What is the protocol for a mass transfusion in cases of significant blood loss?

Mass Transfusion Protocol

Immediately activate your hospital's massive transfusion protocol when you anticipate or identify life-threatening hemorrhage requiring 1-1.5 blood volumes within 24 hours, and begin resuscitation with a 1:1:1 ratio of red blood cells:fresh frozen plasma:platelets while simultaneously controlling the bleeding source. 1, 2

Immediate Protocol Activation

Activate the MTP immediately when massive hemorrhage is declared—do not wait for laboratory confirmation or formal thresholds to be met. 3, 1 The nature of the injury typically alerts you to probable massive hemorrhage before formal criteria are satisfied. 1

Critical First Actions (Within Minutes)

• Control obvious bleeding immediately using direct pressure, tourniquets for extremity hemorrhage, or hemostatic dressings—this is your paramount priority. 3, 2, 4
• Secure large-bore IV access with two large-bore peripheral cannulae; consider 8-Fr central access in adults or intraosseous access if peripheral fails. 2, 4
• Administer high FiO₂ to ensure adequate oxygenation during hemorrhagic shock. 2, 4
• Designate a team leader (most senior physician) to coordinate management and declare the massive hemorrhage situation. 1

Blood Product Resuscitation Strategy

Balanced Ratio Transfusion

Use a 1:1:1 ratio of red blood cells:fresh frozen plasma:platelets for severely traumatized patients with massive hemorrhage. 1, 5 This military-derived approach has demonstrated improved survival compared to historical practices. 1

Blood Product Selection and Timing

• Start with O-negative blood only if blood is needed immediately (limit to 2 units maximum), then transition to group-specific blood without antibody screening, as patients have minimal circulating antibodies during acute hemorrhage. 3, 2
• Begin early FFP administration at 10-15 ml/kg when a senior clinician anticipates massive hemorrhage, before coagulopathy develops—this prevents rather than treats dilutional coagulopathy. 3, 1, 4
• Use warmed blood products with blood warmers when infusion rate exceeds 50 ml/kg/h to prevent hypothermia, which dramatically increases mortality from organ failure and DIC. 2

Coagulopathy Management

Laboratory Targets

• Maintain fibrinogen >1 g/L—levels below this threshold represent established hemostatic failure and predict microvascular bleeding. 3, 1
• Keep PT and aPTT <1.5 times normal—values exceeding this indicate established coagulopathy requiring aggressive correction. 3, 2
• Target platelet count ≥75 × 10⁹/L throughout resuscitation. 3, 1

Fibrinogen Replacement

The most effective rapid fibrinogen replacement is achieved with fibrinogen concentrate or cryoprecipitate (if concentrate unavailable), as established coagulopathy requires more than 15 ml/kg of FFP to correct. 3, 1

Laboratory Monitoring

• Obtain baseline samples immediately: FBC, PT, aPTT, Clauss fibrinogen, blood bank sample, biochemical profile, blood gases. 2, 4
• Repeat coagulation studies every 4 hours or after 1/3 blood volume replacement—you may need to give components before results are available in obvious massive hemorrhage. 2
• Use near-patient testing (TEG or ROTEM) if available for rapid coagulation assessment. 4
• Monitor blood lactate and base deficit as sensitive indicators of hypoperfusion and shock severity. 4

Critical Pitfalls to Avoid

• Blood loss is frequently underestimated—hemoglobin and hematocrit do not fall for several hours after acute hemorrhage, and stable vital signs do not exclude significant blood loss. 2
• Do not delay MTP activation—waiting for laboratory results before administering blood products in obvious massive hemorrhage increases mortality. 4
• Do not administer excessive crystalloid—this causes dilutional coagulopathy and worsens outcomes; transition to blood products early. 4
• Hypothermia, acidosis, and shock create a lethal triad leading to DIC with high mortality—actively warm the patient and all transfused fluids. 2, 4
• Ensure correct sample identity—misidentification is the commonest transfusion risk. 2

Definitive Hemorrhage Control

• Pursue early surgical or obstetric intervention to arrest bleeding at the source—damage control surgery may be necessary, limited to controlling bleeding before complete physiologic normalization. 2, 4
• Consider interventional radiology for hemorrhage control when appropriate. 2
• Employ intraoperative blood salvage if available and appropriate (contraindicated if wound is heavily contaminated). 2

Post-Resuscitation Management

• Once bleeding is controlled, aggressively normalize blood pressure, acid-base status, and temperature, then admit to critical care for ongoing monitoring of coagulation, hemoglobin, blood gases, and wound drains. 1, 4
• Initiate standard venous thromboprophylaxis as soon as hemostasis is secured—patients rapidly develop a prothrombotic state following massive hemorrhage. 3, 1, 2
• Monitor and correct electrolyte abnormalities, particularly hypocalcemia from citrate toxicity, to prevent cardiac dysfunction. 4