Overview
Major Haemorrhage
Topic Overview
Summary
Major haemorrhage is life-threatening blood loss requiring urgent intervention and blood product transfusion. Causes include trauma, GI bleeding, obstetric haemorrhage, and surgery. Activation of the major haemorrhage protocol (MHP) triggers rapid provision of blood products in balanced ratios. Management follows the ABCDE approach with simultaneous resuscitation and source control. "Code Red" activates MHP for immediate release of emergency blood.
Key Facts
- Definition: Blood loss requiring transfusion of over 4 units RBC in 1hr, or over 10 units in 24hr, or causing haemodynamic instability
- Shock index: HR/SBP — over 1 indicates significant blood loss
- Balanced resuscitation: RBC:FFP:Platelets = 1:1:1
- Lethal triad: Hypothermia + acidosis + coagulopathy = death
- Permissive hypotension: SBP 80-90 in non-head-injured trauma (avoids clot disruption)
- TXA: Give within 3 hours of injury (1g bolus, 1g over 8h)
Clinical Pearls
Shock index (HR/SBP) over 1 = assume significant haemorrhage regardless of BP
TXA works only if given within 3 hours of bleeding onset — earlier is better
Treat the "lethal triad" (hypothermia, acidosis, coagulopathy) as aggressively as the bleeding itself
Why This Matters Clinically
Major haemorrhage is a leading cause of preventable death in trauma, obstetrics, and surgery. Rapid activation of MHP, balanced blood product transfusion, and early surgical/radiological source control save lives. All clinicians must know their hospital's MHP.
Visual Summary
Visual assets to be added:
- Major haemorrhage protocol activation flowchart
- Shock classes (Class I-IV) diagram
- Blood product ratios infographic
- Lethal triad triangle diagram
Epidemiology
Incidence
- Trauma: Haemorrhage is leading cause of preventable death (30-40% of trauma deaths)
- Obstetric: Postpartum haemorrhage complicates 1-5% of deliveries
- GI bleeding: ~100,000 admissions/year in UK
- Surgical: Intra-operative blood loss varies by procedure
Demographics
- Trauma: Young adults (RTC), elderly (falls on anticoagulants)
- Obstetric: Women of childbearing age
- GI: Older adults, peptic ulcer, varices
Risk Factors for Major Blood Loss
| Cause | Risk Factors |
|---|---|
| Trauma | High-energy mechanism, penetrating injury, pelvic fracture |
| GI | Varices, anticoagulation, peptic ulcer, NSAIDs |
| Obstetric | Uterine atony, placental abnormalities, coagulopathy |
| Surgical | Major vascular/oncological surgery |
Pathophysiology
Blood Loss Classification (ATLS)
| Class | Blood Loss | HR | BP | Clinical |
|---|---|---|---|---|
| I | Under 15% (under 750ml) | Normal | Normal | None |
| II | 15-30% (750-1500ml) | 100-120 | Normal | Anxious |
| III | 30-40% (1500-2000ml) | 120-140 | Reduced | Confused |
| IV | Over 40% (over 2000ml) | Over 140 | Very low | Lethargic |
The Lethal Triad
1. Hypothermia:
- Under 35°C impairs clotting factor function
- Under 34°C = severe coagulopathy
2. Acidosis:
- Tissue hypoperfusion → lactic acidosis
- pH under 7.2 impairs coagulation
3. Coagulopathy:
- Dilutional (excessive crystalloid)
- Consumptive (DIC)
- Hypothermia/acidosis-induced
Trauma-Induced Coagulopathy (TIC)
- Present in 25% of major trauma on arrival
- Driven by tissue injury, shock, inflammation
- Worse outcomes if present
Clinical Presentation
Signs of Major Haemorrhage
Shock Index
Red Flags
| Finding | Significance |
|---|---|
| Shock index over 1 | Significant haemorrhage likely |
| Falling Hb on repeat test | Ongoing blood loss |
| Rising lactate | Inadequate resuscitation |
| Coagulopathy | Indicates severity |
| No response to fluids | Likely ongoing haemorrhage |
Visible bleeding (external or into drains/surgical field)
Common presentation.
Tachycardia (over 100)
Common presentation.
Hypotension (SBP under 90) — may be late sign in young patients
Common presentation.
Altered mental status (confusion, agitation)
Common presentation.
Pallor, cool peripheries
Common presentation.
Reduced urine output (shock)
Common presentation.
Clinical Examination
Primary Survey
- C-ABCDE approach (Catastrophic haemorrhage first)
- Apply direct pressure / tourniquet to external bleeding
- IV access: Two large-bore cannulae (16G or larger)
Focused Examination
| System | Assessment |
|---|---|
| Airway | Patent, protection |
| Breathing | Chest trauma (haemothorax, tension) |
| Circulation | HR, BP, cap refill, skin colour |
| Disability | GCS (hypoperfused brain?) |
| Exposure | Find all bleeding sources, T°C |
Specific Source Identification
- Trauma: "Blood on the floor plus four more" (chest, abdomen, pelvis, long bones)
- GI: NG aspirate, PR exam
- Obstetric: Uterine tone, placenta
- Surgical: Drains, wound
Investigations
Point-of-Care
| Test | Purpose |
|---|---|
| ABG/VBG | Hb (rapid), lactate, pH |
| Glucose | Baseline |
| ROTEM/TEG | Viscoelastic testing (if available) — guides product use |
Laboratory
| Test | Notes |
|---|---|
| FBC | Hb (may be normal initially), platelets |
| Coagulation | PT, APTT, fibrinogen (under 1.5g/L is critical) |
| Group & Save / Crossmatch | Request early; may need O-neg first |
| U&E | Baseline |
| Lactate | Prognostic, guides resuscitation |
Imaging
- CXR: Haemothorax
- Pelvic XR: Major pelvic fracture
- FAST USS: Free abdominal fluid
- CT: If stable enough — CT trauma series
Classification & Staging
Major Haemorrhage Protocol (MHP) Criteria
Activate MHP if:
- Estimated blood loss over 30% blood volume
- Requirement for over 4 units RBC in one hour
- Shock index over 1 with ongoing bleeding
- Clinical judgement of "exsanguinating haemorrhage"
Pack Composition (UK Standard)
- MHP Pack 1: 4 units RBC, 4 units FFP
- MHP Pack 2: 4 units RBC, 4 units FFP
- Platelets: Ordered separately (1 adult therapeutic dose)
- Cryoprecipitate: If fibrinogen under 1.5g/L
Management
Immediate Actions (Simultaneous)
1. Stop the Bleeding (C-ABC):
- Direct pressure, tourniquet (limbs), haemostatic dressings
- Activate surgical/IR/obstetric team for source control
- Pelvic binder if pelvic fracture
2. Activate MHP:
- "Code Red" or equivalent
- Blood bank releases O-negative (or O-positive male) immediately
3. IV Access + Bloods:
- Two large-bore cannulae
- Group & Save, FBC, coagulation, lactate
4. Tranexamic Acid:
| Dose | Timing |
|---|---|
| 1g IV bolus | Over 10 minutes |
| 1g IV infusion | Over 8 hours |
- Within 3 hours of bleeding onset (no benefit after 3 hours; potential harm)
Blood Product Transfusion
Ratio:
- RBC:FFP:Platelets = 1:1:1 initially
Targets:
| Parameter | Target |
|---|---|
| Hb | Over 70 g/L (80 in IHD) |
| Platelets | Over 75 × 10⁹/L (over 100 in neurotrauma) |
| Fibrinogen | Over 1.5 g/L |
| PT/APTT | Under 1.5 × normal |
Fibrinogen Replacement:
- Cryoprecipitate (2 pools) or fibrinogen concentrate
Avoid the Lethal Triad
| Problem | Action |
|---|---|
| Hypothermia | Warm fluids, blood warmer, Bair Hugger, warm environment |
| Acidosis | Treat shock, limit crystalloid, no bicarb unless severe |
| Coagulopathy | Balanced products, TXA, treat hypothermia/acidosis |
Permissive Hypotension
- Target SBP 80-90 (in non-head-injured trauma)
- Avoids "popping the clot"
- Do NOT over-resuscitate with crystalloid
Surgical / Radiological Source Control
- Emergency surgery for exsanguinating haemorrhage
- Interventional radiology (embolisation) if appropriate
Complications
From Haemorrhage
- Multi-organ failure
- Cardiac arrest
- Death
From Transfusion
- TACO (Transfusion-associated circulatory overload)
- TRALI (Transfusion-related acute lung injury)
- Transfusion reactions
- Hyperkalaemia (stored blood)
- Hypocalcaemia (citrate in products)
Coagulopathic
- Secondary surgical bleeding
- DIC
Prognosis & Outcomes
Mortality
- Class III/IV haemorrhage: 30-50% mortality
- Trauma with TIC: Higher mortality than without
- Delay in transfusion/source control: Increased mortality
Good Outcomes Associated With
- Early MHP activation
- Balanced transfusion
- TXA within 3 hours
- Rapid source control
- Avoidance of lethal triad
Evidence & Guidelines
Key Guidelines
- British Committee for Standards in Haematology — Major Haemorrhage (2015)
- NICE Major Trauma Guidelines (NG39)
- Resuscitation Council UK — Trauma Resuscitation
Key Trials
- CRASH-2: TXA reduces death from bleeding if given within 3 hours (8% relative reduction)
- PROPPR: 1:1:1 vs 1:1:2 — no mortality difference but less death from exsanguination
- PROMMTT: Showed time-dependent benefit of early plasma
Patient & Family Information
What is Major Haemorrhage?
Major haemorrhage means severe blood loss that needs immediate treatment with blood transfusions and often surgery to stop the bleeding.
What Will Happen?
- You'll receive blood through a drip
- Doctors will work to find and stop the source of bleeding
- You may need surgery or other procedures
Blood Transfusion
- Blood products (red cells, plasma, platelets) replace what you've lost
- Reactions are rare but monitored for
Resources
References
Primary Guidelines
- Hunt BJ, et al. A Practical Guideline for the Haematological Management of Major Haemorrhage. Br J Haematol. 2015;170(6):788-803. PMID: 26147359
- NICE. Major Trauma: Assessment and Initial Management (NG39). 2016. nice.org.uk
Key Trials
- CRASH-2 Trial Collaborators. Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage (CRASH-2). Lancet. 2010;376(9734):23-32. PMID: 20554319
- Holcomb JB, et al. Transfusion of plasma, platelets, and red blood cells in a 1:1:1 vs a 1:1:2 ratio and mortality in patients with severe trauma: the PROPPR randomized clinical trial. JAMA. 2015;313(5):471-482. PMID: 25647203