ABC Score for Massive Transfusion

The ABC Score in Trauma was developed to assist clinicians in discerning when massive transfusion would be required to resuscitate trauma patients.

The original retrospective study (Nunez et al. 2009) examined a trauma registry of 596 patients and isolated variables predictive for massive transfusion in the 76 patients that required ≥10 units of pRBCs during the first 24 hours of resuscitation. The ABC score assesses four clinical variables and a score of ≥2 was found to have a sensitivity of 75% and a specificity of 86% for predicting the need for massive transfusion. A validation study (Cotton et al. 2010) applied the ABC score to three trauma cohort registries retrospectively involving 1604 patients and found a NPV of 97% and a PPV of 55% using the rule.

The rule was derived and validated using retrospective data and the authors support its use in predicting the need to active massive transfusion protocols within early phases of resuscitation in trauma. Advantages of this study include that it applies non-laboratory variables to assist in rapidly identifying patients requiring more blood products.

Variable & Associated Points

• Penetrating mechanism (Yes = 1, No = 0)
• Systolic BP ≤ 90 mmHg in the Emergency Department (Yes = 1, No = 0)
• HR ≥ 120 in the Emergency Department (Yes = 1, No = 0)
• Positive FAST Ultrasound (Yes = 1, No = 0)

Score 0 or 1:
Patient is less likely to require massive transfusion, defined as ≥ 10 units of pRBCs in the first 24 hours resuscitation

Score 2, 3 or 4:
Patient is likely to require massive transfusion, defined as ≥ 10 units of pRBCs in the first 24 hours resuscitation