Massive hemorrhage and transfusion

Why examiners ask this

Massive hemorrhage is the examiner's favorite way to test organization under pressure, because the right answer is a sequence rather than a fact. It also opens every door they want: the coagulopathy of trauma, the lethal triad, hyperkalemia and hypocalcemia from banked blood, TRALI and TACO, and the judgment call of when to transfuse on ratios versus on laboratory results. The attributes stressed are organization and adaptability, because the scenario changes every two minutes.

The 60-second answer

Decision points and the "why"

• Activate the protocol early — the trigger is the expectation of bleeding, not a count of units; ACS TQIP uses an ABC score of 2 or more, persistent instability, or transfusion in the trauma bay,² or simply the surgeon telling me they cannot see. Delay means plasma and platelets arrive after the coagulopathy is established.
• Ratios before labs, then labs before ratios — a 1:1:1 ratio approximates whole blood and prevents dilutional coagulopathy while results are pending, and in PROPPR it achieved hemostasis more often than 1:1:2 without changing overall mortality;¹ once a viscoelastic test or a fibrinogen comes back, I switch to targeted replacement because empiric plasma in a patient who needs fibrinogen wastes time and volume.
• Permissive hypotension — a mean of 50–60 mmHg or systolic 80–90 limits clot disruption and dilution until hemostasis. I abandon it in brain or spinal cord injury, holding a MAP of at least 80 mmHg in severe brain injury,¹ and in the elderly or coronary patient.
• Calcium early and repeatedly — citrate binds ionized calcium, the liver cannot clear it fast enough in shock and hypothermia, and the result is hypotension and a coagulopathy that no plasma will fix. I keep ionized calcium in the normal range, 1.1–1.3 mmol/L, with calcium chloride, which carries three times the elemental calcium of gluconate.¹
• Tranexamic acid within 3 hours — in CRASH-2 it cut bleeding deaths most when given within 1 hour (RR 0.68), less at 1–3 hours, and after 3 hours it increased them (RR 1.44), so I do not give it late.³
• Avoid crystalloid — every liter dilutes clotting factors, cools the patient and worsens acidosis. Blood replaces blood.
• Fibrinogen is the first factor to fall — I replace it when the level is 150 mg/dL or less or the viscoelastic clot amplitude is low, starting with 3–4 g: 15–20 single-donor units of cryoprecipitate or 3–4 g of concentrate.¹

The complication they will inject

The bleeding is controlled, the pressure is 70/40 and the ECG shows peaked T waves. I recognize transfusion hyperkalemia and hypocalcemia together, the two electrolyte killers of rapid transfusion. I give calcium chloride 1 g first, because it stabilizes the myocardium and corrects the hypocalcemia at once, then insulin 10 units with dextrose 25 g, bicarbonate if acidotic, and I hyperventilate. I check the gas and the potassium, switch to the freshest red cells available, and ask the blood bank for washed units, which remove most of the supernatant potassium, if the transfusion will continue.⁴ The second version of this inject is the patient who becomes hypoxic with frothy secretions an hour later; I separate TACO from TRALI by the filling pressures and the response to diuretics, and I treat both with oxygen and lung-protective ventilation.

Pitfalls that cost points

• Reciting "two large-bore IVs" and products without saying who is controlling the bleeding.
• Giving liters of crystalloid while waiting for blood.
• Forgetting calcium, or stating it without a target and a dose.
• Quoting the 1:1:1 ratio as the end of the plan rather than the bridge to targeted therapy.
• Resuscitating to a normal pressure before the surgeon has control, then being asked why the patient rebled.

Rapid-why

Q: Why does banked blood cause hyperkalemia? A: Stored red cells leak potassium about 1 mEq/L per day, toward a plateau near 60 mEq/L;⁴ the dose matters only with rapid infusion, in children and in renal failure.

Q: What is the lethal triad? A: Hypothermia, acidosis and coagulopathy, each driving the others; enzyme function falls about 10% per degree,¹ and acidosis further impairs platelets and clotting enzymes.

Q: When do you give uncrossmatched blood? A: Immediately when the patient is unstable; O-negative for women of childbearing potential (under about 45–50), O-positive for everyone else,² and type-specific as soon as the bank can issue it.

Q: What does a viscoelastic test add? A: A whole-blood picture faster than the lab: clotting time for factors (ACS TQIP gives plasma for a TEG R time above 9 minutes),² clot amplitude for fibrinogen and platelets, and lysis for hyperfibrinolysis that would justify tranexamic acid.

Numbers to know

Links

• Trauma: initial management and damage control, Perioperative hypothermia and coagulopathy, Transfusion reactions, TRALI and TACO (coming), dic, Obstetric hemorrhage: previa, accreta, atony, hyperkalemia
• ASA Practice Guidelines for Perioperative Blood Management; ACS TQIP Massive Transfusion in Trauma Guidelines