Discuss the management of massive blood loss in a hospital setting

Massive blood loss

Definition 

• 1 blood volume within 24 hours (Adult blood volume 7% of ideal body weight ie. about 5 litres)
• 50% blood volume within 3 hours 
• >150ml/minute

General principles

• Maintain tissue perfusion and oxygenation
• Arrest bleeding
• Correct coagulopathy with blood products 

Communication

• Between haematology and clinical specialties (surgery, anaesthetics, interventional radiology for embolisation), lab, blood service, 
• Dedicated team member to co-ordinate
• Early senior involvement

Local protocols – role of the hospital transfusion committee

• Other roles include analysis of events
• Contingency plan for national blood shortage and emergencies

 General principles

• Restore circulating volume / monitor signs of poor tissue oxygenation
• Venous access
• Warming of fluids and blood products (hypothermia increase coagulopathy)
• Monitor UO/ BP
• Treat acidosis
• Arrest bleeding
• Surgical/ obstetric / interventional radiology
• Investigations
• Group and Ab screen
• Baseline haem, coag and biochemistry
• Consider near patient testing such as TEG

Haematology targets 

1. HB >8

• Consider cell salvage
• O neg in emergency - ABO group specific – fully cross matched
• Use blood warmer, rapid infuser (level 1)
• HCT 0.35 may be required to sustain haemostasis in massive blood loss
• 30-40% blood loss, PRCs usually required

2. Plts >75 (margin of safety, shouldn’t fall below 50)

• Anticipate plt <50 after 2 x blood volume replacement

3. PTT and APTT <1.5

• FFP 12-15mls/ kg (1L in adults)
• Anticipate need after 1-1.5 x blood volume - now probably would instigate earlier particularly if there has been trauma or there is pre-existing coagulopathy.  Concept of 1:1 FFP to blood ratios.
• Lasts for 24 hours once thawed, therefore should start to dethaw immediately
• 30 minute thaw time

1. Fibrinogen >1

• 2 packs for an adult, usually only needed if DIC
• 30 minute thaw time

Other agents

• PCC if secondary to warfarin
• Not enough evidence to support antifibrinolytics
• rVIIa – off license, consider if continued bleeding despite correction of other parameters
• Fibrinogen concentrate

Risks

• Wrong unit transfused
• DIC – cardinal sign is microvascular oozing
• Hypocalcaemia, hyperkalaemia, TRALI