Massive Transfusion — 1:1:1 + TXA

Massive transfusion definitions: classical (>10 units PRBC in 24 hr), or more modern dynamic (>4 units in 1 hr with hemodynamic instability + ongoing bleeding, or >50% blood volume replaced in 3 hr).

Trauma + obstetric hemorrhage + ruptured AAA + cardiac surgery + transplant are typical contexts.

Primary outcome: 24-hr + 30-day mortality not significantly different.

Secondary: better hemostasis + fewer deaths from exsanguination at 3 hr with 1:1:1.

Balanced resuscitation reduces dilutional coagulopathy from imbalanced replacement.

Most centers maintain pre-mixed product 'coolers' for instant delivery once MTP is activated — saves 30+ minutes vs ordering individual components.

WOMAN trial (2017, 20,060 patients): same regimen for postpartum hemorrhage — same time-dependent benefit.

Mechanism: lysine analog that blocks plasmin-fibrin interaction → antifibrinolytic.

Now standard for trauma + OB; also prophylactic in cardiac, joint replacement, spine fusion to reduce bleeding.

Rapid transfusion → ionized hypocalcemia → hypotension, prolonged QT, T-wave changes, decreased contractility, eventually cardiac arrest.

The liver normally metabolizes citrate to bicarbonate within minutes — but rapid transfusion rate exceeds clearance capacity, and liver dysfunction (hypoperfusion in shock, baseline cirrhosis, transplant) exacerbates accumulation.

Replacement: 1 g calcium chloride IV per 4-6 units of PRBC, OR titrate to measured ionized calcium.

CaCl₂ contains 27% elemental calcium; calcium gluconate contains 9% — CaCl₂ preferred for active resuscitation, but must be given via central or large peripheral line (causes tissue necrosis if extravasated).

Goal-directed transfusion using TEG/ROTEM cuts blood-product use 30-50% vs empiric ratios, with equal or better outcomes.

Now standard at major trauma centers, cardiac surgery, transplant.

Blood bank delivers pre-mixed coolers at 1:1:1.

Activation should be by a designated person (anesthesia attending or trauma surgeon) — not informal.

Post-event debrief with team + blood bank to refine protocol.

Below 35°C: enzymatic clotting slows ~10% per °C.

Below 33°C: platelet function severely impaired.

Core temperature monitoring (esophageal preferred in resuscitation).

Cold blood + cold fluid drops core temperature rapidly — every cold unit you give pushes back against your warming efforts.

Rationale: aggressive resuscitation to normal pressures disrupts forming clots + worsens bleeding + dilutes clotting factors.

Bickell (NEJM 1994) and Morrison (J Trauma 2011) support this in non-TBI penetrating + blunt trauma.

Damage control resuscitation paradigm: minimal crystalloid (≤1 L initial), balanced product resuscitation at 1:1:1, early TXA, hemostatic surgery prioritized over physiologic 'completeness', planned re-look + abdominal closure later.

TACO (transfusion-associated circulatory overload): cardiogenic pulmonary edema from volume — diuresis, slow transfusion rate.

Acute hemolytic reaction (ABO incompatibility — bedside check error): fever, chills, back pain, hemoglobinuria, DIC, AKI — STOP, supportive, treat DIC.

Febrile non-hemolytic: usually leukocyte antibodies — antipyretic, slow rate.

Allergic/anaphylaxis to plasma proteins (IgA deficiency): epi + steroid + benadryl.

Hypothermia + hyperkalemia (older blood) + hypocalcemia (citrate) all in massive transfusion.