypoxia with hypertension and raised jugular venous pressure --> H[Suspected TACO: sit the patient up, oxygen, diuretics]
  E -- Urticaria, laryngeal oedema, bronchospasm --> I[Allergic reaction: antihistamine, adrenaline IM in anaphylaxis]
  E -- Fever alone with nothing else --> J[Febrile non-haemolytic reaction once haemolysis has been excluded]
  F --> K[Send the bag and giving set to the blood bank, report the reaction]
  G --> K
  H --> K
  I --> K
  J --> K

Figure 4. Management of a suspected transfusion reaction. The first step is always the same whatever the cause: stop the transfusion and re-check the identity. The bag is never discarded — it must be returned together with the giving set for investigation.

Delayed complications: a delayed haemolytic reaction after 3–14 days with a falling haemoglobin and rising bilirubin, alloimmunisation that complicates future compatibility testing, and iron overload after repeated transfusions.

Aftercare and follow-up

• Check vital signs before starting, after 15 minutes, at the end of the transfusion, and in between according to local protocol.
• Document the unit number, component type, time, volume given, and the prescribing and administering staff in the record and in the transfusion register. Traceability is a statutory requirement.
• Check the haemoglobin no earlier than 15 minutes after the transfusion has finished in a stable patient; in ongoing bleeding the clinical picture governs.
• If a reaction occurs: report it according to local protocol and to transfusion medicine. Give the patient written information about the reaction.
• After massive haemorrhage: continued monitoring for hypocalcaemia, hyperkalaemia, hypothermia, renal failure and respiratory failure, with follow-up of coagulation status.
• Always reconsider the cause of the anaemia. Transfusion treats the value, not the disease.

Common pitfalls

• An identity check made without the patient present. The check must take place at the bedside, against the patient's own statement or their identity wristband.
• Leaving the room during the first 15 minutes. That is when a haemolytic reaction declares itself.
• Ringer's acetate or drugs in the same line as the blood component.
• Waiting to activate the massive transfusion protocol until the haemoglobin result arrives. Haemoglobin falls late — activate on the clinical picture.
• Red cells alone in massive haemorrhage. Without plasma and platelets a dilutional coagulopathy develops.
• Cold transfusion. Unwarmed blood in large volumes is a direct cause of hypothermia and thereby of coagulopathy.
• Forgetting ionised calcium. Citrate-induced hypocalcaemia is common, easy to miss and easy to correct.
• Discarding the bag when a reaction is suspected. Without the bag and giving set the investigation cannot be carried out.
• Giving two units routinely to a stable patient instead of one unit and a fresh assessment.