Chapter 11 Flashcards

1
Q

How should transfusion be approached in emergent situations of Hemodynamically stable patients?

A

Hemodynamically stable patients:
* Use crystalloid for intravascular volume maintenance.
* Transfusion strategy based on clinical status and use a restrictive RBC transfusion strategy (70-80 g/L), except in some special cases.
* Transfuse one RBC unit at a time, reassess after each unit.
* Suitable for chronic bleeding or contained blood loss.

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2
Q

How should transfusion be approached in emergent situations of Hemodynamically UNstable patients?

A

Requires a different approach for rapid bleeding.
* Massive hemorrhage (e.g., trauma, obstetrics) needs immediate, coordinated intervention.
* Trauma patients often present with coagulopathy, and management has shifted to early recognition and treatment.
* Protocols for massive hemorrhage should be pre-planned and involve the entire care team.
* Emergency transfusion protocols should be institution-specific but apply general principles of trauma care to bleeding patients.

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3
Q

Who develope MHP protocolin a hospital?

A

An MHP is ideally a multidisciplinary process that accounts for local practice, local inventory, logistics, human resource availability, and system limitations. Bedside clinicians (e.g., anesthesiologists, trauma surgeons, emergency physicians, obstetricians, nurses), transfusion medicine specialists (e.g., hematologists, pathologists, hematopathologists), blood bank and laboratory representatives, and allied care staff (e.g., porters, communications specialists) should all be included in the MHP development process to ensure that the MHP is appropriate for, and executable at, that team’s institution.

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4
Q

Establishing a Massive Hemorrhage Protocol (MHP):
Purpose

A

Expedite provision of blood components (RBCs, platelets, plasma) and/or blood products.
Coordinate resources for rapid bleeding control and early identification of the massively bleeding patient.

All hospitals with emergency departments, operating rooms, or an obstetrical service should have an MHP

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5
Q

Establishing a Massive Hemorrhage Protocol (MHP):
Benefits?

A

Improves patient outcomes, reduces overall blood use, and results in cost savings.
For trauma patients, a 1-minute delay in blood delivery is linked to a 5% increase in mortality.

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6
Q

Establishing a Massive Hemorrhage Protocol (MHP):
Key Features:

A

Standardizes communication and best practices for transfusion and bleeding management.
Reduces cognitive load on clinicians, allowing focus on patient care.
Should be in place in all hospitals with emergency departments, operating rooms, or obstetrical services.

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7
Q

Establishing a Massive Hemorrhage Protocol (MHP):
Process:

A

Define processes for initiating and terminating the MHP.
Communicate early with the blood center in cases of limited blood supply.
Review and debrief after MHP activations to ensure continuous improvement.

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8
Q

Question: What is the importance of early identification in massive hemorrhage?

A

Early identification is critical for successful resuscitation.
Helps trigger massive transfusion protocols (MTP) early.
Improves patient outcomes by preventing delays in treatment.

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9
Q

What are some retrospective definitions of massive transfusion?

A

1- Replacement of one blood volume or more in 24 hours.
2- 10 or more units of red blood cells in 24 hours.
3- Replacement of more than 50% blood volume in four hours.

  • Retrospective definitions are not helpful in immediate clinical scenarios.
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10
Q

What is the critical administration threshold?

A

Defined as the need for ≥3 red blood cell units in one hour.
A more clinically useful definition in identifying patients requiring massive transfusion.

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11
Q

Why is clinical judgment alone insufficient for identifying massive hemorrhage?

A

Clinical judgment has poor sensitivity and specificity (~65%).
Using a validated risk assessment tool improves prediction accuracy.

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12
Q

validated tools in MHP trigger

List 3 validated tools in MHP:

A

1- Critical administration threshold
2- shock index
3- ABC score
4- RABT score

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13
Q

What tools are available to identify massive hemorrhage patients?

A

Tools combine:
* Clinical assessment
* Laboratory values
* Bedside ultrasonography (e.g., FAST)
* Shock Index (SI): Calculated by dividing heart rate (HR) by systolic blood pressure (SBP) to assess hypovolemic shock.

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14
Q

Critical administration threshold?

A

> =3 RBC in 1 hour

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15
Q

What increases sensitivity in predicting the need for a massive hemorrhage protocol (MHP)?

A
  1. Mechanism of injury.
  2. Ultrasound assessment

Using these in combination with clinical and laboratory data improves prediction.

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16
Q

How is Shock Index (SI) calculated and when does it trigger an MHP?

A
  • Shock Index = Heart Rate / Systolic BP.
  • **SI >1 after ≥1 L of fluid is **48% sensitive and 91% specific for predicting MHP requirement.
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17
Q

What are the components of the ABC Score used to trigger an MHP?

A

ABC score ≥2 includes:
* Penetrating mechanism
* Systolic BP < 90 mmHg
* Heart Rate > 120 bpm
* + FAST ultrasound

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18
Q

What are the components of the Revised Assessment of Bleeding and Transfusion (**RABT) Score **used to trigger an MHP?

A

RABT score ≥2 includes:
2. Penetrating mechanism
3. Shock Index >1
4. + FAST ultrasound
5. Pelvic fracture

19
Q

What is the most common cause of death in the first hour for severely injured trauma patients?

A
  • Exsanguinating hemorrhage.
  • Accounts for 50% of deaths in the first 24 hours.
20
Q

What percentage of severely injured trauma patients are coagulopathic at the time of hospital presentation?

A
  • It has now been well established that a significant proportion (25–40%) of severely injured trauma patients are already coagulopathic at the time of presentation to hospital,
  • 5-40%.
  • This coagulopathy is associated with an increased risk of mortality.
21
Q

What are the key characteristics of Trauma-Induced Coagulopathy (TIC)?

A
  • Endothelial dysfunction.
  • Dysfibrinogenemia (abnormal fibrinogen).
  • Platelet dysfunction.
  • Imbalance of procoagulant and anticoagulant factors leading to systemic anticoagulation.
  • Exacerbated by hypothermia, acidemia, and resuscitation with hypocoagulable fluids.
22
Q

What factors worsen Trauma-Induced Coagulopathy (TIC) (not initiate it)?

A
  • Hypothermia.
  • Acidemia.
  • Hypoperfusion.
  • Resuscitation with hypocoagulable fluids.
  • Ongoing bleeding leading to further consumption of coagulation factors.
23
Q

How has the understanding of TIC changed the management of severely injured trauma patients?

A
  • Focus on damage control resuscitation.
  • Ratio-driven resuscitation with early provision of plasma, platelets, and procoagulant factors.
  • Development of Massive Hemorrhage Protocols (MHPs) to address early coagulopathy in trauma.

Attempts to ameliorate the coagulopathy of acute trauma have led to the development and proliferation of MHPs

24
Q

Damage control resuscitation (DCR)

What is the primary goal of Damage Control Resuscitation (DCR) in trauma patients?

A

Arrest or limit Trauma-Induced Coagulopathy (TIC) and the physiological consequences associated with resuscitation.

25
Q

What are the four strategies of Damage Control Resuscitation (DCR)?

A

1- Early hemorrhage control (damage control surgery or interventional radiology).
2- Avoidance of crystalloid use or strict limitation (≤1 liter).
3- Limit Hemorrhage:: Permissive hypotension (MAP 50-60 mmHg) unless brain injury is present.
4- Massive Hemorrhage Protocol (MHP) for rapid delivery of blood components in balanced ratios.

26
Q

Why is the use of large-volume crystalloid resuscitation no longer recommended in trauma patients?

A

It exacerbates coagulopathy and is associated with negative side effects like:
* Tissue edema.
* Acidosis.
* Reperfusion injury.
* Multiorgan failure.

27
Q

What is the concept of permissive hypotension in DCR?

A
  • Allowing blood pressure to remain below normal (MAP 50-60 mmHg) to limit hemorrhage.
  • Exception: Brain or spinal cord injury where a higher MAP (≥80 mmHg) is recommended
28
Q

What is the rationale behind the balanced blood component ratio in modern MHPs?

A

Mimicking whole blood with a 1:1:1 ratio (plasma:platelets
blood cells) to prevent trauma-induced coagulopathy.
Early studies show improved outcomes with early provision of plasma and platelets along with red blood cells.

29
Q

How did the Pragmatic Randomized Optimized Platelet and Plasma Ratios (**PROPPR) trial **impact transfusion strategies?

A
  • No overall survival benefit between 1:1:1 and 1:1:2 strategies.
  • A secondary outcome showed a reduction in bleeding and exsanguination in the first 24 hours with a 1:1:1 strategy.
30
Q

How should non-trauma, non-obstetrical massive bleeding patients be resuscitated?

A
  • Start with red blood cell transfusion.
  • Use plasma, platelets, or fibrinogen based on frequent coagulation assessments (e.g., fibrinogen levels, platelet count).
  • Assess coagulation parameters once hourly.
31
Q

What is the significance of tranexamic acid (TXA) in the management of trauma patients?

A

TXA improves outcomes by reducing all-cause mortality and mortality related to bleeding.
TXA is most effective when administered within 3 hours of injury (based on CRASH-2 study).
TXA is included in prehospital algorithms or early Massive Hemorrhage Protocols (MHPs) for trauma patients at risk of bleeding.

32
Q

In what other medical conditions has TXA been shown to improve outcomes?

A

Other than trauma patients it improves:
Postpartum hemorrhage.
Cardiac surgery.
Orthopedic surgery.
Spine surgery.
Mild to moderate traumatic brain injury.

33
Q

Why is fibrinogen supplementation crucial in massively bleeding trauma patients?

A

Fibrinogen levels fall early after injury in trauma patients, leading to increased bleeding risk.
Maintaining fibrinogen levels above 1.5-2.0 g/L improves outcomes in trauma, cardiac surgery, and postpartum hemorrhage.

34
Q

What are the options for fibrinogen replacement in Canada, and what are their advantages?

A

Fibrinogen concentrate or cryoprecipitate can be used for fibrinogen replacement.
Fibrinogen concentrate:
Pathogen-reduced.
Available in freeze-dried form, easier to reconstitute and administer.
Cryoprecipitate: Must remain frozen until use.

35
Q

Why is early fibrinogen replacement recommended, and what ongoing trials are relevant to this?

A

Early replacement improves survival in trauma patients.
Ongoing randomized controlled trials (RCTs) will further define the importance of early fibrinogen supplementation in trauma.

36
Q

What laboratory tests should be conducted in massively bleeding patients, and how often should they be tested?

A

**Baseline tests: **CBC, INR, PTT, fibrinogen, arterial or venous blood gas, lactate, electrolytes, ionized calcium.
Tests should be repeated at least every hour to guide transfusion and monitor for metabolic abnormalities.

37
Q

What are the key considerations for the appropriate selection of blood components in an emergency transfusion?

A

*** Uncrossmatched type O blood: **Used when the patient’s blood group is unknown and transfusion is immediately required.
* Type O Rh-positive: For males with no prior history of transfusion with Rh-positive blood.
* Type O Rh-negative: Reserved for females of childbearing age, children, or patients alloimmunized to the D antigen.
* Type-specific uncrossmatched blood: Can be provided within 15 minutes once the patient’s blood type is known.
* Crossmatched blood: Takes 30–60 minutes to complete antibody screen and crossmatch.
* Switch to group-specific product: Should happen as soon as ABO verification is complete, regardless of the number of type O units received.

Careful patient identification: Crucial to prevent ABO transfusion errors, especially in trauma and urgent clinical situations.

38
Q

list risks and complications associated with large volume resuscitation with blood components and products?

A
  • Hypothermia
  • Impaired Hemostasis
  • Hypocalcemia and Citrate Toxicity
  • Hyperkalemia
  • Volume Overload/Over Transfusion
  • Alloimmunization and Delayed Hemolytic Transfusion Reaction
    *
39
Q

what can Hypothermia cause:

A

Hypothermia dramatically worsens platelet and coagulation function, decreases citrate metabolism, increases hemoglobin-oxygen affinity (decreasing oxygen release to the tissues), and decreases myocardial function.

an approved blood warming device, and employment of external warming devices. The patient’s temperature should be actively monitored (continuously, or at a minimum of hourly). Precautions for avoidance of air embolism must be considered with the use of pressurized infusion systems.

40
Q

What are the risks and complications associated with large volume resuscitation with blood components and products?

A

Hypothermia:
Body temperature drops below 35°C.
Hypothermia worsens platelet and coagulation function, increases oxygen-hemoglobin affinity, decreases myocardial function.

appraoch: aggresive Temperature management: warming devices, blood warmer, active temperature monitoring.
Impaired Hemostasis:
Pre-existing coagulation defects worsened by resuscitation.
Dilution of platelets and clotting factors can occur.
appraoch:Follow the MHP and consider early fibrinogen replacement.
Hypocalcemia and** Citrate Toxicity:**
Citrate in blood components binds calcium, causing hypocalcemia.
Leads to hypotension, impaired coagulation, and muscle excitability.
appraoch:Calcium monitoring and replacement are essential.
Hyperkalemia:
Potassium leaks from red blood cells during storage.
Rarely causes cardiac arrhythmias or arrest.
Volume Overload/Over Transfusion:
Vulnerable to hypovolemia/hypervolemia and myocardial depression.
appraoch:Requires invasive monitoring in critical cases.
Alloimmunization and Delayed Hemolytic Transfusion Reaction:
Risk when using uncrossmatched blood, leading to RBC antibodies (alloimmunization).

Alloimmunization: Higher risk in childbearing females, with a focus on RhD- and Kell negative blood.

41
Q

What are some emerging practices and products in massive hemorrhage protocol-based resuscitation?

A

Prehospital Transfusion:
* Blood components and plasma are used during air transport to reduce delays in resuscitation.
* Red blood cells and tranexamic acid are commonly used.
* Factors favoring outcomes: longer injury-to-arrival times, co-administration of RBCs and plasma, and blunt injuries.
* Prompt transport to definitive care is crucial.
Alternatives to AB Plasma:
Challenge: AB plasma donors are only 4% of the population.
Solutions:
* Prothrombin Complex Concentrate (PCC) and Fibrinogen Concentrate (FC) as alternatives in remote areas.
* Use of group A plasma for emergency transfusion when the patient’s blood type is unknown, supported by safety studies in the U.S.
Whole Blood and Component Alternatives:
* Low-titre Group O Whole Blood (LTOWB): May reduce non-physiologic fluids and improve logistics and coagulopathy treatment.
* Other alternatives: Freeze-dried plasma and cold-stored platelets are being reconsidered for use.
* LTOWB lacks standardization and is not yet licensed in Canada, but emerging evidence is promising.

42
Q

Alternatives to AB Plasma:

A

Prothrombin Complex Concentrate (PCC) and Fibrinogen Concentrate (FC) as alternatives in remote areas.

43
Q

In which patient is an aggressive 1:1:1 resuscitation strategy likely not necessary

A

in non-traumatic bleeding such as that seen in gastrointestinal (GI) bleeds or perioperative bleeding

44
Q

The approach to unstable bleeding non-trauma, non-obstetrical patient

A

For resuscitation of the unstable bleeding non-trauma, non-obstetrical patient, it is reasonable to start with red blood cell transfusion. Consideration of plasma, platelets and/or fibrinogen supplementation will depend more on early and frequent assessment of coagulation parameters, including fibrinogen concentration and platelet count. The frequency of measurement will depend on the rapidity of bleeding and availability of resources.