01Purpose and principlesWhat the treatment does and how it fits into care.
Fluid resuscitation attempts to restore effective circulating volume; it does not provide the oxygen-carrying or haemostatic functions of blood. The prescribing decision must therefore start with the nature of the deficit. Dehydration, septic vasodilatation and traumatic blood loss may all lower blood pressure but require different volumes, products and definitive interventions.
In rapidly evolving haemorrhage, a precise estimated blood loss or low haemoglobin is not required before activating a coordinated response. Replacement must proceed with haemorrhage control, because even technically correct transfusion cannot compensate indefinitely for uncontrolled loss. Once immediate bleeding is controlled, empirical product ratios should give way to reassessment and targeted correction.
Key points
- Identify whether the immediate need is resuscitation, replacement of ongoing losses or routine maintenance.
- Use general crystalloid boluses of 500 mL over less than fifteen minutes only when appropriate to the cause.
- Use the separate NICE sepsis starting regimen of 250 mL with reassessment after each bolus.
- For actively bleeding adult major trauma in hospital, begin blood components with plasma and red cells in a 1:1 ratio.
- Give indicated tranexamic acid promptly after traumatic bleeding; avoid starting after three hours unless hyperfibrinolysis is established.
- Warm the patient and administered products, and monitor calcium, coagulation and physiological response during major transfusion.
02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.
Thirst, recent gastrointestinal loss, reduced intake and hypoperfusion support a volume deficit. Congestion and cardiac history modify whether a standard-sized fluid challenge is tolerated.
External bleeding may be obvious, but chest, abdominal, pelvic or long-bone injuries can conceal substantial losses. A transient response to treatment may indicate continuing haemorrhage.
Diffuse oozing and persistent bleeding after initial source control suggest impaired haemostasis. Anticoagulants, hypothermia, low fibrinogen and dilution can all contribute.
New crackles, worsening oxygen requirement and venous congestion after infusion indicate possible overload. The next decision should reassess the mechanism rather than simply increase the delivery rate.
03Assessment before treatmentTests and checks that guide safe selection.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Group and crossmatch samplesFirst step - Why
- Enable rapid compatible product selection and continuing transfusion.
- Interpretation and limitations
- Label samples at the bedside using verified identity. In immediately life-threatening bleeding, emergency blood may be needed before compatibility testing is complete.
- 02
Blood count and clotting tests - Why
- Guide targeted components once results are available.
- Interpretation and limitations
- Haemoglobin, platelets, fibrinogen and coagulation results provide complementary information. An initially preserved haemoglobin does not exclude a large acute blood loss.
- 03
Blood gas with ionised calcium - Why
- Assess metabolic consequences during ongoing resuscitation.
- Interpretation and limitations
- Acidaemia and lactate reflect physiological stress; falling ionised calcium during citrate-containing transfusion can impair cardiac function and coagulation, prompting measured correction.
- 04
Focused imaging and source localisation - Why
- Direct surgery, embolisation or other haemorrhage control.
- Interpretation and limitations
- The choice depends on stability and suspected anatomy. Imaging must not become a reason to postpone treatment in a patient who cannot tolerate the delay.
04Treatment approachPreparation, options, escalation and aftercare.
01Non-haemorrhagic depletionA measured crystalloid challengeFirst stepClinical assessment identifies hypovolaemia without active haemorrhage and without substantial pulmonary or venous congestion.+
- 1Choose an isotonic crystalloid containing sodium 130–154 mmol/L; for general adult resuscitation give 500 mL over less than fifteen minutes when clinically appropriate.
- 2Use a smaller, cause-specific volume when required, including the 250 mL initial sepsis bolus, and assess frailty, cardiac failure and renal impairment before further doses.
- 3Reassess blood pressure, pulse, capillary refill and respiratory findings after delivery; document the actual response and stop routine repetition if benefit is absent or overload emerges.
02Major bleedingBlood components alongside definitive controlDefinitiveAn adult with major trauma has active bleeding and inadequate perfusion after arrival in hospital.+
- 1Activate the major haemorrhage protocol, state patient identity and location clearly, obtain access and samples, and nominate one person to communicate product requirements to the laboratory.
- 2Begin plasma and red cells in a one-to-one ratio under the trauma pathway, add other components according to the haemorrhage protocol and evolving results, and avoid replacing active hospital traumatic blood loss with crystalloid.
- 3DefinitiveArrange urgent definitive bleeding control and administer indicated early tranexamic acid; reassess haemostasis, temperature, calcium and circulation throughout rather than counting units as the outcome.
03After bleeding controlMoving from emergency packs to targeted treatmentThe source is controlled, perfusion is improving and new laboratory results become available.+
- 1Notify the laboratory that the emergency phase has changed so unnecessary thawing and dispatch can stop while an appropriate reserve is maintained.
- 2Review haemoglobin, clotting, platelets and fibrinogen with the current bleeding status; apply stable-patient transfusion thresholds only when their inclusion criteria genuinely fit.
- 3Reconcile all administered products and drugs, document any reaction, and plan surveillance for overload, recurrent bleeding and electrolyte disturbance during the next phase of care.
05Regimens, contraindications and interactionsTreatment details and the circumstances that modify them.
Tranexamic acid for significant traumatic haemorrhage
Give 1 g IV over 10 minutes as early as possible within 3 hours of injury, followed by 1 g IV infused over 8 hours using the established trauma regimen.Check prior prehospital dosing and avoid duplicate loading. Do not start beyond three hours after injury unless hyperfibrinolysis is demonstrated; this is not a universal regimen for every bleeding cause.
06Complications, monitoring and follow-upAdverse effects, response and longer-term review.
- Follow perfusion and mental state continuously during unstable bleeding, recording blood pressure trends rather than a single post-bolus value.
- Maintain a running record of crystalloid, blood components and tranexamic acid already administered, including treatment before hospital arrival.
- Recheck temperature, gas, ionised calcium and haemostatic tests during significant transfusion at intervals dictated by the pace of bleeding.
- Assess suspected transfusion reactions promptly; stop the implicated component, maintain appropriate access and contact the transfusion team while treating the clinical problem.
07Special situationsVariants, exceptions and circumstances that change the usual approach.
Permissive resuscitation limits
Restrictive volume replacement during uncontrolled haemorrhage differs from neglecting perfusion. Traumatic brain injury requires particular attention to cerebral perfusion and specialist priorities.
Blood-product identification
Emergency release changes compatibility arrangements, but never removes the need for bedside identity checks, traceability and communication of the products actually transfused.
Preventing hypothermia
Exposure, cold fluids and prolonged procedures increase heat loss. Active warming supports coagulation and can be organised concurrently with haemorrhage control.
Red-cell thresholds
The commonly cited 70 g/L restrictive threshold concerns selected patients who need transfusion and excludes major haemorrhage; it must not delay resuscitation of active bleeding.
08Common pitfallsFrequent interpretation and management errors.
- 01
Do not prescribe a fluid volume without stating its indication, rate and point for reassessment.
- 02
Do not use a 1:1 plasma-to-red-cell ratio as a substitute for evaluating platelets, fibrinogen and ongoing haemorrhage.
- 03
Do not forget calcium and temperature while focusing exclusively on haemoglobin during rapid transfusion.
- 04
Do not keep the major haemorrhage response running after the clinical team has safely moved to targeted treatment.