Massive Haemorrhage and Transfusion

Quick Answer

Massive haemorrhage is defined as loss of >50% total blood volume within 3 hours, or blood loss exceeding 150 mL/min. Mortality ranges from 30-40% for trauma-related massive transfusion and 10-20% for surgical bleeding, depending on speed of recognition and treatment. The Lethal Triad of Trauma — hypothermia, acidosis, and coagulopathy — perpetuates bleeding and worsens outcomes if not corrected early. Management follows damage control resuscitation (DCR) principles: (1) Permissive hypotension (SBP 80-90 mmHg) until bleeding controlled, (2) Balanced blood product resuscitation with 1:1:1 ratio of red cells:plasma:platelets, (3) Early tranexamic acid (1 g IV loading within 3 hours of injury), (4) Limit crystalloid use (<2 L before starting blood products), (5) Goal-directed resuscitation using viscoelastic testing (TEG/ROTEM) when available. Massive transfusion protocol (MTP) should be activated early: red cell concentrate 4 units, plasma 4 units, platelets 2 pools (or 1 apheresis unit), cryoprecipitate 10 units delivered in cycles. Monitoring includes serial hemoglobin, coagulation profile, arterial blood gas (lactate, base deficit), and viscoelastic testing to guide component therapy. Complications include transfusion-associated circulatory overload (TACO), transfusion-related acute lung injury (TRALI), and citrate toxicity from massive plasma infusion. Indigenous patients have higher baseline prevalence of coagulopathies (e.g., von Willebrand disease in some communities) and reduced access to blood bank services, requiring culturally safe communication about transfusion risks and early planning for transfer to tertiary centres. [1-10]

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Pathophysiology

Normal Blood Volume and Physiology

Total Blood Volume (TBV):

Adult blood volume varies by body weight and gender:

• Adult male: 70-75 mL/kg (approximately 5.25-5.6 L for 75 kg)
• Adult female: 65-70 mL/kg (approximately 4.6-4.9 L for 70 kg)
• Obese patients: Calculate based on ideal body weight, not actual weight

Component Distribution:

• Red blood cells (RBC): 40-45% of blood volume
• Plasma: 55-60% of blood volume
• Platelets: 150-400 × 10⁹/L (short lifespan 7-10 days)
• Coagulation factors: Synthesized in liver, consumed during clotting

Normal Physiology of Haemostasis:

Primary Haemostasis (0-10 seconds):

1. Vascular spasm: Immediate constriction of damaged vessels
2. Platelet adhesion: Platelets adhere to exposed collagen via von Willebrand factor
3. Platelet activation: Release of thromboxane A2, ADP, serotonin
4. Platelet aggregation: Formation of platelet plug

Secondary Haemostasis (10-120 seconds):

1. Coagulation cascade activation: Intrinsic and extrinsic pathways converge to common pathway
2. Thrombin generation: Thrombin converts fibrinogen to fibrin
3. Fibrin clot formation: Stable clot formation

Fibrinolysis (hours to days):

• Plasminogen activation to plasmin
• Plasmin degrades fibrin clot
• Controlled by tissue plasminogen activator (tPA) and inhibitors (PAI-1)

Massive Haemorrhage Pathophysiology

Definitions:

Massive Haemorrhage (International Consensus):

• Loss of >50% total blood volume (TBV) within 3 hours
• OR blood loss exceeding 150 mL/minute
• OR replacement of entire blood volume within 24 hours

Massive Transfusion Protocol (MTP) Activation:

• Transfusion of >10 units RBC within 24 hours
• OR >4 units RBC within 1 hour with ongoing bleeding

Acute Coagulopathy of Trauma (ACoT):

Massive haemorrhage induces a self-perpetuating coagulopathy through multiple mechanisms:

1. Dilutional Coagulopathy:

• Massive crystalloid infusion → dilution of coagulation factors and platelets
• Blood product resuscitation corrects but requires balanced ratios

2. Consumption Coagulopathy:

• Activation of coagulation cascade → factor consumption
• Platelet activation and consumption
• Fibrinogen depletion (critical substrate for clot formation)

3. Hypothermia-Induced Coagulopathy:

• Temperature <35°C: Enzymatic activity of coagulation cascade ↓ 50%
• Temperature <32°C: Enzymatic activity ↓ 80-90%
• Cryoprecipitate contains fibrinogen, factor VIII, vWF, factor XIII
• Warming is essential to restore enzymatic function

4. Acidosis-Induced Coagulopathy:

• Metabolic acidosis (pH <7.35): Impairs coagulation factor function
• Severe acidosis (pH <7.1): Severe impairment of thrombin generation
• Tissue hypoxia from hypovolaemia → anaerobic metabolism → lactic acidosis

5. Hypocalcaemia (Citrate Toxicity):

• Citrate in plasma products chelates calcium
• Massive plasma transfusion → hypocalcaemia
• Calcium is essential for multiple coagulation steps (factors IV, VII, IX, X)
• Ionised calcium <1.0 mmol/L impairs coagulation and myocardial contractility

The Lethal Triad of Trauma:

Hypothermia + Acidosis + Coagulopathy creates a vicious cycle:

1. Bleeding → Hypovolaemia → Hypoperfusion → Hypothermia + Acidosis
2. Hypothermia + Acidosis → Coagulopathy → More bleeding
3. This cycle continues until addressed simultaneously with balanced resuscitation

Physiological Response to Haemorrhage

Compensatory Mechanisms:

Phase 1: Blood Loss <15% TBV (Class I Shock)

• Minimal physiological changes
• Compensatory tachycardia: HR 80-100 bpm
• Blood pressure maintained (SBP >100 mmHg)
• Mild vasoconstriction

Phase 2: Blood Loss 15-30% TBV (Class II Shock)

• Early decompensated shock
• Tachycardia: HR 100-120 bpm
• Blood pressure: SBP 80-100 mmHg, narrow pulse pressure
• Cold, clammy skin
• Urine output: 20-30 mL/hour

Phase 3: Blood Loss 30-40% TBV (Class III Shock)

• Decompensated shock
• Tachycardia: HR >120 bpm, weak
• Hypotension: SBP 70-80 mmHg
• Marked peripheral vasoconstriction: Cool skin, delayed capillary refill
• Confusion, agitation (cerebral hypoperfusion)
• Urine output: <20 mL/hour, may be anuric

Phase 4: Blood Loss >40% TBV (Class IV Shock)

• Pre-terminal shock
• Extreme tachycardia: HR >140 bpm, may be bradycardic (terminal)
• Severe hypotension: SBP <70 mmHg
• Absent peripheral pulses
• Loss of consciousness
• Anuric

Cellular Response:

• Anaerobic metabolism → lactic acidosis
• ATP depletion → cellular dysfunction
• Endothelial activation → capillary leak, edema
• Organ dysfunction (renal, hepatic, cardiac)

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Clinical Presentation

Recognition of Massive Haemorrhage

Early Warning Signs:

Surgical Field:

• Excessive bleeding: Oozing from raw surfaces despite surgical control
• Failure to clot: Blood remains liquid (suggests coagulopathy)
• Diffuse bleeding: From multiple sites (surgical field, cannula sites, wound edges)
• Blood loss exceeding expected for procedure

Haemodynamic:

• Tachycardia: HR >100 bpm, progressive increase
• Hypotension: SBP <100 mmHg or >30% drop from baseline
• Narrow pulse pressure: SBP - DBP <20 mmHg
• Refractory hypotension: No response to atropine, ephedrine, or phenylephrine
• Cold, clammy skin: Peripheral vasoconstriction
• Delayed capillary refill: >2 seconds

Laboratory:

• Hemoglobin drop: >20 g/L from baseline
• Hemoglobin <70 g/L with ongoing bleeding
• Hematocrit <21% with ongoing bleeding
• Coagulation abnormalities:
  • INR >1.5
  • APTT >45 seconds
  • Fibrinogen <1.5 g/L
  • Platelets <100 × 10⁹/L

Metabolic:

• Metabolic acidosis: Base deficit >6 mmol/L, lactate >4 mmol/L
• Anion gap acidosis: Suggests tissue hypoperfusion

Massive Transfusion Indications:

Activate Massive Transfusion Protocol (MTP) when:

1. Anticipated massive bleeding: High-risk surgery (aortic surgery, liver transplant, trauma)
2. Ongoing bleeding despite 2 L crystalloid resuscitation
3. Blood loss >150 mL/min
4. More than 1 blood volume lost within 3 hours
5. Hypotension with coagulopathy: SBP <80 mmHg + INR >1.5 or fibrinogen <1.5 g/L

Assessment of Coagulopathy

Conventional Coagulation Testing (CCT):

Limitations of CCT:

• Point of care: Turnaround time 30-60 minutes
• Does not assess: Platelet function, clot strength, fibrinolysis
• Guideline-based: Not individualized therapy

Tests:

• INR (International Normalized Ratio): Extrinsic and common pathways
• APTT (Activated Partial Thromboplastin Time): Intrinsic and common pathways
• Platelet count: Platelet number
• Fibrinogen: Key substrate for clot formation

Viscoelastic Testing (VET):

Thromboelastography (TEG) / Rotational Thromboelastometry (ROTEM):

Advantages:

• Point of care: Results within 5-15 minutes
• Global assessment: Platelets, coagulation factors, fibrinogen, fibrinolysis
• Goal-directed therapy: Individualized resuscitation
• Reduced transfusion requirements: Evidence of 20-40% reduction in blood products

Parameters (TEG):

Parameters (ROTEM):

Goal-Directed Therapy Based on VET:

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Management

Damage Control Resuscitation (DCR) Principles

Modern Approach to Massive Haemorrhage:

Damage Control Resuscitation combines resuscitation with haemostatic resuscitation to prevent and correct the Lethal Triad:

1. Permissive Hypotension (Hypotensive Resuscitation):

Rationale:

• Restoring normal blood pressure increases bleeding pressure
• Disrupts forming clots
• Aggravates ongoing haemorrhage

Guidelines:

• Systolic BP 80-90 mmHg until bleeding controlled (trauma)
• MAP 65-70 mmHg for patients with head injury
• Normal BP only after surgical hemostasis achieved

Exceptions:

• Traumatic brain injury: Maintain MAP >80 mmHg for cerebral perfusion
• Spinal cord injury: Maintain MAP >85 mmHg
• Cardiovascular disease: May not tolerate hypotension
• Controlled surgical bleeding: Normal BP after hemostasis

2. Balanced Blood Product Resuscitation:

1:1:1 Ratio (RBC:Plasma:Platelets):

Rationale:

• Simulates whole blood composition
• Prevents dilutional coagulopathy
• Supplies coagulation factors and platelets with red cells
• Evidence of reduced mortality with 1:1:1 vs 2:1 ratio

Implementation:

• Cycle 1 (immediate): 4 units RBC, 4 units plasma, 2 pools platelets (or 1 apheresis unit)
• Cycle 2 (if ongoing): Repeat 1:1:1 ratio
• Add cryoprecipitate 10 units after 4-6 RBC units
• Add fibrinogen concentrate if VET shows fibrinogen deficiency (3-6 g)

Massive Transfusion Protocol (MTP) Components:

3. Limit Crystalloid Resuscitation:

Rationale:

• Crystalloids dilute coagulation factors and platelets
• Contribute to acidosis and coagulopathy
• Excessive crystalloid → transfusion-associated circulatory overload (TACO)
• Blood products preferred for massive haemorrhage

Guidelines:

• <2 L crystalloid before starting blood products
• Prefer balanced crystalloids (Hartmann's) over normal saline
• Normal saline → hyperchloremic metabolic acidosis
• Avoid excessive crystalloid (>3-4 L) in massive transfusion

4. Early Tranexamic Acid (TXA):

Rationale:

• Antifibrinolytic: Inhibits plasminogen activation → reduces fibrinolysis
• CRASH-2 trial (trauma): 1.5% absolute mortality reduction when given within 3 hours
• CRASH-3 trial (non-traumatic bleeding): No mortality benefit but reduces bleeding

Dosing:

• Loading dose: 1 g IV over 10 minutes (within 3 hours of injury/bleeding)
• Maintenance dose: 1 g IV infusion over 8 hours
• Total: 2 g maximum

Contraindications:

• Disseminated intravascular coagulation (DIC)
• Severe renal impairment
• Thrombotic disease history

5. Hypothermia Prevention and Correction:

Rationale:

• Hypothermia <35°C: Coagulation enzyme activity ↓ 50%
• Warming restores enzymatic function
• Prevents exacerbating coagulopathy

Warming Strategies:

• Forced-air warming blankets (Bair Hugger, WarmTouch)
• Warmed IV fluids: Blood warmer (level 1), fluid warmer
• Warmed irrigation fluids for surgical field
• Increase operating theatre temperature: 21-23°C (patient-centered)
• Minimize patient exposure: Cover non-surgical areas

Temperature Targets:

• Core temperature ≥36°C (minimum)
• ≥37°C ideal for normal coagulation
• Monitor continuously (esophageal, nasopharyngeal, bladder)

6. Calcium Replacement (Citrate Toxicity):

Rationale:

• Citrate in plasma binds ionised calcium
• Massive plasma transfusion → hypocalcaemia
• Calcium required for multiple coagulation steps and myocardial contractility

Indications:

• Ionised calcium <1.0 mmol/L
• Massive plasma transfusion (>6 units)
• Signs of hypocalcaemia: Hypotension, prolonged QT interval, decreased myocardial contractility

Dosing:

• Calcium gluconate 10%: 10 mL (1 g) IV over 5-10 minutes
• Repeat based on ionised calcium levels (aim 1.1-1.3 mmol/L)
• Monitor ECG for QT interval changes

7. Goal-Directed Resuscitation with Viscoelastic Testing:

When Available:

• Draw VET sample: Within 5 minutes of MTP activation
• Repeat VET: Every 30-60 minutes or after each blood product cycle
• Adjust transfusion ratio: Based on VET results
• Avoid empiric transfusion of unnecessary components

Benefits:

• Reduced blood product use: 20-40% reduction
• Targeted therapy: Correct specific deficits
• Faster correction: VET results in 5-15 minutes vs 30-60 min for CCT
• Improved outcomes: Evidence of reduced mortality and complications

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Massive Transfusion Protocol (MTP)

MTP Structure and Activation

Massive Transfusion Protocol Activation:

Indications:

1. Anticipated massive bleeding (high-risk surgery)
2. Ongoing bleeding despite 2 L crystalloid resuscitation
3. Blood loss >150 mL/min
4. Hypotension (SBP <80 mmHg) with coagulopathy (INR >1.5 or fibrinogen <1.5 g/L)
5. More than 1 blood volume lost within 3 hours

Activation Process:

1. Call blood bank immediately — "Massive Transfusion Protocol"
2. Specify MTP activation level:
   • Level 1: Trauma activation (immediate)
   • Level 2: Surgical bleeding activation
3. Blood bank prepares:
   • Cycle 1: 4 units RBC, 4 units plasma, 2 pools platelets
   • O2/CO2 transport to theatre
4. Theatre preparation:
   • Blood warmer (Level 1) primed and ready
   • Rapid infuser (e.g., Belmont FMS) prepared
   • Pressure infuser if rapid infuser unavailable

MTP Cycle System:

Cycle 1 (Immediate):

Cycle 2+ (If Ongoing Bleeding):

Total for 6 Units RBC (2 Cycles):

• RBC: 6 units
• Plasma: 6 units (1:1 ratio)
• Platelets: 3 apheresis units or 6 pools
• Cryoprecipitate: 10 units

Termination Criteria:

• Bleeding controlled (surgical hemostasis)
• Hemoglobin stable (>80 g/L) without transfusion
• Coagulation normalized (INR <1.5, fibrinogen >2 g/L)
• Patient hemodynamically stable (SBP >100 mmHg, HR <100 bpm)

Monitoring During MTP

Continuous Monitoring:

Haemodynamic:

• Continuous arterial pressure
• Central venous pressure (if available)
• Urine output (goal >0.5 mL/kg/hour)
• Lactate (trend toward normal <2 mmol/L)

Blood Product Monitoring:

• Hemoglobin — target 70-90 g/L with active bleeding
• Coagulation profile:
  • INR — target <1.5
  • APTT — target <45 seconds
  • Fibrinogen — target >2 g/L
  • Platelets — target >100 × 10⁹/L
• Ionised calcium — target 1.1-1.3 mmol/L
• ABG — pH >7.35, base deficit <6 mmol/L

Viscoelastic Testing (if available):

• TEG/ROTEM every 30-60 minutes
• Adjust MTP components based on results
• Goal-directed therapy reduces unnecessary transfusions

Complication Monitoring:

Transfusion-Associated Circulatory Overload (TACO):

• Signs: Dyspnoea, pulmonary crackles, increased airway pressures, rising CVP
• Incidence: 5-10% in massive transfusion
• Prevention: Rate-limited transfusion, diuretics (furosemide 20-40 mg IV)

Transfusion-Related Acute Lung Injury (TRALI):

• Signs: Dyspnoea, hypoxaemia, bilateral infiltrates on CXR
• Incidence: 1-2% per unit transfused
• Management: Supportive, mechanical ventilation
• Prevention: Plasma from male donors reduces risk

Hypocalcaemia (Citrate Toxicity):

• Signs: Prolonged QT interval, hypotension, decreased myocardial contractility
• Management: Calcium gluconate 10% 10 mL IV (repeat as needed)

Hypothermia:

• Continuous temperature monitoring
• Active warming throughout MTP
• Avoid: Cold blood products, large volumes of unwarmed crystalloids

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ANZCA Final Exam Focus

SAQ Patterns

Massive haemorrhage and transfusion appears regularly in ANZCA Final Written Examination. Common SAQ themes include:

Management-Focused Questions:

• "A patient undergoing liver transplantation is bleeding massively. Outline your management." (2020)
• "Describe damage control resuscitation principles." (2021)
• "What is a massive transfusion protocol and when would you activate it?"

Coagulopathy-Focused Questions:

• "Explain the lethal triad of trauma."
• "Describe acute coagulopathy of trauma."
• "How does viscoelastic testing guide resuscitation?"

Transfusion-Focused Questions:

• "What blood product ratios would you use for massive transfusion?"
• "Describe the role of tranexamic acid in massive haemorrhage."
• "When would you use fibrinogen concentrate?"

Marking Scheme Priorities:

• Recognition of massive haemorrhage
• Activation of MTP (early)
• DCR principles (permissive hypotension, balanced resuscitation, limited crystalloid, TXA)
• Blood product ratios (1:1:1)
• Treatment of lethal triad (hypothermia, acidosis, coagulopathy)
• Viscoelastic testing use
• Monitoring and complication management

Clinical Viva Themes

The Clinical Viva frequently includes massive haemorrhage scenarios:

Scenario Types:

• Intraoperative massive bleeding (aortic surgery, liver transplant)
• Trauma resuscitation
• Postpartum haemorrhage
• Perioperative coagulopathy management
• MTP activation and management

Examiner Expectations:

• Early recognition and MTP activation
• Knowledge of DCR principles
• Understanding of blood product ratios
• Management of lethal triad
• VET interpretation
• Complication recognition and management
• Team communication and leadership

Common Viva Questions:

• "What are the components of damage control resuscitation?"
• "What blood product ratio would you use?"
• "When would you use tranexamic acid?"
• "How does viscoelastic testing differ from conventional coagulation testing?"
• "What is the lethal triad of trauma?"
• "How would you manage hypocalcaemia during massive transfusion?"
• "What are the complications of massive transfusion?"

Medical Viva Considerations

The Medical Viva may include massive haemorrhage within broader discussions:

• Coagulation cascade and physiology
• Blood product types and indications
• Evidence for DCR strategies
• Research in transfusion medicine
• Viscoelastic testing principles
• Complications of transfusion

Key Points for Examination Success

1. DCR principles are foundational — know all 7 components
2. 1:1:1 blood product ratio — RBC:Plasma:Platelets
3. Permissive hypotension — SBP 80-90 mmHg until bleeding controlled
4. Tranexamic acid early — within 3 hours, 1 g loading
5. Limit crystalloids — <2 L before blood products
6. Treat lethal triad — hypothermia, acidosis, coagulopathy
7. Viscoelastic testing — goal-directed therapy when available
8. MTP activation criteria — know when to activate

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Australian Guidelines and Resources

National Blood Authority (NBA) Guidelines

Patient Blood Management (PBM) Guidelines:

• Optimising patient's own blood
• Minimising blood loss and haemodilution
• Optimising tolerance of anaemia
• Evidence-based transfusion practice

Massive Transfusion Guidelines:

• Indications for MTP activation
• Blood product ratios
• Component therapy recommendations

Australian Red Cross Blood Service

Blood Products Available:

Red Cell Concentrate (RBC):

• O-negative universal donor for emergency uncrossmatched transfusion
• Group-specific (A, B, AB, O) when time permits
• Leukoreduced to reduce reactions
• CMV-negative for immunocompromised patients

Fresh Frozen Plasma (FFP):

• Contains all coagulation factors
• Requires thawing (30 minutes)
• Group AB universal recipient

Platelets:

• Apheresis units (single donor, 3-5 × 10¹¹ platelets)
• Pooled units (4-6 donors, 2-3 × 10¹¹ platelets)
• Stored at room temperature (5 days maximum)
• ABO-compatible (but Rh not required)

Cryoprecipitate:

• Fibrinogen-rich (≥15 g/L per 10 units)
• Factor VIII, von Willebrand factor, factor XIII
• Rapid fibrinogen replacement

Australian Resuscitation Council (ARC)

Guideline 10.4: Massive Transfusion

• MTP activation criteria
• Component ratios
• Monitoring and termination criteria

State-Based Blood Banks

Each state provides:

• MTP protocols
• Emergency blood release procedures
• Rare blood product access
• Transfusion reaction management

New Zealand Resources

New Zealand Blood Service:

• Similar blood products to Australia
• MTP guidelines
• Transfusion protocols

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Indigenous Health Considerations

Aboriginal and Torres Strait Islander Perspectives

Aboriginal and Torres Strait Islander patients face unique challenges in context of massive haemorrhage that require culturally safe approaches:

Higher Prevalence of Coagulation Disorders:

Aboriginal and Torres Strait Islander communities have higher prevalence of certain bleeding disorders:

• Von Willebrand Disease: Higher prevalence in some communities
• Hemophilia carriers: Unknown in remote populations
• Platelet function disorders: Due to higher rates of chronic disease

These conditions may:

• Increase baseline bleeding risk
• Worsen outcomes from massive haemorrhage
• Require specialized blood product support
• Complicate postoperative recovery

Access to Blood Bank Services:

Remote and rural communities often have:

• Limited blood product availability: May have only O-negative RBC
• No MTP capability: Blood products not prepared in cycles
• Transfer delays: Hours to receive blood from regional centres
• Limited specialist support: Fewer haematologists

These factors influence:

• Facility choice: Transfer to tertiary centre for high-risk surgery
• Surgical planning: Anticipate bleeding and prepare accordingly
• Transfer activation: Early activation if massive bleeding suspected
• Component limitations: May lack plasma, platelets, cryoprecipitate

Communication and Consent:

Transfusion and blood product discussions require culturally safe approach:

• Religious beliefs: Some communities have specific beliefs about blood
• Family decision-making: May require extended family consent
• Use simple language: Explain coagulation disorders and transfusion clearly
• Visual aids: Diagrams explaining bleeding disorders and blood products
• Involve Aboriginal Health Workers (AHWs) or Aboriginal Hospital Liaison Officers (AHLOs)

Key communication points:

• What massive haemorrhage means
• What blood products are and why they're needed
• What transfusion involves
• Risks and benefits of transfusion
• Alternative options (if available)

Cultural Considerations in Crisis:

In massive haemorrhage requiring MTP:

• Family presence during crisis may be culturally important — facilitate where possible
• Decision-making may involve extended family and community members
• Gender considerations: Some Aboriginal cultures have protocols about who can provide care
• Spiritual practices: May be important during crisis — accommodate where possible
• If death occurs, follow appropriate cultural protocols and involve AHLO for family support

Post-Resuscitation Care:

After MTP and hemostasis:

• Family involvement in care: Many Aboriginal families expect to be constantly present
• Decision-making about ongoing care: May involve extended family
• Explanation of outcomes: Culturally sensitive communication
• Consider local protocols: Repatriation to community if appropriate

Documentation and Planning:

Ensure comprehensive documentation that:

• Is clear and non-technical language
• Includes cultural considerations and family involvement
• Explains blood product use and outcomes
• Considers health record transfer to community health services
• Includes culturally appropriate information for family

Māori Health Considerations (New Zealand)

For Māori patients, cultural safety principles apply:

Whānau (Family) Involvement:

• Involve whānau in all decisions about transfusion and care
• Extended family input in consent and treatment decisions
• Explain procedures and outcomes to family members
• Collective decision-making processes

Tikanga (Cultural Protocols):

• Respect cultural protocols around blood (tapu - sacredness)
• Tapu of blood: May influence consent for transfusion
• Karakia (prayer) may be requested before or after procedures
• Tangihanga (funeral customs) influence post-mortem protocols

Communication:

• Use Māori Health Workers to ensure cultural safety
• Plain language explanations of complex coagulation concepts
• Take time to explain, avoid rushing
• Visual aids and demonstration may be more effective

Health Literacy:

• Many Māori patients may have lower health literacy
• Use simple, non-technical language
• Demonstrate procedures when possible
• Ensure understanding before proceeding

Access Issues:

• Geographic isolation may limit blood product access
• Consider local testing options when possible
• Telehealth for specialist consultation
• Transfer planning for high-risk cases

Documentation:

• Ensure transfusion documentation is clear and culturally appropriate
• Provide clear information for whānau about outcomes
• Coordinate with primary care providers

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Assessment Content

SAQ Practice Question 1 (20 marks)

Question:

A 70-year-old woman (65 kg) is undergoing elective abdominal aortic aneurysm repair. During cross-clamping, massive bleeding occurs from the aorta. Estimated blood loss is 2 L within 15 minutes. Blood pressure is 60/35 mmHg, heart rate 140 bpm.

(a) What are your immediate management priorities? (6 marks)

(b) Describe the massive transfusion protocol you would activate. (8 marks)

(c) How would you manage the lethal triad of trauma? (6 marks)

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Model Answer:

(a) Immediate Management Priorities (6 marks)

1. Call for Help and Activate Massive Transfusion Protocol [1.5 marks]

• Call for help loudly — "Massive bleeding, help!"
• Activate Massive Transfusion Protocol (MTP) immediately
• Specify anticipated blood loss (>150 mL/min)
• Request urgent delivery of blood products to theatre

2. Permissive Hypotension [1 mark]

• Maintain SBP 80-90 mmHg until bleeding controlled
• Avoid aggressive fluid resuscitation that worsens bleeding
• Goal: Adequate organ perfusion without disrupting clots
• Exception: If traumatic brain injury present, maintain MAP >80 mmHg

3. Aggressive Fluid Resuscitation [1.5 marks]

• Rapid crystalloid infusion (Hartmann's or 0.9% saline)
• Limit to <2 L before starting blood products (per DCR principles)
• Prepare blood warmer and rapid infuser for blood products
• Goal: Restore intravascular volume, coronary perfusion

4. Early Tranexamic Acid [1 mark]

• 1 g IV over 10 minutes — administer immediately
• Within 3 hours of bleeding onset (well within window)
• Maintenance: 1 g IV over 8 hours if bleeding continues
• Reduces fibrinolysis, reduces blood loss

5. Communication with Surgical Team [1 mark]

• Request rapid surgical control of bleeding
• Consider temporary measures (aortic cross-clamp if not already)
• Expedite definitive surgical hemostasis

(b) Massive Transfusion Protocol (8 marks)

MTP Activation and Components [3 marks]

Immediate Activation:

1. Call blood bank — "Massive Transfusion Protocol activation"
2. Specify urgency and anticipated volume (2 L within 15 min)
3. Blood bank prepares Cycle 1:
   • 4 units RBC (O-negative for immediate uncrossmatched)
   • 4 units FFP (fresh frozen plasma)
   • 2 pools platelets OR 1 apheresis unit
   • O2/CO2 transport to theatre

1:1:1 Blood Product Ratio [2 marks]

• Red cells:Plasma:Platelets in 1:1:1 ratio
• Rationale: Simulates whole blood, prevents dilutional coagulopathy
• Supplies coagulation factors and platelets with RBCs
• Evidence of reduced mortality with balanced resuscitation

MTP Cycle System [2 marks]

Cycle 1 (Immediate):

• RBC: 4 units
• Plasma: 4 units
• Platelets: 2 pools or 1 apheresis unit
• Deliver immediately via rapid infuser with blood warmer

Subsequent Cycles (if ongoing bleeding):

• Every cycle: 4 units RBC, 4 units plasma
• Every 2 cycles: 1 apheresis unit platelets or 2 pools
• After 4-6 RBC units: Add 10 units cryoprecipitate
• OR fibrinogen concentrate 3-6 g if VET shows fibrinogen deficiency

Monitoring and Adjustment [1 mark]

• Hemoglobin: Target 70-90 g/L with active bleeding
• Coagulation:
  • INR <1.5
  • Fibrinogen >2 g/L
  • Platelets >100 × 10⁹/L
• Ionised calcium: 1.1-1.3 mmol/L
• ABG: pH >7.35, base deficit <6 mmol/L
• Viscoelastic testing (if available): Every 30-60 min, adjust components based on results

Termination Criteria [1 mark]

• Bleeding controlled surgically
• Hemoglobin stable (>80 g/L) without transfusion
• Coagulation normalized
• Patient hemodynamically stable (SBP >100 mmHg, HR <100 bpm)

(c) Management of Lethal Triad of Trauma (6 marks)

The Lethal Triad: Hypothermia + Acidosis + Coagulopathy

1. Hypothermia Prevention and Correction [2 marks]

• Active warming:
  • Forced-air warming blankets (Bair Hugger, WarmTouch)
  • Increase theatre temperature to 21-23°C
  • Cover non-surgical areas
• Warmed blood products:
  • Use blood warmer (Level 1)
  • Warm IV fluids via fluid warmer
• Temperature monitoring:
  • Continuous core temperature (esophageal, nasopharyngeal)
  • Target ≥36°C (ideally ≥37°C)
• If hypothermic:
  • Continue active warming
  • Warming continues until enzymatic function restored

2. Acidosis Correction [2 marks]

• Identify cause:
  • Tissue hypoperfusion → anaerobic metabolism → lactic acidosis
  • Massive crystalloid → dilutional acidosis
  • Liver dysfunction → metabolic acidosis
• ABG monitoring:
  • Serial arterial blood gases
  • Target pH >7.35, base deficit <6 mmol/L
• Correction strategies:
  • Improve perfusion: Adequate volume restoration, hemodynamic support
  • Reduce crystalloid: Limit to <2 L (DCR principle)
  • Sodium bicarbonate: Consider if pH <7.20 and refractory (50-100 mEq IV)
  • Treat underlying cause: Surgical hemostasis, improve perfusion

3. Coagulopathy Treatment [2 marks]

• Balanced blood product resuscitation (1:1:1 ratio):
  • RBC + Plasma + Platelets together
  • Supplies coagulation factors and platelets
  • Prevents dilutional coagulopathy
• Cryoprecipitate (10 units) after 4-6 RBC units:
  • Fibrinogen-rich (≥15 g/L)
  • Rapid fibrinogen replacement
  • Factor VIII, vWF, factor XIII
• Fibrinogen concentrate (3-6 g):
  • If VET shows fibrinogen deficiency (<2 g/L)
  • More rapid than cryoprecipitate
  • Smaller volume (revents dilution)
• Viscoelastic testing (if available):
  • TEG/ROTEM to guide specific therapy
  • Goal-directed: correct specific deficits (factors, fibrinogen, platelets)
  • Repeat every 30-60 minutes

Total: 20 marks

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Viva Scenario (25 marks)

Opening Stem:

You are the consultant anaesthetist supervising a registrar performing emergency laparotomy for ruptured abdominal aortic aneurysm in a 68-year-old man (85 kg). On arrival, patient is hypotensive (BP 50/30 mmHg) with massive abdominal distension. Estimated blood loss is >3 L. Surgical team is about to make incision.

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Expected Viva Progression:

Examiner: What is your immediate management?

Candidate Response: [5 marks]

"This is a catastrophic haemorrhage scenario requiring immediate action.

My priorities are:

1. Call for help loudly — "Massive bleeding, help!"
2. Activate Massive Transfusion Protocol (MTP) immediately
3. Prepare for rapid resuscitation:
   • Rapid infuser primed with blood warmer
   • Large-bore IV access (14-16G) — ensure adequate lines
   • Arterial line for hemodynamic monitoring
4. Apply damage control resuscitation (DCR) principles

DCR Principles:

• Permissive hypotension: Maintain SBP 80-90 mmHg until bleeding controlled
• Balanced blood product resuscitation: 1:1:1 ratio (RBC:Plasma:Platelets)
• Limit crystalloids: <2 L before blood products
• Early tranexamic acid: 1 g IV over 10 minutes (within 3 hours window)
• Hypothermia prevention: Active warming, warmed fluids, increased theatre temperature
• Treat coagulopathy: Cryoprecipitate, fibrinogen concentrate, VET-directed therapy

I would communicate urgently with surgical team for rapid control of bleeding."

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Examiner: Blood bank delivers 4 units O-negative RBC. What are your concerns?

Candidate Response: [3 marks]

"My concerns with uncrossmatched O-negative RBC are:

1. Acute Hemolytic Transfusion Reaction:

• Risk of antibody-antigen reaction if patient has atypical antibodies
• More likely if patient has previous transfusions, pregnancies, or transfusion reactions
• Requires urgent crossmatching when possible

2. Limited Blood Products:

• O-negative may be only RBCs available initially
• Plasma, platelets, cryoprecipitate may be delayed
• MTP requires balanced resuscitation (1:1:1 ratio)
• Plasma and platelets critical for coagulopathy correction

3. Rhesus Sensitization:

• If patient is Rh-negative: O-negative is safe
• If patient is Rh-positive: May cause sensitization to Rh antigen
• Important for females of childbearing age

Management:

• Administer O-negative RBC immediately (need for volume and oxygen-carrying capacity)
• Urgent crossmatch (can be done within 10-15 minutes)
• Request plasma and platelets with O-negative RBC if possible
• Monitor for transfusion reaction: Fever, hypotension, back pain, hemoglobinuria"

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Examiner: After 3 cycles of MTP (12 units RBC), bleeding is ongoing. Hemoglobin is 70 g/L, INR 1.8, fibrinogen 1.2 g/L, platelets 80 × 10⁹/L. Temperature is 34.5°C. What do you do?

Candidate Response: [5 marks]

"This patient has ongoing bleeding with lethal triad present:

Lethal Triad Present:

1. Hypothermia: 34.5°C (<35°C, coagulation enzymes ↓ 50%)
2. Acidosis: (Likely from ongoing hypoperfusion) — would confirm with ABG
3. Coagulopathy: INR 1.8, fibrinogen 1.2 g/L, platelets 80 × 10⁹/L

My Management:

1. Aggressive Hypothermia Correction:

• Forced-air warming blanket at maximum setting
• Increase theatre temperature to 23-24°C
• Warm all IV fluids via blood warmer
• Warmed irrigation fluids for surgical field
• Cover patient completely except surgical site
• Goal: Restore to ≥36°C (enzymatic function restored)

2. Continue Balanced Blood Product Resuscitation:

• Maintain 1:1:1 ratio — Continue MTP cycles
• Emphasize plasma and platelets for coagulopathy:
  • Plasma: Supplies coagulation factors (corrects INR)
  • Platelets: Supplies platelet number and function
• Add cryoprecipitate 10 units (if not already given in this cycle)
  • Fibrinogen-rich: Rapidly corrects fibrinogen deficiency
  • Target fibrinogen >2 g/L
• Consider fibrinogen concentrate 3-6 g:
  • More rapid than cryoprecipitate
  • Smaller volume (prevents dilution)
  • Corrects fibrinogen specifically

3. Address Acidosis:

• ABG assessment — Check pH and base deficit
• If pH <7.35 or base deficit >6 mmol/L:
  • Improve perfusion: Continue volume restoration, hemodynamic support
  • Reduce crystalloid: Already limited per DCR
  • Sodium bicarbonate 50-100 mEq IV if pH <7.20 and refractory
• Treat underlying cause: Continued bleeding requires surgical control

4. Calcium Replacement (Citrate Toxicity):

• Check ionised calcium — likely low from massive plasma infusion
• Calcium gluconate 10% 10 mL IV over 5-10 minutes
• Repeat based on ionised calcium (target 1.1-1.3 mmol/L)
• Monitor ECG for QT interval changes

5. Viscoelastic Testing (if available):

• Draw TEG/ROTEM sample immediately
• Repeat every 30-60 minutes
• Adjust MTP components based on results:
  • Prolonged R time → Give plasma
  • Prolonged K time / decreased α-angle → Give fibrinogen
  • Decreased MA → Give platelets
  • Increased LY30 → Give tranexamic acid

6. Communicate with Surgical Team:

• Reassess surgical hemostasis options
• Consider damage control surgery if uncontrolled:
  • Temporary aortic cross-clamp
  • Abdominal packing
  • Delay definitive repair until patient stable
• Transfer to ICU for ongoing resuscitation if needed"

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Examiner: The bleeding is controlled surgically after 4 MTP cycles. What are your postoperative priorities?

Candidate Response: [4 marks]

"After surgical hemostasis and 4 cycles of MTP, my priorities are:

1. Maintain Hemodynamic Stability:

• Continue blood product support until stable
• Hemoglobin target: >80 g/L (higher once bleeding controlled)
• Continue crystalloid/colloid as needed for volume
• Vasopressor support: Norepinephrine infusion to maintain MAP >65 mmHg
• Wean transfusion as hemoglobin stabilizes

2. Correct Residual Coagulopathy:

• Repeat coagulation studies:
  • INR — target <1.5
  • Fibrinogen — target >2 g/L
  • Platelets — target >100 × 10⁹/L
• Correct deficits:
  • If INR elevated → Additional plasma
  • If fibrinogen low → Additional cryoprecipitate or fibrinogen concentrate
  • If platelets low → Additional platelets
• Viscoelastic testing — guide targeted therapy

3. Temperature Management:

• Continue active warming until normothermic (≥37°C)
• Maintain normothermia postoperatively (36-37°C)
• Monitor core temperature continuously

4. Organ Perfusion Assessment:

• Urine output: Goal >0.5 mL/kg/hour
• Lactate: Trend toward normal (<2 mmol/L)
• Base deficit: Trend toward normal (<2 mmol/L)
• Mixed venous oxygen saturation (ScvO₂) if central line present — target >70%

5. Calcium Homeostasis:

• Repeat ionised calcium — correct if <1.1 mmol/L
• Continue monitoring for 4-6 hours post-MTP
• Calcium gluconate as needed

6. ICU Admission:

• Mandatory ICU admission for post-MTP monitoring
• Invasive monitoring: Arterial line, CVP, cardiac output monitoring
• Serial assessments: Coagulation profile, hemoglobin, calcium, lactate
• Ventilatory support if needed (TACO, pulmonary edema)

7. Transfusion Reaction Monitoring:

• Monitor for TACO (Transfusion-Associated Circulatory Overload):
  • Dyspnoea, pulmonary crackles, increased airway pressures
  • Treatment: Diuretics (furosemide 20-40 mg IV), ventilatory support
• Monitor for TRALI (Transfusion-Related Acute Lung Injury):
  • Hypoxaemia, bilateral infiltrates on CXR
  • Treatment: Supportive, mechanical ventilation

8. Documentation:

• Detailed MTP record:
  • Total blood products given
  • Laboratory values and trends
  • Complications
  • Surgical details of bleeding and control
• Report to transfusion safety committee"

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Examiner: How would your management differ if the patient had refused blood products?

Candidate Response: [4 marks]

"If the patient had refused blood products (Jehovah's Witness or other reasons), management requires:

Preoperative:

1. Detailed discussion about risks of blood transfusion refusal
2. Documented refusal in medical record
3. Optimization strategies:
   • Erythropoietin (EPO) therapy preoperatively to maximize Hb
   • Iron supplementation (IV iron sucrose or ferric carboxymaltose)
   • Folate and B12 supplementation if deficient
4. Informed consent acknowledging understanding of risks

Intraoperative Massive Haemorrhage:

Volume Resuscitation Alternatives:

1. Crystalloids: Larger volumes (3-4+ L) of Hartmann's or 0.9% saline
2. Colloids: Gelatin or starch solutions (if not contraindicated)
3. Cell salvage: Intraoperative cell saver if available (collects, washes, reinfuses patient's own RBCs)
4. Perfluorocarbon-based oxygen carriers (if available and patient agrees)
5. Hemoglobin-based oxygen carriers (Oxyglobin) — if available and patient consents

Coagulation Support Without Plasma:

1. Tranexamic acid: 1 g loading, 1 g over 8 hours (reduces fibrinolysis)
2. Desmopressin: Can increase factor VIII and vWF (if available)
3. Recombinant factor VIIa (NovoSeven):
   • Can promote haemostasis without plasma
   • Off-label for this indication
   • Costly, limited availability
   • Evidence in trauma is mixed
4. Fibrinogen concentrate: 3-6 g — replaces fibrinogen without plasma
5. Prothrombin complex concentrate: (if available)

Hemodynamic Support:

1. Permissive hypotension remains essential
2. Aggressive crystalloid (limited by TACO risk)
3. Vasopressors:
   • Norepinephrine: Vasopressor to maintain MAP >65 mmHg
   • Vasopressin: If refractory hypotension
   • Inotropes: Dobutamine or milrinone for myocardial support
4. Veno-arterial ECMO:
   • Provides circulatory support without blood products
   • Can maintain oxygenation despite severe anaemia
   • Expensive, limited availability

Post-Resuscitation Management:

1. Hemodynamic optimization with vasopressors
2. Accept lower Hb:
   • Hb 70-80 g/L if hemodynamically stable
   • Tolerate higher degree of anaemia than with transfusion
3. Erythropoietin therapy:
   • EPO 40,000 units IV 3 times/week
   • Stimulates red cell production
   • Takes 5-7 days for Hb rise
4. Iron supplementation:
   • IV iron (iron sucrose or ferric carboxymaltose)
   • Rapidly increases iron stores
   • Supports erythropoiesis
5. Close monitoring for end-organ hypoxia:
   • Lactate: Rising lactate indicates tissue hypoxia
   • ScvO₂: <50% indicates inadequate oxygen delivery
   • Urine output: <0.5 mL/kg/hour
   • Electrocardiogram: Ischaemic changes
6. Minimize oxygen consumption:
   • Sedation and paralysis to reduce metabolic demand
   • Temperature control: 34-36°C (reduces metabolic rate 7-10% per °C)
   • Ventilation: Lung-protective, avoid excessive PEEP

Ethical Considerations:

• Respect patient autonomy while ensuring informed decision-making
• Document discussions thoroughly
• Clear communication about risks and outcomes without transfusion
• Multidisciplinary approach with ethics committee if needed

Surgical Considerations:

• Damage control surgery: Abdominal packing, temporary closure
• Delayed definitive repair until patient stable and Hb improves
• Minimize ongoing bleeding as coagulopathy will be worse without plasma

This approach acknowledges patient autonomy while maximizing chances of survival with available non-blood options."

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Total: 25 marks