"MTP STR" likely refers to the Massive Transfusion Protocol with an emphasis on the 1:1:1 ratio strategy. Here is a concise overview:
Massive Transfusion Protocol (MTP)
Definition
Massive transfusion is generally defined as transfusion of ≥10 units of packed red blood cells (pRBCs) within 24 hours, or ≥4 units within 1 hour with ongoing hemorrhage.
Activation Criteria
MTP is activated in the setting of uncontrolled, life-threatening hemorrhage — most commonly in:
- Trauma
- Obstetric emergencies (e.g., postpartum hemorrhage)
- GI bleeding
- Surgical hemorrhage
Scoring tools such as the Assessment of Blood Consumption (ABC) Score or Trauma Associated Severe Hemorrhage (TASH) Score can guide activation.
The 1:1:1 Ratio (STR = Standard Transfusion Ratio)
The core principle of MTP is damage control resuscitation using blood products in a balanced ratio to replicate whole blood and combat the "lethal triad" (hypothermia, acidosis, coagulopathy):
| Component | Ratio |
|---|
| Packed Red Blood Cells (pRBC) | 1 |
| Fresh Frozen Plasma (FFP) | 1 |
| Platelets | 1 |
"All hospitals managing severe trauma should have a massive transfusion protocol that aims to provide blood and blood products in a ratio of 1 packed red cells : 1 fresh-frozen plasma : 1 platelets." — Bailey & Love's Surgery, 28th Ed., p. 377
Key Principles
- Avoid crystalloids/colloids for resuscitation in exsanguinating patients — they dilute clotting factors and worsen coagulopathy.
- Warm all products before administration.
- Tranexamic acid (TXA): Give early (within 3 hours of injury) — 1 g IV bolus, then 1 g over 8 hours.
- Calcium supplementation: Citrate in blood products chelates calcium; replace with IV calcium chloride or gluconate.
- Permissive hypotension: Target systolic BP ~80–90 mmHg (unless TBI is present) until hemorrhage is controlled.
- Goal-directed therapy: Use TEG/ROTEM (viscoelastic testing) to guide ongoing product replacement once initial resuscitation is underway.
Monitoring
| Parameter | Target |
|---|
| Hb | ≥7–8 g/dL (≥10 in cardiac/TBI) |
| Platelets | ≥50 × 10⁹/L (≥100 if TBI) |
| Fibrinogen | ≥1.5–2.0 g/L |
| PT/APTT | < 1.5× normal |
| pH | ≥7.35 |
| Temperature | ≥35°C |
| Ionized Ca²⁺ | ≥1.1 mmol/L |
Complications of Massive Transfusion
- TACO (Transfusion-Associated Circulatory Overload)
- TRALI (Transfusion-Related Acute Lung Injury)
- Hypocalcemia
- Hyperkalemia
- Hypothermia
- Dilutional coagulopathy (if ratio not maintained)
- Transfusion reactions
If "STR" refers to something other than the standard transfusion ratio in your context (e.g., a specific protocol acronym used locally), please clarify and I can tailor the answer further.